ML16207A549

Revision 18 to Updated Safety Analysis Report, Chapter 6, Engineered Safety Features

ML16207A549
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Site:	South Texas
Issue date:	04/28/2016
From:	South Texas
To:	Office of Nuclear Reactor Regulation
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STPEGS UFSAR 6.1-1 Revision 16 6.0 ENGINEERED SAFETY FEATURES 6.1 ENGINEERED SAFETY FEATURES MATERIALS

6.1.1 Metallic

Materials 6.1.1.1 Materials Selection and Fabrication. Materials specifications used for components in the Engineered Safety Features (ESF) are list ed in Table 6.1-1, "Engineered Safety Features Materials". In some cases, this list of materials may not be totally incl usive; however, the listed specifications are representative of those materials used.

Materials utilized are procured in accordance with the materials specification requirements of the American Society of Mechanical Engineers (A SME) Boiler and Pressure Vessel (B&PV) Code,Section III, and applicable Code cases.

ESF components within the Containment that would be exposed to core cooling water and Containment sprays in the unlikely event of a Loss-of -Coolant Accident (LOCA) utilize materials listed in Table 6.1-1. These components are manufactured primarily of st ainless steel or other corrosion-resistant, high-temperature material. The integrity of the materials of construction for ESF equipment when exposed to post-Design Basis Accide nt (DBA) conditions has been evaluated. Post-DBA conditions were conservatively represented by test conditions.

The test program performed by Westinghouse Electric Corporation (Westinghouse) considered spray and core cooling solutions of the design chemical compositions as well as the design chemical compositions contaminated with corrosion and deterioration products which may be transferred to the solution during recirculation.

The effects of sodium (free caustic), chlorine (chlor ide), and fluorine (fluoride) on austenitic stainless steels were considered. Based on the results of this i nvestigation, as well as testing by Oak Ridge National Laboratory and others, the behavior of austenitic st ainless steels in the post-DBA environment will be acceptable. No cracking is anticipated on any equipment even in the presence of postulated levels of contaminants, provided the core cooling and spray solution pH is maintained at an adequate level (Section 6.2.2.2.2).

The inhibitive properties of alkalinity (hydroxylion) against chloride cracking have been demonstrated.

All parts of components in contact with borated water are fabricated of or are clad with austenitic

stainless steel or equivalent corrosion-resistant material. The integrity of the safety-related components of the ESF is maintained during all stages of component manufacture. Austenitic stainless steel is utilized in th e final heat-treated condition as required by ASME Section II, material specification for the particular type or grade of alloy. Furthermore, it is required that austenitic stainless steel materials used in the ESF compon ents be handled, protected, stored, and cleaned according to recognized and accepted methods that are designed to minimize contamination which could lead to stress corrosion cracking. These me thods are stipulated in balance-of-plant (BOP) construction specifications and in plant procedures and specifications for the operational phase. Also, the requirements of Regulatory Guide (RG) 1.37 are met as discussed in Section 5.2.3.4. Additional information concerning austenitic stainless steel, includi ng the avoidance of sensitization and the prevention of intergranula r attack, can be found in Section 5.2.3. No cold-worked austenitic stainless steels having yield stre ngths greater than 90,000 psi are used for components of the ESF.

STPEGS UFSAR 6.1-2 Revision 16 Information regarding the selection, procurement, testing, storage, and installation of nonmetallic thermal insulation for the Reactor Coolant Pressure Boundary (RCPB), is contained in Section 5.2.3. The welding materials used for joining the ferritic base materials of the ESF conform to or are equivalent to ASME Material Specifications SFA 5.1, 5.2, 5.5, 5.17, 5.18, 5.20, 5.28, and 5.30. The welding materials used for joining nickel-chromium-iron alloy in similar base material combination and in dissimilar ferritic or austenitic base material combination conform to ASME Material Specifications SFA 5.11 and 5.14. The welding materi als used for joining the austenitic stainless steel base materials conform to ASME Material Specifications SFA 5.4 and 5.9. The welding materials used for joining copper or copper-alloy base material conform to ASME Material Specifications SFA 5.6 and 5.7. These materials are te sted and qualified to the requirements of the ASME Code and are used in procedures which have been qualified to these same rules. The methods utilized to control delta ferrite content in austenitic stainless steel weldment s are discussed in Section 5.2.3.

The procedures utilized to avoid hot cracking (fissuring) during weld fabrication and assembly of austenitic stainless steel components of the ESF are the same as those used for the RCPB. Therefore, discussion of the procedures is found in Section 5.2.3.

6.1.1.2 Composition, Compatibility, and Stability of Containment Spray Coolants. The initial Containment spray will be boric acid solution from the refueling water storage tank which has a pH of approximately 4.5. Trisodium phosphate, which is stored in baskets st rategically located in the post-LOCA flooded region, dissolves during the in itial spray and subsequent recirculation mode raising the equilibrium pH of the sump solution to a minimum of 7.0.

Radiolytic decomposition of water will occur, but boric acid and trisodium phosphate will not be affected by radiation. No pyrolytic decomposition of boric acid or trisodium phosphate is expected.

The vessels used for storing ESF coolants include the accumulators and the refueling water storage tank.

The accumulators are carbon steel cl ad with austenitic stainless st eel. Because of the corrosion resistance of these materials, significant corrosive attack on the storage vessels is not expected.

The accumulators are vessels filled with borated water and pressurized with nitrogen gas. The boron concentration, as boric acid, is given in Table 6.3-1. A sample of the solution in the accumulators is taken periodically to veri fy the boron concentration.

The refueling water storage tank is a source of borated cooling water for injection. The boron concentration, as boric acid, is given Table 6.3-1. The tank cubicle is maintained above 50 F, thus ensuring that the boric acid remains soluble.

The spray solution is not corrosive to the stainless steel components of the system with which it comes into contact. The spray and sump solutions will tend to corrode zinc materials and aluminum alloys, but will not attack stainless steel or copper-nickel alloys.

6.1.2 Organic

Materials STPEGS UFSAR 6.1-3 Revision 16 Organic materials located inside the Reactor Containment Building (RCB) are limited to coating materials on painted surfaces, electrical cable insulation, and lubricating oils and greases. There are no significant amounts of other organic materials, such as wood or asphalt, located inside the RCB.

6.1.2.1 Protective Coatings.

Certain coatings that are in common industrial use may deteriorate in the post-accident environment and may contribute substantial quantities of foreign solids and residue to the Containment sump.

Consequently, protective coatings used inside the Containment have been tested and selected to assure that they will withstand nuclear, chemical, and physical conditions of a DBA, as required by RG 1.54 and American National Standards Institu te (ANSI) N101.2-1972. Th e tests are performed by independent laboratories and show that no significant decompositi on or radiolytic or pyrolytic failures will occur during a DBA. Inorganic zinc, epoxy, and modified phenolic systems are the most desirable of the generic types evaluated. This evaluation cons iders resistance to radiation, temperature, pressure and chemical conditions anticipated during a LOCA.

The original design conditions for the chemical environment were based on the use of NaOH. As described in section 6.5.2, there has been a change to the use of TSP. As discussed in WCAP-12477, the qualification of coatings for the original de sign conditions using NaOH bounds the change to the current use of TSP.

Steel and concrete surfaces in side the RCB with protective coa tings can be grouped into three categories:

1. Major surfaces: This category includes large surfaces such as the Containment liner, structural steel, large uninsulated equipment and equipmen t supports, pipe whip restraints, polar crane, jib cranes, and concrete surfaces receiving epoxy surfacer systems.

Coatings for major surfaces are selected in accordance with the require ments of Section 4 of ANSI N101.2 and applied per RG 1.54, thus assuring that the majority of protective coatings inside the RCB will remain intact in the post-accident environment.

2. Minor surfaces: This category includes such areas as routine touchup of damaged qualified coatings less than 30 in.2, spot priming of bare areas, bolt heads/threads, nuts, miscellaneous

fasteners, tack and stud welds, and coating of surfaces with limited accessibility for optimal performance of coating work.

Coating products that have b een tested and approved for use inside Containment are applied to such surfaces in accordances with the paint manufacturer's instructions. Enforcement of proper application and inspection procedures, as stated in project specifications, provide a high degree of assurance of post-LOCA film integrity for such cases where total compliance with RG 1.54 is impracticable.

3. Miscellaneous surfaces: This category includes surfaces of limited square footage consisting primarily of smaller, off-the-shelf equipment and components supplied with manufacturers' standard finishes (unkown or unqualifiable coating products). Examples of such items are electrical cabinetry, control pane ls, loudspeakers, light fixtures, small standard product line pumps, motors, and valves. This category also includes such field applications as repairs to galvanizing and identification painting (e.g., stenciling, pipe banding, etc.).

STPEGS UFSAR 6.1-4 Revision 16 In addition to the above general criteria, it should be noted that the requirements of RG 1.54 will not be imposed in the following applications:

1. Coating of surfaces that are insulated or otherwise enclosed in normal service; e.g., interiors of cabinets, heating, ventilati ng, and air-conditioning (HVAC) ducts.

2. Concrete receiving a non-film forming clear sealer coat only.

For equipment in Westinghouse's scope of supply, coatings quality assurance meets the intent of RG 1.54 as described in letter NS-CE-1352 from Westinghouse to the Nuclear Regulatory Commission (NRC) dated February 1, 1977, as accepted and approved by the NRC in a letter dated April 27, 1977 (C. J. Heltemes, Jr. to C. Eicheldinger). These two letters were transmitted from Westinghouse to Houston Lighting & Power by correspondence ST-WN-HL-00600.

The quantity of organic debris within the RCB is estimated and reco rded. All coatings which do not fit into the major or minor categories described a bove are considered unqualified and are assumed to fail by disintegrating or disbonding under DBA conditions. Coatings on surfaces which are insulated

or otherwise enclosed, and clear sealer applied to concrete , are not included.

Table 6.1-3 provides a coating schedule for Westinghouse-supplied equipment inside the Containment.

Table 6.1-4 provides a coating schedule for painted surfaces inside the RCB including equipment in STPEGS scope of supply.

6.1.2.2 Cable Insulation. Cable insulation in the RCB is qualif ied to Institute of Electrical and Electronics Engineers (IEEE) 383-1974 requirements and consists of ethylene propylene rubber (EPR), polyethylene (XLPE), and hypalon / Chlorosulfonated Polyethylene. The quality of cable in the RCB is monitored to assure that its potential contribution to the effects of organic decomposition under accident conditions is accounted for in design. CN-3036 6.1.2.3 Oils and Greases. Significant quantities of lube oils used inside the Containment are located in the reactor coolant pumps, with approximately 265 gallons per pump. Other pumps require only approximately one gallon of lube oil each or are greas e lubricated and represent an insignificant amount, as noted below.

Oil-lubricated pumps 4 reactor coolant pumps 265 gallons/pump 2 reactor coolant drain tank pumps 1 gallon/pump 2 normal sump pumps 1 gallon/pump 1 equipment drain sump pump 1 gallon/pump

Grease-lubricated pumps 3 Residual Heat Removal System pumps

STPEGS UFSAR 6.1-5 Revision 16 All oils are contained in sealed re servoirs and are not exposed to the outside environment. When oil changes are effected, the used oil is drained directly into waste oil sumps outside the Containment prior to disposal.

In the event small leaks might o ccur during operation, all pumps are equipped with drip pans placed and secured to prevent possible oil drops from coming into contact with adjacent piping or equipment.

6.1.2.4 Decomposition Products. An insignificant amount of radiolytic decomposition in the reactor coolant pump lube oil will occur during operation; however , the effect on oil properties, and the hydrogen generated by th e reaction, are negligible.

Under DBA conditions, the Containment spray and sump water react with those surfaces coated with zinc-rich primer that are not e poxy topcoated. This reaction results in the generation of hydrogen.

Further details are provided in Section 6.2.5.

6.1.3 Post Accident Chemistry Following a DBA, the equilibrium pH of the fluid inside Containment remains between 7.0 and 9.5 following completion of the dissolving of the stored trisodium phosphate as described in Section

6.1.4.

6.1.4 Post Accident Sump Solution Chemistry Adjustment Following a large break LOCA, the water accumulated in the containment will be a boric acid solution having a pH of about 4.5. The desired pH range is 7.0 to 9.5 to assure iodine retention in the sump, to limit corrosion and production of hydrogen from corrosion, and to limit chloride induced stress corrosion cracking of stainless steel. To adjust the sump solution pH into the desired range, 11,500 pounds of trisodium phosphate (NA 3 PO 4 -12 H 2O) are stored in six baskets located on the containment floor where they would be submerge d in the event of a LOCA. This amount of trisodium phosphate is sufficient to assure that the equilibrium sump solution would be in the desired range.

The baskets are stainless steel with mesh sides and bottoms to permit a large surface to be exposed to the solution and thus maximize the rate of dissolution into the sump. Figu re 6.5-1 provides curves showing the calculated sump pH function of time following a large break LOCA.

STPEGS UFSAR 6.1-6 Revision 16 TABLE 6.1-1 ENGINEERED SAFETY FEATURES MATERIALS Materials Employed for Safety Injection and Containment Spray Systems Components Component Material*

Pumps High-Head Safety Injection, Low-Head Safety Injection, and Containment Spray Pumps:

Shaft A-276 Type 410 Impeller, Stage 1, Flights A-240 Type 304 Hubs A-276 Type 304 Remaining stages A-296 CA40 Outer Barrel, Top Flange SA-182 F304 Top Cylinder SA-182 F304 Suction Nozzle SA-182 F304 Bottom Cylinder SA-358, Type 304; Class 1, Welded Cap SA-182 F304 Residual Heat Exchangers Tube Sheets SA-156 Gr. 70 with 304 stainless steel cladding Tubes SA-249 Type304 Heads: Shell Side Tube Side SA-516 Gr. 70 SA-240 Type 304 Nozzle Necks: Shell Side Tube Side SA-106-B (SMLS)

SA-312 Type 304 Shells: Shell Side Tube Side SA-516 Gr. 70 Sa-240 Type 304 Flanges: Shell Side Tube Side SA-182 Gr. F304

SA-105 Valves Containing Radioactive Fluids:

Pressure-Containing Parts SA-182 F316 or F304

Seating Surfaces Stellite No. 6 or equivalent STPEGS UFSAR 6.1-7 Revision 16 TABLE 6.1-1 (Continued)

ENGINEERED SAFETY FEATURES MATERIALS Materials Employed for Safety Injection and Containment Spray Systems Components (Continued)

Component Material*

Valves (Cont'd)

Stems Type 630 and 410 or 17-4PH stainless Containing Nonradioactive, Boron-Free Fluids: Pressure-Retaining Parts SA-105, SA-182 F304 or F316 Stems Type 630, 410 or 17-4PH stainless Relief Valves Bodies SA-351 Gr. CF8M All Nozzles, Discs, Spindles, and Guides SA-479 Type 316 or SA-193 Gr. B6 or Type 410 or 416 Stainless or Stellite or Inconel or Monel Bonnets SA-351 Gr. CF8M or SA-216 Gr. WCB Piping All Piping in Contact with Borated Water SA-312, Gr. TP 304, 304L, 316, or 316L; SA-376 Gr. TP 304, or 316 SA-358 TP316L, CL.1 welded All Piping not in Contact with Borated

Water A-106 Gr. B SA-106 Gr. B

STPEGS UFSAR 6.1-8 Revision 16 TABLE 6.1-1 (Continued)

ENGINEERED SAFETY FEATURES MATERIALS Materials Employed for Electric Hydrogen Recombiners Component Material*

Outer Structure SA-240 Type 304 Inner Structure Incoloy-800 Heater Element SheathIncoloy-800

STPEGS UFSAR 6.1-9 Revision 16 TABLE 6.1-1 (Continued)

ENGINEERED SAFETY FEATURES MATERIALS Materials Employed for Containment System Component Material*

Reinforcing Steel A-615, Gr. 60 Containment Liner (Greater than 5/8" thick) (5/8" and less thick) SA-516 Gr. 60 SA-285 Gr. A RCFC Enclosure A-36/A-366 Frame A-36 Damper Blades A-606 type 4 Cooling Coils:

Frame A-570 Gr. D Flanges SA-181 Gr. I or II Tubes SB-75 Alloy 122 Fins B-152 Alloy 110 Headers SB-42 Alloy 122 Fans: Housing A-283 Rotor Hubs A-296 Gr. CA-40, A-105 Blades A-564 type 630 (17-4PH)

Guide Vanes A-570 Shaft A-675 Grade 1045 Ductwork:

Ducts A-36/A-167 Hangers & Casing A-36 Fasteners A-307

• A - ASTM material designator SA - ASME material designator STPEGS UFSAR 6.1-10 Revision 16 TABLE 6.1-3 PROTECTIVE COATINGS ON WESTINGHOUSE-SUPPLIED EQUIPMENT INSIDE CONTAINMENT MATERIALS

Component Painted Surface Area (ft

2)

RCS component supports 11,230*

Cooling shroud 4,000 Reactor coolant pump motors 1,600 Accumulator tanks 5,115 Manipulator crane 2,600 Remaining equipment (such as other refueling equipment, cable tray, valves, auxiliary tanks, and heat exchanger supports)

<5,085 Miscellaneous items (such as transmitters, alarm

horn, loud speaker, junction boxes) 40

• Primer only; topcoat provided by HL&P (historical context).

STPEGS UFSAR 6.1-11 Revision 16 TABLE 6.1-4 COATING SCHEDULE FOR SURFACES INSIDE CONTAINMENT (EXCLUDING NSSS SCOPE OF SUPPLY)

Estimated Meets Anticipated Substrate Generic Total Reg. Nominal DFT (mils) or Type of Square Ft Guide Mfg. Initial After Category Item Description Coating Per Unit (7) 1.54 Std. DFT (mils)(4) 40 Yrs Carbon Steel Liner Plate Dome - Unit I Dome - Unit II Walls - Unit I Walls - Unit II IOZ + Epoxy IOZ Epoxy + Epoxy IOZ + Epoxy 35,340 35,340 77,400 77,400 Yes Yes Yes Yes 8-10 2-5 10-12 8-10 8-10 2-5 10-18 8-16 Concrete Walls Ceilings Ceilings Floors Reactor Cavity Epoxy System Epoxy System Clear Sealer Epoxy System Epoxy System 109,250 5,650 14,290 38,140 4,050 Yes Yes No (2) Yes No 10-40 10-25 N.A. 15-40 37 (average) 10-46 10-25 N.A. 18-52(5) Structural Steel Primary & Second Stl.

IOZ 64,750 Yes 2-5 2-5 Primary & Second Stl.

IOZ + Epoxy 34,860 Yes 8-10 8-10 Pipe Whip Restraints IOZ + Epoxy 48,560 Yes 8-10 8-10 Hatches (Equipment and Personnel) IOZ + Epoxy 740 Yes 8-10 14-16 Crane Spts. & Rail Unit I Epoxy + Epoxy 11,240 Yes 7-14 7-14 Crane Supts. & Rail Unit II IOZ 11,240 Yes 2-5 2-5 Personnel Doors Alkyd 750 No X 3-5 10-15 Embedded Plates IOZ + Epoxy 13,240 Yes 7-14 7-18 Embedded Plates IOZ 3,570 Yes 2-5 2-5 Misc. Steel IOZ 2,000 No (3,6) IOZ + Epoxy 2,500 No (3,6) Epoxy 2,500 No (3,6) HVAC Air Handling Units IOZ + Epoxy 820 Yes 8-10 8-10 Ring Duct & R.A. Risers IOZ 63,170 Yes 2-5 2-5 Ducts (RCFC) IOZ 3,040 Yes 2-5 2-5 Carbon Units IOZ + Epoxy 2,300 Yes 8-10 8-10 STPEGS UFSAR 6.1-12 Revision 16 TABLE 6.1-4 (Continued)

COATING SCHEDULE FOR SURFACES INSIDE CONTAINMENT (EXCLUDING NSSS SCOPE OF SUPPLY)

Estimated Meets Anticipated Substrate Generic Total Reg. Nominal DFT (mils) or Type of Square Ft Guide Mfg. Initial After Category Item Description Coating Per Unit (7) 1.54 Std. DFT (mils)(4) 40 Yrs Electrical Control Panels Terminal Boxes, Light Fixtures, etc. Intumescent

Baked Enamel 350 11,100 No No X 12-14 2-4 12-14 2-4 Carbon Steel Pipe Uninsulated IOZ 1,200 Yes 2-5 2-5 Piping Systems Pipe Uninsulated IOZ 11,600 No X 2-5 2-5 Pipe Supports IOZ 5,340 Yes 2-5 2-5 Pipe Supports Epoxy 2,670 Yes 1-1/2 (5) 1-1/2 (5) Valves & Operators IOZ + Epoxy 1,280 Yes 8-10 10-16 Small Pumps & Motors Baked Enamel 250 (6) No X 3-6 8-12 Valves & Operators IOZ 600 (6) No X 2-5 2-5 Valves & Operators Unkown 250 (6) No X Unkown Mechanical Equipment Polar Crane IOZ + Epoxy 16,000 Yes 8-10 8-10 monorails & Hoists Zinc-Rich 665 No X 4-6 8-10 Equip. Supports IOZ + Epoxy 7,200 Yes 8-10 10-16 Equip. Supports IOZ 3,880 Yes 2-5 2-5 Misc. Equip. & Items Unkown 2,000 (6) No X Unkown Firehose Cabinets Baked Enamel 500 No X Unkown 2 Jib Cranes Epoxy 4,100 Yes 4-7 4-7 STPEGS UFSAR 6.1-13 Revision 16

Notes for Table 6.1-4

(1) Not used.

(2) Sealer is a nonfilm-forming surface conditioner to minimize concrete dusting.

(3) Paint materials used are qualif ied to ANSI N101.2, but were applied without complete QA documentation.

(4) For multiple coats, the stated numbers represent the typical total film thickness range expected. In local areas, higher o r lower thicknesses are expected as a result of variations within the specified ranges for individual coats.

(5) One to four additional topcoats of 8 mils (less weardown of 5 mils) assumed.

(6) The quantity of paint that does not meet the requirements of RG 1.54 is estimated and will be verified as work progresses d uring plant maintenance activities. Quantities of qualified coating are not similarly tracked.

(7) The total estimated surface area painted with inorganic zinc silicate (1oz) is 159,815 ft 2 (825 lbs) for Unit 1 and 206,395 ft 2 (900 lbs) for Unit 2.

(8) This table estimates the total quantity of coating systems to indicate that the majority of surfaces have qualified coatings (i.e.

provide a relationship of qualifie d vs. unqualified coatings).

Abbreviations used in Table 6.1-4

DFT = Dry Film Thickness

IOZ = Inorganic Zinc Coating

Epoxy System = High solids water-borne epoxy surfacer with polyamide-cured epoxy topcoat.

Intumescent = Fire-retardant, solvent-based modified epoxy coating.

STPEGS UFSAR 6.2-1 Revision 18 6.2 CONTAINMENT SYSTEMS 6.2.1 Containment Functional Design 6.2.1.1 Containment Structure.

6.2.1.1.1 Design Bases: Containment design basis is the limitation of calculated offsite radiation dose which may be potentially caused by radioactive release from postulated accidents, to levels less than 10CFR100 guideline values. Design maximum Containment leakage rate supports this requirement and considers performance of other Engineered Safety Feature (ESF) systems. Containment leak-tight integrity provides a predictable environment for operation of ESF systems and is ensured through comprehensive analysis, design, and a testing program that considers:

1. Peak Containment pressure and temperature associated with the most severe postulated accident, coincident with the Safe Shutdown Earthquake (SSE), and

2. The maximum external pressure to which the Containment structure may be subjected as a result of inadvertent operations that reduce Containment internal pressure below outside atmospheric pressure. 6.2.1.1.1.1 Postulated Accident Conditions - The spectrum of accidents postulated in determining Containment design peak pressure and temperature, subcompartment peak pressure, and external pressure is summarized in Table 6.2.1.1-1. The breaks used to analyze Emergency Core Cooling System (ECCS) effect on minimum Containment backpressure are discussed in Section 6.2.1.5. Break locations considered in subcompartment pipe break accident analyses are discussed in Section 3.6.2. As discussed in Reference 3.6-14 and Section 3.6.2.1.1.1, item a, reactor coolant loop (RCL) ruptures and associated dynamic effects are not included in Containment design bases. However, subcompartment analyses ar e based on RCL branch pipe breaks or secondary system pipe breaks. Containment pressure and temperature design is based on non-mechanistic, double-ended guillotine breaks. For Containment structure and subcompartment peak pressure analysis, it is assumed that each accident can occur concurrently with a loss of offsite power (LOOP) and the most limiting single active failure. No two Design Basis Accidents (DBAs) are assumed to occur simultaneously or consecutively. For each of the categories of Containment peak pressure, subcompartment peak pressure, Containment external pressure, and Containment minimum pressure, the DBA is defined as the postulated accident case in each category representing the most severe challenge to Containment design limits. Containment calculated peak maximum and minimum pressu re, design pressure, and margin between the calculated peak and design pressures are given in Table 6.2.1.1-2. Containment parameters used in the analys is are given in Table 6.2.1.1-3. 6.2.1.1.1.2 Mass and Energy Release - Mass and energy released for the most severe accident cases under the categories of Containment peak pressure and subcompartment peak pressure are given in Sections 6.2.1.2, 6.2.1.3, and 6.2.1.4. Mass and energy releases used in minimum STPEGS UFSAR 6.2-2 Revision 18 Containment backpressure analysis for ECCS performance capability studies are discussed in Section 6.2.1.5. The sections on subcompartment an alyses provide design and peak pressures for various subcompartment pressurization analyses. Computer codes and assumptions used in deriving each of the mass and energy release rates are also discussed in these subsections.

6.2.1.1.1.3 Effects of ESF Systems on Energy Removal - Energy released to Containment atmosphere from the postulated accidents referenced in Section 6.2.1.1.1.2 is removed by the Containment Heat Removal Systems (CHRS), i.e., the Containment Spray System (CSS) and Reactor Containment Fan Cooler System (RCFC), discussed in Section 6.2.2. Containment analyses consider ope ration of either two or three ECCS and CHRS trains (with one RCFC unit out for maintenance) at time of accident initiation.

Loss of coolant accidents (LOCAs) for the doub le-ended pump suction break consider both maximum and minimum safety injection (SI) to assure coverage of all failure modes for the DBA. Minimum SI is based on single-failure of a standby diesel generator (SDG). This represents the most substantial loss of ESF equipment. Engineered Safety Features equipment lost with the SDG includes one train of SI, one train of CSS, one train of component cooling water (CCW) to a residual heat removal (RHR) heat exchanger, and one train of RCFC (two RCFC units), in addition to the single RCFC unit assumed to be out of service for maintenance at time of accident initiation. All possible combinations of ESF failures have been considered in the LOCA analyses by evaluating:

(1) loss of an SDG (minimum SI with two SI trains in operation), (2) the conservative non-mechanistic case of maximum SI with all six SI pumps running, (3) the most substantial failure (loss of an entire train of CHRS resulting from a SDG failure), and (4) loss of two RHR heat exchangers (one lost du e to SDG failure, and th e second is out due to maintenance). Main steam line break (MSLB) analyses consider either a main steam isolation valve (MSIV) failure with maximum CHRS, a main feedwater isolation valve failure with maximum CHRS, or an SDG failure with minimum CHRS.

Further discussion of single failures associated with secondary system pipe ruptures inside Containment is given in Section 6.2.1.4. 6.2.1.1.1.4 Effects of ESF Systems on Pressure Reduction - Assuming the most limiting single active failure identified in Section 6.2.1.1.1.3, the CHRS are capab le of reducing post-accident pressures to less than 50 percent of the peak calculated pressure for the DBA LOCA within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> following the postulated accident. 6.2.1.1.1.5 Containment Leakage Rate Bases - The design Containment leakage rate specified in Table 6.2.1.1-3 was established as the minimum practicable rate based on consideration of reactor power level, site characteristics, type of Containment, iodine removal capability, constructability, and testability. Ac ceptability of the established de sign leakage rate is verified by analysis of offsite radiological c onsequences of the design basis LOCA, as discussed in Section 15.6. 6.2.1.1.1.6 Bases for Analysis of Minimum Containment Pressure - The analysis of Containment minimum pressure is based on confirming ECCS core reflood capability under a STPEGS UFSAR 6.2-3 Revision 18 conservative set of assumptions that maximize the heat removal effectiveness of ESF systems, structural heat sinks, and other po tential heat removal processes.

The assumptions are discussed in Section 6.2.1.5. 6.2.1.1.2 Design Features: Design features of the Containment and its internal structures are described in Sections 3.8.1 and 3.8.3, respectively. 6.2.1.1.2.1 Protection from the Dynamic Effect s of Postulated Accidents - The Containment structure, subcompartments, and ESF systems safety functions are protected from loss due to the dynamic effects of postulated accidents. Containment design provi des separation, barriers, or restraints as required to protect essential structures, systems, and components from accident-generated missiles, pipe whip, and jet impingement forces. Detailed criteria, locations, and descriptions of devices used for prot ection are given in Sections 3.5 and 3.6. 6.2.1.1.2.2 Codes and Standards - Codes and sta ndards applied to the design, fabrication, and erection of the Containment and internal struct ures are given in Sections 3.8.1 and 3.8.3. In each case, the codes and standards used are consistent with equipment safety function. 6.2.1.1.2.3 Protection Against External Pressure Loads - No special provisions are required for protection against loss of Containment integrity under external loading conditions.

Inadvertent operation of CHRS and other possible modes of plant operation (e.g., Containment purging) that could potentially resu lt in significant external struct ural loading, have resulted in pressure differentials lower than the design Containment pressure differential for external loading.

Details of this evaluation are provided in Section 6.2.1.1.3.6. 6.2.1.1.2.4 Potential Water Traps Inside the Containment - Drains from potential water traps discharge into the Containment sump. All significant water traps are thereby eliminated. 6.2.1.1.2.5 Containment Cooling and Ventilation Systems - During normal reactor operation, Containment atmosphere is maintained at or below the Technical Specification limit by continuous operation of the RCFC system. This system is described in detail in Section 6.2.2.2. 6.2.1.1.3 Design Evaluation: 6.2.1.1.3.1 Containment Pressure and Temperature Analysis - In the event of a postulated LOCA, MSLB, or main feedwater line break (FWLB), mass and energy will be released from the rupture and high-temperature, high-pressure fluid will flash to steam. This release of mass and energy raises Containment atmosphere pressure and temperature. The magnitude of the resulting pressure and temperature peaks is a function of the nature, location, a nd size of the postulated rupture. To establish the controlling rupture for Containment design, a range of primary and secondary breaks, as described in Table 6.2.1.1-1, was analyzed to determine the effect of each break on Containment. The LOCA analysis is discussed in Section 6.2.1.3. The MSLB analysis is discussed in Section 6.2.1.4. As discussed in Section 6.2.1.4, the FWLB does not produce peak Containment pressure or temperature as severe as LOCA or MSLB cases. Therefore, the FWLB cases are not analyzed.

CN-3136 STPEGS UFSAR 6.2-4 Revision 18 The Containment analysis is performed in two stages. In the first stage, the mass and energy release is calculated for a spectrum of breaks (double-ended pump suction, DEPS; double-ended hot leg, DEHL; and double-ended and split break MSLBs). The mass and energy release models and break sizes are described in Secti on 6.2.1.3 (LOCA) and 6.2. 1.4 (MSLB).

In the second stage, the mass and energy releases are used in the Containment ru1alysis model for calculating the peak pressure and temperature. The Containment analysis model is described below.

(a) Containment Model

The containment pressure and temperature tran sients are analyzed by using the GOTHIC code (References 6.2.1.1-11 and 6.2.1.1-13). GOTHIC is an integrated, general purpose thermal hydraulics software for design, licensing, safe ty and operating analysis of nuclear power plant containments, confinement buildings and system components.

Applications of GOTHIC include evaluation of containment and sub-compartment response to the full spectrum of high energy line breaks within the design basis envelope and systems evaluations involving multiphase flow a nd heat transfer, gas mixing and other thermal hydraulic behavior.

The LOCA and MSLB analyses use a single volume (node) for the containment building with separate treatment given to the sump and containment atmosphere regions. Inherent in this lumped parameter approach is the assumption that within each region the fluid is well mixed.

During a LOCA or MSLB, the mixing induced by the break jet is significant. Later in the transient, containment sprays and/or reactor containment fan coolers (RCFCs) continue to promote mixing in the containment.

(b) Containment Initial Conditions

To determine the maximum containment pressure and temperature, the most restricting Containment normal operating pressure and temperature are assumed to be at the Technical Specification operating limit and. the outside atmosphere temperature is assumed to be at design maximum value. The initial conditions for the lim iting Containment peak pressure case are given in Table 6.2.1.1-3.

For Containment LOCA peak pressure analysis, the Safety Injection Syst em (SIS) and the CHRS (i.e., CSS and RCFC) are assumed to operate in the mode that maximizes Containment peak Pressure. The initial conditions are listed in Table 6.2.l.1-5.

For calculating the Containment peak pressure, the minimum CHRS capacity is the conservative condition. Thus, the CHRS equipment were assumed to be affected by the most restrictive single active failure, which is the loss of one SDG train coupled with one RCFC unit being out of service for maintenance. The analyses show that a sustained loss of one safety-related electrical distribution train (i.e., one SDG) will minimize ESF response and maximize Containment pressures. The LOCA analysis gives the highest pressure, and the analysis is discussed in Section 6.2.1.3. CN-3136 CN-3136 CN-3136 STPEGS UFSAR 6.2-5 Revision 18 For Containment peak temperature analysis (due to MSLB}, a spectrum of single active failures and break sizes were considered. The MSLB analysis is discussed in Section 6.2.1.4.

(c) Mass and Energy Releases

For LOCA, the mass and energy release analysis is discussed in Section 6.2.1.3.

For MSLB, the mass and energy release analysis is discussed in Section 6.2. 1.4.

(d) Heat Sinks (Thermal Conductors)

Containment structures are one of the major passive heat sinks for energy removal and are modeled as thermal conductors.

The thermal conductors are made of up a number of layers of different materials. The thermal conductors are divided into regions, one for each material layer, with an appropriate thickness and material ther mos-physical properties for each region. One- dimensional heat conduction solutions are used.

The small air gap or contact resistance between the containment liner and the concrete is modeled as a separate material layer at the nominal gap thickness with applicable material properties. This approach conservatively overestimates the contact resistance because convec tion and radiation effects will be ignored.

Concrete, Metal, and protective coating properties are typical values for the temperature range observed in the analyses. Table 6.2.1.1-7 gives a summary of containment structural heat sinks used in the analysis. Thermo-physical properties of these heat sinks are listed in Table 6.2.1.1-8.

(e) Passive Heat Sink Heat Transfer Coefficients The GOTHIC Direct heat transfer option with the DLM (Diffusion Laye r Model) condensation option is used for all containment passive heat sinks except the sump floor. W ith the Direct option, all condensate goes directly to the liquid pool at the bottom of the volum

e. The effects of the condensate film on the heat and mass transfer are incorporated in the formul ation of the DLM option. Under the DLM option, the condensation rate is calculated using a heat and mass transfer analogy to account for the presence of noncondensing gases.

For a conductor representing the containment floor or sump walls that will eventu ally be covered with water from the break and condensate, the Split heat transfer is used to switch the heat transfer from the vapor phase to the liquid phase as th e liquid level in the containment builds up.

For conductors with both sides exposed to the containment, the Direct heat transfer with DLM option is applied to both sides. If the conductor is symmetric about the center plane, ahalf thickness conductor is used with the total surface area of two sides and an insulated back side heat transfer option is used. The conductor face that is not exposed to the atmosphere is assumed insulated. For the insulated side, the Specified Heat Flux option is used with the nominal heat flux set to zero. CN-3136 CN-3136 STPEGS UFSAR 6.2-6 Revision 18 Containment walls above grade and the containment dome have a specified external temperature boundary condition with a heat transfer coefficient of 2.0 Btu/hr-ft 2-F to model convective heat transfer to the outside atmosphere.

Surface heat transfer coefficients used in the analysis for LOCA and MSLB cases are shown in Table 6.2.1.1-9. (f) RCFC Model.

The reactor containment fan coolers (RCFCs) arc modeled by specifying input values using heat removal rate versus Containment atmosphere saturation temperature curve. This performance curve is based on the cooling coil design data incl uding fouling and is shown in Figure 6.2.1.5-2. Start times are based on SDG start time, loading sequencing time, and startup time for the various ESF systems. The start times are provided in Table 6.2.1.1-10 and the RCFC parameters are given in Table 6.2.1.1-5. (g) Containment Spray Model For the containment spray syst em (CSS), spray water is taken from the RWST during the injection phase and the liquid region of the containment eluting the sump recirculation phase. The spray flow is added directly to the containment vapor space. The analysis uses the general modeling practices for spray nozzles, spray pumps, spray system delivery times including piping fill time and pump start dela ys. The model calculates the se nsible heat transfer between the spray drops and vapor and evaporation or condensation at the drop surface.

(h) RWST Model

The refueling water storage tank (R WST) liquid volume is used to determine a reasonable prediction of inventory draw down for determining the time of transfer to the sump recirculation phase. The RWST parameters are shown in Table 6.2.1.1-3.

(i) Sump Recirculation Model The sump recirculation phase starts after depletion of the RWST liquid inventory. At the time of transfer to the sump recirculation phase, th e safety injection syst em (HHSI and LHSI) and containment sprays* swap suction from the RWST to the containment sump. During this phase, the LHSI is cooled by the RHR heat exchanger.

The HHSI and CSS flows are not cooled. Two LHSI-RHR heat exchanger train combination are used to cool the recirculation flow to the RCS during the post-SG depressurizations phase (after 3600 seconds).

(j) Heat Exchanger Model The RHR exchanger is modeled using the GOTIHC HEAT EXCHANGER option. Fouling factors and tube plugging are applied for conservatism.

CN-3136 CN-3136 STPEGS UFSAR 6.2-7 Revision 18 6.2.1.1.3.2 Long-Term Contai nment Performance The results of the most severe cases for primary and secondary side breaks were evaluated to verify the ability of the CHRS to maintain Containment conditions within design limits. These evaluations were based upon conservative assu mptions for ESF equipm ent performance. The minimum CHRS operation was based on loss" of offsite power (LOOP) with one SDG failure. Thus, only two of three CHRS trains minus one additional RCFC unit out for maintenance were assumed in the analysis. During the sump recirculation phase, two LHSI-RHR heat exchanger train combination are used to cool the recirculation flow to the RCS. The containment sprays are not cooled by any heat exchanger. Hot leg recirculation is not considered since it has no significant impact on Containment analysis resu1ts.

The spectrum of accidents postulated for determining the Containment peak pressure and temperature, subcompartment peak pressure, and external pre ssure is summarized in Table 6.2.1.1-1. The calculated peak maximum pressure, design pressure, and margin between the calculated peak and design pressures are given in Table 6.2.1.1-2. Containment parameters used in the analysis are given in Table 6.2.1.1-3.

For LOCA, the scenarios analyzed are the double-ended pump section (DEPS) and the double-ended hot leg (DEHL) breaks coincident with LOOP. These analyses were performed with both minimum safety injection (SI) and maximum SL The minimum SI case includes flow from two SI trains (LHSI

+ HHSI). The maximum SI case includes flow from all three SI trains.

For the analyzed LOCA cases, the pipe break locations, break areas, peak pressures and temperatures are summarized in Tab le 6.2.1.1-2. Based on the results, the DEHL break provided the highest peak Containment pressure. For long-term analysis, all analyzed cases have similar pressure and temp erature profiles.

A summary of the peak containment LOCA pressures and temperat ures is given in Table 6.2.1.1-2. Figures 6.2.1.1-30 to 6.2.1.1-38 show the results of two representative LOCA analyses. The long-term analysis shows that the Containment pressure is reduced below 50 percent of the peak calculated pressure within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

For MSLB, several double-ended a nd split break cases were analyzed at different power levels and different single-active failures. A summary of the peak containment MSLB pressures and temperatures is given in Table 6.2.1.1-14. The highest temperature occurs for a double-ended MSLB where no entrainment is in cluded in the mass and energy releases (discussed in Section 6.2.1.4). This is conservative since the Containment response to a mass and energy release with entrainment effects would result in lower temperatures at or near the saturated conditions.

Figures 6.2.1.1-25, 6.2.1.1-27, 6.2.1.1-28 and 6.2.1.1-29 show plots of various parameters for the most limiting MSLB temperature case.

6.2.1.1.3.3 Accident Chronology - The accident chronology for the most severe RCS break (LOCA) is provided in Table 6.2.1.1-10. The chronology for the design basis MSLB is shown in Table 6.2.1.1-15. CN-3136 CN-3136 STPEGS UFSAR 6.2-8 Revision 18 6.2.1.1.3.4 Energy Balance - This section not used. 6.2.1.1.3.5 Functional Capability of Containment Normal Ventilation Systems - Containment maximum and minimum design pressure s are based on conservative assumptions of initial atmospheric pressures and temperatures in Containment. Functional capability of the Containment normal ventilation systems to maintain initial Containment temperature and pressure within the range defined for normal plant operation is discu ssed in Section 9.4. Technical Specifications stipulate limits for Containmen t temperature and pressure during normal plant operation and describe the actions to be taken if they are exceeded. 6.2.1.1.3.6 Protection Against Severe External Loading - The DBA for external Containment design pressure has been determined to be inadvertent actuation of the CSS. Improper operation of the containment normal purge system wa s also considered, i.e., operation of the exhaust train with the supply train isolated. The maximum feasible internal vacuum for this case is limited to a few inches of water (gauge) provided by exhaust fan operation. Table 6.2.1.1-2 gives the maximum ex ternal pressure to which Containment may be subjected by assuming an inadvertent actuation of the CSS. This pressure is based on an initial Containment atmosphere of 113 o F, 14.6 psia, and 100 percent relative humidity. Spray water at a minimum temperature of 45 oF then cools the Containment atmosphere to 45 o F and 100 percent relative humidity. Results are presented in Table 6.2.1.1-2. 6.2.1.1.3.7 Post-Accident Containment Monitoring - Containment pressure and sump water level are indicated and recorded in the main control room. Sectio n 7.5 contains a detailed discussion of the Regulatory Guide (RG) 1.97 instrumentation, including equipment qualification requirements. 6.2.1.1.3.8 Equipment Qualification - Electrical components of safety-related equipment were qualified for their potential normal operational environment a nd worst case DBA environment.

The two general categories of postulated accidents considered in equipment qualification for equipment in the Reactor Containment Building (RCB) are LOCA and MSLB. A spectrum of break sizes was considered for equipment qualification. The MSLB provides the highest RCB atmosphere temperature and LOCA provides the highest RCB atmosphere pressure. Combined MSLB/LOCA pressure and temperature profiles have been used for qualification of the Containment safety-related equipment. 6.2.1.2 Containment Subcompartments. 6.2.1.2.1 Design Bases: Subcompartments within the Containment, principally the reactor cavity, the SG compartments, the pressurizer compartment, the surge line compartment, the main steam line compartment, and the feedwater line compartment, are designed to withstand the transient differential pressures and jet impingement forces of a postulated pi pe break. Venting of these chambers is employed to keep the differential pressures within structural limits. In addition, neither pipe whip nor forces transmitted through component supports threaten the integrity of the subcompartments of the Containment structure. The spectrum of pipe breaks analyzed for each subcompartment is listed in Table 6.2.1.1-1. The characteristics of the pipe ruptures were determined in accordance with the methods and criteria of STPEGS UFSAR 6.2-9 Revision 18 Section 3.6.2. As discussed in Reference 3.6-14 and Section 3.6.2.1.1.1, item a, RCL ruptures and the associated dynamic effects are not included in the design bases. The accide nt that results in the maximum differential pressure across the walls of the respective compartment is designated as the subcompartment design basis. Calculated differential pressures are compared to the design pressure values used in the structural design of subcompartment walls and equipment to ensure that peak calculated values are less than design values. Th ese design and calculated pressure differentials are presented under each subcompartment section below.

6.2.1.2.2 Design Features:

6.2.1.2.2.1 Reactor Cavity - The reactor cavity is a heavily reinforced concrete structure that performs the dual function of providing reactor vess el support and radiati on shielding. It is described in Section 3.8.3.1 and is shown in the general arrangement drawings listed in Table 1.2-1. At the elevation of the primary piping nozzles, th e reactor vessel is surrounded by an inspection toroid. No pipe ruptures are postulated in the reactor cavity or inspection toroid.

6.2.1.2.2.2 Steam Generator Compartments -The SG and its supports have been described in Section 3.8.3.1, and the general arrangement of the SG and associated structural arrangement are listed as Figures 1.2-13 through 1.2-20 in Table 1.2-1. These general arrangement drawings have been used to define nodal boundaries. The SG subcompartments consist of the entire free volume between the primary shield and the secondary shield walls and from El. 19 ft to 83 ft. Each quadrant vents to the containment at the top of the SG compartment. See Tables 6.2.1.2-5A, 6.2.1.2-5B, and 6.2.1.2-6B for nodal volume and junction properties. In addition to the above vent path, two more vent paths vent the break nodes to the Containment. These are (a) the eight penetration paths that lead the hot and cold leg pipes to the reactor cavity and (b) the six heati ng, ventilation, and air-conditioning (HVAC) vents between the SG compartm ents above El. 19 ft a nd subpedestal region below El. 16 ft. Steam generator compartments A and D, and B and C are directly connected together while A and B, and C and D are connected vi a a passage. No blowout panels are used, thus the flow area is assumed to be constant with respect to time. Some junctions are considered partially blocked by debris.

6.2.1.2.2.3 Pressurizer Compartment - The pressurizer subcompartment, shown in the general arrangement drawings liste d in Table 1.2-1, consists of a vertical, rectangular, reinforced concrete structure surrounding the pr essurizer which is supported at its base by a steel skirt. No blowout panels are used, thus the flow area is assumed to be constant with respect to time.

6.2.1.2.2.4 Surge Line Subcompartment - The surge line subcompartment consists of the area above the grating at El. 37 ft

-3 in., the area below El. 37 ft-3 in., and the vestibule where the surge line penetrates the secondary shield wall. These subcompartments are shown in the general arrangement drawings listed in Table 1.2-1. See Section 6.2.1.2.3.5 for elimination of surge line breaks due to leak-before-break.

6.2.1.2.2.5 Main Steam Line and Feedwater Line Subcompartments - The main steam line and feedwater line subcompartments are located between the secondary shield wall and the Containment wall. The general arrangement drawings listed in Table 1.2-1 show the equipment and structures in these locations. The most confined spaces resulting in maximum local pressures from either break are near the pipe pene trations to the outside of the Containment. Vent paths consist of a combination of series and parallel flow resistances joining major elevations of approximately CN-3136 STPEGS UFSAR 6.2-10 Revision 18 one-half of the Containment. No blowout panels are used, thus the flow area is assumed to be constant with respect to time.

6.2.1.2.2.6 Regenerative Heat Exchanger Subcompartment - The regenerative heat exchanger subcompartment arrangement is shown in the general arrangement drawings listed in Table 1.2-1. The nodal model net free volumes and vent areas are listed in Tables 6.2.1.2-15 and 6.2.1.2-16. The vent areas out of the regenerative heat exchanger subcompartment consist of two openings: the auxiliary feedwater pipe penetration opening and the wire mesh door. The subcompartment volumes and vent area are reduced to account for obstructions caused by equipment and insulation around piping and vessels. No blowout panels are used, thus the flow area is assumed to be constant with respect to time.

6.2.1.2.2.7 Radioactive Pipe Chase Compartment - The radioactive pipe chase subcompartment is shown on Figure 6.2.1.2-8. The nodal model net free volumes and vent areas are listed in Table 6.2.1.2-17 and 6.2.1.2-18. The vent area out of the subcompartment is a manway hole in the floor. The subcompartment volumes and ve nt areas are reduced to account for obstructions caused by equipment and insulation around piping and ve ssels. No blowout panels are used, thus the flow area is assumed to be constant with respect to time.

6.2.1.2.2.8 RHR Valve Room Subcompartment -The RHR valve room subcompartment is shown in the general arrangement drawings listed as Figures 1.2-14 and 1.2-15 in Table 1.2-1. The Chemical and Volume Control Sy stem (CVCS) letdown line passe s through both RHR 1A and RHR 1B valve rooms. Because the valve rooms are identical, only the valve room for RHR 1A is modeled and the results of the analysis are representative of both rooms. The nodal model net free volumes and vent areas are listed in Tables 6.2.1.2-19 and 6.2.1.2-20. The vent area out of the subcompartment is via a wire mesh door. The subcompartment volumes and vent areas are reduced to account for obstructions caused by equipment and insulation around piping and vessels. No blowout panels are used, thus the flow area is assumed to be constant with respect to time.

6.2.1.2.3 Design Evaluation:

6.2.1.2.3.1 General - With the exception of the Main Steam, Steam Generator Loop Compartment, and Feedwater Line Subcompartments, the subcompartment pressure transients were determined using the COPDA computer code (R ef. 6.2.1.2-1). The COPDA code employs a finite difference technique to solve the time dependent equations for the conservation of mass, energy and momentum. This code and the assumptions inherent to it are fully explained in Reference 6.2.1.2-2.

Loss coefficients utilized were based on the formulations of References 6.2.1.2-3 and 6.2.1.2-4.

The steam generator loop compartment pressure transients were determined using the COMPARE computer code (Ref. 6.2.1.2-9). The COMPARE code calculates the transient condition in a system of volumes connected by vents. Each volume is considered as a quasi-steady state homogeneous mixture of steam, water and air. The code allows for addition and removal of mass and energy from each volume. This code and the assumptions inherent to it are fully explained in Reference 6.2.1.2-9.

The main steam and feedwater subcompartment pressure transients were determined using the GOTHIC 4.0 computer code. A description of this computer code is presented in Section 3.6.A.6.

STPEGS UFSAR 6.2-11 Revision 18 Nodalization of each subcompartment was based on the physical arrangement of the interconnected subcompartment and the structure, equipment, pi ping, ventilation ducting, floor grating, and other physical obstructions to flow.

By appropriate selection of nod e boundaries based on the physical arrangement, pressure differences within a node are minimized while pressure differences between nodes are maximized.

The LOCA blowdown model used to calculate the short-term mass and energy release rates for all primary system rupture is fully described in Reference 6.2.1.2-5. The mass and energy release data are presented in Table 6.2.1.2-1.

The total mass and energy release rates for the RHR pump suction line break are the sum of the RCS side mass and energy release rates and the RHR side mass and energy release rates. The RCS side mass and energy release rates were generated by scaling the previously limiting surge line mass and energy release rates by the ratio of the pipe areas. The surge line mass and energy release rates were generated using the LOCA blowdown model descri bed in Reference 6.2.1.2-5. The RHR side mass and energy release rates were generated using the RETRAN-02 code. The total RHR pump suction mass and energy release rates are presented in Table 6.2.1.2-1P.

The RETRAN-03 computer code was used to calculate the short-term mass a nd energy release of the main steam line (in the containment subcompartment) and the feedwater line (in the SG subcompartment only). The RELAP5 computer code (Ref. 6.2.1.2-6) was used to calculate the short-term mass and energy release of the main feedwater line breaks in other compartments. The mass and energy release rates for the main steam and main feedwater line breaks are presented in Tables 6.2.1.2-1J and -K. The mass and ener gy release rates for the feedwate r line break at the SG nozzle connection were calculated using the RETRAN-03 computer code. A FW temperature of 448ºF gave the highest differential pressure; the mass and energy release rates for this case are presented in Table 6.2.1.2-1Q.

Using the ANSI/ANS 58.2-1980 (Reference 6.2.1.2-7) methodology, a subcooled blowdown from a pipe break results in a decompression wave propagating through the system at sonic velocity with the pressure behind the wave corresponding to saturation pressure of the liquid. Because of the very low compressibility of subcooled water, subcooled blowdown cannot be sustained for more than a few milliseconds and the total mass release under subcooled blowdown conditions is quite small. Following this extremely short-term initial phase, the pressure will correspond to saturation pressure.

The CVCS letdown line break mass and energy release rates for saturate d and subcooled water conditions is determined using Henry-Fauske and Moody relationship as discussed in the ANSI/ANS 58.2-1980 methodology. The letdown line break mass and energy rele ase rates are given in Tables 6.2.1.2-1L, -M and -N.

6.2.1.2.3.2 Reactor Cavity - No pipe breaks are postulated in the reactor cavity and inspection toroid.

6.2.1.2.3.3 Steam Generator Subcompartment - Steam generator subcompartment design basis pressure profiles are determined by breaks in the residual heat removal (R HR) line that connects to the RCS hot leg and main feedwater (FW) line at the steam generator main feedwater nozzle connection. The following discusses the analysis of each break.

STPEGS UFSAR 6.2-12 Revision 18 RHR Line Break Double-ended ruptures of the RHR piping were assumed to occur be tween the hot leg piping and the first isolation valve in the 12" section of the RHR piping. The remainder of the RHR piping is not modeled because of break exclusion due to Arbitrary Intermediate Break (Ref. 6.2.1.2-10). The mass and energy release rates from the isolated piping section was calculated using RETRAN-02 computer code. The mass and energy release rates for the RCS side of the break was calculated using the methodology from Reference 6.2.1.2-5. The total ma ss and energy releases for the double-ended rupture are shown in Table 6.2.1.2-1P. These releases are based on an initial RCS pressure of 2,296 psia and a hot leg temperature of 629.9 o F.

Three break cases were investigated. These were a break in Node 15 (at the hot leg junction), a break in Node 4 (at the first valve upstream of the RCS), and a break in Node 12 (at the hot leg junction, but artificially moved to the opposite side of the hot leg). The Node 12 break was modeled to conservatively envelop the results of the 8" Safety Injection line break case.

The COMPARE computer code (Ref. 6.2.1.2-9) was used to perform the SG subcompartment pressurization analysis. The nodalization of the SG subcompartment is shown on Figure 6.2.1.2-3 and 6.2.1.2-11. The node and junction parameters for the SG loop compartment are given on Table 6.2.1.2-6. The flow parameters were evaluated to account for all obstructions such as cable tray supports and various small-sized piping. The principal obstructions within the SG loop compartments are the SG and reactor coolant pumps.

The flow from one node to the other was calculated using the homogeneous equilibrium model option for the analysis. The peak differential pressures for each subcompartment are listed in Table 6.2.1.2-5A. The pressure differential given on Table 6.2.1.2-5A is gene rally evaluated with respect to the containment (Node 41.) The pressure-time histories for all cases are presented in Figure 6.2.1.2-20A to -20C. These nodes are in the SG compartment in which the RHR breaks occur. Force and moment coefficients on the SG and reactor coolant pump have been evaluated to help facilitate determination of forces and moments due to the pressures generated by the analyzed breaks. Force coefficients represent the projections of the SG and RCP on three mutually perpendicular planes selected for this purpose (Figure 6.2.1.2-30). For the steam generator loop "C" compartment, the positive "Z" direction is north, the positive "X" direction is west, the positive "Y" direction is vertically up. The origin for the steam generator at the bottom center of the SG while the origin for the reactor coolant pump is at the bottom center of the reactor coolant pump. Moment coefficients represent the force coefficients multiplied by the moment arm from the base of the steam generator or reactor coolant pump to the centers of the projected areas used in the development of the force coefficients. The force and mome nt coefficients are presented in Table 6.2.1.2-7A, -7B, -8A and -8B for the SG and RCP. The forces and moments plots versus time for the SG and the RCP are presented on Figures 6.2.1.2-21A and 6.2.1.2-22A for the specific break ca ses identified on the figures. Feedwater Line Break Analysis CN-3136 CN-3136 STPEGS UFSAR 6.2-13 Revision 18 The RETRAN-03 (Ref. 6.2.1.2-8) com puter code was used to calculate the short term mass and energy release rates for the 16" FW line break at the steam generato r nozzle connection. A description of RETRAN-03 is pr ovided in Section 6.2.1.4.7. The FWLB mass and energy release rates are based on a break opening time of 1 millisecond. The total mass and energy release rates for the 16" FWLB is provided in Table 6.2.1.2-1Q.

The COMPARE computer code (Ref. 6.2.1.2-9) was used to perform the steam generator subcompartment pressurization analysis. The nodalization of the SG subcompartment is shown on Figure 6.2.1.2-11A. The node and junction parameters for the SG loop compartment are given on Table 6.2.1.2-6A. The flow parameters were eval uated to account for all obstructions such as platforms, supports and piping. The principal obstructions within the SG loop compartments are the SG and reactor coolant pumps.

Flow from one node to the other was calculated using the homogeneous equilibrium model. The peak differential pressures for each subcompartment are listed in Table 6.2.1.2-5B. The differential pressure curves for Nodes 1 and 17 (at the bios hield wall cut location) with respect to the containment are shown in Figure 6.2.1.2-20D.

The FWLB analysis incorporates the effects of a slight tilt in Unit 1 steam generators "A" and "D". The other two steam generators in Unit 1 and all the steam generators in Unit 2 are not tilted. The results presented in this section are for the subcompartment in the tilted steam generator, which bound the results for the non-tilted steam generators.

Force and moment coefficients on the SG have been calculated to help facilitate determination of forces and moments due to the pressures generated by the FWLB. The impact on the reactor coolant pumps is considered negligible due to the location of the break with respect to the reactor coolant pump. Force coefficients represen t the projections of the SG on three mutually perpendicular planes selected for this purpose (Figure 6.2.1.2-30). For the steam generator "C" subcompartment, the positive "Z" direction is north, the positive "X" direction is west, the positive "Y" direction is vertically up. The origin for the steam generator is at the bottom center of the SG. Moment coefficients represent the force coefficients multiplied by the moment arm from the base of the steam generator to the centers of the pr ojected areas used in the development of the force coefficients. These coefficients are calculated for each level based on nodalization and are presented in Table 6.2.1.2-7C and -7D. The steam generator forces and moments plots at each level are presented on Figure 6.2.1.2-21B.

6.2.1.2.3.4 Pressurizer Subcompartment - The pressurizer subcompartment design pressure is established by a double-ended break in the pressurizer spray line at the side of the pressurizer. This break location is in the most restrictive location and results in the maximum pressure and equipment load. The noding of the pressurizer subcompartment is shown on Figure 6.2.1.2-4 with a node and junction diagram provided on Figure 6.2.1.2-12. The spray line break mass and energy release rates have been evaluated for the T hot reduction and the increase in uncertainties due to the V5H fuel upgrade. The evaluation shows that the current mass and energy release rates continue to bound both the results of the T hot reduction program and the results associated with the V5H fuel upgrade analysis. Plot s of spray line break calculated pressure are given on Figure 6.2.1.2-23, and calculated and design peak pressure are compared in Table 6.2.1.2-9. Mass and energy release rates are provided in Table 6.2.1.2-1G.

STPEGS UFSAR 6.2-14 Revision 18 6.2.1.2.3.5 Surge Line Subcompartment - Appendix A to 10CFR50, GDC 4, permits elimination of RCS primary loop breaks when proper ju stification is pr ovided. This is referred to as Leak Before Break (LBB) methodology. Acceptable t echnical procedures and criteria for the LBB technology are defined in NUREG-1061, Volume 3.

The large bore lines eliminated by the LBB methodology are the pr essurizer surge line, and the 8-inch, 10-inch, and 12-inch accumulator lines, which include a portion of the residual heat removal lines. There is no negative safety impact as a result of the leaks which must be assumed in accordance with the LBB criteria. All lines covered by LBB are located inside the containment which is provided with leak detection equipment capable of detecti ng an unidentified leak rate of 1.0 gpm. The NRC approved the LBB analysis for the large bore lines mentioned above as documented in Section 3.6 of SSER 4 (Ref. 6.2.1.2-11).

The application of LBB methodology eliminated the surge and accumulator lines mentioned above. This leaves only the spray line and RHR line breaks as the design basis accidents for containment subcompartment analysis. Section 6.2.1.2.3.4 di scusses the spray line break analysis.

6.2.1.2.3.6 Main Steam and Feedwater Line Subcompartments - The main steam and feedwater line subcompartments are shown on Fi gure 6.2.1.2-6, with a node and junction diagram given on Figure 6.2.1.2-14. A double-ended main steam line rupture was assumed to occur in either Node 1 or 3 at the containment penetration. Th e calculated peak pressure occurred in Node 3.

A double-ended rupture of the main feedwater line was assumed to occur in either Node 5 or 7. The calculated peak pressure occurred in Node 7. Results of the analysis show that the main steam line break bounds the main feed water line break case.

Node and junction parameters utilized in the analyses are given in Tables 6.2.1.2-13 and 6.2.1.2-14.

Plots of calculated pressures are given on Figures 6.2.1.2-25 and 6.2.1.2-26, while calculated and design values are compared in Table 6.2.1.2-13.

Mass and energy release rates for FWLB are provided in Table 6.2.1.2-1K. For MSLB, the mass a nd energy releases were calculated using the RETRAN-03 computer code as discussed in Section 6.2.1.4.7. Table 6.2.1.2-1J provides the MSLB mass and energy release rates used in the analysis.

6.2.1.2.3.7 Regenerative Heat Exchanger Subcompartment - A double-ended rupture of the CVCS letdown line is the limiting break in the regenerative heat exchanger subcompartment. See Figure 6.2.1.2-7 for a detailed drawing of the area. A node and junction diagram is given on Figure 6.2.1.2-15. The nodal model initial conditions, control volumes, vent areas and corresponding flow coefficients and inertial terms are given in Tables 6.2.1.2-15 and 6.2.1.2-16. The calculated subcompartment pressure response is shown on Figure 6.2.1.2-27. Calculated and design pressures are compared in Table 6.2.1.2-15. The blowdown rate for the CVCS letdown lin e break is calculated using ANSI 58.2, Appendix E2 methodology (Ref. 6.2.1.2-7) and applying that to a one-dimensional Henry-Fauske model for saturated liquid. Mass and energy release rates are shown in Table 6.2.1.2-1N (refer to Section 6.2.1.2.3.1 for more details). Plant operation is assumed to be in the heatup mode. The break is assumed to occur at the inlet to the re generative heat exchanger. The break area is 0.0884 ft 2 for each end of the double-ended break (0.1768 ft 2 total area). There are no significant restrictions to forward flow, but the reverse flow is restrict ed by the CVCS letdown orifices (0.00166 ft

2) located immediately downstream of the regenerative heat exchanger. In STPEGS UFSAR 6.2-15 Revision 18 addition, the reservoir of reverse flow is limited since high energy fluid conditions extend only to the letdown heat exchanger.

6.2.1.2.3.8 Radioactive Pipe Chase Subcompartment - A double-ended rupture of the CVCS letdown line is the limiting break in the radioactive pipe chase subcompartment. See Figure 6.2.1.2-8 for a detailed drawing of the area. A node and junction diagram is illustrated on Figure 6.2.1.2-16. The flow model initial conditions, control volumes, inter-compartment flow paths, and corresponding flow coefficients and inertial terms are listed in Tables 6.2.1.2-17 and 6.2.1.2-18. The calculated subcompartment pressure response is shown on Figure 6.2.1.2-28. The calculated and design pressures are compared in Table 6.2.1.2-17.

The blowdown rate for the CVCS letdown line break is calculated using ANSI 58.2, Appendix E2 methodology a nd applying that to a one-dimensional Henry-Fauske model for saturated li quid. Mass and energy release rates are given in Table 6.2.1.2-1L (refer to Section 6.2.1.2.3.1 for more details). Plant operation is assumed to be in the heatup mode. The break is assumed to occur at the Containment penetra tion. The break area is 0.0884 ft 2 for each end of double-ended break (0.1768 ft 2 total area). A significant restriction to forward flow is the CVCS letdown orifices (0.00166 ft

2) located immediately downstream of the regenerative heat exchanger. For reverse flow, the letdown heat exchanger reduces the line temperature to 115F and a pressure reducing valve immediately downstream of the letdown heat exchanger reduces the line pressure to 300 psig, thereby limiting the reser voir of high energy fluid downstream of the break.

6.2.1.2.3.9 RHR Valve Room Subcompartment

- A double-ended rupture of the CVCS letdown line is the limiting break in the RHR 1A and RHR 1B valve rooms. See Figure 6.2.1.2-9 for a detailed drawing of the area. Because the valve rooms are identi cal, a break was analyzed for the RHR 1A valve room. The results are representative for both valve rooms. A node and junction diagram is shown on Figure 6.2.1.2-17. The nodal model initial conditions, control volumes, vent areas, and corresponding flow coefficients and inertial terms ar e listed in Table 6.2.1.2-19 and 6.2.1.2-20. The calculated subcompartment pressu re response is shown on Figure 6.2.1.2-29. Calculated and design pressures are compared in Table 6.2.1.2-19. The blowdown rate for the CVCS letdown line break is calculated using ANSI 58.2, Appendix E2 methodology and applying that to a one-dimensional Henry-Fauske model for saturated liquid (refer to Section 6.2.1.2.3.1 for more details). Mass and energy releas e rates are given in Table 6.2.1.2-1M. Plant operation is assumed to be in the heatup mode. The break is assumed to occur at the penetration of the valve room wall. The break area is 0.0884 ft 2 for each end of the double-ended break (0.1768 ft 2 total area). Significant restrictions to forward flow are the CVCS letdown orifices (0.00166 ft

2) located immediately downstream of the regenerative heat exchanger.

For reverse flow, the letdown heat exchanger reduces the line temperature to 115F and the pressure reducing valve, immediately downstream of the letdown heat exchanger, reduces the line pressure to 300 psig, thereby limiting the reservoir of high energy fluid downstream of the break.

6.2.1.3 Mass and Energy Release Analyses For Postulated Loss of Coolant Accidents. 6.2.1.3.1 Loss of Coolant Accident Mass and Energy Release Phases: The containment receives mass and energy releases following a postulated rupture of the RCS. These releases continue through blowdown and post-blowdown phases.

CN-3136 STPEGS UFSAR 6.2-16 Revision 18 The LOCA transient is di vided into the following:

(1) Blowdown - which includes the period from accident initiatio n (when the reactor is at steady state operation) to the time that the RCS pressure reaches initial equilibrium with containment.

(2) Refill - the period of time when the lower plenum is being filled by accumulator and ECCS water. At the end of blowdown, a large amount of water remains in the cold legs, downcomer, and lower plenum. To conservati vely consider the refill period for the purpose of containment mass and energy releases, this water is instantaneously transferred to the lower plenum along with sufficient accumulator water to completely fill the lower plenum. This allows an uninterrupted release of mass and energy to containment. Thus, the refill period is conservatively neglected in the mass and energy release calculation.

(3) Reflood - begins when the water from the lower plenum enters the core and ends when the core is completely quenched.

(4) Post-reflood -*describes the period following the end of reflood up to the time the steam generators are depressurized to atmospheri c pressure at 3600 s econds. The post-reflood mass and energy releases follow the NRC-approved methodol ogy of WCAP-10325 P-A (Ref. 6.2.1.3-1).

(5) Post-SG Depressurization- After 3600 seconds; the mass and energy release using the revised post-recirculation methodology is used. The mass an d release calculation during this long-*term phase of the transient use the NRC approved methodology discussed in Reference 6.2.1.3-6. This methodology is summarized in Section 6.2.1.3.4.5.

6.2.1.3.2 Break Size and Location: Generic studies have been performed with respect to the effect on the LOCA mass and energy releases relative to postulated break size. The double-ended guillotine break has been found to be limiting due to larger mass flow rates during the blowdown phase of the transient. During the reflood and frot h phases, the break size ha s little effect on the releases.

Three distinct locations in the reactor coolant system loop can be postulated for pipe rupture: - Hot leg (between vessel and steam generator)

- Cold leg (between pump and vessel)

- Pump suction (between steam generator and pump) The breaks analyzed are the double-ended hot leg (DEHL) guillotine break (9.18 ft

2) and the double-ended pump suction guill otine (DEPS) break (10.48 ft 2). Pump suction break releases have been calculated for the blowdown, reflood, and pos t-reflood phases of the LOCA. The following information provides a discussion on each break location. The DEHL guillotine break has been shown in previous studies to result in the highest blowdown mass and energy release rates.

Although the core flooding rate w ould be highest for this break location, the amount of energy released from the steam generator secondary side is minimal because the majority of the fluid which exits the core bypasses the steam generators in venting to containment. As a result, the reflood mass and energy releases are reduced significantly as compared CN-3136 CN-3136 STPEGS UFSAR 6.2-17 Revision 18 to either the pump suction or cold leg break locations where the core exit mixture mu st pass through the steam generators before venting through the break.

For the hot leg break, there is no reflood peak as determined by generic studies, i.e., from the end of the blowdown period the releases would continually decrease. Therefore, the reflood and subsequent post-reflood releases are not calculated for a hot leg break. For the DEHL analysis, the DEPS mass and energy releases for the post-blowdown period were used. As discussed below for the DEPS break, this assumption results in the highest release rates.

The cold leg break (DECL) location has been found in previous studies to be much less limiting in terms of the overall containment peak pressure. Th e cold leg blowdown is faster than that of the pump suction break and more mass is released into the containment.

However, the core heat transfer is greatly reduced, result ing in considerably lower energy release into containment. Studies have determined that the blowdown transient for the cold leg is, in general, less limiting than that for the pump suction break. During reflood, the flooding rate is greatly reduced and the energy release rate into the containment is reduced. Therefore, the containment peak pre ssure for a cold leg break occurs at the end of blowdown. An analys is of the cold leg break is not usually performed because the hot leg break is expected to result in the highest blowdown peak pressure and the pump suction break results in the highest post-blowdown energy releases into containment.

For the double-ended pump suction break (DEPS), a two-phase mixtur e exits the core, which passes through the hot legs, and is superheated in the steam generators. After the broken loop steam generator cools, the break flow becomes two phase. The pump suction break combines the effects of the relatively high core flooding rate, as in the hot leg break, and the addition of the stored energy in the steam generators. As a result, the pump sucti on break yields the highest energy flow rates during the post-blowdown period.

6.2.1.3.3 Application of Single Failure Criteria:

An analysis of the effects of the single failure criteria has been performed on the mass a nd energy release rates for the DEPS break. For the DEPS break, an inherent assumption in the generation of the mass and energy release is loss of offsite power (LOOP). This results in the actuation of the sta ndby diesel generators, required to power the ECCS. The effects of a single failure are considered with both minimum and maximum safeguards. In the minimum safeguards case, the single failure postulated to occur is the lo ss of one train (out of a three train system) of ECCS equipment due to the failure of a diesel generator to start. This is labeled as a "Two Train" case and it results in the loss of one pumped emergency core cooling train, thereby minimizing the ECCS flow. For the case analyzing maximum ECCS, all six SI pumps are assumed to be available and the limiting single failure occurs in one component of the CHRS (i.e., a spray pump and a fan cooler train). This maximizes ECCS flow by assuming op erability of all ECCS pumps. The analysis of both maximum and minimum safegu ards cases bounds the effects of credible single failures. 6.2.1.3.4 Mass and Energy Release Data: 6.2.1.3.4.1 Significant Modeling Assumptions - The following items are incorporated so that the mass and energy releases are conservatively calculated for maximum containment pressure: CN-3136 CN-3136 CN-3136 CN-3136 CN-3136 STPEGS UFSAR 6.2-18 Revision 18 Maximum expected operating temperature of the RCS Allowance in temperature for instrument error and dead band (+5.1 o F) Margin in volume of 3% (composed of 1.6% allowance for thermal expansion and 1.4% for uncertainty) Core power level of 3,876 MWt (includes calorimetric errors) Conservative coefficients of heat transfer (i.e., SG primary/secondary heat transfer and RCS metal heat transfer) Allowance in core stored energy effect of fuel densification Margin in core stored energy (+15%) Allowance for RCS pressure uncertainty (+46 psi) Maximum containment backpressure equal to design pressure.

Nitrogen Injection During a LOCA, most of the react or vessel water will be displa ced by the steam generated by flashing. The vessel is then ref illed by the SI accumulators and the high and low head safety injection systems. For the blowdown, refill and reflood stages, the mass and energy release rates are obtained from the Westinghouse LOCA analysis using NRC-approved methods (Reference 6.2.1.3-1). The releases include water from the ECCS accumulators, but the compressed nitrogen release is modeled separately in the GOTHIC containment analysis model. In the m odel, a boundary condition injects the nitrogen gas volume into the containment atmosphere consistent with the timing in the mass and energy releases. The nitrogen pressure, temperature, and volume are based on allowable operating ranges in the plant Technical Specifi cations with consider ation of uncertaint

y. Decay Heat

Two decay heat models are used for calculating the mass and energy releases as discussed below.

Up to 3600 Seconds After the initial depressurization, the mass and energy releases from the effect of decay heat are based on ANS-5.1-1979 Decay Heat Power (Ref. 6.2.1.3-4), which include the following:

Decay heat sources considered are fission product decay and heavy element decay of U-239 and Np-239. Decay heat power from fission isotopes other than U-235 and U-238 are assumed identical to that of U-235. Fast fissions for U-238 are included in a conservative manner. Fission rate is constant over the operating history of maximum power level. The factor accounting for neutr on capture in fission products is taken from Table 10 of ANS-5.1-1979 Standard. The fuel is assumed to operate at full power for 10 8 seconds. The total recoverable energy associated with one fission is assumed to be 200 MeV. Two sigma uncertainty (two times the standard deviation) has been applied to the fission product decay.

CN-3136 CN-3136 STPEGS UFSAR 6.2-19 Revision 18 After 3600 Seconds After 3600 seconds, the mass and energy releases are calculated using the revised post-recirculation methodology approved by the NRC in Reference 6.2.1.3-6. The core decay heat is calculated using BTP ASB 9-2 decay heat correl ations as defined in Section 9.2.5 of NUREG- 0800 (Reference 6.2.1.3-8). The BTP ASB 9-2 decay heat data is presen ted in Table 6.2.1.3-6A.

Table 6.2.1.3-6 shows the decay heat data used in this analysis.

6.2.1.3.4.2 Blowdown Mass and Energy Release Data

- The SATAN-VI code is used for computing the blowdown transient and is the same as that used for the ECCS calculation in Reference 6.2.1.3-2. The methodology for the use of this model is described in Reference 6.2.1.3-1.

Tables 6.2.1.3-4 and 6.2.1.3-5 present the calculated mass and energy releases for the blowdown phase of the break analyzed for the DEHL and DEPS breaks, respectively. The mass and energy release for the DEHL break and the DEPS br eak, given in Table 6.2.1.3-4 and Table 6.2.1.3-5, terminate within 25 seconds after the initiation of the postulated accident. 6.2.1.3.4.3 Reflood Mass and Energy Release Data

- The WREFLOOD code is used for computing the reflood transient and is a modified ve rsion of that used in the ECCS calculation in Reference 6.2.1.3-2. The methodology for the use of this model is described in Reference 6.2.1.3-1. Steam Water Mixing Even though the Reference 6.2.1.3-1 model credits steam/water mixing only in the intact loop, steam/water mixing in the broken loop has been in cluded in this analysis. This assumption is justified and is supported by test data. It is summarized as follows: The model assumes a complete mixing condition (i.e., thermal equilibrium) for the steam/water interaction. However, the complete mixing process is made up of two distinct physical processes. The first is a two phase interaction with condensati on of steam by cold injecti on water. The second is a single phase mixing of condensat e and injection water. Since the mass and energy of the steam released is the most important influence to the containment pressure transient, the steam condensation part of the mixing process is the on ly part that need be considered.

Any spillage dire ctly heats only the sump. The most applicable steam/water mixing test da ta has been reviewed for validation of the containment integrity reflood steam/water mixing mode

l. These data were generated in 1/3 scale tests (Ref. 6.2.1.3-3), which are the larg est scale data available. They most closely simulate the flow regimes and gravitational effects that would occur in a pressurized water reactor (PWR). These tests were designed specifically to study the steam

/water interaction fo r PWR reflood conditions. From the entire series of 1/3 scale tests, a group corresponds almost directly to containment integrity reflood conditions. The injection flow rates for this group cover all phases and mixing conditions calculated during the reflood transient. The data from these tests were reviewed and discussed in detail in Reference 6.2.1.3-1. For all of these tests, the data clearly indicates the occurrence of very effective mixing with rapid steam condensation. Therefore, the mixing model used in the containment integrity reflood calculation is supported by the 1/3 scale steam/water mixing data. CN-3136 CN-3136CN-3136 CN-3136 STPEGS UFSAR 6.2-20 Revision 18 Post-Blowdown Phase The limiting break for the containment integrity peak pressure analysis during the post-blowdown phase is the DEPS break. For this break, two flow paths are available in the RCS by which mass and energy may be released to containment. One is through the outlet of the steam generator, the other via reverse flow through the reactor coolant pump. Steam, which is not condensed by ECCS injection in the intact RCS loops, passes around the downcomer and through the broken loop cold leg and pump in venting to containment. This steam al so encounters ECCS injection water as it passes through the broken loop cold leg, complete mixing occurs, and a portion of it is condensed. Credit is taken in this analysis for that portion of steam which is condensed. This assumption is justified by the postulated break locati on and the physical presence of the ECCS injection nozzle. A description of the test and test re sults is contained in References 6.2.1.3-1 and 6.2.1.3-3.

Table 6.2.1.3-5A and Table 6.2.1.3-5B present the calculated mass and energy re lease for the reflood phase of the DEPS break, with minimum and maximum ECCS, respectively. The principal parameters during reflood are gi ven in Tables 6.2.1.3-9 and 6.2.1.3-10 for the minimum and maximum ECCS DEPS break cases. The temperature that was assumed for the RWST for these transients, and therefore the pumped safety in jection flow during the injection phase, was 130 o F. 6.2.1.3.4.4 Post-Reflood Mass and Energy Release Data - The FROTH code (Ref. 6.2.1.3-5) is used for computing the post-reflood transient. The methodology for the use of this model is described in Reference 6.2.1.3-1. The mass and energy release rates calculated by FROTH are used in the containment analysis until the time of containment depressurization.

Table 6.2.1.3-5A presents the two-phase (froth) mass and energy re lease data for the DEPS break with minimum ECCS. Table 6.2.1.3-5B presents the two-phase mass and energy release data for the DEPS break with maximum ECCS. 6.2.1.3.4.5 Post-Depressurization Phase - Fo r the LOCA mass and energy release calculation, the steam generators are conservatively cooled and de pressurized to the saturation temperature of 212 oF at 14.7 psia at approximately 3600 s econds after accide nt initiation.

In the post-SG depressurization sump recirculation phase (after 3600 seconds), the revised post-recirculation methodology is *used (Refere nce 6.2.1.3-6). The safety injection (SI) flow into the reactor vessel is a mixture of the HHSI and LHSI flows. The HHSI pumps take suction from the sump and injects directly into the reactor vessel. The LHSI pumps also take suction from the sump but the flow is cooled by the RHR heat exchanger and then injected into the reactor vessel. The STP LOCA containment analyses conservativel y do not use the HHSI flows in this phase of the transient. In this model, if the enthalpy of the water leaving the core is less than the liquid saturation enthalpy at the containm ent steam partial pressure, the water is returned to the sump. If the pressure of the water leaving the core is greater than the saturation pressure of the containment, a pressure flash mode l is used to determine the flow split that is returned to the sump and the steam that is released to the containment atmosphere. During this phase of transient, the BTP-ASB 9-2 de cay heat model is used as discussed in Section 6.2.1.3.4.1. 6.2.1.3.5 Sources of Mass and Energy: The sources of mass considered in the LOCA mass and energy release analysis for the DEPS breaks are given in Tables 6.2.1.3-13 and 6.2.1.3-14. The CN-3136 CN-3136 CN-3136 CN-3136 CN-3136 STPEGS UFSAR 6.2-21 Revision 18 mass inventories for the DEHL break are given in Table 6.2.1.3-15. These sources are the RCS accumulators and pumped ECCS injection. The energy inventories for the LOCA mass and energy release analysis for the DEPS breaks are given in Tables 6.2.1.3-16 and 6.2.1.3-17. The energy i nventories for the DEHL break are given in Table 6.2.1.3-18. The energy sources include: reactor coolant system water accumulator water pumped injection water decay heat core stored energy reactor coolant system metal steam generator metal steam generator secondary energy secondary transfer of energy (feedwater into and steam out of the steam generator secondary) In the mass and energy release data presented, no Zirc-water reaction heat is presented because the clad temperature does not rise high enough for the rate of the Zirc-water reac tion heat to be of any significance.

The consideration of the various energy sources in the mass and energy release analysis provides assurance that all available sources of energy have been included in this analysis. Thus the review guidelines presented in Sta ndard Review Plan Section 6.2.1.3 have been satisfied. The mass and energy inventories are presented at the following times, as appropriate: time zero (initial conditions) end of blowdown time end of refill time end of reflood time time of broken loop steam generator depressurization time of intact loop steam generator depressurization one hour after accident initiation The methods and assumptions used to releas e the various energy sources are given in Reference 6.2.1.3-1, except as noted in section 6.2.1.3.4.3.

The sequence of events for the DEPS and the DEHL break transients are shown in Table 6.2.1.1-10. 6.2.1.4 Mass and Energy Release Analysis for Postulated Secondary System Pipe Ruptures Inside the Containment. CN-3136 CN-3136 STPEGS UFSAR 6.2-22 Revision 18 Following a postulated MSLB or a FWLB inside the Containment, the contents of one SG will be released to the Containment. Most of the conten ts of the other SGs will be isolated by the main steam isolation valves (MSIVs), main feedwater isolation valves (MFIVs) and the feedwater flow control valves (FCV). Containment pressuriza tion following a secondary side rupture depends on how much of the break fluid enters the Containment atmosphere as steam. Main steam line break flows can be pure steam or two-phase, while FWLB flows are two-phase. With a pure steam release, all of the break flow enters the Containment vapor space atmosphere. With two-phase release, part of the liquid in the break flow boils off in the Containment and is added to the vapor space atmosphere, while the remaining liquid falls to the sump and contributes nothing to Containment pressurization. For MSLB cases with large break area, steam cannot escape fast enough from the two-phase region of the ruptured SG, and the two-phase level rises rapidly to the steam line nozzle. A two-phase blowdown results. The duration of this release is short, thereby reducing prim ary-to-secondary heat transfer, and the break flow is largely liquid. For MSLB cases with small break areas, steam can escape fast enough from the two-phase region of the SG with the ruptured line that the level swell does not reach the steam line nozzle, and a pure steam blowdown results. Because of the pressure reducing effects of active and passive Containment heat sinks, the highest peak Containment pressure resulting from a MSLB for a given set of initial SG conditions occurs for that case where the break area is the maximum at which a pure steam blowdown can occur. For conservatism, the MSLB analysis assumed only pure steam blowdown for all break sizes and power levels. Main steam line isolation is initiated on the following signals: high-2 Containment pressure, low steam line pressure (above P-11 setpoint), high negative steam line pressure rate (below the P-11 setpoint), and manual. Main feedwater line isolation is initiated by SG high-high water level, reactor trip in conjunction with low T avg, and SI. The MSIV and MFIV closure times are given in Table 16.1-1. The MSLB blowdown calculation conservative ly used 8 seconds for MSIV closure and 13 seconds for MFIV closure from the time the isola tion setpoint was reached. These values include signal delay and valve closure times. The Auxiliary Feedwater System (AFWS) functions automatically following a secondary system line break to assure that a heat sink is always avai lable to the RCS by supplying cold feedwater to the SGs. For conservatism, it was assumed that the AFWS attains full flow to the SG immediately following the initiation of the even

t. Following feedwater isolation, only AFW is available to supply feedwater to the SGs. The analysis assumes the following manual operator actions within 30 minutes of the break: (1) isolate the AFW to the faulted steam generator, (2) re-pressurize the RCS using normal pressure control, and (3) control AFW to the intact steam generators and control cooldown.

In addition, the analysis includes flashing of fluid located between the MFIV and the affected SG.

This fluid then flows through the affected SG and into the Containment. To determine the effect of MS LB on Containment pressure and temperature response, a spectrum of break sizes was assumed to occur inside the Contai nment, downstream from the integral steam line flow restrictors and upstream of the MSIVs. The analysis assumed critical flow from the rupture. Feedwater Line Break (FWLB) CN-3136 CN-3136 CN-3136 STPEGS UFSAR 6.2-23 Revision 18 The feedwater enters the SG in the two-phase region; therefore, FWLB cases always result in two-phase blowdowns through smaller size lines a nd do not produce peak Containment pressures and temperatures as severe as MSLB cases. 6.2.1.4.1 Long-Term MSLB Mass and Energy Release Data: The MSLB mass and energy release transient is analyzed by using the RETRAN-02 computer code (Ref. 6.2.1.4-2). Safety analysis methods using this c ode are described in WCAP-14882 (Ref. 6.2.1.4-3). The code simulates a multiloop system, neutron kinetics, the pressurizer, feedwater system, SG, and SG safety valves. The code computes pertinent plant variables including primary and secondary temperatures and pressures, steam flow, and power level during the cooldown. The DER and split break MSLBs analyzed are listed in Table 6.2.1.1-1. Table 6.2.1.4-1 presents the mass and energy release rate data for the limiting break for peak pressure, 1.4 ft 2 double-ended rupture at 30% power with failure of one MSIV. Table 6.2.1.4-2 presents the mass and energy release rate data for the peak-temperature case, 1.4 ft 2 double-ended rupture at 0% power with failure of one MSIV. All mass and energy releases used in the analyses were conservatively assumed to consist of dry steam although considerable entrainment can be expected for double-ended breaks. Mass and Energy Release Through MSIV Above Seat Drain Line Flow Re striction Orifices Additional mass and energy ar e released through the above seat main steam line orifices, since the condensers are assumed not available for steam dump. This has negligible affect on the mass and energy release rates. The significant parameters affecting the mass and energy releases to Containment following a steam line break are discussed below. 6.2.1.4.2 Plant Power Level: Steam line breaks can be postulated to oc cur with the plant in any operating condition ranging from hot shutdown to full power. Since SG water mass decreases with increasing power level, breaks occurring at a lower power generally result in a greater total mass release to the Containment. However, because of increased energy storage in the primary plant, increased heat transfer in the SGs, and the additional energy generation in the nuclear fuel, the energy release to the Containment from breaks postulate d to occur during power operation may be greater than for breaks occurring with the plant in a hot shutdown condition. Additionally, the steam pressure and the dynamic conditions in the SGs cha nge with increasing power and have significant influence on the rate of release following a steam lin e break event. The power generated in the core due to the cooldown effect from the negative moderator coefficient is included in the analysis for each power level since it adds to the energy released to Containment. Because of the opposing effect of changing power level on steam line break mass and energy releases, no si ngle power level can be singled out as a worst case initial condition for a steam line break. Therefore, a spectrum of power levels spanning the operating range, as well as the hot zero power conditions, has been considered. 6.2.1.4.3 Break Type, Area, and Location: 1. Break Type CN-3136 STPEGS UFSAR 6.2-24 Revision 18 There are two possible types of pipe ruptures which must be considered in evaluating steam line breaks. The first is a split rupture in which a hole opens at some point on the side of the steam pipe or steam header but does not result in a complete se verance of the pipe. A single, distinct break area is fed uniformly by all SGs until steam line isolation occurs. The releases from the individual SGs are not indepe ndent since fluid coupling exists between all steam lines. Because of the flow limiting orifices in each SG, the largest possible split rupture can have an effective area prior to isolation that is no greater than the throat area of the flow restrictor times the number of plant primary coolant loops.

Following isolation, the effective break area for the SG with the broken line can be no greater than the flow restrictor throat area. The second break type is the double-ended guill otine rupture (DER) in which the steam pipe is completely severed and the ends of the break displace from each other. Guillotine ruptures are characterized by two distinct break locations, each of equal area but being fed by different SGs. The largest possible guillotine rupture can have an effective area per SG no greater than the throat area of one steam line flow restrictor. 2. Break Area The breaks analyzed include a spectrum of break ar eas (full double-ended and split ruptures) at each of the four initial power levels, as follows: a. A full double-ended pipe rupture downstream of the steam line flow restrictor. For this case, the actual break area equals the cross-sectional area of the steam line

(4.2 ft 2), but the mass and energy release from the SG with the broken line is controlled by the flow restrictor throat area (1.4 ft 2). The reverse flow from the intact SGs is controlled by the smaller of the pipe cross section or the to tal flow restrictor throat area in the intact loops. b. Split breaks that represent the largest break which will not generate a steam line isolation signal from the primary protection equipment. Steam and feedwater line isolation signals with be generated for these cases by high Containment pressure signals. 3. Break Location Break location affects steam line blowdown by virtue of the pressure losses which would occur in the length of piping between the SG and the break. The effect of the pressure loss is to reduce the effective break area seen by the SG. Although this would reduce the rate of mass and energy release, it woul d not significantly change the total energy release to the Containment. Piping loss effect s have been considered in the MSLB mass and energy release calculation. 6.2.1.4.4 Main Feedwater Addition Prior to Feedwa ter Line Isolation: All of the double-ended ruptures generate main steam and feedwater is olation signals very quickly following the break. Isolation of the steam lines due to low steam line pressure is assumed to be complete following a time delay sufficiently long to allow for instrument response time and signal processing delay and valve closing time (total of 8 seconds). The total delay time assumed for feedwater isolatio n is 13 seconds. CN-3136 STPEGS UFSAR 6.2-25 Revision 18 For the split ruptures, the feedwater line isolation and main steam line isolation signals are conservatively assumed to result from High-1 Containment pressure signal. The Containment pressure at which feedwater line and steam line isolation signals are assume d to occur is 5.5 psig. Main steamline isolation is assumed to be complete after a time delay of 8.0 seconds after the setpoint is reached. The feedwater line isolation is assumed to be complete after a time delay of 13.0 seconds after the setpoint is reached.

Prior to complete isolation, the de pressurization of the SG results in significant amounts of feedwater being added to the broken loop SG through the main feedwater system. The quantity of feedwater added is conservatively evaluate d using the following assumptions: 1. The main feedwater flow is conservatively calculated assuming the appropriate number of pumps operating for the power level analyzed and assuming main feedwater control valves fully open. 2. Prior to receipt of an isolation signal, all main feedwater control valves maintain the position that exists at power operation. 3. Feedwater isolation valves and control valves in the intact loops close upon receipt of the isolation signal, after a delay time. 4. No flow reduction through the feedwater isolat ion valve and control valve in the broken loop prior to complete closure (i.e., no credit is taken for decrease in flow during valve closure).

These assumptions were used along with the Feedwater System hydraulic resistances and pump performance curves to determine the amount of feedwater added to the SG with the broken loop. 6.2.1.4.5 Auxiliary Feedwater System Design: Generally, within the first minute following a steam line break, the AFWS is initiated on any one of several protection system signals. Addition of auxiliary feedwater (AFW) to the SGs increases the secondary mass available for release to the Containment as well as increasing the heat transferred to the secondary fluid. The effects on SG water mass are maximized in the calculation by assuming full auxiliary feedwater flow to the faulted SG starting at time zero after receipt of the SI signal and continuing until manually stopped by the plant operator. Although operator action after 10 minutes following th e break is anticipated, it is conservatively assumed auxiliary feedwater is manually terminated after 30 minutes. The AFWS design is such that only one AFW pump feeds each SG. The maximum flow that can be delivered to a depressurized SG is the pump runout flow. This flow is assumed, although the AFW flow control valve, in combination with the AFW flow element and the Qualified Display Processing System (QDPS) (described in Sections 7.5 and 10.4.9), will begin to limit and control AFW flow delivered to the SGs. The mass and energy release data are conservatively based on AFW at pump runout flow to the SG with the broken line. For the RETRAN-02 model, the AFW addition to each of the intact SGs is a minimum value, consistent with the restrictions imposed by the flow control valve for each AFW pump. Fluid Stored in the Feedwater Piping Prior to Isolation STPEGS UFSAR 6.2-26 Revision 18 The mass and energy releases were determined assuming the maximum calculated unisolated volume in each main feedline.

Fluid Stored in the Steam Piping Prior to Isolation All the steam in the steam lines up to the turbine steam chest is assumed to be released to the Containment following the break for the case of the main steam line isolation valve (MSIV) failure. Availability of Offsite Power Loss of offsite power following a steam line rupture would result in tripping of the reactor coolant pumps and steam-driven main feedwater pumps, and delay of AFW initiation due to standby DG starting and sequencer loading delays. Each of these occurrences aids in mitigating the effects of the steam line break releases by either reducing the fluid inventory available for mass and energy release or reducing the energy transferred from the primary coolant system to the SGs. Thus, breaks which occur in conjunction with a LOOP are less severe than cases where offsite power is available. Therefore, the releases have been determined assuming offsite power is available. However, for purposes of determining the activation time of the RCFCs and CSS, the MSLBs are conservatively assumed to occur simultaneously with a LOOP.

Safety System Failures

1. Failure of Main Feedwater Line Isolation Valve There are two valves in series (MFIV and FC V) that open during power operation in each feedwater line. Both are assumed to close wi thin 13 seconds after the feedwater isolation setpoint is reached including instrument response and valve closure time. Failure of the downstream valve following a steam line break increases the unisolatable feedwater line by the volume between the MFIV and FCV.

2. Failure of Main Feedwater Pump Trip No credit is taken for feedwater pump trip and coastdown in calculating main feedwater addition prior to feedwater line is olation. Therefore, this fail ure has no effect on the results presented.

3. Failure of a Main Steam Line Isolation Valve Failure of an MSIV is assumed to increase the volume of steam piping, which empties into the Containment, between the MSIVs of the intact loops and the main steam header.

4. Failure of One ESF Train AFW pumps on Loops A and D are on ESF train "A." The other two AFW pumps are on dedicated ESF trains (B & C). Therefore, the worst case scenario is to lose ESF train "A" which can result in two AFW pumps not being able to start automatically. Two scenarios are possible with two AFW pumps unavailable.

STPEGS UFSAR 6.2-27 Revision 18 Case 1 One AFW pump failing to feed the faulted steam generator, and one AFW pump failing to feed one intact SG, and Case 2 Two AFW pumps failing to feed two intact steam generators The mass and energy release ana1ysis was performed with all four AFW pumps starting immediately on SI signal, without any time delay. Th is is conservative becau se it will increase the mass of water available for release to the containment in addition to increasing the heat transferred to the secondary fluid.

5. Failure of One Containment Heat Removal Train One of the worst single failures following a steam line break is the failur e of one of the three redundant CHRS trains. The fan cool er setpoint is at the initiati on of Safety Injection signal. The containment P/T analyses conservative ly used a fan cooler setpoint based on Containment Pressure High-1 sign al plus uncertainties (5.5 psig). Conservative delay time (SDG sequencer, fan startup, etc.) as sociated with initiation of the fan cooler was used in the analysis. The containment spray initiation setpoint used is the Containment Pressure High-3 signal plus uncertainties (12.0 psig). Delay times (SDG sequencer, startup, pipe fill, etc.) associated with initiation of the sprays were used in the analysis. 6.2.1.4.6 This section is not used.

6.2.1.4.7 Short-Term Steam Line and Feed water Line Breaks: The RETRAN-03 (Ref. 6.2.1.2-8) computer code was used for the short-term MSLB analysis. The RETRAN-03 computer code has been verified by station personnel for calculating short-term mass and energy release rate data following a postulated MSLB. RETRAN-03 also meets the requirements of ANSI/ANS-56.10-1982 to perform this function.

RETRAN-03 is a best-estimate transient therma l-hydraulic code designed to analyze operational transients, small break loss-of-coolant accidents, anticipated transients without scram, natural circulation, long-term transients, and events involving limited nonequilibrium conditions in light water reactors. RETRAN-03 is a derivative of the RELAP4 code referenced in ANSI/ANS-56.10-1982. RETRAN-03 is the result of a program sponsored by the Electric Power Research Institute since 1975 to analyze thermal-hydraulic transients. Major assumptions of the main steam line break short-term mass and energy release analysis are as follows: 1. The initial conditions for the main steam system are at zero power operating conditions plus instrument error (1266 psia and 574 F). 2. The postulated high energy line double-ended rupture is assumed to reach maximum opening area within one millisecond of break initiation. Each pipe end discharges through a break area equal to the internal cross-sectional area of the pipe.

STPEGS UFSAR 6.2-28 Revision 18 3. During the transient, the SG pressure and temperature are assumed to remain constant at the initial conditions. This is conservative, because the actual SG pressure would decrease during this event. 4. The quality of the moisture carryover is conservatively assumed to be 4% and is assumed to continue until the mass of the affected steam generator (including AFW flow) is depleted. The 4% quality assumption is taken from Appendix E of ANSI 58.2-1980. 5. The analysis continues until the water mass in the affected steam generator (included AFW flow) is depleted. After the mass in the affected steam generator is depleted, the mass and energy release from this generator is significantly reduced. At this time, the MSIVs are also assumed to close. This is conservative because MSIV closure is expected to occur at approximately 15 seconds based on a low steam line pressure signal. 6. AFW flow begins at the time of the break at the runout flow 1250 gal/min. 7. A sink volume is maintained at a constant pressure of 14.7 psia. 8. A throat with an area of 1.388 ft 2 is assumed to limit the MSLB mass and energy release from the SG side. The feedwater line break short-term mass and energy release analysis was performed using the RETRAN-03 (Ref. 6.2.1.2-8) computer program. Assumptions used in this analysis include: 1. Feedwater inlet nozzle area of 1.1175 ft 2 2. One millisecond break opening time.

3. Break junctions releasing mass into an environment that is maintained at a constant temperature and pressure of 120 o F and 14.7 psia.

4. Feedwater pump characteristics are not included in this analysis

5. The mass and energy release analysis was evaluated for three bounding plant operating conditions. at hot zero power (1350 psia and 211 o F feedwater conditions), at hot full power (1150 psia and 448 o F feedwater conditions), and at hot full power (1194 psia and 390 o F feedwater conditions). The short-term mass and energy release rates were used in subcompartment pressurization analysis discussed in Section 6.2.1.2. 6.2.1.5 Minimum Containment Pressure Analysis for Performance Capability Studies of Emergency Core Cooling System. The Containment backpressure used for the limiting case C D=0.8 (Min. SI, High T avg), double-ended cold leg guillotine break for the ECCS analysis presented in Section 15.6.5 is presented on Figure 6.2.1.5-1. C ontainment backpressure is calculated using the CN-3136 STPEGS UFSAR 6.2-29 Revision 18 methods and assumptions described in Appendix A of Reference 6.2.1.5-1. Input parameters used in the analysis are described below. 6.2.1.5.1 Mass and Energy Release Data: The mass and energy releases to the Containment during the blowdown portion of the limiting break transient are shown in Table 6.2.1.5-1. The mass and energy flow rates during blowdown of the broken loop (safety injection is assumed to spill directly to Containment) are presented in Table 6.2.1.5-1A. Table 6.2.1.5-2 presents the mass and energy flow rates to Containment during the reflood portion of the transient. The mathematical models that calculate mass and energy releases to the Containment are described in Section 15.6.5. Since the requireme nts of Appendix K of 10CFR50 ar e very specific as to the modeling of the RCS during blowdown, and since the models used are in conformance with Appendix K, no alterations to those models have been made with regard to the mass and energy releases. A break spectrum analysis is performe d (see references in Section 15.6.5) that considers various break sizes, break locati ons, and Moody discharge coefficien ts for the double-ended cold leg guillotine breaks that affect the mass and energy released to the Containment. This effect is considered for each case analyzed. During refill, the mass and energy released to the Containment is assumed to be zero, which minimizes the Containment pressure. During reflood, the effect of steam/water mixing between the SI water and the steam flowing through the RCS intact loops reduces the available energy released to the Containment vapor space and therefore tends to minimize Containment pressure. 6.2.1.5.2 Initial Containment Internal Condition s: The following initial values were used in the analysis: Containment pressure 14.5 ps ia (includes uncertainty) Containment temperature 90 F Refueling water storage tank temperature 50 F Service water temperature 33 F Outside temperature 29 F Relative humidity 99 percent The Containment initial conditions of 90 F and 14.5 psia are representati vely low values anticipated during normal full-power operation. 6.2.1.5.3 Containment Volume: The maximum free volume used in this analysis is 3.56 x 10 6 ft 3 (based on the actual net free volume of 3.42 x 10 6 ft 3 with a conservative evaluation to bound the effects of the containment purge system). The Containment free volume used in the analysis is larger than the calculated value in accordance with ANSI/ANS-56.4-1983 Standards. The larger Containment free volume decreases the LOCA re flood rate, which increases the fuel peak clad temperature, and so is conservative. 6.2.1.5.4 Active Heat Sinks: The CSS and the RCFCs operate to remove heat from the Containment. Pertinent data used in the analysis for these systems are presented in Table 6.2.1.5-3. Figure 6.2.1.5-2 presents heat removal rate versus Containment temperat ure (in the post-LOCA environment) per RCFC unit. Conservatively high RCFC System heat removal rates were calculated STPEGS UFSAR 6.2-30 Revision 18 by using the minimum expected component cooling water temperature. Fan cooler heat removal performance was conservatively based on a fouling factor of 0.0. The sump temperature was not used in the analysis because the maximum peak cladding temperature occurs prior to initiation of the recirculation phase for the CSS.

In addition, heat transfer between the sump water and the Containment vapor space was not considered in the analysis.

6.2.1.5.5 Steam/Water Mixing: Water spillage rates from the broken-loop accumulator are determined as part of the core reflooding calculation and are included in the Containment code calculational model (COCO). 6.2.1.5.6 Passive Heat Sinks: The passive heat sinks used in the analysis, along with their thermophysical properties, ar e given in Table 6.2.1.5-4. Note that all heat sink areas given in Table 6.2.1.5-4 include a 10% margin. 6.2.1.5.7 Heat Transfer to Passive Heat Sinks:

The condensing heat transfer coefficients used for heat transfer to the steel Containment structures are given on Figure 6.2.1.5-3 for the limiting break. The Containment pressure transient for the limiting break is shown on Figure 6.2.1.5-1. 6.2.1.5.8 Other Parameters: No other parameters, including the Containment purge system performance, have a substantial effect on the minimum Containment pressure analysis. The effect of purge system operation concurrent with a LOCA has been conservatively modeled in the calculations. 6.2.1.6 Testing and Inspection. Structural in tegrity tests and inse rvice surveillance requirements are discussed in Section 3.8.1.7. Containment leakage testing is discussed in Section 6.2.6. Testing and inspection requirements for other ESFs that interface with the Containment structure are discussed along with the applicable system descriptions. 6.2.1.7 Instrumentation. Containment instrume ntation consists of pressure, radiation, temperature, and humidity monitoring equipment (Figure 9.4.5-1). Hydrogen monitoring equipment is also provided. Pressure monitoring equipment consists of six pressure transmitters and four pressure switches. Four pressure transmitters are used by the Engineered Safety Features Actuation System (ESFAS) to generate SI and Containment spray signals, as discussed in Section 7.3. Logic details are shown on Figure 7.2-8. These transmitters and the remaining two (extended ranges) are also used for post-accident moni toring, as discussed in Section 7.5. The pressure switches provide Containment high and low pressure alarms (common annunciator window). The high pressure alarm alerts the operator to increasing Containment pressure, which indicates an abnormal condition prior to ESFAS actuation. The low pressure alarm is a vacuum alarm, which signals Containment pressure decreasing to a value less than the outside pressure. Containment air monitoring for particulate, iodine, and gaseous radioactivity is provided by the RCB atmosphere monitor. A detailed description of this monitor and its function is provided in Section 11.5.

STPEGS UFSAR 6.2-31 Revision 18 A temperature sensor with a control room indicator and computer monitoring is provided. The temperature indicator serves as an operator aid in determining increased leakage of liquid to the Containment atmosphere and verifying normal operation of the Containment HVAC equipment. The humidity sensor is provided as an operator aid in determining increased leakage of liquid to the Containment atmosphere. A humidity indicator and computer monitoring is provided in the control room. Two redundant hydrogen monitors are provided for combustible gas measurement in the Containment following a LOCA. These m onitors are discussed in Section 7.6.5. 6.2.2 Containment Heat Removal Systems The CHRS consist of the RCFC Subsystem , which is a part of the Reactor Containment HVAC System, and the CSS. The ECCS assists the CHRS by transferring heat from the reactor core to the Containment sump. The RHR heat exchangers (HXs

), in conjunction with the ECCS low-head SI pumps, are used to transfer heat from the Containment sumps to the Component Cooling Water System (CCWS). The RCFCs are also cooled by the CCWS following an SI signal. The CCWS rejects this heat to the ultimate heat sink via the Essential Cooling Water System (ECWS). The CSS transfers heat from the Containment atmosphere to the Containment sump; it also removes iodine from the Containment atmosphere. The capability of the CSS to remove iodine is discussed in Section 6.5.2. The Containment emergency sump and ECCS recirculation pipi ng are included in this section. The ECCS is discussed in Section 6.3. The mathematical model used to predict fission product removal by the CSS is discussed in Section 6.5.2. 6.2.2.1 Design Bases. 6.2.2.1.1 Containment Heat Removal Systems Design Bases: The CHRS meets the following design bases: 1. The CHRS is capable of removing sufficient energy to limit the peak Containment pressure and to limit the Containment pressure to a lo w value at the end of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after a DBA. 2. In order to ensure the satisfactory operation of the systems after a DBA, each active component is testable duri ng reactor power operation. 3. The system is divided into three trains, with each train receiving power from a separate ESF power supply. 4. The sources and amounts of energy that were considered in evaluating the system performance are listed in Section 6.2.1.3. 5. The CHRS is sized based on the following:

a. Three out of six RCFC units operating

b. Two out of three CSS trains operating STPEGS UFSAR 6.2-32 Revision 18 c. Two out of three RHR HXs operating d. Three ECCS accumulators operating through blowdown with two ECCS trains operating during the reflood and post-reflood periods This configuration of the CHRS is used in the post-DBA evaluation of accidents listed in Section 6.2.1.1. 6. The CHRS is designed to operate over an extended period of time and under environmental conditions existing following a LOCA or steam line break accident. 7. The CHRS is designed so that it will tolerate a single active failure during the short-term, or a single active or passive failure during the long-term, following a DBA without loss of protective function. 8. The CHRS is designed to accommodate the Operating Basis Earthquake (OBE) within stress limits of applicable codes and to with stand the SSE without loss of function. 9. The CHRS and the RHRS are protected from the effects of missiles and postulated pipe ruptures without loss of safe ty function (Section 3.5 and 3.6).

10. The CHRS is designed to permit periodic inspection of the system, including important subsystems and components. 6.2.2.1.2 Containment Emergency Sump Design Bases: The Containment emergency sump meets the following design bases:

1. Sufficient capacity and redundancy to satisfy the single-failure criteria. To achieve this, each CSS/ECCS train draws water from a separate Containment emergency sump.

2. Capable of satisfying the flow and net positive suction head (NPSH) requirements of the ECCS and the CSS under the most adverse co mbination of credible occurrences. This includes minimizing the possibility of vortexing in the sump.

3. Minimizes entry of high-density particles (specific gravity of 1.05 or more) or floating debris into the sump and recirculating lines.

4. Sumps are designed in accordance with RG 1.82, proposed revision 1, May 1983 and with Generic Letter 2004-02 as described in NOC-AE-08002372.

6.2.2.1.3 Fission Product Removal Design Basis: The Containment Spray System is:

1. Designed such that it will tolerate a single active failure.

2. Designed to accommodate the OBE within stress limits of applicable codes and to withstand the SSE without loss of function.

STPEGS UFSAR 6.2-33 Revision 18 3. Designed to assist in reducing offsite exposures resulting from a DBA to less than the limits of 10CFR100 by rapidly reducing the airborne elemental iodine a nd particulate concentrations in the Containment following a DBA.

6.2.2.2 System Design Description.

6.2.2.2.1 Reactor Containment Fan Cooler System

Description:

The RCFC System is shown on Figure 6.2.2-4. The RCFC units are designed to remove heat from the Containment during both normal operation and accident conditions. System operation and design requirements that are associated with the normal operation of the RCFC units are given in Section 9.4.5. The RCFC System and its components required for post-DBA operation are classified as an ESF system designed to SC 2 requirements with the exception of those compone nts identified in Table 3.2.A-1. The intakes for the RCFC System are located at approximately the same elevation as the Containment crane rail. The flow of air is routed through the intake ductw ork and then induced through the cooling coils by the RCFC fans. The RCFC then discharges all but approxima tely 8 percent of the total airflow inside the secondary shield wall. The remaining 8 pe rcent is diverted through ductwork to outside the secondary shield wall. To protect the ring duct and RCFC enclosure against pressurization and RCFC fans and motors against po ssible adverse effects of DBA transient-induced reversed flow, backdraft dampers are provided in the discharge ductwork.

The backdraft dampers are normally closed when the fan is not running. Dampers open under the fan discharge pressure but close on any reverse flow to prevent back flow through the fan.

The steam line break or LOCA generates an SI si gnal, which starts the standby DGs. The DGs are up to speed and ready to accept load within 10 seconds.

Should a LOOP occur, ESF load sequencers contro l the loading of the DGs. The sequencers delay the starting of the RCFCs for 15 s econds after the DG breakers are closed. Without a LOOP, the ESF load sequencers start those RCFCs that are not in opera tion prior to receipt of the SI signal after a 15 second delay. Those already in operation remain operating following the SI signal. The ESF actuation system is described in further detail in Section 7.3 and th e ESF load sequencers in Section 8.3.

The RCFCs are manually operated from the control room for normal operation. No manual actions are required for RCFC operati on during accident conditions.

Figures 6.2.2-13 and 6.2.2-14 show the RCFCs and the related ductwork. The RCFC performance is not affected by flooding following LOCA, as the di scharge points of the supply duct are located above the flood level.

6.2.2.2.1.1 Reactor Containment Fan Cooler System Component Description - Table 3.2.A-1 lists the safety classification, seismic category, and design codes for the RCFC System components. Each train of the RCFC System incl udes two fan cooler units, each consisting of the following subassemblies:

1. Fan and motor assembly

2. Cooling coils STPEGS UFSAR 6.2-34 Revision 18

3. Backdraft damper

The following is a description of each of the RCFC components.

6.2.2.2.1.1.1 Fan/Motor Drive - Each RCFC fan is a vane axial type directly driven by a totally-enclosed, single-speed, air-cooled motor. The RCFC fan is statically and dynamically balanced and is the nonoverloading type. The motor is in conformance with the requirements of Institute of Electrical and Electronics Engineers (IEEE)

Standards 334-1974 and 344-1975.

Fan motor space heaters are provided to maintain favorable conditions of temperature and humidity within the motor during fan shutdown.

6.2.2.2.1.1.2 Cooling Coils - The finned-tube cooling coils remove heat from the Containment air. During normal operation, the main m ode of heat transfer is sensible heat removal, while during accident operation condensation is dominant. The condensate is collected in drain troughs and piped to the Containment sumps. Chilled water is used during normal operation as the cooling medium. The chilled water is provided by water chillers located outside the Containment.

The chiller condensers are cooled by the Auxili ary Cooling Water System (ACWS). During post-DBA operation, the Chilled Water System is automatically isolated, and the CCWS circulates water through the RCFCs. The RCFC heat load is automatically transferred from the chiller to the CCWS by an SI signal. During LOOP, the Chilled Water System is automatically isolated. The cooling water for the RCFCs is transferred from the Chilled Water System to the CCWS by remote-manual operation from the control room within 30 minutes.

Since the RCFC System consists of multiple but identical cooling coil sections, one section undergoes a test program to verify the coil performance capability under simulated post-DBA environmental conditions as specif ied in Section 3.11. The test program used for the cooling coil is described in Topical Report AAF-TR-7101, "Design and Testing of Fan Cooler-Filter Systems for Nuclear Applications".

6.2.2.2.1.1.3 Backdraft Dampers - Backdraft dampers are designed for a maximum pressure increase rate of 15 psi per 0.5 second against a maximum pressure difference of 15 psi.

The RCFC Enclosure and ducting have been designed to be adequate to withstand the effects of containment pressure following design basis accidents (LOCA and MSLB).

6.2.2.2.2 Containment Spray System

Description:

The CSS piping and instrumentation diagram is shown on Figure 6.2.2-1. The CSS consists of three independent, identical trains, each consisting of a spray pump, valves, piping and instrumentation. Design parameters are shown in Table 6.2.2-1. Following a LOCA, the CSS:

1. Maintains RCB pressure within design limits.

2. Reduces the quantity of ai rborne iodine (Section 6.5.2).

3. Establishes the sump pH for retention of elemental iodine.

STPEGS UFSAR 6.2-35 Revision 18 The spray water flow path is as follows: Water flows from the refueling water storage tank (RWST) through the CSS pumps to the spray nozzles, falls through the Containment atmosphere, and passes through grating on the operating floor. The water then collects on the floor of the Containment. During the recirculation phase, the water passes through a perforated plate with nominal 0.095 in. diameter holes before entering the Containment emergency sump to be pumped back through the spray nozzles. Trisodium phosphate, stored in Containment at an el evation that will be flooded post-LOCA, dissolves in the sump solution raising the solution pH to enhance materials compatibility and retention of iodine in the sump water. A sufficient quantity of TSP is available to assure an equilibrium pH of the post-LOCA sump soluti on between 7.0 and 9.5 depending on the solution boric acid concentration.

The CSS is actuated by a Containmen t HI-3 pressure signal. Manua l operation is not required during any mode of operation, but the ability to operate the system from the control room is provided.

Descriptions of the actuation system are provided in Sect ion 7.3. The setpoints are established at a level to prevent inadvertent operation of the system and yet provide as surance that the design pressure of the Containment is not exceeded.

A steam line break or LOCA generates an SI signal , which starts the DGs as described in Section 6.2.2.2.1. With a LOOP, the ESF load sequencers dela y sequencing of loads until closure of the DG breaker. Without a LOOP, the sequencers begin sequencing of loads onto offsite power immediately, as discussed in Section 8.3. The ESF load seque ncers allow the starting of the CSS pumps between 15 and 17 seconds following the start of the load sequencing. If the Containmen t HI-3 signal is not received within this time period, the starting of the CSS pumps will be delayed to 40 seconds following the start of the load sequencing. After this delay period, receipt of a Containment HI-3 signal will start the CSS pumps.

The actuation of the CSS discharge valves to the spray headers is delayed one second following the star t of the load sequencing with LOOP, after which receipt of a Containment HI-3 signal opens the valves; without LOOP the valves open immediately on receipt of the HI-3 signal.

The transit time for the water to reach the last nozzle and for full spray to be developed is a maximum of 54.1 seconds following the starting of the CSS pumps and opening of the CSS pump discharge valve. The CSS pump discharge valve maximum opening time is 15 seconds.

6.2.2.2.2.1 Component Descriptions - Tables 3.2.A

-1 and 3.2.B-1 list safety classification, seismic category, and code requirements for the CSS components. The load combinations and transients to which these components are designe d are discussed in Section 3.9. Environmental qualification of the components is discussed in Section 3.11. Seismic qualific ation is discussed in Section 3.10.

The RWST serves as a source of bor ated cooling water for initial spra y operation and safety injection. During normal operation, the RWST is aligned to the suction connections of the ECCS pumps and CSS pumps.

6.2.2.2.2.1.1 Containment Spray Pumps - The Containment spray pumps are the vertical centrifugal type, driven by electric motors. The pumps are designed to perform at rated capacity against a total head composed of Containment design pressure, spray nozzle elevation head, line losses, and spray nozzle pressure losses. Adequate NPSH is available with a minimum level in the STPEGS UFSAR 6.2-36 Revision 18 RWST during the injection phase. A discussion of NPSH requirements is provided in Section 6.2.2.3.5.

6.2.2.2.2.1.2 Spray Additive Tanks - There tanks were originally included to provide sodium hydroxide solution as a spray additive. The spray additive has been eliminated from the CSS design. The tanks remain in place but have been drained and the piping connecting them to the rest of the CSS has been isolated.

6.2.2.2.2.1.3 Spray Additive Eductor - the educto rs were originally provided to draw sodium hydroxide solution from the spray additive tanks into the spray flow. With the deletion of the spray additive, the eductors remain in place as part of the spray pump miniflow line but do not deliver any caustic since the lines to the spray additive tanks are isolated.

6.2.2.2.2.1.4 Spray Nozzles - The CSS spray nozzles are distributed on spray ring headers located in the uppermost part of the Containment in such an array that the maximum volume of the Containment is sprayed. The spray nozzles are hollo w-cone type, with a 3/8-inch-diameter orifice, and are fabricated from stainless steel. The nozzle atomizing capability is discussed in Section 6.5.2.

6.2.2.2.2.1.5 Spray Headers - A plan view of the Containment spray headers is shown on Figure 6.2.2-3. Spray nozzle location and orientation are also shown. The spray headers are located as high as possible in the Containment without allowing interruption of spray pattern by impingement on the dome.

Four concentric Containment spray headers are provided. Piping to the spray headers from the Containment spray pumps and valv ing arrangement assures delivery of 100 percent of the required spray flow assuming any single active failure.

6.2.2.2.3 Containment Emergency Sump

Description:

The Containment emergency sumps are illustrated in Figure 6.2.4-2 and represented on the piping diagrams for the Safety Injection System (Figure 6.3-1 through 6.3-3). There are three independent sumps to serve as reservoirs to the ECCS and CSS pumps during the recirculation phase post-DBA. Each sump is stainless steel lined, contains a Vortex Suppressor, and is provided wi th four stainless steel strainer assemblies.

The strainer assemblies for each sump consist of two 5-module assemblies, one 4-module assembly, and one 6-module assembly with each module made up of eleven strainer discs. The strainer screen consists of perforated plate with nominal 0.095 inch diameter openings. Flow leaving the strainer enters a four inlet plenum box (one inlet for each strainer assembly). The plenum box collects the flow from the strainer assemblies and directs the flow vertically downward directly into the sump pit. An access cover is provided on the plenum box for internal inspections of the sump structures, vortex suppressor, and the strainer assemblies.

The sumps are located at El. (-)11 ft-3 in. The sumps are physically separated from each other with

no high-energy piping in the area. The floor around the emergency sumps slopes away from them and toward normal sumps located in the area. The drains from the upper levels of the Containment Building do not terminate in the immediate area of the sumps.

The sump structures are designed to withstand the SSE without loss of structural integrity.

STPEGS UFSAR 6.2-37 Revision 18 Water entering the suction pipe from the sump may contain a small amount of particulate and fibrous debris (less than 0.095-inch in diameter). This debris cannot clog the Containment spray nozzles (3/8-in. orifice diameter) which are the limiting restrictions found in any system served by the sump.

At the beginning of the recirculation phase, the minimum water level above the Containment floor is adequate to provide the required NPSH for the ECCS and CSS pumps. The sumps are designed to RG 1.82, proposed revision 1, May 1983 and to th e requirements of Gene ric Letter 2004-02 as described in NOC-AE-08002372. The sump structures are designed to limit approach flow velocities to less than 0.009 ft/sec permitting high-density particles to settle out on the floor and minimize the possibility of clogging the strainers. The sump structures are designed to withstand the maximum expected differential pressure imposed by the accumulation of debris.

Most potential sources of debris are remote from the emergency sumps and are separated by shield walls or other partitions. Expected debris are pieces of insulation and paint. The possibility of paint chips peeling off has been minimized by requiring proper surface preparation and by painting large surface components (such as: the Containment liner, RCS supports, floors, and structural steel) with coatings which have been qualified under DBA conditions.

The major insulation types used in the RCB are stai nless steel reflective, blanket fiberglass, and cellular glass. The stainless steel reflective insulation is used on the major NSSS components. The

blanket fiberglass type is used on the hot piping and equipment. Cellu lar glass insulation is used on cold piping for antisweat purposes. Microtherm is also used for piping in the wall penetrations.

The Containment emergency sumps are inspected periodically as delineated in the Technical Specifications.

6.2.2.3 Design Evaluation.

6.2.2.3.1 Reactor Containment Fan Cooler System Performances: The design characteristics of an RCFC are given in Table 6.2.2-2 and represent the minimum required functional capability of the cooling unit. The RCFCs are designed to meet these specifications. To assure the performance capability of the air-cooling units, the manufacturers have developed analytical methods and models for design selection and for assessing the performance of the selected design. The analytical model used is presented herein.

The analytical model simulates the heat and mass transfer process in a cro ss-flow HX with extended surfaces or fins.

A steam-air mixture enters the HX and passes th rough it following the flow paths created by the presence of fin plates and coil tubes. Cooling water flows through the tubes, which are aligned perpendicular to the flow direction of the steam-air mixture. As the steam-air mixture passes through the cooling unit, some sensible heat is transferred to the fin plates , which in turn pass it along to the coil tubes where it is removed by the cooling water. In addition, some moisture condenses on the fin plates. Latent heat is transferre d through the film of the condensate to the fin plates and the tubes and is removed by the cooling water. The condensate fl ows down and is collected in drain pans under the cooling coils to be finally drained into the normal and secondary sumps. Thus, both thermal energy and moisture are removed from the entering steam-air mixture, resul ting in a reduction of Containment pressure and temperature.

STPEGS UFSAR 6.2-38 Revision 18 The analysis employs a finite element technique for analyzing the simultaneous heat and mass transfer process. This is accomplished by dividing the cooling unit into many small elements, each being analyzed individually and sequentially. The thermodynamic states for each finite element must then be solved by iterative proced ures until reasonable convergence is reaches. Boundary conditions are either available or established by trial and error.

The basic criterion is to satisfy the requirements for energy balance and mass balance. In addition to the traditional considerati ons of fouling effects, the effect of noncondensible gas on the condensation process is taken into account. Sufficient conservatism is worked into the mathematical model to assure an adequate design margin. The validity of such models and methods has been proven by experimental verification (discussed in AAF-TR-7101).

6.2.2.3.2 Performance Following a Design Bases Loss-of Coolant Accident: The cooling capability of the CHRS is demonstrated by the results of the post-accident performance analyses as described in Section 6.2.1.1.

The heat removal rate of one RCFC unit is shown in Table 6.2.2-2. The RCFC performance curves are shown if Figure 6.2.1.5-2.

The ductwork and component housing of the RCFCs must remain operable post-LOCA. To ensure operability, the components are designed to Amer ican Society of Mechanical Engineers (ASME) Code Section III, Subsection NC, and are subject to a qualification test (see AAF-TR-7101). In addition, supports are designed to ASME Code Section III, Subsection NF.

6.2.2.3.3 Single-Failure Analysis: A single-failure analysis employing a failure modes and effects analysis (FMEA) methodology was conduc ted for the CHRS. Table 6.2.2-3 presents a summary of components included in the analysis. Da ta presented by the table demonstrates that the CHRS can sustain the failure of any single active component and still meet the level of performance required for Containment cool ing and iodine removal.

6.2.2.3.4 Containment Atmosphere Mixing: The Containment atmosphere mixing is accomplished by the RCFC operation and the Spray System. The majority of the RCFC air supply, except a small portion discharged outside the secondary shield wa ll, is discharged inside the secondary shield wall where it is relieved to th e balance of the Containm ent volume through the vent areas. This provides adequate purging of all subcompartments in the space contained within the secondary shield wall and below the operating floor. For the Containment volume outside the secondary shield wall, the mixing is accomplished as follows:

1. A portion of the supply air (4,000 ft 3/min per RCFC) is discharged outside the secondary shield wall, where it rises through various levels to be finally picked up through the RCFC return air risers.

2. A major portion of the recirculated air is retu rned to the RCFC through the return air risers, which are located at the polar crane rail level.

The rising air with the action of the spray provides adequate mixing of the Containm ent atmosphere above the operating floor.

STPEGS UFSAR 6.2-39 Revision 18 Figures 6.2.2-13 and 6.2.2-14 show the RCFC an d related ductwork. Figures 6.2.2-6 through 6.2.2-12 illustrate the CSS spray coverage at various elevations in the Containment. Table 6.2.2-5 provides estimates of the spray mass flow rates in the individual regions identified above.

6.2.2.3.5 Pump Net Positive Suction Head Requirements: The minimum available net positive suction head (NPSH) for the CSS pumps is such that an adequate margin is maintained between the required and the available NPSH for both the injection a nd recirculation phase, ensuring the proper operation of the CSS. Recirculation operation gives the limiting NPSH requirements for the CSS pumps.

The Westinghouse CSS pump design provides for the NPSH requirement to be met by the inherent design of the pump. CSS pumps are vertical motor-driven pumps, each sitting in an individual barrel.

The design calls for a distance of 15 ft in this barrel between the suction nozzle centerline and the pump first-stage impeller. The 15-ft liquid-head in the pump barrel is thus expected to inherently satisfy the 15-ft NPSH requirement.

The analysis of available NPSH to the CSS pumps concerns itself with the NPSH at the pump suction nozzle, located at the top of the barrel. Since the pump barrels provide the required NPSH at the first-stage impeller, the piping la yout need provide only sufficient NPSH at the pump suction nozzle to prevent flashing in the barrel.

Two modes of operation have been analyzed for the CSS pumps:

1. Pump taking suction from the RWST and delivering spray to the Containment

2. Pump taking suction from the Containment sump and delivering spray to the Containment

Case 2 represents the "worst case" since it gives the minimum available NPSH.

The assumptions and conservatisms used in the analysis are listed below. No exceptions are taken to RG 1.1.

1. Containment pressure equals the vapor pressure of the sump water.

2. The runout flows of each pump are used to account for maximum friction loses.

The minimum flood level in Containment is determined by considering the quantities of water

trapped by the refueling cavity.

The results of the analysis show the available NPSH at the first-stage impeller of the CSS pumps to be greater than the required NPSH an d show that the fluid at the sucti on flange is subcooled. There is sufficient NPSH at the suction nozzle to prevent flashing in the barrel, and the analysis meets the guideline of RG 1.1. The NPSH parameters are listed in Table 6.2.2-4.

NPSH for the ECCS pumps is addressed in Section 6.3.

6.2.2.4 Testing and Inspections. Testing provisi ons are incorporated in the system design to enable periodic evaluation of the operability and performance of system components and actuation STPEGS UFSAR 6.2-40 Revision 18 circuitry and to permit flow continuity tests. Pr eoperational tests of the CHRS were performed in accordance with test programs described in Chapter 14. Periodic tests are performed according to technical specifications.

Inservice inspection of the components are performed in accordance with the ASME Code,Section XI, where applicable.

Visual inspection of th e CHRS components are performed during each refueling.

6.2.2.4.1 RCFC Testing: Sufficient RCFCs are operated continuously to remove excess heat during normal operation, and malfunction of system components can be detected and corrected as necessary. This design further enhances the reliability of the RCFCs in performing their intended function following a postulated accident. Sufficient instrumentation is provided to permit monitoring of RCFC performance from the control room.

The RCFCs are subjected to the following tests in the factory to verify performance capability and equipment integrity.

6.2.2.4.1.1 Cooler Performance Test - A represen tative section of th e cooling coils is tested under normal and simulated post-LOCA conditions to demonstrate heat removal capability. The tests are accomplished in the following manner:

1. A cooling coil section is tested in an environmental chamber. The test results are then extrapolated to determine the performance of the RCFC. An analysis is then performed to ensure functional capability. The analys is is in accordance with AAF-TR-7101.

2. The test unit was a newly constructed piece of equipment with clean surfaces. The effect of fouling on heat removal capability was evaluated based on past performance. To ensure adequate performance of the cooling units after an extended period of operation, ample design margin is incorporated into the equipment design. The cooling unit performance under both clean and conservatively assumed fouled conditions is determined using the same analytical methods. A fair agreement between the calculated and the test performances verifies the soundness of the analytical methods and justifies its applicability to the prediction of equipment performance under fouled conditions.

6.2.2.4.1.2 Cooling Coil Hydrostatic Test - Ea ch RCFC cooling coil is subjected to a hydrostatic test in accordance with the requirements of ASME Code Section III to verify the integrity of the pressure boundary.

Each fan and motor is tested as an integrated unit for excessive vibration at full-rated speed.

6.2.2.4.2 CSS Testing: The components of the CSS are periodically tested as follows.

Test lines are provided to run the pump on a reduced flow basis with flow to the nozzles blocked.

The nozzles can be tested using the available air test connections. A special test tap is available to provide testing capability to ensure unrestricted flow.

The motor-operated spray pump discharge isolation valves can be opened periodically for testing.

Any abnormalities discovered during the surveillance testing will be corrected in accordance with the time requirements specified in the Technical Specifications.

STPEGS UFSAR 6.2-41 Revision 18 6.2.2.4.3 Environmental Qualification Test of Motors: Discussed in Section 3.11.

6.2.2.5 Instrumentation Requirements.

6.2.2.5.1 Containment Spray System: Instrume ntation and associated logic circuitry employed for initiation of the CSS are discussed in Section 7.3.

Containment spray injection is initiated either manually from the control room or on coincidence of two sets out of four HI-3 Containment pressure signals. The spray actuation signal starts the spray pumps (start permissive is also required from th e sequencer) and opens the discharge valves to the spray headers. The recirculation phase of spray operation is actuated by the automatic recirculation signal, which is the SI signal concurrent with a low-low RWST level signal from the RWST level transmitter associated with the actuation train. This signal opens the containment sump isolation valves allowing the ECCS and CSS pumps to take suction from the containment sump.

The following describes the instrumentation that is used for monitoring the system during normal and post-LOCA operating conditions:

1. Containment Emergency Sump Water Level - Each sump is provided with a level transmitter which gives control room indication through the QDPS.

2. Refueling Water Storage Tank Level - Three level transmitters are provided with control room indication for each transmitter. An annunciator alarm is provided for high, low, low-low, and empty conditions. The low-low signal is provided for automatic switchover to the recirculation mode of CSS and ECCS operation.

3. Containment Spray Pump Pressure - Each pump is provided with local suction and discharge pressure indicator.

4. Containment Spray Pump Flow - Each pump is provided with a discharge flow transmitter and control room flow indicator. An annunciator alarm is provided for low flow.

5. System Flow Testing Instruments - A local fl ow indicator is provide d on the recirculation flow line back to the RWST for testing the Containment spray pumps.

6. Containment Pressure - Six Containment pressure trasnmitters with control room indication provided through the QDPS are employed as diverse instruments to indi cate the effectiveness of the system in cooling the Containment atmosphere. Temperature indication, although nonqualified, may also be used in determining the cooling effectiveness.

6.2.2.5.2 Reactor Containment Fan Cooler System: Instrumentation and associated logic circuitry employed for initiation of the RCFC System are discussed in Section 7.3.

The following describes the instrumentation used for monitoring the system during normal and post-LOCA operating conditions:

STPEGS UFSAR 6.2-42 Revision 18 1. Cooling Water Temperature - Each cooling water loop is provided with a temperature sensor. Temperature monitoring is provided in the control room.

2. Cooling Water Flow - Each cooling water loop is provided with a flow transmitter and control room indicator.

3. Cooler Air Temperature - Each air cooler is provided with a temperature sensor on the inlet and outlet. Temperature indicators are provided in the control room and are also monitored by the plant computer.

4. Fan - Each fan is provided with an indicat ing, differential pressure switch. The switch provides an annunciator alarm in the control room and is also monitored on the Emergency Response Facilities (ERF) computer.

5. Each fan motor overcurrent trip is alarmed in the control room and monitored on the ERF computer.

6.2.2.6 Materials: Discussi on of CHRS materials is provided in Section 6.1.1.

6.2.3 Secondary

Containment Functional Design The section does not apply to STPEGS.

6.2.4 Containment

Isolation System The Containment Isolation System (CIS) is designed to limit the leakage of radioactive materials through lines penetrating the RCB so that the s ite boundary dose guidelines specified in 10CFR100 are not exceeded following a LOCA or other design basis accident.

Upon receipt of the appropriate si gnals, isolation of the RCB is accomplished by automatic isolation of all nonessential fluid systems which penetrate the RCB. Special Containment isolation provisions are discussed in Section 6.2.4.2.1.

6.2.4.1 Design Bases. Lines for which isolation is required are provided with two barriers so that no single failure can prevent isolation. Each of these barriers is fully adequate to limit leakage of radioactivity within acceptable values over the entire range of normal and accident conditions.

An "isolation barrier" is either an isolation valve or a closed system. A closed system is defined as a fluid system which is neither a part of the reac tor coolant pressure boundary (RCPB) nor connected directly to the RCB atmosphere.

The design bases of the CIS are as follows:

1. Containment isolation valves provide the ne cessary isolation of th e RCB in the event of accidents or other conditions when the free release of the RCB contents cannot be permitted.

2. The design of isolation valving for lines penetrating the RCB follow the requirements of General Design Criteria (GDC) 54 through 57.

STPEGS UFSAR 6.2-43 Revision 18

3. Isolation valving for instrument lines which penetrate the Containment Building conform to the requirements of RG 1.11 and GDC 55 and 56.

4. Isolation valves, actuators, and controls are protected against the effects of missiles and postulated pipe ruptures (Sections 3.5 and 3.6).

5. Design of the RCB isolation valves and associated piping and penetrations meets seismic Category I requirements.

6. The RCB isolation valves, associated piping, and penetrations meet SC 2 requirements.

7. The Containment isolation valves are designed to meet leaktightness sta ndards consistent with the overall leaktightness of the RCB.

8. The system is designed with redundancy and physical separation so that no single active failure can result in loss on Containment integrity.

9. The system is designed to withstand the environmental conditions which accompany an accident without loss of function.

10. Containment isolation valve closure speeds and leaktightness limit radiological effects from exceeding guideline values as established in 10CFR100.

11. Provisions are made for periodi cally testing the operability an d leaktightness of the isolation valves to the extent necessary to ensure that the system will meet its performance requirements in the event of an accident requiring RCB isolation.

Leak rate testing is in accordance with 10CFR50, Appendix J.

12. The system is designed in accordance with the quality group classifications in RG 1.26, seismic categories in RG 1.29, and the power supply requirement in RG 1.32.

13. All power-operated Containment isolation valves are provided with st atus indication in the main control room.

6.2.4.2 System Design. The signals utilized to actuate the CIS are as follows:

1. Safety injection, Phase A Containment isolation, Phase B Containment isolation and Containment ventilation isolati on signals isolate all nonessential lines and the CCW lines to the RCPs.

2. The steam line isolation signal automatically closes all MSIVs to prevent the continuous, uncontrolled blowdown of more than one SG and thereby uncontrolled RCS cooldown.

3. The main feedwater (FW) line isolation signal automatically closes all FW isolation valves. The FW isolation prevents or mitigates the effects of excessive RCS cooldown.

These isolation signals and details of th eir derivation are described in Section 7.3.

STPEGS UFSAR 6.2-44 Revision 18 Figure 6.2.4-1 identifies the types of isolation valves and isola tion schemes provided for lines which penetrate the Containment Building. This Figure includes: (1) open or closed status under normal operating conditions, as well as sh utdown or accident conditions, (2) modes of actuation, (3) the signals to initiate isolation valve closure, and (4) closure time for the isolation valves.

The three types of fluid lines, as described in the General De sign Criteria (GDC) of 10CFR50, Appendix A, penetrating the Containment Building which require Containment isolation valves are:

GDC 55 - Lines which form part of the reactor coolant pressure boundary.

GDC 56 - Lines which connect directly with the Containment atmosphere.

GDC 57 - Lines which are part of a closed system

those which are neither part of the RCPB nor connected to the Containment atmosphere.

Isolation valves are also provided in other fluid lines penetrating the Containment (i.e., SG isolation) shown in Figure 6.2.4-1.

6.2.4.2.1 Special Containment Isolation Provisions:

1. Essential Systems

Certain systems are required to perform a sa fety function following an accident and the isolation valves for these systems must to opened automatically or remote-manually or remain open for the system to operate. Closing of thes e valves would defeat their intended purpose. Special provisions for Containment isolation for each of these systems is described below.

a. Low Head Safety Injection (LHSI), High Head Safety Injection (HHSI) and Containment Spray

These valves are designed to be operated remote-manually from the control room. The operator is made aware of leakage in these systems by the following provisions after which the valves can be closed.

1) Sump level alarms are provided for each sump in the pump cubicles. The detection and alarm capability of the sump level instrumentation and design criteria are discussed in Section 9.3.3.

2) Increased radiation levels in the pump cubicles as a result of leaks will be indicated and alarmed by the Area Radiation Monitoring System described in Section 12.3.4. The monitor locations are given in Table 12.3.4-1 (Monitors N1RA-RE-8084, N1RA-RE-8085 and N1RA-RE-8086).

b. Component Cooling Water System to RCFCs and RHR HXs

In the unlikely event of a tube rupture in one of these HXs, radioactive materials would be entrained in the CCWS. The operator in the control room would be made STPEGS UFSAR 6.2-45 Revision 18 aware of this condition by the CCWS radi ation monitor discussed in Section 11.5.

Additional indications of this conditi on would be given by the CCWS flow indications, the high and low flow alarms, surge tank level indications, and tank high level alarms. The isolation valves in this system are designed to be operated remote-manually from the control room.

Leakage (normal or abnormal) from the CCWS will not result in releases of radioactive material. Leakage is collected in building sumps and conveyed to the Liquid Waste Processing System (LW PS) as described in Section 9.3.3.

c. Auxiliary Feedwater System

Leakage from the AFW System will not result in release of radioactive material. The water being conveyed to the SGs is free from radioactive contamin ation. The isolation valves used for AFW to each SG are motor-operated stop-check valves that permit flow into the RCB only.

d. Steam Supply Line to Turbine-Driven AFW Pump (from SG D) In the unlikely event of a tube rupture in SG D the operator can take the action necessary to close the steam supply line isolation valve from the control room. This condition would be indicated to the ope rator by a rising wa ter level in the D SG.

e. RCP Seal Injection

The seal injection valves are isolated upon receipt of a Containment phase A isolation signal concurrent with a char ging header low pressure signal. Since continued seal injection to the RCP is highly desirable, the isolation valves are permitted to remain open as long as seal injec tion is actually occurring.

f. Containment Sump Recirculation Lines

The SIS and CSS are closed systems designed to seismic Category I standards, classified SC 2, protected from missiles and have a design temper ature and pressure rating at least equal to that for the Containment.

The three RCB emergency sump recirculation lines, each of which supplies suction to a LHSI pump, HHSI pump, and Containment spray pump, are each provided with a single remote-manual gate valve outside th e RCB. In lieu of encapsulation of the recirculation lines and sump isolation valves , the piping and valves are conservatively designed, to preclude a breach of piping integrity. Level instrumentation in the FHB SIS cubicle sumps will detect leakage in the recirculation loop, including the valve seals. This leakage will be terminated by manually isolating that pump train from the control room.

The SI recirculation phase is automatically initiated by a low-low level in the RWST coincident with the SI signal. The HHSI and LHSI pump's miniflow valves are automatically closed and the sump isolation valves automatically opened.

STPEGS UFSAR 6.2-46 Revision 18 With this system, no single failure of either an active or passive component will prevent the recirculation of co re cooling water or adversely affect the integrity of the RCB. The present arrangement meets all safety requirements.

g. Containment Pressure Sensing

Each of the six channels has a separate penetration and each pressure transmitter is located immediately adjacent to the outside of the RCB wall.

It is connected to a sealed bellows located immediately adjacent to the inside of the RCB wall by means of an armored, sealed, fluid-filled tube. This tubing, along with the transmitter and

bellows, is conservatively designed and subjec t to strict quality c ontrol and to regular inservice inspections (ISIs) to assure its integrity. This arrangement provides a double barrier (one inside and on e outside) between the RCB and the outside atmosphere.

Should a leak occur outside the RCB, the sealed bellows inside the RCB, which is

designed to withstand full Containment design pressure, will preven t the escape of the RCB atmosphere. Should a leak occur inside the RCB, the diaphragm in the transmitter, which is designed to withstand full RCB design pressure, will prevent any escape from the RCB. This arrangement provides automatic double barrier isolation without operator action and does not jeopardize reliability w ith regard to its safety functions, i.e., no valves can be inadve rtently closed or close spuriously.

In addition to these six Containment pressure transmitters, there are four pressure switches, two for low pressure and two for high pressure, used to annunciate conditions approaching the limits allowed by the Technical Specifications. These switches also use sealed sensing lines, similar to those used for the pressure transmitters.

h. Reactor Coolant System Wide Range Pressure

Sealed sensing lines similar to those provided for Containment pressure sensing are provided for the RCS wide range pressure sensing lines.

2. Containment Hydrogen Monitoring/Post Accident Sampling

These systems are put into operation by the operator following a postulated accident. The Containment valves are normally closed and receive a Containment isol ation signal. When the operator deems that system operation is a dvisable, reset of the isolation signal and subsequent remote manual operati on of the valves is required.

3. Leak Rate Test Connections

Each leak rate test connec tion is equipped with flanges ha ving double O-ring or spiral wound gaskets inside and outside the RCB. Capped test connections are used only during Integrated Leak Rate Testing (ILRT) or Local Leak Rate Test (LLRT) activities. This arrangement meets the functional requirements of GDC 56 and Type B testing.

STPEGS UFSAR 6.2-47 Revision 18

4. Chilled Water System Interface with the Component Cooling Water System

During normal plant operation the Chilled Water System provides cooling water to the RCFCs. After a design basis accident resulting in an SI signal, the Chilled Water System is automatically isolated (at the containment isol ation valves) and the CCWS isolation valves open providing cooling water to the RCFCs. After a LOOP, the Chilled Water System is automatically isolated at the Containment isol ation valves. Operator action is required to remote-manually open the CCWS valves to provide cooling water to the RCFCs.

The CCW and Chilled Water Systems share a common containment pipe penetration to provide cooling water return from the RCFCs. Isolation of this service during a DBA is not permissible. Therefore, two valves in series with separate train isola tion signals are used to isolate the Chilled Water System from th e CCWS immediately outside Containment.

6.2.4.2.2 Basis for Containment Isolation Valve Closure Time: Closure times for Containment isolation valves are chosen to limit radiological impact to the environs or for ECCS performance considerations. The maximum valve closure times are listed in Table 16.1-1 and Figure 6.2.4-1. (Table 16.1-1 does not list the 2-in. or smaller manual valves associated with test connections, vents, and drains.)

6.2.4.2.3 Environmental Qualifications: Environmental qualifica tion of electrical equipment is discussed in Section 3.11.

6.2.4.3 Design Evaluation. Containment isolation valves, actuators, and controls are protected from the effects of missiles and the dynamic effects associated with the postulated failure of pipes as described in Sections 3.5 and 3.6. Containment isolation valves, actuators, and controls outside the Containment are located in seismic Category I structures as close to the RCB as practicable.

To assure the operability of the CIS in an accident environment, provisions are made to satisfy the redundancy, reliability, and performance capability requirements of GDC 54. The system is designed to withstand SSE loads, as well as temperature, pressure, humidity, and ra diation conditions which are those expected to be present in the equipment location. This is discussed in Section 3.9, 3.10, and 3.11.

The redundancy requirement is satisfi ed by having two isolation valves in series, one on each side of type A and type B penetrations. For Type C penetrations, the redundancy requirement may be achieved by two isolation valves in series on either side of the Containment pene tration. Reliability is assured by conducting periodic te st to check the operability of th e isolation valves, actuators, and controls. Furthermore, a "fail-safe" feature is incorporated into solenoid and air-operated isolation valve design so that in the event actuating power is lost, the valve assumes the position which assures safety.

The isolation valves may be operated remote-manually from the control room to provide a secondary means of actuation. Performance capabilities, such as closing time and valve status (open or closed) indicator lights, are ch ecked and observed during the periodic testing.

STPEGS UFSAR 6.2-48 Revision 18 Analyses are performed to assure the integrity of the CIS and connecting pi ping under the application of dynamic forces which would result from in advertent closure of a valve during operating conditions; e.g., closure of a steam line isolation valve under full steaming rate. These analyses examined the pressure transients which would deve lop in such situations. The forces and stresses resulting from these pressure tr ansients are calculated, and displacements and support reactions are determined. The piping system, along with the suppor t system, is analyzed for the above forces, and assurance is provided that the Containment Isolation Valve System piping stresses are within allowable limits.

Regular functional testing of the CIS during shutdow n periods assures operability of all isolation valves. Leakage rate testing during the same peri ods assures that leakage through isolation valves and piping penetrations does not exceed Technical Specification values. Th e use of double isolation barriers assures that no single failure of any active or passive component will render the CIS either partially or wholly inoperable.

Open or closed isolation valve status during normal plant operation are regularly checked and controlle d, particularly with regard to administratively controlled manual isolation valves.

The use of double isolation barriers, the test program described in S ection 6.2.4.4, administrative control of manual isolation valves, and surveillance of automatic isola tion valves assure that the CIS will perform its intended function.

6.2.4.4 Tests and Inspections. A rigorous program of tests and inspections are performed in accordance with 10CFR50, Appendix J, as described in Section 6.2.6, to assure Containment isolation valve pressure integrity, to check leakag e rate, and assure reliability of operation. The Technical Specifications provide surveillance requirements for Containment isolation valves. These tests assure that the leakages from the CIS are held within allowable 10C FR50, Appendix J leakage rate limits. Furthermore, these tests verify the operability of the Containmen t isolation valves. The testing program to assure valve operability under design loading conditions and preoperational testing to assure valve operability when subjected to dynamic loading conditions associated with system transient conditions are described in Section 3.9. ISI requirements are discussed in Section 6.6.

Preoperational testing is performed as described in Chapter 14 to provide baseline data for comparison to subsequent tests.

6.2.5 Combustible

Gas Control in Containment The RCFC Subsystem provides adequate mixing of the Containment atmosphere to assure that relatively high concentrations of combustible gases are not allowed to build up within the Containment. Per 10CFR50.44, hydrogen recombiner s are no longer required for design basis accidents. A Containment Hydrogen Monitoring System is provided to determine the volume percent of hydrogen in the Containment atmosphere. The hydrogen monitoring system is required for beyond design basis accidents (Reference 6.2.5-5, 6.2.5-6 and 6.2.5-7). The Supplementary Containment Purge Subsystem can be used to dilute the hydrogen concentration in the Containment atmosphere.

GDC 41 of Appendix A to 10CFR50 requires that systems to control the concentrations of hydrogen, oxygen, and other substances, which may be released into the reactor Containment, be provided as necessary following postulated accidents to ensure that Containment integrity is maintained. However, per 10CFR50.44, hydrogen recombiners are no lo nger required for desi gn basis accidents.

STPEGS UFSAR 6.2-49 Revision 18 Following a LOCA, hydrogen gas is generated within the Containment as a result of the following:

1. Metal-water reaction involving the zirconium fuel cladding and the reactor coolant.

2. Radiolytic decomposition of the post-LOCA emergency cooling solutions (oxygen also evolves in this process).

3. Corrosion of metals and paints by solutions used for emergency cooling or containment spray.

6.2.5.1 Design Bases. The following are the design bases for the Containment Combustible Gas Control System:

1. Capability is provided to c ontrol the hydrogen concentration in the Containment below its lower combustible limit following LOCA by purging the Containment atmosphere through the Supplementary Containment Purge Subsystem, which is not a safety-related system. This system is available in the latter stages of an accident when the Containment pressure is nearly atmospheric.

2. The capability to mix the atmosphere in the Containment following a LOCA is provided by the RCFC Subsystem and the Containment Spray System. The RCFC Subsystem eliminates stagnant pockets in the Containment.

3. The Containment Hydrogen Monitoring System is a safety-related system and utilizes redundant and independent subsystems to monitor the hydrogen concentration inside the Containment.

4. The RCFC subsystem provides continued mixing of the Containment air during normal plant operation.

6.2.5.2 System Design. Not Used

6.2.5.2.1 Principles of Operation: The Containment purge system is available for use to force the hydrogen-air mixture out of the Containment through the Supplementary Containment Purge Subsystem. The air thus removed is replaced with air via the Supplementary Containment Purge Subsystem Supply, thus reducing the overall hydrogen concentration.

6.2.5.2.2 Hydrogen Monitoring: The hydrogen concentration will be continuously monitored following a LOCA and displayed in the control room. The Containment Hydrogen Monitoring System is described in Section 7.6.5.

6.2.5.2.3 Containment Mixing: One of the functions of the Containment mixing subsystem (RCFC Subsystem) is to provide homogeneous mixing of the Containment atmosphere to assure that pockets of hydrogen do not occur. The system is SC 2, seismic Category I. It is completely redundant, with duplicate piping, equipment, and instrumentation located in opposite quadrants of the Containment for maximum functional independence.

STPEGS UFSAR 6.2-50 Revision 18 The RCFC Subsystem as described in Section 6.2.2 has six 33-1/3-percent-capacity fans which take suction from the upper levels of the Containment. The Containment atmosphere is then forced through the fan coolers and discharges into th e lower portion of the Containment within the secondary shield wall, circulating around the reacto r vessel, SGs, and pressu rizer, and rising in the center of the Containment to the upper and dome levels of the Containment.

Subcompartments, such as the RHR HXs and pumps, pressurizer, reactor cool ant drain tank, etc., are designed to avoid pocketing and th e resultant buildup of gases.

6.2.5.2.4 Electric Hydrogen Recombiners: Per 10CFR50.44, hydrogen recombiners are no longer required for design basis accidents.

6.2.5.2.5 Containment Hydrogen Purging: If purging is necessary, dilution of the Containment atmosphere is achieved through the use of the Supplementary Containment Purge Subsystem, described in Section 9.4.5.2.7.

The Supplementary Containment Purge Subsystem meets the requirements of RG 1.7.

6.2.5.3 Design Evaluation. Not used

6.2.5.4 Testing and Inspections. Not used

6.2.5.5 Instrumentation Requirements. The Containment Hydrogen Monitoring System, consisting of redundant hydrogen an alyzers, is described in Section 7.6.5.

The Containment Supplementary Purge Subsystem is monitored and controlled by the following controls located in the control room:

1. Manual supply and exhaust fan start/stop switches with indicating run lights

2. Isolation valve manual open/close switc hes with valve positi on indicating lights

6.2.5.6 Materials.

6.2.5.6.1 Electric Recombiner: Per 10CFR50.44, hydrogen recombiners are no longer required for design basis accidents.

6.2.5.6.2 Supplementary Containment Purge Equipment: This equipment is described in Section 9.4.5.

6.2.6 Containment

Leakage Testing The Reactor Containment Integrated Leakage Rate Test (Type A), the Containment Penetration Leakage Rate Test (Type B), and the Containment Isolation Valve Leakage Rate Test (Type C) comply with 10CFR50, Appendix A, "General Desi gn Criteria for Nuclear Power Plants", and Appendix J, "Primary Reactor Containment Leakage Testing for Water Cooled Power Reactors".

STPEGS UFSAR 6.2-51 Revision 18 6.2.6.1 Containment Integrated Leakage Rate Test (Type A). After completion of construction of the primary Reactor Containment, including installation of all portions of mechanical, electrical, and instrumentation systems penetrating the primary reactor coolant pressure boundary (RCPB), and prior to any reactor op eration, a peak pressure integrat ed leak rate test (ILRT) was performed in accordance with Appendix J to 10CFR50.

The purpose of this test was: (a) to verify that the integrated leakage rate will not exceed the 0.3 percent by weight of Containment free air volume in 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> at the calculate d peak accident pressure given in Section 6.2.1.1.3; and (b) to obtain data to establish a baseline leakage rate to serve as a reference for future Containment leak testing. A preoperational reduced pressure leak rate test was not perf ormed. No consistent correlation has been observed between reduced and full pressure ILRTS.

A general inspection of the accessible interior and exterior surfaces of the Containment structure shall be performed prior to any Type A test. The purpose of this inspection is to uncover any evidence of structural deterioration which may affect either the Containment structural integrity or leaktightness.

Any evidence of structural deterioration shall be cause not to perform Type A tests until corrective action is taken in accordance with repair procedures, nondestructive examinations, and tests as specified in the applicable code stated in 10CFR50.55a.

During preoperational testing, a struct ural integrity test (SIT) was performed prior to the first ILRT.

The SIT is discussed in Section 3.8.1.7.

The ILRT is performed at the calculated peak accident pressure to demonstrate that the leakage rate of the Reactor Containment Building does not exceed 0.3 percent by weight Containment free air volume at the test pressure per 24-hour period. The ILRT shall be performed and containment leakage rate determined in conformance with the criteria, methods, and provisions specified or endorsed in Appendix J of 10 CFR Part 50. Localized pressure tests may be employed prior to Type A tests.

Those portions of fluid systems that are part of the RCPB or are open directly to the Containment atmosphere under post-accident conditions, and become an extension of the boundary of the Containment, are designed to be opened or vented to the Containment atmosphere prior to and during the test. Portions of closed systems inside the Containment that penetrate the Containment and are assumed to rupture as a result of a LOCA are designed to be vented to the Containment atmosphere. All vented systems can be drained of water to the extent necessary to ensure that those isolation valves which may not be water-sealed under acci dent conditions are not water-sealed under test conditions, and to ensure that they are subjected to the test differential pressure. Systems that are required to maintain the plant in a safe condition during the tests are operable in their normal mode and need not be vented. Systems that are normally filled with water and operating under post-accident conditions, such as the CHRSs, need not be vented or drained. The SG shell and the associated piping systems passing through the Containment liner are c onsidered an extension of the Containment. Therefore, the secondary side of the SG and connecting systems are not vented to the Containment atmosphere. The secondary system isolation valves are not given Type C tests. Those systems which need not be vented during T ype A testing are identified in Table 6.2.6-1.

Valves which remain open throughout the DBA need not be tested.

STPEGS UFSAR 6.2-52 Revision 18 Closure of Containment isolation valves is accomplished by normal operation and without preliminary exercising or adjustments such as tigh tening of valves after closure by valve actuator. Containment isolation valve leakage rate tests are discussed in Section 6.2.6.3.

The period of testing, the verifi cation of leakage rate accur acy, the acceptance criteria for Containment leakage rate tests and verification te sts, and the provisions fo r additional testing (if necessary) are all in accordance with 10CFR50, Appe ndix J. The test procedure is described in Chapter 14.

6.2.6.2 Containment Penetration Leakage Rate Test (Type B). This type of leakage testing is done with portable leakage testing equipment. Provisions are made to accommodate Type B tests on the following components (Section 3.8.2):

1. Personnel lock and auxili ary hatch and door seals

2. Equipment hatch

3. Fuel transfer tube (which is fitted with expansion bellows)

4. Electrical penetrations as listed in Table 8.3-12. (Preoperati onal leakage rate tests are also performed in accordance with IEEE 317, Section 8.3).

5. Flanged closures such as the ILRT pressurization/depre ssurization lines.

Type B tests are conducted in accordance with 10CFR50, Appendix J, with the exception that an alternate test method is measurement of the makeup flow rate necessary to keep the test volume at constant pressure. Test pressure, acceptance criteria, and testing intervals are as specified in 10CFR50, Appendix J. Additional information concerning Type B tests is provided in the Technical Specifications.

6.2.6.3 Containment Isolation Valve Leakage Rate Test (Type C). This type of leakage testing is done with portable leakage testing equipment. The leakage test of the Containment isolation valves are performed to comply with 10CFR50, Appendix J, Type C tests. Figure 6.2.4-1 contains a complete list of Containment penetrations and identifies those penetr ations that are Type C tested. Table 6.2.6-3 contains a list of Containment isolation valves that are locally (Type C) leak-tested in a direction opposite to that in which the pressure will exist when the valve is required to perform its safety function. The criteria for selecting the Containment isol ation valves for Type C tests, as well as the acceptance criteria, are in accordance with 10CFR50, Appendix J. These tests are performed by local pressurization to the maximum calculated pressure. Additional information is

supplied in the Technical Specifications.

6.2.6.4 Scheduling and Reporting of Periodic Tests. The schedule for the performance of Type A, B, and C Containment leakage testing is presented in the Tec hnical Specifications. Administrative procedures c oncerning the reporting of test results that fail to meet acceptance criteria are in conformance with 10CFR50, Appendix J, and are discussed in the Technical Specifications.

6.2.6.5 Special Testing Requirements. Any major modification, replacement of a component that is part of the primary Reactor Containment boundary, or resealing of a seal-welded STPEGS UFSAR 6.2-53 Revision 18 door that is performed after the preoperational leakage rate test will be followed by either a Type A Type B, or Type C test, as applicable for the area affected by the modification. If performed directly prior to the conduct of a scheduled Type A test, minor modifications, replacements, or resealing of seal-welded doors do not require a separate test. Administra tive procedures concerning the reporting of test results are in conforma nce with 10CFR50, Appendix J, and are discussed in the Technical Specifications.

STPEGS UFSAR 6.2-54 Revision 18 REFERENCES Section 6.2:

References 6.2.1.1-1 through 6.2.1.1-7 are not used.

6.2.1.1-8 Peterson, C.E. et al, "RETRAN-03-A Program or Transient Thermal-Hydraulic Analysis of Complex Fluid Flow Systems, MOD 001," developed by Computer Simulation and Analysis, Inc. for the Electric Power Research

Institute, July 1991.

6.2.1.1-9 R.G. Gido, C.I. Grimes, R.G. Lawton and J.A. Kurdick, "COMPARE: A Code for the Transient Analysis of Volumes with Heat Sinks, Flowing Vents and Doors," Los Alamos Scientific Laboratory, LA-7199-MS, March 1978.

6.2.1.1-10 R.E. Schwirian and C.H. Boyd, "Justification for Increasing Postulated Break Opening Times in Westinghouse Pressurized Water Reactors," WCAP-14748, Revision 0, October 1996.

6.2.1.1-11 George, T.L., et al, GOTHIC 7.2b, Containment Analysis Package; developed by Numerical Application, Inc. for the Electric Power Research Institute, March, 2009.

6.2.1.1-12 Not Used

6.2.1.1-13 GOTHIC Thermal Hydraulic Analysis Package, Version 8.0 (QA), EPRI, Palo Alto, CA: 2012.

6.2.1.2-1 Bechtel Power Corporation, "COPDA Compartment Pressure Design Analysis," (Bechtel computer code), 1973.

6.2.1.2-2 Bechtel Power Corporation, "Subcompartment Pressure and Temperature Transient Analysis," Topical Report No. BN-TOP-4, Rev. 1, October 1977.

6.2.1.2-3 Crane Co., "Flow of Fluids," Technical Paper No. 410, 1969.

6.2.1.2-4 Idel'chik, I.E., "Handbook of Hydraulic Re sistance Coefficients of Local Resistance and of Friction," AEC-TR-6630, 1966.

6.2.1.2-5 Shepard, R.M., H.W. Massie, R.H. Mark and P.J. Doherty, "Westinghouse Mass and Energy Release Data for Containment Design,"

WCAP-8264-P-A (Proprietary), June 1975 and WCAP

-8312-A Revision 1 (Nonproprietary), June 1975.

6.2.1.2-6 RELAP 5/MOD1 Code Manual Volume 1: System Models and Numerical Methods, NUREG/CR-1826, EGG-2070, 1980. CN-3136 STPEGS UFSAR 6.2-55 Revision 18

REFERENCES (Continued)

Section 6.2:

6.2.1.2-7 American Nuclear Standard, "Design Basis for Protection of Light Water Nuclear Power Plant Against Effects of Postulated Pipe Rupture," ANSI/ANS-58.2-1980.

6.2.1.2-8 Peterson, C.E. et al, "RETRAN-03 MOD01 HLP-001," developed by Computer Simulation and Analysis, Inc. for the Electric Power Research Institute, July 1991.

6.2.1.2-9 R.G. Gido, C.I. Grimes, R.G. Lawton a nd J.A. Kudrick, "COMPARE: A Code for the Transient Analysis of Volumes with Heat Sinks, Flowing Vents and Doors," Los Alamos Scientific Laboratory, LA-7199-MS, March 1978.

6.2.1.2-10 "Safety Evaluation Report Related to the Operation of South Texas Project, Units 1 and 2," NUREG-0781, Appendix G, "Safety Evaluation for the Elimination of Arbitrary Intermediate Breaks," April 1986.

6.2.1.2-11 "Safety Evaluation Report Related to the Operation of South Texas Project, Units 1 and 2," NUREG-0781, Supplement No. 4, Section 3.6, "Protection Against Dynamic Effects Associated with the Postulated R upture of Piping," July 1987.

6.2.1.3-1 "Westinghouse LOCA Mass and Energy Release Model for Containment Design - March 1979 Version," WCAP-10325-P-A (Proprietary),

WCAP-10326-A (Non-Proprietary), May 1983.

62.1.3-2 "Westinghouse ECCS Evaluation Mode l - 1981 Version," WCAP-9220-P-A, Rev. 1 (Proprietary), WCAP-9221-A, Rev.

1 (Non-Proprietary), February 1982.

6.2.1.3-3 EPRI 294-2, Mixing of Emergency Core Cooling Water with Steam: 1/3 Scale Test and Summary, (WCAP-8423), Final Report June 1975.

6.2.1.3-4 "American National Standard for Decay Heat Power in Light Water Reactors," ANSI/ANS-5.1-1979, August 1979.

6.2.1.3-5 NUREG-0800, Standard Review Plan, Section 9.2.5, Rev. 2, July 1981.

6.2.1.3-6 Letter, T.W. Alexion to W.T. Cottle, "South Texas Project Units 1 and 2 - Issuance of Amendments - Revised Calculation Met hodology for Large Break Loss-of-Coolant Accident Mass and Energy Release Analysis (TAC Nos. MA3768 and MA3769),"

dated May 20, 1999 (ST-AE-NOC-000417)

STPEGS UFSAR 6.2-56 Revision 18 REFERENCES (Continued)

Section 6.2:

6.2.1.3-7 "Westinghouse Mass and Energy Release Data for Containment Design, "WCAP-8264-P-A Rev. 1 (Proprietary) and WC AP-8312-A (Non-Proprietary), August 1975.

6.2.1.3-8 NUREG-0800, Standard Review Plan, Rev 2, 1981.

6.2.1.4-2 McFadden, J.H., et al., "RETRAN-02:A Program for Transient Thermal-Hydraulic Analysis of Complex Fluid Flow Systems," EPRI NP-1850-CCM-A.

6.2.1.4-3 Huegel, D.S., et al., "RETRAN-02 Modeling and Qualification for Westinghouse Pressurized Water Reactor Non-LOCA Safety Analyses," WCAP-14882-P-A, April 1999

6.2.1.5-1 Bordelon, F.M., Massie, H.W., Jr., Zordon T.A., "Westinghouse Emergency Core Cooling System Evaluation Model Summary," WCAP-8339, June 1974.

6.2.5-1 Wilson, J. F., "Qualification Testing fo r Model B Electric Hydrogen Recombiner," WCAP-9346 and WCAP-7709L, Supplements 1 to 7.

6.2.5-2 Cottrell, W. B., "ORNL Nuclear Safety Research and Development Program, Bimonthly Report for July-August 1968," Report No. ORNL-TM-2412, Part 3, November 1968.

6.2.5-3 Cottrell, W. B., "ORNL Nuclear Safety Research and Development Program, Bimonthly Report for September-October 1968," Report No. ORNL-TM-2425, January 1969, p. 53.

6.2.5-4 Burchell, R. C., and D. D. Whyte, "Corrosion Study for Determining Hydrogen Generation from Aluminum and Zinc during Post-Accident Conditions,"

WCAP-8776, April 1976.

6.2.5-5 10CFR50.44, Combustible Gas Control for Nuclear Power Reactors (1-1-04 Edition).

6.2.5-6 Regulatory Guide 1.7, Control of Combustible Gas Concentrations in Containment, Revision 3, May 2003.

6.2.5-7 Jaffee, D.H., "Issuance of Amendment Re: Elimination of Requirements for Hydrogen Recombiners and Hydrogen Monitors (TAC Nos. MC4229 and MC4230),"

November 30, 2004 (ST-AE-NOC-04001311).

CN-3136 CN-3136 STPEGS UFSAR 6.2-57 Revision 18 TABLE 6.2.1.1-1 CONTAINMENT DESIGN ACCIDENTS CONTAINMENT DESIGN PARAMETER PO STULATED ACCIDENTS ANALYZED Loss-of-Coolant Accidents (LOCA) DEPS, Min. SI, Min. CHRS Containment Peak Pressure/Temperature DEPS, Max. SI, Min. CHRS DEHL, Min. SI, Min. CHRS DEHL, Max. SI, Min. CHRS

Secondary System Breaks (MSLB) 1.4 ft 2 DER @ HFP, Minimum CHRS 1.4 ft 2 DER @ HFP, MSIV Failure 1.4 ft 2 DER @ HFP, MFIV Failure 1.4 ft 2 DER @ 70% Power, Minimum CHRS 1.4 ft 2 DER @ 70% Power, MSIV Failure 1.4 ft 2 DER @ 70% Power, MFIV Failure 1.4 ft 2 DER @ 30% Power, Minimum CHRS 1.4 ft 2 DER @ 30% Power, MSIV Failure 1.4 ft 2 DER @ 30% Power, MFIV Failure 1.4 ft 2 DER @ 0% Power, Minimum CHRS 1.4 ft 2 DER @ 0% Power, MSIV Failure 1.4 ft 2 DER @ 0% Power, MFIV Failure Containment Peak Pressure/Temperature 1.08 ft 2 Split Break @HFP, Minimum CHRS 1.08 ft 2 Split Break @HFP, MSIV Failure 1.08 ft 2 Split Break @HFP, MFIV Failure 1.22 ft 2 Split Break @ 70% Power, Minimum CHRS 1.22 ft 2 Split Break @ 70% Power, MSIV Failure 1.22 ft 2 Split Break @ 70% Power, MFIV Failure 1.43 ft 2 Split Break @ 30% Power, Minimum CHRS 1.43 ft 2 Split Break @ 30% Power, MSIV Failure 1.43 ft 2 Split Break @ 30% Power, MFIV Failure 1.47 ft 2 Split Break @ 0% Power, Minimum CHRS 1.47 ft 2 Split Break @ 0% Power, MSIV Failure 1.47 ft 2 Split Break @ 0% Power, MFIV Failure

SG Loop Compartment Sub-compartment Peak Pressure DER - RHR 12" Line DER - FW 16" Line at SG Nozzle

Pressurizer Subcompartment Sub-compartment Peak Pressure Spray Line Break on Pressurizer Side Surge Line Subcompartments Sub-compartment Peak Pressure Surge Line Break in Pressurizer Skirt Area Surge Line Break in Vestibule

Steam Line Subcompartment Sub-compartment Peak Pressure Double-ended MS Line Break at Containment Wall CN-3136 CN-3136 STPEGS UFSAR 6.2-58 Revision 18 TABLE 6.2.1.1-1 (Continued)

CONTAINMENT DESIGN ACCIDENTS CONTAINMENT DESIGN PARAMETER PO STULATED ACCIDENTS ANALYZED Feedwater Line Subcompartment Sub-compartment Peak Pressure Double-ended FW Line Break at Containment Wall Miscellaneous High Energy Lines CVCS Line Break in Regenerative HX Compartment CVCS Letdown Line Break in Radioactive Pipe Chase Sub-compartment Peak Pressure Compartment CVCS Letdown Line Break in RHR Valve Room Sub-compartment

External Pressure Inadvertent Spray Actuation NOTES:

DER Double-ended Rupture CHRS Containment Heat Removal System CVCS Chemical Volume and Control System DEHL Double-ended Hot Leg Break DEPS Double-ended Pump Suction Break FWLB Feedwater Line Break MFIV Main Feedwater Line Isolation Valve MSIV Main Steam Line Isolation Valve MSLB Main Steam Line Break RHR Residual Heat Removal SI Safety Injection CN-3136 CN-3136 STPEGS UFSAR 6.2-59 Revision 18 TABLE 6.2.1.1-2 DESIGN BASIS ACCIDENT CALCULAT ED PRESSURES IN CONTAINMENT Parameter

[5] Design Basis Accident

[1] Design Pressure Peak Pressure Time of Peak Pressure Peak Pressure Margin Peak Temperature Peak Internal Pressure LOCA- Double-Ended Hot Leg Break (DEHL) with Minimum Safety Injection and Minimum Containment Heat Removal Systems (CHRS) in Operation 56.5 psig 40.1 psig [2, 3, 4] 21.5 sec 29% 258 F Peak Internal Pressure LOCA - DEHL with Maximum Safety Injection and Minimum CHRS 56.5 psig 40.1 psig [2, 3, 4] 21.5 sec 29% 258 F Peak Internal Pressure LOCA - Double-Ended Pump Suction Break (DEPS) with Minimum Safety Injection and Minimum CHRS 56.5 psig 38.6 psig 22 sec 32% 256 F Peak Internal Pressure LOCA- DEPS with Maximum Safety Injection and Minimum CHRS 56.5 psig 38.6 psig 22 sec 32% 256 F External Pressure Inadvertent Operation of the Containment Spray System (-) 3.5 psid (-) 3.1 psid 11.4% 1. DEHL Break Area= 4.587 ft 2 per side (9.18 ft 2 total), Pipe inside diameter = 2.42 ft. DEPS Break Area= 5.241 ft 2 per side (10.48 ft 2 total), Pipe inside diameter= 2.58 ft. 2. STP uses a conservative value of 41.2 psig as the peak calculated internal containment pressure in Technical 6.8.3j, Technical Specification Bases 3/4.6.1.2 and 3/4.6.1.4, and UFSAR Tables 3.11-1 and 6.5-2.

3. At 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, the Containment pressure is less than 50% of the peak.

4. Section 6.2.1.3 provides a discussion of post-blowdown period mass and energy release rates for this case.

5. For each LOCA case, two analyses were performed by selecting inputs to give either a high pressure or a high temperature in the containment.

CN-3136 STPEGS UFSAR 6.2-60 Revision 18 TABLE 6.2.1.1-3 CONTAINMENT DATA USED IN P/T ANALYSIS General Information

Internal Design Pressure 56.5 psig External Design Pressure (-)3.5 psig Structural Design Temperature 286 F Free Volume 3.41E6 ft 3 [1] Design Leak Rate 0.3% per day

Initial Conditions for M&E and P/T Analyses

Reactor Coolant System (at design overpower and at normal liquid levels) Reactor Power Level 3,876 Mwt [2]

Nominal SG Outlet Coolant Temperature 549.4 to 560.8 F Nominal Reactor Vessel Outlet Temperature 614.8 to 624.8 F Reactor Coolant Mass See Tables 6.2.1.3-13 to -18 Liquid Plus Steam Energy S ee Tables 6.2.1.3-13 to -18 Containment Pressure [2] Temperature Humidity LOCA Peak Pressure Case 15.1 psia 61.8 F [2] 20% LOCA Peak Temperature Case 15.1 psia 114 F [2] 100% MSLB Peak Pressure Case 15.1 psia 114 F [2] 20% MSLB Peak Temperature Case 14.5 psia 114 F [2] 20% Essential Cooling Water Temperature 103 F [2] Refueling Water Temperature 130 F Outside Temperature 110 F Stored Water (as applicable) Refueling Water Storage Tank 360,000 gal

[2]All Accumulators (safety injection tanks) 3,600 ft 3

1. An error band of +0.1%, -0.85% applies to the calculated free volume. A volume of 3.3x10 6 ft 3 was used in the analysis. 2. Includes uncertainties.

CN-3136 CN-3136 CN-3136 STPEGS UFSAR 6.2-61 Revision 18 TABLE 6.2.1.1-5 ENGINEERED SAFETY FEATURES SYSTEM INFORMATION USED IN CONTAINMENT ANALYSIS Design / Capacity Used for Containment Mass & Energy Release and Pressure/ Temperature Analysis (Minimum SI)

Used for Containment Mass & Energy Release and Pressure/ Temperature Analysis (Maximum SI) A. Passive Safety Injection System 1. No. of Accumulators 2. Pressure Setpoint (psig) M&E (liquid release) M&E (nitrogen gas release) 3 670 670 3 585 710 3 585 710 B. Active Safety Injection Systems B.1 Up To End of SG Depressurization (3600 seconds)

1. High Head Safety Injection System

a. Number of Lines b. Number of Pumps

3 3 2 2 3 3 2. Low Head Safety Injection System a. Number of lines b. Number of Pumps 3 3 2 2 3 3 3. High Head + Low Head Safety Injection a. Total SI Flow Minimum SI 7851 gpm (1049.5 lbm/sec) Flow for 2 SI trains Maximum SI 12717 gpm (1757 lbm/sec) Flow for 3 SI trains Function of RCS Pressure See Table 6.2.1.3-2 Function of RCS Pressure See Table 6.2.1.3-3 B.2 After 3600 seconds

1. High Head Safety Injection System

a. Number of Lines

b. Number of Pumps 3 3 0 0 0 0 2. Low Head Safety Injection System a. Number of lines

b. Number of Pumps

3 3 2 2 2 2 CN-3136 CN-3136 CN-3136 STPEGS UFSAR 6.2-62 Revision 18 TABLE 6.2.1.1-5 (Continued)

ENGINEERED SAFETY FEATURES SYSTEM INFORMATION USED IN CONTAINMENT ANALYSIS Design / Capacity Used for Containment Pressure & Temperature Analysis (Minimum SI)

Used for Containment Pressure & Temperature Analysis (Maximum SI)

C. Containment Spray System (CSS) [1] 1. Number of Lines

2. Number of Pumps 3. Flow Rate (gpm) 3 3 3,863 [2]

2 2 3,663 [2]

2 2 3,663 [2] D. Reactor Containment Fan Coolers (RCFC) [1]

1. Number of Units 2. Air Side Flow Rate, cfm 3. Heat Removal rate, Btu/hr Function of CCW temperature and Containment atmosphere saturation temperature. (Value shown is at 125

ûF CCW, 0.0005 fouling factor, and 235 oF containment saturation temperature) 6 53,500 77.8e6 3 53,500 62.2e6 [3] 3 53,500 62.2e6 [3] E. Recirculation Systems RHR Heat Exchanger [1] a. Number b. Type c. Overall Heat Transfer Coefficient U, Btu/hr-ft 2-o F d. Heat Transfer Area (A), ft 2 f. Flow rates/Unit 1) Recirculation side (LHSI), lbm/hr (each)

2) Exterior side (CCW), (lbm/hr) g. Source of Cooling Water h. Recirculation Cooling Begins, (sec) 3 Vert. U-tube 387 5440 1.5x10 6 (3000 gpm) 2.6x10 6 CCW [3] N/A 2 Vert. U-tube Calculated by GOTHIC 4532 2531 gpm 2.6x10 6 CCW [3] 1465 2 Vert. U-tube Calculated by GOTHIC 4532 2531 gpm 2.6x10 6 CCW [3] 1000 F. Others Component Cooling Water Heat Exchanger a. Number 3 Not Modeled Not Modeled NOTES: 1. CSS and RCFCs were not used in M&E release analysis, but were used in P/T analysis. RHR Heat Exchangers were used in both M&E and P/T analysis after 3600 seconds. 2. Data for 2 trains.

3. CCW supply temperatures used in P/T analysis: 125 oF from 0 - 5 hrs 115 oF from 5 - 10 hrs 110 oF after 10 hrs 125 oF for MSLB P/T analysis CN-3136 STPEGS UFSAR 6.2-63 Revision 18 TABLE 6.2.1.1-7 MODELING OF STRUCTURAL HEAT SINKS FOR CONTAINMENT ANALYSES Heat Sink No. Passive Heat Sinks Material Thickness Exposed Surface (ft

2) 1 Containment Dome Amercote 90 Paint Dimetcote 6 Paint Carbon-Steel Liner Air Concrete 8 mils 4 mils 0.375in 2 mils 36.0 in 35300 2 Containment Wall Amercote 90 Paint Carbon-Steel Liner Air Concrete 16 mils 0.375in 2 mils 48.0 in 76800 3 Containment Floor Nutech Paint Concrete 50 mils 20 ft 14700 4 Concrete Internal Structure Nutech Paint Concrete 50 mils 15.36 in 123400 5 Concrete Internal Wall (4.39 ft) Nutech Paint Concrete 50 mils 52.68 in 8800 6 Internal Wall Amercote Paint Dimetcote Paint Carbon-Steel Air Concrete 8 mils 6 mils 0.475 in 2 mils 27.29 in 24700 7 Internal Walls Amercote Paint Dimetcote Paint Carbon-Steel Air Concrete 8 mils 6 mils 0.786 in 2 mils 17.64 in 12800 8 Stainless Steel Walls Stainless Steel 0.576 in 400 9 Carbon Steel Wall Amercote Paint Dimetcote Paint

Carbon-Steel 8 mils 6 mils 0.35 in 301500 10 Carbon Steel Components t < 0.125 in Amercote Paint Dimetcote Paint Carbon-Steel 8 mils 6 mils 0.109 in 6800 11 Carbon Steel Components 0.125 in. < t < 0.25 in Amercote Paint Dimetcote Paint Carbon-Steel 8 mils 6 mils 0.156 in 800 12 Carbon Steel Components 0.25 in. < t < 0.5 in Amercote Paint Dimetcote Paint Carbon-Steel 8 mils 6 mils 0.409 in 8100 CN-3136 STPEGS UFSAR 6.2-64 Revision 18 TABLE 6.2.1.1-7 (continued) MODELING OF STRUCTURAL HEAT SINKS FOR CONTAINMENT ANALYSES Heat Sink No. Passive Heat Sinks Material Thickness Exposed Surface (ft

2) 13 Carbon Steel Components 0.5 in. < t < 1.0 in Amercote Paint Dimetcote Paint Carbon-Steel 8 mils 6 mils 0.827 in 10900 14 Carbon Steel Components 1.0 in. < t < 2.5 in Amercote Paint Dimetcote Paint Carbon-Steel 8 mils 6 mils 1.859 in 9500 15 Carbon Steel Components t > 2.5 in. Amercote Paint Dimetcote Paint Carbon-Steel 8 mils 6 mils 3.696 in 2000 16 Stainless Steel Components Stainless Steel 0.40 in 1700 17 Stainless Steel Piping Stainless Steel 0.264 in 3900 18 Carbon Steel Piping Amercote Paint Dimetcote Paint Carbon-Steel 8 mils 6 mils 0.231 in 700 19 Electrical Components (not painted) Carbon-Steel (galvanized) 0.11 in 115300 20 Electrical Components (painted) Amercote Paint Carbon-Steel 16 mils 0.117 in 15200 21 Carbon Steel Components thickness <0.125 in Carbon Steel 0.075 in 15400 22 Carbon Steel Components 0.125 in. < t < 0.25 in Carbon Steel 0.23 in 29500 23 Carbon Steel Components t >0.25 in Carbon Steel 0.458 in 4400 TOTAL 822600

___________________________________________________________ NOTE: This table provides passive heat sink data used in containment peak pressure/temperature response analyses.

In peak P/T analyses, it is conservative to ignore additional heat sinks since it will give higher containment pressures and temperatures.

CN-3136 STPEGS UFSAR 6.2-65 Revision 18 TABLE 6.2.1.1-8 THERMOPHYSICAL PROPERTIES OF STRUCTURAL HEAT SINK MATERIALS FOR CONTAINMENT ANALYSIS

Material Density Thermal Conductivity Specific Heat (lbm/ft 3) (Btu/hr-ft-F) (Btu/lbm- F) Paint (Amercote, Organic, Topcoat) 109.8 0.375 0.454 Paint (Dimetcote, Inorganic Primer) 293.0 0.633 0.074 Paint (Nutech) 121.7 0.126 0.232 Air 0.0523 0.0174 0.174 Carbon Steel 490.0 25.0 0.110 Concrete 144.0 0.8 0.208 Stainless Steel 488.0 9.4 0.111 Copper 558.0 200 0.092 CN-3136 STPEGS UFSAR 6.2-66 Revision 18 TABLE 6.2.1.1-9 CONTAINMENT HEAT SINK SURFACE HEAT TRANSFER MODEL Interface Convective Heat Transfer Coefficient Condensation Heat Transfer Coefficient Notes 1 Containment Structure (Dome, Wall) to Ambient Air 2.0 Btu/hr-ft 2- F N/A Heat transfer coefficient to outside atmosphere.

2 Containment Vapor & Liquid to Containment Structures (except Sump Floor) Natural Convection Diffusion Layer Model (DLM) The DLM model calculates the condensation rate and sensible heat transfer rate.

3 Containment Vapor & Liquid to Sump Floor for LOCA Natural Convection N/A GOTHIC Correlation Set with Split option heat transfer model. The Split option switches heat transfer from the vapor to the liquid phase as the liquid level in the containment floor builds up. The Correlation Set is Natural Convection. It allows sensible heat transfer by convection to the liquid or vapor phase based on the liquid volume fraction and the Split option settings. The Correlation Set with Split Option excludes any direct condensation on the floor before it is covered with water.

4 Containment Vapor & Liquid to Sump Floor for MSLB Natural Convection Diffusion Layer Model (DLM) Natural Convection and DLM condensation Split option. The Split option switches heat transfer from the vapor to the liquid phase as the liquid level in the containment floor builds up.

CN-3136 STPEGS UFSAR 6.2-67 Revision 18 TABLE 6.2.1.1-10 ACCIDENT CHRONOLOGY FOR DBA LOCA ANALYSIS

[1] DEHL [1, 2] DEHL [1, 2] DEPS [1, 2] DEPS [1, 2] Min. SI [3, 4, 5] Max. SI [3, 4, 5] Min. SI [3, 4] Max. SI [3, 4] EVENT Time (sec) Time (sec) Time (sec) Time (sec) Accident Initiation - Pipe Break Coincident with LOOP 0.0 0.0 0.0 0.0 Pressurizer Low Pressure Reactor Trip Setpoint Reached 2.4 2.4 3.0 3.0 Accumulators Begin to Inject 15.7 15.7 18.9 18.9 End of Blowdown Phase 24.8 24.8 25.2 25.2 Pumped SI Begins 33.0 33.0 33.0 33.0 RCFCs at Full Speed 45.0 45.0 45.0 45.0 Accumulator Injection Ends 46.9 47.2 46.9 47.2 Containment Spray Flow Delivered to Containment Atmosphere 85.0 85.0 85.0 85.0 End of Reflood Phase 173.1 220.0 173.1 220.0 Broken Loop SG Depressurizes to Containment Design Pressure 640.0 1045.7 640.0 1045.7 Switchover to Sump Recirculation Occurs 1465 1000 1465 1000 Intact Loop SGs Depressurize to Containment Design Pressure 1613.1 1754.4 1613.1 1754.4 All SGs Forced to Depressurize to 14.7 psia and 212ûF 3600.0 3600.0 3600.0 3600.0 Transient Simulation Ends 3.6x10 6 3.6x10 6 3.6x10 6 3.6x10 6 Notes: 1. DEHL = double-ended hot leg break. DEPS = double-ended pump suction break. 2. All cases analyzed with minimum containment heat removal systems in operation (3 RCFC units and 2 Containment Sprays). 3. Minimum SI = 2 LHSI + 2 HHSI flow up to end of SG depressurization phase (3600 seconds). Maximum SI = 3 LHSI + 3 HHSI flow up to end of SG depressurization phase (3600 seconds).

4. 2 LHSI / 2 RHR trains during post-SG depressurization phase (3600+ seconds). 5. For the DEHL cases, the calculated mass and energy release data ends at 24.8 seconds and the DEPS M&E releases for the post-blowdown period were used. As discussed in Section 6.2.1.3.2, this results in the highest release rates.

CN-3136 STPEGS UFSAR 6.2-68 Revision 18 TABLE 6.2.1.1-14

SUMMARY

OF CONTAINMENT MSLB P/T ANALYSIS RESULTS Peak Temperature (o F) Peak Pressure (psig) No. Description 1 1.4 ft 2 DER @ HFP, Minimum CHRS 286 26.7 2 1.4 ft 2 DER @ HFP, MSIV Failure 297 27.0 3 1.4 ft 2 DER @ HFP, MFIV Failure 286 26.5 4 1.4 ft 2 DER, @ 70% Power, Minimum CHRS 286 27.6 5 1.4 ft 2 DER, @ 70% Power, MSIV Failure 297 27.8 6 1.4 ft 2 DER, @ 70% Power, MFIV Failure 286 27.2 7 1.4 ft 2 DER, @ 30% Power, Minimum CHRS 286 28.6 8 1.4 ft 2 DER, @ 30% Power, MSIV Failure 298 28.8 9 1.4 ft 2 DER, @ 30% Power, MFIV Failure 286 28.6 10 1.4 ft 2 DER, @ 0% Power, Minimum CHRS 287 27.8 11 1.4 ft 2 DER, @ 0% Power, MSIV Failure 299 28.1 12 1.4 ft 2 DER, @ 0% Power, MFIV Failure 287 27.2 13 1.08 ft 2 Split Break @ HFP, Minimum CHRS 260 23.8 14 1.08 ft 2 Split Break @ HFP, MSIV Failure 262 23.9 15 1.08 ft 2 Split Break @ HFP, MFIV Failure 259 23.6 16 1.22 ft 2 Split Break @ 70% Power, Minimum CHRS 263 24.6 17 1.22 ft 2 Split Break @ 70% Power, MSIV Failure 266 24.9 18 1.22 ft 2 Split Break @ 70% Power, MFIV Failure 263 24.1 19 1.43 ft 2 Split Break @ 30% Power, Minimum CHRS 267 26.0 20 1.43 ft 2 Split Break @ 30% Power, MSIV Failure 271 26.1 21 1.43 ft 2 Split Break @ 30% Power, MFIV Failure 267 25.3 22 1.47 ft 2 Split Break @ 0% Power, Minimum CHRS 268 26.8 23 1.47 ft 2 Split Break @ 0% Power, MSIV Failure 271 27.1 24 1.47 ft 2 Split Break @ 0% Power, MFIV Failure 268 26.1 25 1.4 ft 2 DER, @ 30% Power, MSIV Failure (Peak Pressure Case) 295 29.6 STPEGS UFSAR 6.2-69 Revision 18 TABLE 6.2.1.1-15 ACCIDENT CHRONOLOGY FOR DBA MSLB (Peak Temperature Case)

(1.4 ft 2 DER, 0% Power MSIV Failure)

Time (Sec) Event Description

0.0 Break

0.024 Low steam line pressure setpoint reached 2.8 HI-1 pressure setpoint reached (5.5 psig) 6.65 HI-3 pressure setpoint reached (12.0 psig) 8.03 All Main steam isolation valves closed 13.03 All Main feedwater isolation valves closed 13.7 Peak temperature occurs (299 o F) 45.0 Reactor Containment Fan coolers begin operation 85.0 Containment Sprays begin operation 1800 Auxiliary feedwater pumps in faulted loop secured (end of blowdown)

STPEGS UFSAR 6.2-70 Revision 18 TABLE 6.2.1.2-1 SHORT-TERM MASS AND ENERGY RELEASE RATES FOR SUBCOMPARTMENT ANALYSES G. PRESSURIZER SPRAY LINE DOUBLE-ENDED GUILLOTINE BREAK*

Time (sec) Mass Flow (lbm/sec)Ener gy Flow (Btu/sec)Av g Enthal py (Btu/lbm) .00000 0 0.0.00.00100 4.2655151E+032.8861196E+06676.62

.00201 4.6098832E+033.0842862E+06669.86

.00302 4.7129947E+033.1433438E+06666.95

.00401 4.7351351E+033.1556165E+06666.43.00502 4.6794560E+033.1228404E+06667.35.00602 4.5067502E+033.0225825E+06670.68

.00701 4.3062850E+032.9068057E+06675.01

.00801 4.5342749E+033.0379570E+06670.00

.00900 4.7577980E+033.1664127E+06665.52.01005 4.7605634E+033.1673506E+06665.33.01102 4.7118969E+033.1387093E+06666.12

.01204 4.6670362E+033.1123553E+06666.88

.01305 4.6637526E+033.1101076E+06666.87

.01405 4.7224037E+033.1436411E+06665.69

.01501 4.7689590E+033.1701496E+06664.75.01602 4.7553680E+033.1619088E+06664.91.01704 4.7466956E+033.1566204E+06665.01

.01806 4.7805766E+033.1759812E+06664.35

.01904 4.8401734E+033.2101958E+06663.24

.02002 4.8968373E+033.2427152E+06662.21.02100 4.9320743E+033.2628467E+06661.56.02200 4.9502443E+033.2731158E+06661.20

.02306 4.9725007E+033.2858235E+06660.80

.02407 5.0107856E+033.3078429E+06660.14

.02509 5.0483929E+033.3294774E+06659.51.02605 5.0784824E+033.3467725E+06659.01.02700 5.1067356E+033.3630141E+06658.54

.02807 5.1420012E+033.3833532E+06657.98

.02910 5.1844745E+033.4078402E+06657.32

.03007 5.2205322E+033.4285665E+06656.75.03103 5.2451381E+033.4426262E+06656.35.03204 5.2576303E+033.4496265E+06656.12

.03309 5.2582455E+033.4497086E+06656.06

.03412 5.2489632E+033.4440490E+06656.14

.03506 5.2335346E+033.4348315E+06656.31.03609 5.2092290E+033.4204214E+06656.61.03711 5.1781481E+033.4021298E+06657.02

.03804 5.1501208E+033.3856915E+06657.40

.03904 5.1227948E+033.3696830E+06657.78* Includes 10% margin not used in subcompartment analysis. To obtain mass and energy release rates used in subcompartment analyses, multiply by 0.9091.

STPEGS UFSAR 6.2-71 Revision 18 TABLE 6.2.1.2-1 (Continued)

SHORT-TERM MASS AND ENERGY RELEASE RATES FOR SUBCOMPARTMENT ANALYSES G. PRESSURIZER SPRAY LINE DOUBLE-ENDED GUILLOTINE BREAK*

Time (sec) Mass Flow (lbm/sec)Ener gy Flow (Btu/sec)Av g Enthal py (Btu/lbm) .04007 5.1000499E+033.3563528E+06658.10.04105 5.0836003E+033.3466936E+06658.33

.04211 5.8704720E+033.3389549E+06658.51

.04300 5.0627332E+033.3343633E+06658.61

.04404 5.0568310E+033.3308190E+06658.68.04515 5.0531990E+033.3285851E+06658.71.04605 5.0514454E+033.3274642E+06658.72

.04702 5.0501171E+033.3265872E+06658.71

.04813 5.0489416E+033.3257880E+06658.71

.04908 5.0482146E+033.3252693E+06658.70.05005 5.0477741E+033.3249199E+06658.69.05109 5.0475692E+033.3247072E+06658.67

.05207 5.0476657E+033.3246829E+06658.66

.05317 5.0483926E+033.3250252E+06658.63

.05407 5.0498297E+033.3258038E+06658.60.05510 5.0528453E+033.3274989E+06658.54.05604 5.0571610E+033.3299599E+06658.46

.05711 5.0639994E+033.3338878E+06658.35

.05814 5.0726756E+033.3388905E+06658.21

.05912 5.0831198E+033.3449246E+06658.05.06009 5.0949369E+033.3517575E+06657.86.06101 5.1077529E+033.3591692E+06657.66

.06205 5.1229700E+033.3679677E+06657.42

.06307 5.1377248E+033.3764943E+06657.20

.06408 5.1511612E+033.3842507E+06656.99.06509 5.1627712E+033.3909419E+06656.81.06612 5.1721557E+033.3963359E+06656.66

.06704 5.1781999E+033.3997930E+06656.56

.06805 5.1821789E+033.4020443E+06656.49

.06916 5.1838782E+033.4029606E+06656.45

.07003 5.1835201E+033.4026889E+06656.44.07104 5.1816709E+033.4015428E+06656.46.07211 5.1787635E+033.3997845E+06656.49

.07302 5.1759206E+033.3980750E+06656.52

.07403 5.1728577E+033.3962389E+06656.55

.07503 5.1700652E+033.3945645E+06656.58.07602 5.1675822E+033.3930738E+06656.61.07701 5.1652759E+033.3916885E+06656.63

.07812 5.1625939E+033.3900808E+06656.66

• Includes 10% margin not used in subcompartme nt analysis. To obtain mass and energy release rates used in subcompartment analyses, multiply by 0.9091.

STPEGS UFSAR 6.2-72 Revision 18 TABLE 6.2.1.2-1 (Continued)

SHORT-TERM MASS AND ENERGY RELEASE RATES FOR SUBCOMPARTMENT ANALYSES G. PRESSURIZER SPRAY LINE DOUBLE-ENDED GUILLOTINE BREAK*

Time (sec) Mass Flow (lbm/sec)Ener gy Flow (Btu/sec)Av g Enthal py (Btu/lbm) .07906 5.1604211E+033.3887710E+06656.68

.08003 5.1571869E+033.3868475E+06656.72.08105 5.1528273E+033.3842764E+06656.78

.08207 5.1481963E+033.3815394E+06656.84

.08302 5.1431392E+033.3785684E+06656.91

.08417 5.1354841E+033.3746589E+06657.00

.08510 5.1278027E+033.3695577E+06657.12

.08614 5.1193428E+033.3646106E+06657.23.08719 5.1097952E+033.3590225E+06657.37.08801 5.1005950E+033.3536436E+06657.50

.08905 5.0891644E+033.3469588E+06657.66

.09005 5.0776001E+033.3402056E+06657.83

.09103 5.0659978E+033.3334350E+06658.00

.09204 5.0533647E+033.3260682E+06658.19

.09307 5.0403544E+033.3184828E+06658.38

.09401 5.0296282E+033.3122193E+06658.54

.09503 5.0168556E+033.3047858E+06658.74

.09610 5.0049415E+033.2978555E+06658.92

.09703 4.9958730E+033.2925797E+06659.06

.09810 4.9866541E+033.2872101E+06659.20

.09910 4.9798298E+033.2832333E+06659.31

.10015 4.9752631E+033.2805734E+06659.38

.10502 4.9878564E+033.2878219E+06659.17.11010 5.0569145E+033.3278901E+06658.09.11512 5.1539287E+033.3842381E+06656.63

.12002 5.2363757E+033.4321962E+06655.45

.12502 5.2682651E+033.4506565E+03654.99

.13011 5.2351375E+033.4311926E+06655.42

.13511 5.1624321E+033.3887285E+06656.42

.14003 5.0877634E+033.3452221E+06657.50

.14505 5.0411013E+033.3180817E+06658.21

.15009 5.0374828E+033.3160190E+06658.27

.15507 5.0586769E+033.3283552E+06657.95

.16005 5.0721415E+033.3361506E+06657.74

.16514 5.0570460E+033.3273147E+06657.96

.17015 5.0159823E+033.3033941E+06658.57

.17507 4.9709312E+033.2772197E+06659.28

.18003 4.9422233E+033.2605409E+06659.73.18513 4.9410589E+033.2598568E+06659.75.19010 4.9639357E+033.2730966E+06659.38

• Includes 10% margin not used in subcompartment analysis. To obtain mass and energy release rates used in subcompartment analyses, multiply by 0.9091.

STPEGS UFSAR 6.2-73 Revision 18 TABLE 6.2.1.2-1 (Continued)

SHORT-TERM MASS AND ENERGY RELEASE RATES FOR SUBCOMPARTMENT ANALYSES G. PRESSURIZER SPRAY LINE DOUBLE-ENDED GUILLOTINE BREAK*

Time (sec) Mass Flow (lbm/sec)Ener gy Flow (Btu/sec)Av g Enthal py (Btu/lbm) .19502 4.9955360E+033.2913881E+06658.87.20006 5.0247688E+033.3082734E+06658.39

.21024 5.0439890E+033.3192187E+06658.05.22001 5.0132145E+033.3011447E+06658.49.23002 4.9631166E+033.2719004E+06659.24.24009 4.9461482E+033.2619036E+06659.48.25009 4.9823185E+033.2827315E+06658.88

.26018 5.0121777E+033.2998735E+06658.37.27006 5.0003486E+033.2928434E+06658.52.28005 4.9973162E+033.2909793E+06658.55.29002 5.0215325E+033.3049488E+06658.16.30000 5.018389E+03 3.3029986E+06658.18

.31001 4.9729952E+033.2765364E+06658.87.32004 4.9367008E+033.2553972E+06659.43.33006 4.9349881E+033.2543288E+06659.44.34009 4.9427731E+033.2587327E+06659.29.35011 4.9408431E+033.2574801E+06659.30

.36004 4.9288529E+033.2503780E+06659.46.37003 4.9157082E+033.2426018E+06659.64.38006 4.9119379E+033.2402506E+06659.67.39007 4.9139937E+033.2412621E+06659.60.40012 4.9096916E+033.2385784E+06659.63

.41007 4.9047927E+033.2355565E+06659.67.42002 4.9121670E+033.2396617E+06659.52.43008 4.9234326E+033.2460276E+06659.30.44007 4.9236416E+033.2459820E+06659.26.45012 4.9167941E+033.2418519E+06659.34

.46003 4.9140923E+033.2401301E+06659.35.47005 4.9142364E+033.2400565E+06659.32.48008 4.9113147E+033.2382057E+06659.34.49003 4.9056056E+033.2347444E+06659.40.50004 4.8993768E+033.2309857E+06659.47

.51001 4.8941600E+033.2278117E+06659.52.52007 4.8896958E+033.2250665E+06659.56.53003 4.8847498E+033.2220324E+06659.61.54013 4.8796922E+033.2189213E+06659.66.55004 4.8785305E+033.2177763E+06659.65

.56001 4.8795862E+033.2184880E+06659.58.57002 4.8798432E+033.2184413E+06659.54.58010 4.877852E+03 3.2170564E+06659.53

.59013 4.8775687E+033.2167302E+06659.50.60018 4.8811257E+033.2186082E+06659.40

• Includes 10% margin not used in subcompartment analysis. To obtain mass and energy release rates used in subcompartment analyses, multiply by 0.9091.

STPEGS UFSAR 6.2-74 Revision 18 TABLE 6.2.1.2-1 (Continued)

SHORT-TERM MASS AND ENERGY RELEASE RATES FOR SUBCOMPARTMENT ANALYSES G. PRESSURIZER SPRAY LINE DOUBLE-ENDED GUILLOTINE BREAK*

Time (seec) Mass Flow (lbm/sec)Ener gy Flow (Btu/sec)Av g Enthal py (Btu/lbm) .61009 4.8859862E+033.2212284E+06659.28.62009 4.8894734E+033.2230548E+06659.18.63007 4.8910429E+033.2237725E+06659.12.64001 4.8906677E+033.2233744E+06659.09.65015 4.882540E+03 3.2217974E+06659.09

.66010 4.8841892E+033.2192712E+06659.12.67017 4.8794018E+033.2163211E+06659.16.68012 4.8760632E+033.2142142E+06659.18.69021 4.8753932E+033.2135915E+06659.16.70019 4.8759578E+033.2137818E+06659.11

.71007 4.8757212E+033.2134544E+06659.07.72112 4.8740549E+033.2122905E+06659.06.73012 4.8722265E+033.2110376E+06659.05.74016 4.8713313E+033.2103226E+06659.02.75008 4.8723128E+033.2105256E+06658.97

.76012 4.8744785E+033.2117567E+06658.89.77027 4.8782213E+033.2137251E+06658.79.78011 4.8817172E+033.2155471E+06658.69.79007 4.8834598E+033.2163691E+06658.63.80001 4.8829273E+033.2158726E+06658.60

.81009 4.8782769E+033.2143972E+06658.59.82013 4.8782769E+033.2128100E+06658.60.83005 4.8768105E+033.2117836E+06658.58.84006 4.8764535E+033.2113932E+06658.55.85011 4.8766749E+033.2113398E+06658.51

.86006 4.8767331E+033.2111888E+06658.47.87011 4.8760012E+033.2105775E+06658.44.88007 4.8743557E+033.2094398E+06658.43.89000 4.8722812E+033.2080552E+06658.43.90000 4.8707234E+033.2069708E+06658.42

.91006 4.8706984E+033.2067665E+06658.38.92007 4.8719639E+033.2073164E+06658.32.93012 4.8736585E+033.2081177E+06658.26.94003 4.8746954E+033.2085401E+06658.20.95008 4.8745591E+033.2082798E+06658.17

.96004 4.8733341E+033.2074010E+06658.15.97006 4.8715117E+033.2061678E+06658.15.98004 4.8699392E+033.2050935E+06658.14.99005 4.8690508E+033.2044054E+06658.121.00004 4.8688821E+033.2041386E+06658.09 1.01011 4.8688668E+033.2039590E+06658.051.02005 4.8684204E+033.2035329E+06658.02

• Includes 10% margin not used in subcompartment analysis. To obtain mass and energy release rates used in subcompartment analyses, multiply by 0.9091.

STPEGS UFSAR 6.2-75 Revision 18 TABLE 6.2.1.2-1 (Continued)

SHORT-TERM MASS AND ENERGY RELEASE RATES FOR SUBCOMPARTMENT ANALYSES G. PRESSURIZER SPRAY LINE DOUBLE-ENDED GUILLOTINE BREAK*

Time (sec) Mass Flow (lbm/sec)Ener gy Flow (Btu/sec)Av g Enthal py (Btu/lbm) 1.03000 4.8672902E+033.2027065E+06658.01 1.04005 4.8657205E+033.2016256E+06658.001.05004 4.8641669E+033.2005572E+06657.991.06007 4.8630791E+033.1997572E+06657.971.07011 4.8626112E+033.1993175E+06657.941.08008 4.8625473E+033.1991134E+06657.91 1.09009 4.8624862E+033.1989101E+06657.881.10007 4.8620367E+033.1984829E+06657.851.11022 4.860 655E+033.1977537E+06657.831.12011 4.8597878E+033.1968497E+06657.821.13001 4.8585990E+033.1960005E+06657.80 1.14002 4.8577691E+033.1953552E+06657.781.15014 4.8573666E+033.1949596E+06657.761.16004 4.8571536E+033.1946757E+06657.731.17006 4.8567812E+033.1942990E+06657.701.18022 4.8559888E+033.1936796E+06657.68 1.19011 4.8547224E+033.1927901E+06657.671.20001 4.8530856E+033.1916830E+06657.661.21006 4.851441E+03 3.1905811E+06657.661.22011 4.8439175E+033.1895296E+06657.651.23005 4.8486794E+033.1886637E+06657.64 1.24028 4.8476160E+033.1878943E+06657.621.25010 4.8465494E+033.1871215E+06657.611.26013 4.8453849E+033.1862924E+06657.591.27032 4.8441326E+033.1854146E+06657.581.28012 4.8428909E+033.1845431E+06657.57 1.29005 4.8417589E+033.1837350E+06657.561.30009 4.8407985E+033.1830271E+06657.541.31014 4.8399587E+033.1823910E+06657.521.32008 4.8390765E+033.1817305E+06657.511.33006 4.8380332E+033.1809854E+06657.50 1.34001 4.8366365E+033.1800228E+06657.491.35010 4.8350093E+033.1789355E+06657.481.36008 4.8332155E+033.1777514E+06657.481.37016 4.8313896E+033.1765502E+06657.481.38006 4.8296427E+033.1753958E+06657.48 1.39011 4.8279864E+033.1742936E+06657.481.40012 4.8264130E+033.1732394E+06657.471.41003 4.8248776E+033.1722089E+06657.471.42010 4.8233293E+033.1711699E+06657.461.43008 4.8217860E+033.1701328E+06657.46 1.44004 4.8203018E+033.1691341E+06657.46

• Includes 10% margin not used in subcompartment analysis. To obtain mass and energy release rates used in subcompartment analyses, multiply by 0.9091.

STPEGS UFSAR 6.2-76 Revision 18 TABLE 6.2.1.2-1 (Continued)

SHORT-TERM MASS AND ENERGY RELEASE RATES FOR SUBCOMPARTMENT ANALYSES G. PRESSURIZER SPRAY LINE DOUBLE-ENDED GUILLOTINE BREAK*

Time (sec) Mass Flow (lbm/sec)Ener gy Flow (Btu/sec)Av g Enthal py (Btu/lbm) 1.45008 4.8188697E+033.1681659E+06657.45 1.46002 4.8174975E+033.1672359E+06657.441.47016 4.8162554E+033.1662575E+06657.441.48010 4.8145577E+033.1652509E+06657.431.49011 4.8129427E+033.1641792E+06657.431.50005 4.8112108E+033.1630436E+06657.43 1.51004 4.8093236E+033.1618137E+06657.431.52008 4.8073576E+033.1605399E+06657.441.53001 4.8053976E+033.1592712E+06657.441.54007 4.8034866E+033.1580336E+06657.451.55002 4.8016901E+033.1568068E+06657.45 1.56008 4.7997698E+033.1556129E+06657.451.57005 4.7979944E+033.1544534E+06657.451.58004 4.7962513E+033.1533131E+06657.451.59018 4.7945088E+033.1521732E+06657.451.60003 4.7927351E+033.1510142E+06657.46 1.61018 4.7909751E+033.1498672E+06657.461.62002 4.7891338E+033.1486706E+06657.461.63006 4.7872700E+033.1474625E+06657.471.64007 4.7853460E+033.1462190E+06657.471.65034 4.7833093E+033.1449658E+06657.48 1.66004 4.7813750E+033.1436640E+06657.481.67004 4.7793601E+033.1423712E+06657.491.68015 4.7773599E+033.1410869E+06657.491.69001 4.7753929E+033.1398249E+06657.501.70003 4.7734236E+033.1385582E+06657.51 1.71007 4.7714984E+033.1373187E+06657.511.72001 4.7696092E+033.1361014E+06657.521.73001 4.7676738E+033.1348551E+06657.521.74002 4.7657524E+033.1336206E+06657.531.75001 4.7637737E+033.1323510E+06657.54 1.76003 4.7617624E+033.1310645E+06657.541.77019 4.7596828E+033.1297366E+06657.551.78001 4.7576302E+033.1284285E+06657.561.79006 4.7555095E+033.1270777E+06657.571.80013 4.7534339E+033.1257559E+06657.58 1.81009 4.7513836E+033.1244495E+06657.591.82011 4.7493343E+033.1231401E+06657.601.83009 4.7473538E+033.1218754E+06657.601.84010 4.7453656E+033.1206044E+06657.611.85005 4.7433983E+033.1193460E+06657.62

• Includes 10% margin not used in subcompartment analysis. To obtain mass and energy release rates used in subcompartment analyses, multiply by 0.9091.

STPEGS UFSAR 6.2-77 Revision 18 TABLE 6.2.1.2-1 (Continued)

SHORT-TERM MASS AND ENERGY RELEASE RATES FOR SUBCOMPARTMENT ANALYSES G. PRESSURIZER SPRAY LINE DOUBLE-ENDED GUILLOTINE BREAK*

Time (sec) Mass Flow (lbm/sec)Ener gy Flow (Btu/sec)Av g Enthal py (Btu/lbm) 1.86007 4.7414469E+033.1181005E+06657.631.87000 4.7394641E+033.1168335E+06657.631.88011 4.7374491E+033.1155486E+06657.641.89008 4.7354157E+033.1142532E+06657.651.90002 4.7333688E+033.1129521E+06657.66 1.91001 4.7312749E+033.1116248E+06657.671.92014 4.7291463E+033.1102755E+06657.681.93012 4.7270119E+033.1089235E+06657.691.94000 4.7249028E+033.1075875E+06657.701.96005 4.7228274E+033.1062742E+06657.71 1.96005 4.7207515E+033.1049559E+06657.721.97011 4.7187317E+033.1036717E+06657.731.98008 4.7167519E+033.1024108E+06657.741.99005 4.7147915E+033.1011639E+06657.752.09001 4.7128437E+033.0999235E+06657.76 2.01003 4.7108602E+033.0986620E+06657.772.02003 4.7088773E+033.0974035E+06657.782.03015 4.7068132E+033.0960939E+06657.792.04016 4.7047716E+033.0948014E+06657.802.05003 4.7027144E+033.0934995E+06657.81 2.06013 4.7006222E+033.0921770E+06657.822.07007 4.6985425E+033.0908639E+06657.832.08010 4.6964456E+033.0895397E+06657.852.09016 4.6943987E+033.0882461E+06657.862.10000 4.6923370E+033.0869434E+06657.87 2.11008 4.6902817E+033.0856419E+06657.882.12000 4.6883116E+033.0843943E+06657.892.13207 4.6863214E+033.0831330E+06657.902.14009 4.6843741E+033.0818981E+06657.912.15017 4.6824192E+033.0896591E+06657.92 2.16004 4.6804573E+033.0794162E+06657.932.17002 4.6784422E+033.0781419E+06657.942.18008 4.6764328E+033.0768734E+06657.952.19008 4.6744003E+033.0755916E+06657.962.20008 4.6723695E+033.0743090E+06657.98 2.21001 4.6719652E+033.0739702E+06657.962.22014 4.6725812E+033.0742183E+06657.932.23005 4.6738273E+033.0748301E+06657.882.24005 4.6744567E+033.0750843E+06657.852.25020 4.6741254E+033.0747810E+06657.83 2.26013 4.6741223E+033.0746702E+06657.81* Includes 10% margin not used in subcompartment analysis. To obtain mass and energy release rates used in subcompartment analyses, multiply by 0.9091.

STPEGS UFSAR 6.2-78 Revision 18 TABLE 6.2.1.2-1 (Continued)

SHORT-TERM MASS AND ENERGY RELEASE RATES FOR SUBCOMPARTMENT ANALYSES G. PRESSURIZER SPRAY LINE DOUBLE-ENDED GUILLOTINE BREAK*

Time (sec) Mass Flow (lbm/sec)Ener gy Flow (Btu/sec)Av g Enthal py (Btu/lbm) 2.27004 4.6750420E+033.0750968E+06657.772.28027 4.6758892E+033.0754779E+06657.73 2.29008 4.6758211E+033.0753273E+06657.712.3006 4.6754148E+033.1749859E+06657.692.31005 4.6754285E+033.0748881E+06657.672.32002 4.6755362E+033.0748475E+06657.652.33020 4.6753516E+033.0746380E+06657.63 2.34000 4.6750391E+033.0743539E+06657.612.35007 4.6747591E+033.0740894E+06657.592.36017 4.6748701E+033.0740555E+06657.572.37013 4.6754546E+033.0742962E+06657.542.38004 4.6751029E+033.0739955E+06657.52 2.39010 4.6740738E+033.0733019E+06657.522.40007 4.6731645E+033.0726799E+06657.522.41007 4.6724647E+033.0721781E+06657.512.42003 4.6715498E+033.0715551E+06657.502.43023 4.6706309E+033.0709283E+06657.50 2.44010 4.6702643E+033.0706212E+06657.482.45005 4.6702209E+033.0705040E+06657.462.46000 4.6703137E+033.0704652E+06657.442.47001 4.6702752E+033.0703451E+06657.422.48010 4.6700765E+033.0701371E+06657.41 2.49004 4.6699672E+033.0699811E+06657.392.50003 4.6700264E+033.0699239E+06657.372.51003 4.6698626E+033.0697406E+06657.352.52019 4.6692695E+033.0692727E+06657.342.53006 4.6684081E+033.0687213E+06657.34 2.54006 4.6677479E+033.0682535E+06657.332.55000 4.6670257E+033.0677505E+06657.322.56219 4.6662296E+033.0672052E+06657.322.57098 4.6657021E+033.0668176E+06657.312.58004 4.6654220E+033.0665725E+06657.30 2.59009 4.6651152E+033.0663145E+06657.292.60010 4.6647338E+033.0660129E+06657.272.61002 4.6643942E+033.0657365E+06657.262.62012 4.6640397E+033.0654539E+06657.252.63012 4.6634965E+033.0650631E+06657.25 2.64012 4.6626740E+033.0645101E+06657.242.65011 4.6616763E+033.0638577E+06657.242.66067 4.6606564E+033.0631914E+06657.242.67067 4.6596758E+033.0625495E+06657.25* Includes 10% margin not used in subcompartment analysis. To obtain mass and energy release rates used in subcompartment analyses, multiply by 0.9091.

STPEGS UFSAR 6.2-79 Revision 18 TABLE 6.2.1.2-1 (Continued)

SHORT-TERM MASS AND ENERGY RELEASE RATES FOR SUBCOMPARTMENT ANALYSES G. PRESSURIZER SPRAY LINE DOUBLE-ENDED GUILLOTINE BREAK*

Time (sec) Mass Flow (lbm/sec)

Energy Flow (Btu/sec) Avg Enthalpy (Btu/lbm) 2.68012 4.6587098E+03 3.0619181E+06 657.25 2.69012 4.6577695E+03 3.0613022E+06 657.25 2.70009 4.6568822E+03 3.0607164E+06 657.25 2.71002 4.6560654E+03 3.0601742E+06 657.24 2.72016 4.6552689E+03 3.0596433E+06 657.24 2.73004 4.6545526E+03 3.0591596E+06 657.24 2.74003 4.6538729E+03 3.0587003E+06 657.24 2.75005 4.6531147E+03 3.0581936E+06 657.24 2.76005 4.6522735E+03 3.0576409E+06 657.24 2.77009 4.6513787E+03 3.0570583E+06 657.24 2.78009 4.6534436E+03 3.0564525E+06 657.24 2.79018 4.6494781E+03 3.0558314E+06 657.24 2.80001 4.6484733E+03 3.0551890E+06 657.25 2.81002 4.6474318E+03 3.0545255E+06 657.25 2.82003 4.6465504E+03 3.0539564E+06 657.25 2.83013 4.6459992E+03 3.0535781E+06 657.25 2.84004 4.6457701E+03 3.0533902E+06 657.24 2.85012 4.6457164E+03 3.0532985E+06 657.23 2.86011 4.6458349E+03 3.0533099E+06 657.21 2.87005 4.6461439E+03 3.0534326E+06 657.20 2.88007 4.6466059E+03 3.0536437E+06 657.18 2.89004 4.6470845E+03 3.0538661E+06 657.16 2.90007 4.6474456E+03 3.0540228E+06 657.14 2.91000 4.6476617E+03 3.0540963E+06 657.13 2.92007 4.6477561E+03 3.0541000E+06 657.11 2.93003 4.6477843E+03 3.0540692E+06 657.10 2.94006 4.6476298E+03 3.0539334E+06 657.09 2.95001 4.6470806E+03 3.0535702E+06 657.09 2.96012 4.6460798E+03 3.0529465E+06 657.10 2.97015 4.6449218E+03 3.0522332E+06 657.11 2.98012 4.6440546E+03 3.0516912E+06 657.12 2.99007 4.6438913E+03 3.0514413E+06 657.12 3.00017 4.6436823E+03 3.0513992E+06 657.11

• Includes 10% margin not used in subcompartment analysis. To obtain mass and energy release rates used in subcompartment analyses, multiply by 0.9091.

STPEGS UFSAR 6.2-80 Revision 18 TABLE 6.2.1.2-1 (Continued)

SHORT-TERM MASS AND ENERGY RELEASE RATES FOR SUBCOMPARTMENT ANALYSES J. MAIN STEAM LINE BREAK Faulted Steam Generato rIntact Steam Generators Time (sec) Mass Flowrate (lbm/sec) Enthalpy (Btu/lbm)Mass Flowrate (lbm/sec) Enthalpy (Btu/lbm)0.0 0.0 1181.800.01181.800.0052 10736.33 1181.0210786.27 1181.42 0.0055 10447.29 1178.6810643.55 1180.270.006 9981.35 1174.7610408.88 1178.360.0065 9535.65 1170.8310178.47 1176.440.007 9110.68 1166.919952.60 1174.510.008 8367.48 1159.919527.17 1170.840.009 7705.64 1153.279123.27 1167.200.01 7125.61 1147.158742.84 1163.630.02 4965.88 1141.486275.50 1139.430.03 5709.45 1164.185551.19 1138.08 0.04 6033.59 1157.595306.55 1138.800.05 5706.00 1145.905159.65 1141.360.06 5351.76 1140.915259.66 1149.89 0.07 5254.75 1142.635547.22 1157.540.08 5338.03 1146.295749.57 1158.450.09 5446.62 1148.905721.76 1154.430.1 5503.53 1150.025551.53 1149.660.2 4833.05 1144.545399.93 1147.73 0.3 7223.09 704.165397.82 1153.450.4 8753.02 635.634940.64 1148.790.5 9336.88 616.374581.46 1149.97 0.6 9622.20 610.104538.98 1158.520.7 9882.68 607.854479.43 1167.100.8 10137.81 606.904437.43 1172.91 0.9 10321.51 606.384394.91 1175.281.0 10457.57 606.074380.58 1176.742.0 11196.84 605.174288.42 1178.56 3.0 11334.12 605.0164300.54 1180.974.0 11360.29 604.994355.52 1181.895.0 11365.32 604.988130.58 653.49 6.0 11366.29 604.988692.11 641.367.0 11366.48 604.989114.71 633.998.0 11366.51 604.989366.55 636.649.0 11366.52 604.989227.59 639.3310.0 11366.52 604.989424.36 626.36 15.0 11366.52 604.989990.62 614.8020.0 11366.52 604.9810176.90 610.76 STPEGS UFSAR 6.2-81 Revision 18 TABLE 6.2.1.2-1 (Continued)

SHORT-TERM MASS AND ENERGY RELEASE RATES FOR SUBCOMPARTMENT ANALYSES K. MAIN FEEDWATER LINE BREAK

Time (sec) Mass Flow (lbm/sec) Energy Flow (Btu/sec) Avg Enthalpy* (Btu/lbm) 0.0 0.0 0.0 419.6 0.0402 2.4692E+03 1.0360E+06 419.6 0.0403 2.3733E+03 1.4154E+06 419.6 0.0404 3.1175E+03 8.8850E+05 419.6 0.0405 2.9219E+03 1.2260E+06 419.6 0.0405 4.0817E+03 1.7126E+06 419.6 0.0407 5.9422E+03 2.4933E+06 419.6 0.0408 7.5768E+03 3.1792E+06 419.6 0.0409 1.0869E+03 4.5606E+06 419.6 0.0410 1.6123E+04 6.7652E+06 419.6 0.0411 2.2005E+04 9.2333E+06 419.6 0.0412 2.4941E+04 1.0465E+07 419.6 0.0413 2.3687E+04 9.9391E+06 419.6 0.0414 2.1551E+04 9.0428E+06 419.6 0.0415 1.9729E+04 8.2783E+06 419.6 0.0416 1.2524E+04 5.2551E+06 419.6 0.0417 7.3587E+03 3.0877E+06 419.6 0.0418 8.1942E+03 3.4383E+06 419.6 0.0424 8.4810E+03 3.5586E+06 419.6 0.0430 8.4491E+03 3.5452E+06 419.6 0.0436 8.4104E+03 3.5290E+06 419.6 0.0442 8.3673E+03 3.5109E+06 419.6 0.0448 8.3208E+03 3.4914E+06 419.6 0.0454 8.2714E+03 3.4706E+06 419.6 0.0460 8.2198E+03 3.4490E+06 419.6 0.0468 8.1479E+03 3.4177E+06 419.6 0.0474 8.0928E+03 3.3957E+06 419.6 0.0480 8.0223E+03 3.3661E+06 419.6 0.0486 7.9488E+03 3.3353E+06 419.6

• An enthalpy of 419.6 Btu/lbm was assumed conservatively thr oughout the transient.

STPEGS UFSAR 6.2-82 Revision 18 TABLE 6.2.1.2-1 (Continued)

SHORT-TERM MASS AND ENERGY RELEASE RATES FOR SUBCOMPARTMENT ANALYSES K. MAIN FEEDWATER LINE BREAK

Time (sec) Mass Flow (lbm/sec) Energy Flow (Btu/sec) Avg Enthalpy* (Btu/lbm) 0.0492 7.8721E+03 3.3031E+06 419.6 0.0498 7.7928E+03 3.2699E+06 419.6 0.0504 7.7119E+03 3.2359E+06 419.6 0.0510 7.6306E+03 3.2018E+06 419.6 0.0524 7.4496E+03 3.1258E+06 419.6 0.0536 7.3222E+03 3.0723E+06 419.6 0.0548 7.2332E+03 3.0350E+06 419.6 0.0560 7.1811E+03 3.0131E+06 419.6 0.0574 7.1620E+03 3.0051E+06 419.6 0.0600 7.1906E+03 3.0171E+06 419.6 0.0640 7.3024E+03 3.0640E+06 419.6 0.0700 7.4047E+03 3.1070E+06 419.6 0.0744 7.3643E+03 3.0900E+06 419.6 0.0768 7.3110E+03 3.0676E+06 419.6 0.0800 7.2264E+03 3.0321E+06 419.6 0.0900 7.0232E+03 2.9469E+06 419.6 0.1000 7.0539E+03 2.9598E+06 419.6

• An enthalpy of 419.6 Btu/lbm was assumed conservatively thr oughout the transient.

STPEGS UFSAR 6.2-83 Revision 18 TABLE 6.2.1.2-1 (Continued)

SHORT-TERM MASS AND ENERGY RELEASE RATES FOR SUBCOMPARTMENT ANALYSES L. CVCS LETDOWN LINE BREAK - RADIOACTIVE PIPE CHASE SUBCOMPARTMEN T BLOWDOWN

Time (sec) Mass Flow (lbm/sec) Energy Flow (Btu/sec) 0.0 640.0 226,560 1.6 640.0 226,560 1.6 355.0 125,670 5.7 355.0 125,670 5.7 360.0 128,520 6.0 360.0 128,520 6.0 40.0 15,160 1,800.0 40.0 15,160 1,800.0 0.0 0

STPEGS UFSAR 6.2-84 Revision 18 TABLE 6.2.1.2-1 (Continued)

SHORT-TERM MASS AND ENERGY RELEASE RATES FOR SUBCOMPARTMENT ANALYSES M. CVCS LETDOWN LINE BREAK - RHR 1A VALVE ROOM SUBCOMPARTMENT BLOWDOWN

Time (sec) Mass Flow (lbm/sec) Energy Flow (Btu/sec) 0.00 640.0 226,560 0.09 640.0 226,560 0.09 320.0 113,280 6.19 320.0 113,280 6.19 320.0 113,280 9.63 320.0 113,280 9.63 40.0 15,160 1,800.00 40.0 15,160 1,800.00 0.0 0

STPEGS UFSAR 6.2-85 Revision 18 TABLE 6.2.1.2-1 (Continued)

SHORT-TERM MASS AND ENERGY RELEASE RATES FOR SUBCOMPARTMENT ANALYSES N. CVCS LETDOWN LINE BREAK - REGENERATIVE HEAT EXCHANGER SUBCOMPARTMENT BLOWDOWN

Time (sec) Mass Flow (lbm/sec) Energy Flow (Btu/sec) 0.00 1,403.0 753,411 1.4 1,403.0 753,411 1.4 1,196.0 627,900 1.9 1,196.0 627,900 1.9 934.0 536,116 353.9 934.0 536,116 1,800.0 927.0 533,952 1,800.0 0.0 0

STPEGS UFSAR 6.2-86 Revision 18 TABLE 6.2.1.2-1 (Continued)

SHORT-TERM MASS AND ENERGY RELEASE RATES FOR SUBCOMPARTMENT ANALYSIS P. RHR 12" LINE DOUBLE-ENDED GUILLOTINE Time (sec) Mass Flow (lbm/sec) Energy Rate (Btu/sec) 0.001 93.65 64718.46 0.0011 102.92 71121.96 0.0012 1227.75 780183.14 0.0013 2338.17 1471794.91 0.0014 3473.13 2182947.96 0.0015 4532.00 2845694.11 0.0016 5764.27 3617747.57 0.0017 7298.33 4577205.78 0.0018 7333.63 4600828.22 0.0019 8155.57 5114340.87 0.002 8821.40 5530769.13 0.0021 9128.33 5723269.43 0.0022 8569.44 5375805.70 0.0023 8175.83 5131100.72 0.0024 7811.59 4903924.73 0.0025 7492.96 4705203.63 0.0026 7209.86 4528500.88 0.0027 6961.40 4373418.91 0.0028 6745.14 4238371.30 0.0029 6559.21 4122260.36 0.003 6401.94 4024042.33 0.0031 6270.70 3942401.72 0.0032 6326.44 3978069.28 0.0033 6331.55 3981637.57 0.0034 6338.29 3986340.24 0.0035 6344.63 3990732.12 0.0036 6350.99 3995196.70 0.0037 6357.34 3999661.13 0.0038 6363.69 4004119.15 0.0039 6370.05 4008583.29 0.004 6376.41 4013047.27 0.0041 6382.94 4017631.76 0.0042 6389.47 4022209.79 0.0043 6396.00 4026793.87 0.0044 6402.54 4031377.74 0.0045 6409.06 4035955.15 0.0046 6415.61 4040484.67 0.0047 6422.14 4045067.94 0.0048 6428.68 4049651.00 0.0049 6435.22 4054240.11 0.005 6441.77 4058829.02 0.0051 6447.78 4063047.26 0.0052 6453.79 4067265.27 0.0053 6459.80 4071483.04 0.0054 6465.82 4075706.85 0.0055 6471.83 4079924.17 0.0056 6477.96 4084156.26 0.0057 6484.13 4088473.25

STPEGS UFSAR 6.2-87 Revision 18 TABLE 6.2.1.2-1 (Continued)

SHORT-TERM MASS AND ENERGY RELEASE RATES FOR SUBCOMPARTMENT ANALYSIS P. RHR 12" LINE DOUBLE-ENDED GUILLOTINE Time (sec) Mass Flow (lbm/sec) Energy Rate (Btu/sec) 0.0058 6490.31 4092796.27 0.0059 6496.48 4097112.80 0.006 6502.65 4101429.10 0.0061 6541.64 4128357.60 0.0062 6580.64 4155352.44 0.0063 6619.63 4182341.06 0.0064 6658.63 4209329.72 0.0065 6697.62 4236258.42 0.0066 6736.61 4263247.16 0.0067 6775.60 4290235.93 0.0068 6814.58 4317218.49 0.0069 6853.57 4344207.34 0.007 6892.57 4371136.29 0.0071 6945.45 4407723.22 0.0072 6998.33 4444304.29 0.0073 7051.22 4480892.01 0.0074 7104.09 4517473.86 0.0075 7156.98 4554002.45 0.0076 7209.86 4590585.09 0.0077 7262.73 4627168.11 0.0078 7315.61 4663751.53 0.0079 7368.49 4700275.48 0.008 7421.37 4736865.94 0.0081 7463.95 4766337.79 0.0082 7506.53 4795809.86 0.0083 7549.11 4825222.31 0.0084 7591.68 4854688.54 0.0085 7634.26 4884161.24 0.0086 7676.84 4913634.14 0.0087 7719.42 4943107.25 0.0088 7761.99 4972514.54 0.0089 7804.57 5001988.07 0.009 7847.14 5031455.55 0.0091 7885.66 5058124.81 0.0092 7924.17 5084728.21 0.0093 7962.68 5111391.48 0.0094 8001.20 5138061.13 0.0095 8039.71 5164724.65 0.0096 8078.22 5191388.29 0.0097 8116.73 5217992.39 0.0098 8155.24 5244656.30 0.0099 8193.75 5271320.33 0.01 8232.26 5297984.49 0.02 10704.04 7009551.08 0.03 11474.60 7544051.12 0.04 11500.68 7562085.53 0.05 11211.35 7360496.28 0.06 10783.47 7062610.96 0.07 10312.71 6735642.66 STPEGS UFSAR 6.2-88 Revision 18 TABLE 6.2.1.2-1 (Continued)

SHORT-TERM MASS AND ENERGY RELEASE RATES FOR SUBCOMPARTMENT ANALYSIS P. RHR 12" LINE DOUBLE-ENDED GUILLOTINE Time (sec) Mass Flow (lbm/sec) Energy Rate (Btu/sec) 0.08 9860.42 6423144.00 0.09 9467.41 6153935.27 0.1 9160.81 5946156.29 0.105 9038.11 5863737.06 0.11 8933.51 5793923.61 0.115 8840.14 5731899.79 0.12 8764.87 5682203.49 0.125 8693.99 5635526.34 0.13 8620.67 5587176.85 0.135 8551.82 5541725.64 0.14 8473.74 5489969.72 0.145 8400.24 5441151.11 0.15 8310.72 5381492.35 0.155 8211.77 5315554.30 0.16 8110.41 5248024.69 0.165 8000.32 5174754.63 0.17 7881.69 5095752.88 0.175 7754.72 5011307.66 0.18 7626.52 4926164.29 0.185 7490.50 4836006.19 0.19 7353.82 4745532.97 0.195 7216.83 4654970.50 0.2 7079.87 4564833.18 0.201 7051.82 4546381.27 0.202 7023.80 4527928.14 0.203 6995.81 4509505.51 0.204 6967.83 4491107.29 0.205 6939.89 4472739.54 0.206 6911.97 4454402.24 0.207 6884.10 4436077.48 0.208 6856.26 4417789.69 0.209 6828.47 4399538.84 0.21 6800.72 4381307.73 0.211 6775.08 4364510.69 0.212 6749.50 4347785.25 0.213 6723.97 4331063.15 0.214 6698.50 4314406.49 0.215 6673.09 4297776.55 0.216 6647.74 4281223.59 0.217 6622.47 4264682.24 0.218 6597.27 4248223.81 0.219 6572.14 4231814.38 0.22 6547.10 4215451.20 0.221 6522.82 4199626.96 0.222 6498.62 4183863.91 0.223 6474.53 4168153.92 0.224 6450.51 4152505.44 0.225 6426.59 4136930.45 0.226 6402.78 4121428.87 STPEGS UFSAR 6.2-89 Revision 18 TABLE 6.2.1.2-1 (Continued)

SHORT-TERM MASS AND ENERGY RELEASE RATES FOR SUBCOMPARTMENT ANALYSIS P. RHR 12" LINE DOUBLE-ENDED GUILLOTINE Time (sec) Mass Flow (lbm/sec) Energy Rate (Btu/sec) 0.227 6379.06 4106000.62 0.228 6355.44 4090626.64 0.229 6331.94 4075332.29 0.23 6308.54 4060117.47 0.231 6287.32193 4046372.826 0.232 6266.215695 4032688.95 0.233 6245.229461 4019090.253 0.234 6224.373226 4005582.624 0.235 6203.636991 3992159.952 0.236 6183.020756 3978804.958 0.237 6162.544521 3965547.12 0.238 6142.198287 3952380.33 0.239 6120.342052 3938356.12 0.24 6096.775817 3923338.56 0.241 6074.883348 3909420.11 0.242 6053.300878 3895700.02 0.243 6032.008409 3882166.10 0.244 6011.005939 3868818.10 0.245 5990.303469 3855646.69 0.246 5969.891 3842675.98 0.247 5949.75853 3829869.91 0.248 5929.926061 3817255.18 0.249 5910.373591 3804819.64 0.25 5891.101122 3792563.03 0.251 5872.805535 3780958.48 0.252 5854.779948 3769526.29 0.253 5837.034361 3758258.88 0.254 5819.568774 3747182.77 0.255 5802.373187 3736265.43 0.256 5785.4476 3725519.90 0.257 5768.792013 3714958.38 0.258 5752.396426 3704549.60 0.259 5736.270839 3694299.84 0.26 5720.405252 3684227.26 0.261 5704.789665 3674310.89 0.262 5689.444079 3664553.40 0.263 5674.348492 3654965.89 0.264 5659.502905 3645525.32 0.265 5644.917318 3636259.80 0.266 5630.571731 3627135.23 0.267 5616.476144 3618168.39 0.268 5602.620557 3609353.17 0.269 5589.00497 3600689.33 0.27 5575.629383 3592176.66 0.271 5563.867561 3584730.97 0.272 5552.33574 3577420.06 0.273 5541.043918 3570269.26 0.274 5529.972096 3563256.68 0.275 5519.130275 3556378.72 STPEGS UFSAR 6.2-90 Revision 18 TABLE 6.2.1.2-1 (Continued)

SHORT-TERM MASS AND ENERGY RELEASE RATES FOR SUBCOMPARTMENT ANALYSIS P. RHR 12" LINE DOUBLE-ENDED GUILLOTINE Time (sec) Mass Flow (lbm/sec) Energy Rate (Btu/sec) 0.276 5508.518453 3549653.87 0.277 5498.116631 3543051.77 0.278 5487.944809 3536602.04 0.279 5477.992988 3530280.82 0.28 5468.251166 3524091.00 0.281 5458.032462 3517596.92 0.282 5448.033757 3511231.34 0.283 5438.235053 3504990.87 0.284 5428.646349 3498881.17 0.285 5419.257645 3492896.20 0.286 5410.07894 3487049.30 0.287 5401.090236 3481313.06 0.288 5392.301532 3475700.98 0.289 5383.712827 3470212.85 0.29 5375.314123 3464842.66 0.291 5367.782301 3460046.66 0.292 5360.45048 3455373.93 0.293 5353.298658 3450812.65 0.294 5346.326836 3446362.63 0.295 5339.545014 3442029.51 0.296 5332.933193 3437801.50 0.297 5326.501371 3433684.24 0.298 5320.249549 3429677.56 0.299 5314.157728 3425775.81 0.3 5304.305906 3419753.97 0.301 5295.400319 3414184.34 0.302 5289.914732 3410549.34 0.303 5287.079145 3408402.21 0.304 5280.993558 3404430.69 0.305 5274.507971 3400244.69 0.306 5268.192384 3396167.95 0.307 5262.026797 3392177.81 0.308 5256.01121 3388284.87 0.309 5250.155624 3384484.21 0.31 5244.440037 3380774.51 0.311 5238.87445 3377174.77 0.312 5233.448863 3373660.52 0.313 5228.163276 3370231.64 0.314 5223.027689 3366893.73 0.315 5218.022102 3363635.18 0.316 5213.166515 3360467.34 0.317 5208.430928 3357377.29 0.318 5203.835341 3354367.44 0.319 5199.369754 3351440.72 0.32 5195.034167 3348588.37 0.321 5190.131698 3345381.86 0.322 5185.359228 3342253.85 0.323 5180.706759 3339198.51 0.324 5176.184289 3336221.44 STPEGS UFSAR 6.2-91 Revision 18 TABLE 6.2.1.2-1 (Continued)

SHORT-TERM MASS AND ENERGY RELEASE RATES FOR SUBCOMPARTMENT ANALYSIS P. RHR 12" LINE DOUBLE-ENDED GUILLOTINE Time (sec) Mass Flow (lbm/sec) Energy Rate (Btu/sec) 0.325 5171.77182 3333311.10 0.326 5167.47935 3330476.87 0.327 5163.30688 3327711.03 0.328 5159.244411 3325015.24 0.329 5155.291941 3322385.64 0.33 5151.459472 3319827.82 0.331 5147.727002 3317351.18 0.332 5144.104533 3314943.83 0.333 5140.592063 3312598.87 0.334 5137.179594 3310317.20 0.335 5133.867124 3308095.35 0.336 5130.664655 3305938.93 0.337 5127.552185 3303836.47 0.338 5124.539716 3301793.59 0.339 5121.627246 3299813.16 0.34 5118.804776 3297886.35 0.341 5115.385424 3295589.72 0.342 5112.056072 3293352.41 0.343 5108.82672 3291171.49 0.344 5105.677368 3289041.05 0.345 5102.618016 3286961.29 0.346 5099.648663 3284937.44 0.347 5096.749311 3282957.98 0.348 5093.949959 3281034.70 0.349 5091.220607 3279155.58 0.35 5088.571255 3277323.68 0.351 5086.001903 3275562.38 0.352 5083.512551 3273848.21 0.353 5081.093198 3272177.71 0.354 5078.753846 3270551.92 0.355 5076.484494 3268971.78 0.356 5074.295142 3267436.25 0.357 5072.16579 3265936.19 0.358 5070.106438 3264479.26 0.359 5068.117085 3263063.26 0.36 5066.197733 3261690.13 0.361 5065.025264 3260820.15 0.362 5063.922794 3259992.78 0.363 5062.880325 3259200.37 0.364 5061.897855 3258442.89 0.365 5060.985386 3257727.69 0.366 5060.122916 3257041.65 0.367 5059.320446 3256390.35 0.368 5058.577977 3255775.41 0.369 5057.895507 3255193.44 0.37 5057.263038 3254642.09 0.371 5055.316803 3253266.41 0.372 5053.420568 3251918.26 0.373 5051.574334 3250600.72

STPEGS UFSAR 6.2-92 Revision 18 TABLE 6.2.1.2-1 (Continued)

SHORT-TERM MASS AND ENERGY RELEASE RATES FOR SUBCOMPARTMENT ANALYSIS P. RHR 12" LINE DOUBLE-ENDED GUILLOTINE Time (sec) Mass Flow (lbm/sec) Energy Rate (Btu/sec) 0.374 5049.778099 3249312.17 0.375 5048.031864 3248052.61 0.376 5046.345629 3246828.99 0.377 5044.699394 3245628.64 0.378 5043.09316 3244451.53 0.379 5041.546925 3243310.13 0.38 5040.04069 3242191.87 0.381 5039.948221 3242006.54 0.382 5039.905751 3241849.69 0.383 5039.903281 3241716.94 0.384 5039.940812 3241607.00 0.385 5040.018342 3241519.85 0.386 5040.135873 3241455.48 0.387 5040.293403 3241414.96 0.388 5040.490934 3241397.12 0.389 5040.728464 3241402.99 0.39 5040.995995 3241424.87 0.391 5040.616643 3241049.42 0.392 5040.26729 3240692.06 0.393 5039.957938 3240356.38 0.394 5039.678586 3240038.70 0.395 5039.439234 3239743.62 0.396 5039.219882 3239460.87 0.397 5039.04053 3239199.78 0.398 5038.881177 3238950.96 0.399 5038.761825 3238724.64 0.4 5038.662473 3238510.48 0.401 5038.593121 3238340.37 0.402 5038.553769 3238187.16 0.403 5038.544417 3238050.82 0.404 5038.555064 3237926.50 0.405 5038.595712 3237819.00 0.406 5038.65636 3237722.76 0.407 5038.737008 3237637.76 0.408 5038.847656 3237570.19 0.409 5038.978304 3237513.83 0.41 5039.128952 3237468.65 0.411 5039.986482 3237895.49 0.412 5040.874012 3238338.96 0.413 5041.771543 3238787.95 0.414 5042.689073 3239248.02 0.415 5043.626604 3239719.65 0.416 5044.584134 3240202.31 0.417 5045.551665 3240690.44 0.418 5046.539195 3241189.59 0.419 5047.546726 3241700.19 0.42 5048.564256 3242215.80 0.421 5049.601787 3242761.66 0.422 5050.649317 3243313.34

STPEGS UFSAR 6.2-93 Revision 18 TABLE 6.2.1.2-1 (Continued)

SHORT-TERM MASS AND ENERGY RELEASE RATES FOR SUBCOMPARTMENT ANALYSIS P. RHR 12" LINE DOUBLE-ENDED GUILLOTINE Time (sec) Mass Flow (lbm/sec) Energy Rate (Btu/sec) 0.423 5051.716847 3243875.61 0.424 5052.794378 3244443.68 0.425 5053.881908 3245017.15 0.426 5054.979439 3245596.34 0.427 5056.086969 3246180.61 0.428 5057.2145 3246776.10 0.429 5058.34203 3247371.43 0.43 5059.489561 3247977.66 0.431 5060.637091 3248602.89 0.432 5061.794622 3249233.48 0.433 5062.962152 3249869.43 0.434 5064.139682 3250510.73 0.435 5065.327213 3251157.38 0.436 5066.514743 3251804.01 0.437 5067.702274 3252450.42 0.438 5068.909804 3253107.68 0.439 5070.117335 3253764.73 0.44 5071.324865 3254421.66 0.441 5073.229278 3255541.97 0.442 5075.143691 3256667.52 0.443 5077.058104 3257792.77 0.444 5078.982517 3258923.30 0.445 5080.936931 3260070.10 0.446 5083.021344 3261288.55 0.4461 5083.284785 3261440.81

STPEGS UFSAR 6.2-94 Revision 18 TABLE 6.2.1.2-1 (Continued)

SHORT-TERM MASS AND ENERGY RELEASE RATES FOR SUBCOMPARTMENT ANALYSIS Q. 16" FW LINE DOUBLE-ENDED GUILLOTINE BREAK AT SG NOZZLE CONNECTION, HFP, FW @ 448 o F Time (seconds) Mass Flow Rate (lbm/sec) Energy Release Rate (Btu/sec) 0.00001 0.0 0.0000E+00 0.00125 8995.2 3.8482E+06 0.00150 11904.2 5.0847E+06 0.00175 15868.9 6.7712E+06 0.00200 18842.2 8.0343E+06 0.00225 18754.5 7.9970E+06 0.00250 18748.4 7.9954E+06 0.00275 18742.4 7.9939E+06 0.0030 15736.6 7.9924E+06 0.0055 18685.7 7.9780E+06 0.0080 18643.9 7.9643E+06 0.0105 18606.6 7.9509E+06 0.0130 18570.8 7.9369E+06 0.0155 18534.1 7.9224E+06 0.0160 18497.5 7.9068E+06 0.0205 18458.5 7.8904E+06 0.0230 18417.4 7.8730E+06 0.0255 18374.0 7.8545E+06 0.0280 18327.8 7.8348E+06 0.0305 18278.7 7.8138E+06 0.0330 18226.4 7.7915E+06 0.0355 18170.6 7.7677E+06 0.0390 18111.2 7.7423E+06 0.0405 18047.9 7.7152E+06 0.0430 17980.4 7.6863E+06 0.0455 17908.5 7.6556E+06 0.0480 17831.9 7.6228E+06 0.0505 17750.5 7.5588E+06 0.0530 17664.1 7.5511E+06 0.0555 17572.6 7.5119E+06 0.0580 17476.1 7.4706E+06 0.0605 17374.5 7.4272E+06 0.0630 17268.2 7.3817E+06 0.0655 17157.6 7.3344E+06 0.0680 17043.3 7.2855E+05 0.0705 16926.1 7.2354E+06 O.0730 16807.0 7.1845E+06 0.0755 16687.0 7.1333E+06 0.0780 16567.5 7.0822E+06 0.0805 16449.9 7.0321E+06 0.0830 16335.5 6.9833E+06 0.0855 16225.7 6.9165E+06 0.0880 16121.6 6.8922E+06 0.0905 16024.3 6.8509E+06 0.0930 15934.3 6.8127E+06 0.0955 15852.0 6.7778E+06 0.0980 15777.7 6.7454E+06 0.1000 15723.8 6.7236E+06

STPEGS UFSAR 6.2-95 Revision 18 TABLE 6.2.1.2-5A STEAM GENERATOR LOOP COMPARTMENT PEAK PRESSURE

SUMMARY

FOR RHR LINE BREAK ANALYSIS

Elevation

Node No.

Volume (ft3) Maximum Differential Pressure (psid)

Break Node

Break Type

Design Pressure (psid) Margin (percent) [b] 1 715.4 4.4 # 12 12" RHR 7.125 63 2 1369.0 5.7 # 12 12" RHR 7.125 25 3 1918.4 4.4 # 12 12" RHR 7.125 64 19' 0" 4 1920.6 6.2 # 4 12" RHR 7.125 15 5 1920.6 4.6 # 4 12" RHR 7.125 55 to 6 4002.8 2.2 # 4 12" RHR 7.125 230 7 6020.7 1.7 # 4 12" RHR 7.125 325 28' 01/2" 8 4594.7 0.9 # 12 12" RHR 7.125 719 9 4409.2 0.7 # 4 12" RHR 7.125 915 10 4594.7 0.9 # 12 12" RHR 7.125 712 11 3021.8 3.2 # 12 12" RHR 7.125 123 12 1419.5 6.8 # 12 12" RHR 13.0 92 13 757.6 3.5 # 4 12" RHR 13.0 279 28' 01/2" 14 2159.1 3.6 # 4 12" RHR 13.0 267 15 2166.4 5.7 # 15 12" RHR 13.0 128 to 16 2186.6 2.8 # 4 12" RHR 13.0 365 17 4372.1 2.1 # 4 12" RHR 13.0 521 38' 4" 18 4372.1 0.9 # 12 12" RHR 13.0 1450 19 4373.1 0.7 # 12 12" RHR 13.0 1869 20 4372.1 0.9 # 12 12" RHR 13.0 1429 21 2052.4 2.4 # 12 12" RHR 3.625 55 22 3669.0 3.1 # 12 12" RHR 3.625 18 38' 4" 23 6103.0 2.6 # 15 12" FW 3.625 39 24 5312.3 2.3 # 15 12" RHR 3.625 62 to 25 5312.3 2.1 # 15 12" RHR 3.625 80 26 11792.4 2.0 # 12 12" RHR 3.625 89 66' 71/2" 27 11792.4 0.9 # 12 12" RHR 3.625 340 28 10646.0 0.8 # 4 12" RHR 3.625 387 29 11792.4 0.7 # 4 12" RHR 3.625 490 CN-3136 STPEGS UFSAR 6.2-96 Revision 18 TABLE 6.2.1.2-5A (Continued)

STEAM GENERATOR LOOP COMPARTMENT PEAK PRESSURE

SUMMARY

FOR RHR LINE BREAK ANALYSIS Elevation Node No. Volume (ft3) Maximum Differential Pressure (psid) Break Node Break Type Design Pressure(psid) Margin (percent) [b] 30 6766.6 1.1 # 4 12" RHR 1.75 63 66' 71/2" 31 2517.0 1.0 # 15 12" RHR 1.75 84 32 2517.0 1.1 # 15 12" RHR 1.75 59 to 33 6766.6 1.1 # 12 12" RHR 1.75 67 34 6766.6 0.4 # 12 12" RHR 1.75 340 83' 0" 35 5033.9 0.4 # 4 12" RHR 1.75 360 36 6766.6 0.35 # 4 12" RHR 1.75 460 37 24099.1 0.5 # 4 12" RHR 6.25 1260 (-) 11' 3" 38 24099.1 0.45 # 4 12" RHR 6.25 1330 to 39 24099.1 0.6 # 4 12" RHR 6.25 1010 19' 0" 40 24099.1 0.7 # 12 12" RHR 6.25 807 Containment 41 3.109E+6 N/A N/A N/A [a] [a] Inspection Torus 42 2157.1 1.9 # 12 12" RHR [a] [a] NOTES: a. Design of Nodes 41 and 42 are not based on steam generator loop compartment P/T analysis. b. Margin is defined as: 100 * {design pressure - calculated pressure}/{calculated pressure}

STPEGS UFSAR 6.2-97 Revision 18 TABLE 6.2.1.2-5B STEAM GENERATOR LOOP COMPARTMENT PEAK PRESSURE

SUMMARY

FOR FWLB ANALYSIS Node No. Volume Calculated Peak Differential Pressure Break Case No.

Design Peak Differential Pressure Pressure Margin (f) (a) (b)(c) (b)(e) (ft 3) (psid) (psid) (Percent) 1 405.6 7.2 1 7.2 0.0 2 3005.0 3.9 1 4.0 2.3 3 645.8 5.7 1 5.7 0.0 4 2989.3 1.1 1 1.1 6.8 5 8172.7 N/A (d) N/A (d) N/A (d) N/A (d) 6 728.7 7.6 1 N/A (d) N/A (d) 7 1391.3 1.7 1 N/A (d) N/A (d) 8 289.5 3.1 1 N/A (d) N/A (d) 9 1433.4 0.75 1 0.8 6.9 10 3842.7 N/A (d) N/A (d) N/A (d) N/A (d) 11 766.1 2.9 1 3.0 7.1 12 1421.9 3.2 1 3.3 5.0 13 334.7 3.6 1 4.1 15.3 14 1412.8 0.75 1 0.9 20.3 15 3935.4 N/A (d) N/A (d) N/A (d) N/A (d) 16 3.0 10 6 N/A (d) N/A (d) N/A (d) N/A (d) 17 1127.0 5.8 1 5.8 0.0 18 8405.6 1.6 1 1.8 19.3 19 7588.5 0.65 1 1.8 184.1 20 8405.6 N/A (d) N/A (d) N/A (d) N/A (d) 21 4372.1 1.1 1 1.3 30.7 22 4373.1 0.85 1 1.3 59.0 23 4372.1 N/A (d) N/A (d) N/A (d) N/A (d) 24 4594.7 1.3 1 1.6 28.2 25 4409.2 1.2 1 1.6 33.6 26 4594.7 N/A (d) N/A (d) N/A (d) N/A (d) 27 3021.8 N/A (d) N/A (d) N/A (d) N/A (d) 28 6020.7 N/A (d) N/A (d) N/A (d) N/A (d) 29 11846.8 N/A (d) N/A (d) N/A (d) N/A (d) 30 13061.3 N/A (d) N/A (d) N/A (d) N/A (d) 31 34241.4 N/A (d) N/A (d) N/A (d) N/A (d) 32 18567.2 N/A (d) N/A (d) N/A (d) N/A (d)

STPEGS UFSAR 6.2-98 Revision 18 TABLE 6.2.1.2-5B (Continued) STEAM GENERATOR LOOP COMPARTMENT PEAK PRESSURE

SUMMARY

FOR FWLB ANALYSIS Notes: a. Initial conditions for all nodes are identical: Temperature = 110°F, Pressure = 14.6 psia, Relative humidity

= 20%.

a. These are peak differential pressures between the node and the containment (Node 16) except where specified. The peak pressures occur at different times in the transient.

b. Break Case: 1 = Feedwater @ 448°F, HFP, FWLB M&E release in Nodes 1 (25%), 6 (50%) & 17 (25%).

c. The SG "D" cut wall section is in Nodes 1 and 17 only. Node 16 corresponds to the free containment volume. Nodes 6, 7, 8, and 9 are above the bio-shield wall. Nodes 5, 10, 15, 20, 23, and 26 are in SG "A" compartment and are not used for design purposes. Nodes 27 to 32 are in the other two SG compartments and are also not used for design purposes.

a. Design pressures for all SG loop compartments are based on breaks within the affected compartment, which include RHR, SI and spray line breaks. The containment design pressure is not based on steam generator loop compartment P/T analysis pressures.

d. Margin is defined as: 100 * {design peak pressure - calculated pressure}/{calculated pressure}. This is the margin applied to the calculated differential pressures for use in structural design of the subcompartment walls and equipment supports.

a. A pressure margin of 0.0% means that the pressure value used in structural analysis is the same value as the subcompartment pressurization analysis. In addition to the pressure values given in this table, the wall design uses other loads such as live, dead, seismic, thermal, jet and pipe whip loads which are not shown here.

e. The nodalization diagrams are shown in Figure 6.2.1.2-11A.

STPEGS UFSAR 6.2-99 Revision 18 TABLE 6.2.1.2-6 STEAM GENERATOR LOOP COMPARTMENT PRESSURE - JUNCTION PROPERTIES FOR RHR/SI ANALYSIS (42-Node Model)

Forward Forward Forward Reverse Reverse Reverse Head Head Head Head Head Head Junction From To Area Length/Area Loss Loss Loss Loss Loss Loss Number Volume Volume (ft2) (ft-1) Contraction Expansion Total Contraction Expansion Total Remarks 1 1 2 33.24 0.4869 0.381 1.00 1.381 0.391 1.00 1.391 2 2 4 85.326 0.1777 0.268 1.00 1.268 0.339 1.00 1.339 3 4 5 160.847 0.0609 0.164 1.00 1.164 0.164 1.00 1.164 4 5 6 185.766 0.0843 0.149 1.00 1.149 0.178 1.00 1.178 5 6 7 206.15 0.1258 0.131 1.00 1.131 0.127 1.00 1.127 6 7 8 206.15 0.1258 0.127 1.00 1.127 0.131 1.00 1.131 7 1 3 56.69 0.2490 0.170 1.00 1.170 0.304 1.00 1.304 8 12 42 16.839 1.1773 0.463 1.00 1.463 0.500 1.00 1.500 9 3 2 43.943 0.1997 0.411 1.00 1.411 0.380 1.00 1.380 10 38 39 429.188 0.1147 0.203 1.00 1.203 0.203 1.00 1.203 11 42 39 0.0 4.9126 0.500 1.00 1.500 0.500 1.00 1.500 12 3 4 94.86 0.1760 0.172 1.00 1.172 0.310 1.00 1.310 13 42 15 6.358 1.3168 0.500 1.00 1.500 0.475 1.00 1.475 14 42 16 6.358 1.3168 0.500 1.00 1.500 0.475 1.00 1.475 15 42 17 16.839 1.2007 0.500 1.00 1.500 0.463 1.00 1.463 16 37 38 441.45 0.1116 0.195 1.00 1.195 0.195 1.00 1.195 17 42 18 16.839 1.2007 0.500 1.00 1.500 0.463 1.00 1.463 18 40 8 19.5 0.1713 0.494 1.00 1.494 0.485 1.00 1.485 19 42 19 12.717 0.6675 0.500 1.00 1.500 0.475 1.00 1.475 20 40 39 336.394 0.1116 0.267 1.00 1.267 0.267 1.00 1.267 21 3 38 19.5 0.1770 0.469 1.00 1.469 0.494 1.00 1.494 22 3 14 155.52 0.0467 0.254 1.00 1.254 0.254 1.00 1.254 Partial grating 23 1 13 80.648 0.1079 0.150 1.00 1.150 0.150 1.00 1.150 24 2 12 130.601 0.0588 0.216 1.00 1.216 0.216 1.00 1.216 Partial grating 25 4 38 9.75 0.3353 0.484 1.00 1.484 0.497 1.00 1.497 26 4 15 75.55 0.0801 0.375 1.00 1.375 0.375 1.00 1.375 Partial grating 27 32 33 147.267 0.0757 0.546 1.00 1.546 0.559 1.00 1.559 28 5 16 75.55 0.0801 0.375 1.00 1.375 0.375 1.00 1.375 29 6 17 401.148 0.0197 0.193 1.00 1.193 0.193 1.00 1.193 Junctions 29 and 85 connect the same nodes, 6 and 17 30 21 30 58.933 0.2514 0.244 1.00 1.244 0.448 1.00 1.448 STPEGS UFSAR 6.2-100 Revision 18 TABLE 6.2.1.2-6 (Continued)

STEAM GENERATOR LOOP COMPARTMENT PRESSURE - JUNCTION PROPERTIES FOR RHR/SI ANALYSIS (42-Node Model)

Forward Forward Forward Reverse Reverse Reverse Head Head Head Head Head Head Junction From To Area Length/Area Loss Loss Loss Loss Loss Loss Number Volume Volume (ft2) (ft-1) Contraction Expansion Total Contraction Expansion Total Remarks 31 8 9 185.766 0.1143 0.178 1.00 1.178 0.149 1.00 1.149 32 8 18 401.148 0.0197 0.193 1.00 1.193 0.193 1.00 1.193 33 6 39 19.5 0.1713 0.485 1.00 1.485 0.494 1.00 1.494 34 28 27 321.987 0.0572 0.506 1.00 1.506 0.522 1.00 1.522 35 5 39 9.75 0.3353 0.484 1.00 1.484 0.497 1.00 1.497 36 12 22 98.67 0.1570 0.435 1.00 1.435 0.435 1.00 1.435 Grating in the path 37 12 15 90.238 0.1631 0.484 1.00 1.484 0.550 1.00 1.550 38 13 14 49.421 0.2615 0.447 1.00 1.447 0.550 1.00 1.550 39 14 15 81.902 0.1833 0.451 1.00 1.451 0.556 1.00 1.556 40 13 21 53.016 0.2869 0.420 1.00 1.420 0.420 1.00 1.420 Grating in the path 41 14 23 95.161 0.1628 0.521 1.00 1.521 0.521 1.00 1.521 Grating in the path 42 9 19 151.101 0.0401 0.375 1.00 1.375 0.375 1.00 1.375 Partial grating 43 10 37 19.5 0.1713 0.485 1.00 1.485 0.494 1.00 1.494 44 10 20 401.148 0.0197 0.193 1.00 1.193 0.193 1.00 1.193 45 35 36 147.267 0.1025 0.546 1.00 1.546 0.559 1.00 1.559 46 34 35 147.267 0.1025 0.559 1.00 1.559 0.546 1.00 1.546 47 28 35 144.86 0.1052 0.351 1.00 1.351 0.312 1.00 1.312 48 15 16 74.993 0.0996 0.363 1.00 1.363 0.363 1.00 1.363 49 16 17 172.14 0.0838 0.553 1.00 1.553 0.468 1.00 1.468 50 18 19 172.14 0.1336 0.468 1.00 1.468 0.553 1.00 1.553 51 19 20 172.14 0.1336 0.553 1.00 1.553 0.468 1.00 1.468 52 20 29 233.285 0.0606 0.459 1.00 1.459 0.459 1.00 1.459 Partial grating 53 15 24 169.422 0.0933 0.203 1.00 1.203 0.130 1.00 1.130 54 16 25 179.922 0.0933 0.203 1.00 1.203 0.130 1.00 1.130 55 17 26 233.285 0.0606 0.459 1.00 1.459 0.459 1.00 1.459 Partial grating 56 18 27 233.285 0.0606 0.459 1.00 1.459 0.459 1.00 1.459 57 19 28 359.843 0.0467 0.203 1.00 1.203 0.130 1.00 1.130 58 21 22 124.539 0.1020 0.474 1.00 1.474 0.487 1.00 1.487 59 22 23 186.281 0.0507 0.338 1.00 1.338 0.380 1.00 1.380 60 23 24 179.738 0.0992 0.504 1.00 1.504 0.587 1.00 1.587 STPEGS UFSAR 6.2-101 Revision 18 TABLE 6.2.1.2-6 (Continued)

STEAM GENERATOR LOOP COMPARTMENT PRESSURE - JUNCTION PROPERTIES FOR RHR/SI ANALYSIS (42-Node Model)

Forward Forward Forward Reverse Reverse Reverse Head Head Head Head Head Head Junction From To Area Length/Area Loss Loss Loss Loss Loss Loss Number Volume Volume (ft2) (ft-1) Contraction Expansion Total Contraction Expansion Total Remarks 61 24 25 609.938 0.0174 0.093 1.00 1.093 0.093 1.00 1.093 62 25 26 321.987 0.0431 0.306 1.00 1.306 0.322 1.00 1.322 63 26 33 254.73 0.0664 0.260 1.00 1.260 0.208 1.00 1.208 64 21 23 197.352 0.0754 0.249 1.00 1.249 0.399 1.00 1.399 65 23 30 140.196 0.1266 0.205 1.00 1.205 0.356 1.00 1.356 66 24 31 72.43 0.2104 0.316 1.00 1.316 0.257 1.00 1.257 67 25 32 72.43 0.2104 0.316 1.00 1.316 0.257 1.00 1.257 68 32 31 268.512 0.0373 0.144 1.00 1.144 0.144 1.00 1.144 69 31 30 147.308 0.0757 0.547 1.00 1.547 0.559 1.00 1.559 70 29 28 321.987 0.0572 0.522 1.00 1.522 0.506 1.00 1.506 71 27 34 254.73 0.0664 0.260 1.00 1.260 0.208 1.00 1.208 72 22 30 55.601 0.2713 0.344 1.00 1.344 0.344 1.00 1.344 Partial grating 73 10 11 139.224 0.1733 0.240 1.00 1.240 0.204 1.00 1.204 74 10 9 185.766 0.1143 0.178 1.00 1.178 0.149 1.00 1.149 75 12 13 24.787 0.4285 0.629 1.00 1.629 0.622 1.00 1.622 76 30 41 346.717 0.0391 0.206 1.00 1.206 0.500 1.00 1.500 77 31 41 108.456 0.1308 0.134 1.00 1.134 0.500 1.00 1.500 78 32 41 108.456 0.1308 0.134 1.00 1.134 0.500 1.00 1.500 79 41 33 346.717 0.0424 0.500 1.00 1.500 0.206 1.00 1.206 80 41 34 346.717 0.0424 0.500 1.00 1.500 0.206 1.00 1.206 81 41 35 216.911 0.0654 0.500 1.00 1.500 0.134 1.00 1.134 82 41 36 346.717 0.0424 0.500 1.00 1.500 0.206 1.00 1.206 83 22 24 145.249 0.0850 0.574 1.00 1.574 0.612 1.00 1.612 84 12 14 84.689 0.1189 0.550 1.00 1.550 0.519 1.00 1.519 85 6 17 0.0 0.0 0.171 1.00 1.171 0.171 1.00 1.171 Junctions 29 and 85 connect the same nodes, 6 and 17 86 29 36 254.73 0.0664 0.260 1.00 1.260 0.208 1.00 1.208 87 42 20 16.839 1.1827 0.500 1.00 1.500 0.463 1.00 1.463 88 1 11 48.397 0.3731 0.218 1.00 1.218 0.322 1.00 1.322 89 2 11 90.828 0.2276 0.253 1.00 1.253 0.166 1.00 1.166 90 7 17 105.829 0.2270 0.308 1.00 1.308 0.295 1.00 1.295 STPEGS UFSAR 6.2-102 Revision 18 TABLE 6.2.1.2-6 (Continued)

STEAM GENERATOR LOOP COMPARTMENT PRESSURE - JUNCTION PROPERTIES FOR RHR/SI ANALYSIS (42-Node Model)

Forward Forward Forward Reverse Reverse Reverse Head Head Head Head Head Head Junction From To Area Length/Area Loss Loss Loss Loss Loss Loss Number Volume Volume (ft2) (ft-1) Contraction Expansion Total Contraction Expansion Total Remarks 91 9 37 9.75 0.3353 0.484 1.00 1.484 0.497 1.00 1.497 92 9 40 9.75 0.3353 0.484 1.00 1.484 0.497 1.00 1.497 93 37 40 213.627 0.1964 0.352 1.00 1.352 0.352 1.00 1.352 STPEGS UFSAR 6.2-103 Revision 18 TABLE 6.2.1.2 - 6A STEAM GENERATOR LOOP COMPARTMENT PRESSURIZATION ANALYSIS JUNCTION PROPERTIES FOR FWLB ANALYSIS Junction Number From Node To Node Area Inertia Factor (Length/Area)

Forward Head Loss Forward Head Loss Forward Head Loss Reverse Head Loss Reverse Head Loss Reverse Head Loss (ft 2) (ft-1) Contraction Expansion Total Contraction Expansion Total 1 1 3 83.70 0.0750 0.080 1.0 1.080 0.119 1.0 1.119 2 1 6 26.12 0.3301 0.042 1.0 1.042 0.379 1.0 1.379 3 1 11 17.46 0.3337 0.194 1.0 1.194 0.422 1.0 1.422 4 1 17 82.72 0.0854 0.089 1.0 1.089 0.089 1.0 1.089 5 2 4 51.23 0.6282 0.371 1.0 1.371 0.439 1.0 1.439 6 2 7 185.23 0.0580 0.049 1.0 1.049 0.051 1.0 1.051 7 2 12 152.84 0.0595 0.127 1.0 1.127 0.126 1.0 1.126 8 2 17 229.79 0.0473 0.216 1.0 1.216 0.022 1.0 1.022 9 3 4 72.27 0.2560 0.195 1.0 1.195 0.414 1.0 1.414 10 3 8 36.08 0.2768 0.090 1.0 1.090 0.079 1.0 1.079 11 3 13 40.50 0.2722 0.040 1.0 1.040 0.055 1.0 1.055 12 4 5 356.89 0.0579 0.077 1.0 1.077 0.077 1.0 1.077 13 4 9 190.49 0.0564 0.047 1.0 1.047 0.051 1.0 1.051 14 4 14 108.93 0.0587 0.241 1.0 1.241 0.238 1.0 1.238 15 5 10 495.22 0.0208 0.062 1.0 1.062 0.064 1.0 1.064 16 5 15 371.04 0.0214 0.173 1.0 1.173 0.174 1.0 1.174 17 6 7 99.05 0.1331 0.050 1.0 1.050 0.232 1.0 1.232 18 6 8 40.30 0.2739 0.050 1.0 1.050 0.100 1.0 1.100 19 6 16 246.65 0.0388 0.052 1.0 1.052 0.497 1.0 1.497 20 6 17 66.57 0.1402 0.190 1.0 1.190 0.072 1.0 1.072 21 7 9 24.57 1.3098 0.365 1.0 1.365 0.436 1.0 1.436 20 6 17 66.57 0.1402 0.190 1.0 1.190 0.072 1.0 1.072 21 7 9 24.57 1.3098 0.365 1.0 1.365 0.436 1.0 1.436 22 7 16 410.22 0.0221 0.049 1.0 1.049 0.495 1.0 1.495 23 8 9 32.00 0.5782 0.205 1.0 1.205 0.417 1.0 1.417 24 8 16 107.10 0.0904 0.055 1.0 1.055 0.499 1.0 1.499 25 9 10 173.82 0.1188 0.050 1.0 1.050 0.050 1.0 1.050 26 9 16 534.30 0.0216 0.044 1.0 1.044 0.495 1.0 1.495 27 10 16 512.37 0.0104 0.049 1.0 1.049 0.486 1.0 1.486 28 11 12 98.87 0.1333 0.089 1.0 1.089 0.253 1.0 1.253 29 11 13 46.36 0.2381 0.050 1.0 1.050 0.075 1.0 1.075 30 11 17 58.96 0.1438 0.236 1.0 1.236 0.125 1.0 1.125 31 12 14 24.20 1.3298 0.378 1.0 1.378 0.442 1.0 1.442 32 13 14 37.07 0.4991 0.184 1.0 1.184 0.411 1.0 1.411 33 14 15 165.69 0.1247 0.104 1.0 1.104 0.104 1.0 1.104 34 11 18 87.27 0.0627 0.109 1.0 1.109 0.395 1.0 1.395 35 12 18 170.29 0.0439 0.083 1.0 1.083 0.296 1.0 1.296 36 13 18 37.24 0.1145 0.091 1.0 1.091 0.455 1.0 1.455 37 14 18 9.41 0.0442 0.477 1.0 1.477 0.489 1.0 1.489 38 14 19 155.33 0.0468 0.118 1.0 1.118 0.294 1.0 1.294 39 15 19 155.33 0.0339 0.365 1.0 1.365 0.294 1.0 1.294 40 15 20 313.05 0.0313 0.228 1.0 1.228 0.124 1.0 1.124 41 18 19 231.72 0.1027 0.320 1.0 1.320 0.304 1.0 1.304 42 18 21 233.29 0.0365 0.459 1.0 1.459 0.459 1.0 1.459 43 19 20 231.72 0.1027 0.304 1.0 1.304 0.320 1.0 1.320 44 19 22 359.84 0.0405 0.130 1.0 1.130 0.203 1.0 1.203 45 20 23 233.28 0.0365 0.459 1.0 1.459 0.459 1.0 1.459 STPEGS UFSAR 6.2-104 Revision 18 TABLE 6.2.1.2 - 6A STEAM GENERATOR LOOP COMPARTMENT PRESSURIZATION ANALYSIS JUNCTION PROPERTIES FOR FWLB ANALYSIS Junction Number From Node To Node Area Inertia Factor (Length/Area)

Forward Head Loss Forward Head Loss Forward Head Loss Reverse Head Loss Reverse Head Loss Reverse Head Loss (ft 2) (ft-1) Contraction Expansion Total Contraction Expansion Total 46 21 22 172.14 0.1336 0.468 1.0 1.468 0.553 1.0 1.553 47 21 24 401.15 0.0197 0.193 1.0 1.193 0.193 1.0 1.193 48 22 23 172.14 0.1336 0.553 1.0 1.553 0.468 1.0 1.468 49 22 25 151.10 0.0401 0.375 1.0 1.375 0.375 1.0 1.375 50 23 26 401.15 0.0197 0.193 1.0 1.193 0.193 1.0 1.193 51 24 25 185.77 0.1143 0.178 1.0 1.178 0.149 1.0 1.149 52 24 27 139.22 0.1733 0.240 1.0 1.240 0.204 1.0 1.204 53 25 26 185.77 0.1143 0.149 1.0 1.149 0.178 1.0 1.178 54 26 28 206.15 0.1258 0.131 1.0 1.131 0.127 1.0 1.127 55 27 29 139.23 0.1962 0.050 1.0 1.050 0.344 1.0 1.344 56 28 29 206.15 0.1325 0.050 1.0 1.050 0.269 1.0 1.269 57 29 30 919.02 0.0075 0.220 1.0 1.220 0.220 1.0 1.220 58 30 31 829.48 0.0157 0.313 1.0 1.313 0.245 1.0 1.245 59 31 32 654.32 0.0189 0.261 1.0 1.261 0.269 1.0 1.269 60 32 16 910.35 0.0113 0.184 1.0 1.184 0.500 1.0 1.500 STPEGS UFSAR 6.2-105 Revision 18 TABLE 6.2.1.2-7A STEAM GENERATOR LOOP COMPARTMENT ANALYSIS - FORCE COEFFICIENT (AREA PROJECTIONS) FOR STEAM GENERATOR SUBJECTED TO RHR LINE BREAK Node Coefficient Force in X - Direction (west) ft 2 Coefficient Force in Y - Direction (uplift force) ft 2 Coefficient Force in Z - direction (north) ft 2 El 28' 1/2" to 38' 4" 12 (on SG) -33.96 41.96 10.71 12 (on Crossover Leg) -18.84 NA NA 12 (on Hot Leg) -8.21 NA 20.33 14 (on SG) 23.48 65.31 43.23 14 (on Crossover Leg) 18.84 NA NA 14 (on Hot Leg) NA NA NA 15 (on SG) 10.48 83.91 -53.94 15 (on Crossover Leg) NA NA NA 15 (on Hot Leg) 8.21 NA -20.33 El 38' 4" to 66' 7 1/2" 22 (on SG) -223.93 -13.42 70.61 23 (on SG) 155.28 -20.89 285.09 24 (on SG) 68.65 -26.84 -355.70 El 66' 7 1/2" to 83' 0" 30 (on SG) -44.66 56.59 229.73 31 (on SG) 44.66 44.27 -229.73 Free Volume 41 (on SG) NA -232.49 NA STPEGS UFSAR 6.2-106 Revision 18 TABLE 6.2.1.2-7B STEAM GENERATOR LOOP COMPARTMENT ANALYSIS - MOMENT COEFFICIENT (AREA PROJECTIONS) FOR STEAM GENERATOR SUBJECTED TO RHR LINE BREAK Node Moment Coefficient with respect to X-Axis (west) ft x ft 2 Moment Coefficient with respect to Y-Axis (uplift force) ft x ft 2 Moment Coefficient with respect to Z-Axis (north) ft x ft 2 El 28' 1/2" to 38' 4" 12 (on SG) 105.02 0.16 300.15 12 (on Crossover Leg) NA 113.04 -48.05 12 (on Hot Leg) -22.44 -169.58 -9.06 14 (on SG) 462.82 0.11 -220.69 14 (on Crossover Leg) NA -113.04 48.05 14 (on Hot Leg) NA NA NA 15 (on SG) -567.84 -0.27 -79.46 15 (on Crossover Leg) NA NA NA 15 (on Hot Leg) 22.44 169.58 9.06 El 38' 4" to 66' 7 1/2" 22 (on SG) 1328.76 1.00 4247.85 23 (on SG) 5350.29 -0.88 -2954.98 24 (on SG) -6679.05 -0.12 -1292.87 El 66' 7 1/2" to 83' 0" 30 (on SG) 10146.42 -0.0796 1972.56 31 (on SG) -10146.42 0.0796 -1972.56 STPEGS UFSAR 6.2-107 Revision 18 TABLE 6.2.1.2-7C STEAM GENERATOR LOOP COMPARTMENT ANALYSIS - FORCE COEFFICIENT (AREA PROJECTIONS) FOR STEAM GENERATOR SUBJECTED TO FWLB Level Node Coefficient Force in X - Direction (west) ft 2 Coefficient Force in Y - Direction (uplift force) ft 2 Coefficient Force in Z - direction (north) ft 2 1 El 90.5' - 105.81' 16 (on SG) 0 0 -239.43 2 El 83.0' - 90.5' 6 57.23 -25.19 0 7 60.04 65.25 0 8 13.68 -40.06 0 9 -130.95 0 0 3 El 66.63' - 83.0' 1 40.27 -34.56 6.42 2 120.60 131.06 23.55 3 27.48 -80.46 10.43 4 -263.02 0 49.73 17 74.67 -16.04 9.33 4 El 58.5' - 66.63' 11 47.41 -20.87 0 12 49.73 54.05 0 13 11.33 -33.18 0 14 -108.47 0 0 5 El 37.92' - 58.5' 18 266.38 47.21 0 19 -266.38 -47.21 0 6 El 33.72' - 37.92' 21 54.36 9.64 77.80 22 -54.36 -9.64 62.17

STPEGS UFSAR 6.2-108 Revision 18 TABLE 6.2.1.2-7D STEAM GENERATOR LOOP COMPARTMENT ANALYSIS MOMENT COEFFICIENT (AREA PROJECTIONS) FOR STEAM GENERATOR SUBJECTED TO FWLB Level Node Moment Coefficient with respect to Z-Axis ft x ft 2 Moment Coefficient with respect to X-Axis ft x ft 2 Moment Coefficient with respect to ZY-Axis ft x ft 2 Moment Coefficient with respect to XY-Axis ft x ft 2 1 EL: 90.5' - 105.81' 16 (on SG) 0 0 0 0 2 EL 83.0' - 90'.5' 6 1335.83 3034.91 0 0 7 -3460.21 3183.92 0 0 8 2124.38 725.45 0 0 9 0 -6944.28 0 0 3 EL 66.63' - 83'.0' 1 1436.31 1673.61 56.05 56.05 2 -5446.85 5012.14 -205.59 205.59 3 3343.92 1142.07 91.05 91.05 4 0 -10931.11 0 -434.15 17 666.62 3103.29 58.49 81.45 4 EL: 58.5' - 66.63' 11 601.89 1367.30 0 0 12 -1558.80 1434.21 0 0 13 956.91 326.76 0 0 14 0 -3128.27 0 0 5 EL: 37.92' - 58.5' 18 -684.51 3862.74 0 0 19 684.51 -3862.74 0 0 6 EL: 33.72' - 37.92' 21 -20.24 114.24 -52.17 414.98 22 20.24 -114.24 52.17 -414.98

STPEGS UFSAR 6.2-109 Revision 18 TABLE 6.2.1.2-8A STEAM GENERATOR LOOP COMPARTMENT ANALYSIS - FORCE COEFFICIENT (AREA PROJECTIONS) FOR REACTOR COOLANT PUMP SUBJECTED TO RHR LINE BREAK Node Coefficient Force in X - Direction (west direction) ft 2 Coefficient Force in Y - Direction (uplift force) ft 2 Coefficient Force in Z - direction (north direction) ft 2 El 19' 0" - 28' 1/2" 1 -7.29 4.37 17.61 2 -7.29 4.37 NA 3 14.58 2.92 -17.61 El 28' 1/2" - 38' 4" 12 -23.485 11.28 -60.74 13 -23.485 12.67 61.05 14 46.97 7.53 -0.31 El 38' 4" - 66' 7 1/2" 21 -40.38 -16.18 93.64 22 -40.38 -16.18 -94.78 23 80.76 -10.77 1.14 STPEGS UFSAR 6.2-110 Revision 18 TABLE 6.2.1.2-8B STEAM GENERATOR LOOP COMPARTMENT ANALYSIS - MOMENT COEFFICIENT (AREA PROJECTIONS) FOR REACTOR COOLANT PUMP SUBJECTED TO RHR LINE BREAK

Node Moment Coefficient with respect to X-Axis (west direction) ft x ft 2 Moment Coefficient with respect to Y-Axis (uplift force) ft x ft 2 Moment Coefficient with respect to Z-Axis (north direction) ft x ft 2 El 19' 0" - 28' 1/2" 1 -83.67 -0.089 -35.055 2 83.67 0.089 -35.055 3 NA NA 70.11 El 28' 1/2" - 38' 4" 12 -400.0 19.39 154.15 13 401.27 -17.61 148.69 14 -1.27 -1.78 -302.84 El 38' 4" - 66' 7 1/2" 21 1378.06 -10.25 623.57 22 -1378.06 10.25 623.57 23 NA NA -1247.14 STPEGS UFSAR 6.2-111 Revision 18 TABLE 6.2.1.2-9 PRESSURIZER SUBCOMPARTMENT ANALYSIS SPRAY LINE BREAK Net Peak Time to Peak Design Design Volume Differential Differential Pressure(1) Margin(4) Node (ft 3) Pressure (psid)Pressure (sec) (psid) (%) 1 693.50 8.140.018.64 6%

2 659.60 5.760.258.64 50%

3 663.06 5.510.298.64 56%

4 703.44 5.640.258.64 53%

5 1 ,101.25 5.780.237.05 21%

6 1 ,007.41 5.480.217.05 27%

7 1 ,007.41 5.380.247.05 31%

8 1 ,078.95 5.440.247.05 29%

9 3.36 x 10 6 N/AN/AN/A(2) N/A(2) 10 4 ,128.59 0.403.25N/A(3) N/A(3)(1) The design pressure is governed by surge line break.

Initial conditions for all nodes are identical. Temp. = 110F, Press. = 14.7 psia, and relative humidity = 50%.

(2) Node 9 represents the free containment volume. Design pressure and margin are presented elsewhere. See Table 6.2.1.1-2.

(3) HVAC duct. This system (Containment Cubicle Exhaust) is shut down under accident conditions. The design margin is not defined.

(4) Pressure al Differenti Peak Pressure)al Differenti Peak Pressure (Design Margin Design STPEGS UFSAR 6.2-112 Revision 18 TABLE 6.2.1.2-13 MAIN STEAM LINE AND FEEDWATER LINE SUBCOMPARTMENT ANALYSIS Net Pea kTime to Pea k Desi g n Desi g n Volume DifferentialDifferentialPressure Mar g i n Node (ft 3) Pressure (psid)Pressure (sec)(p sid) (%) 1 6 ,030 13.10.01930.15 130 2 16 ,982 1.20.05515.00 1

, 150 3 5 ,332 13.90.01830.15 116 4 19 ,518 1.50.05415.00 900 5 6 ,766 5.10.03114.25 179 6 15 ,748 1.60.04515.00 837 7 5 ,958 4.80.03014.25 196 8 19 ,100 1.80.04515.00 733 9 35 ,385 0.80.03725.50 3

, 087 10 32 ,975 0.90.05425.50 2

, 733 11 3.00 x 10 6 ---- 12 50 ,653 0.60.08ne g li g ible N.A. 13 48 ,905 0.10.09ne g li g ible N.A. 14 58 ,770 0.10.09ne g li g ible N.A. 1. The MSLB results bound the FWLB results. Initial conditions for all nodes are identical. Temp. = 120F, Press. = 14.7 psia, and relative humidity = 0%

2. Pressure al Differenti Peak Pressure)al Differenti Peak Pressure (Design Margin Design 6.2-113 STPEGS UFSAR STPEGS UFSAR Revision 18 TABLE 6.2.1.2-14 MAIN STEAM LINE AND FEEWATER SUBCOMAPRTMENT ANALYSIS JUNCTION DESCRIPTION STEAM LINE BREAK ANALYSIS Nodes Head Loss Coefficients Vent Area Length/Area From To (ft 2) (ft-1) Contraction Expansion Grating KTotal 1 2 154.92 0.23 0.1962 1.0 - 1.1962 1 3 68.85 0.23 0.365 1.0 - 1.365 1 5 204.43 0.025 0.3163 1.0 0.3 1.6163 2 6 555.83 0.012 0.2787 1.0 0.3 1.5787 2 11 539.79 0.0064 0.2787 1.0 0.3 1.5787 2 12 77.16 0.61 0.376 1.0 - 1.376 3 4 189.34 0.16 0.138 1.0 - 1.138 3 7 190.72 0.028 0.306 1.0 0.3 1.606 4 8 676.39 0.01 0.2791 1.0 0.3 1.5791 4 11 468.04 0.0052 0.2791 1.0 0.3 1.5791 4 12 36.00 0.76 0.453 1.0 - 1.453 5 6 136.8 0.22 0.269 1.0 - 1.269 5 7 58.6 0.19 0.401 1.0 - 1.401 5 9 204.43 0.17 0.316 1.0 0.3 1.616 6 9 555.83 0.0099 0.2787 1.0 0.3 1.5787 6 13 192.49 0.604 0.165 1.0 - 1.165 7 8 219.03 0.15 0.1378 1.0 - 1.1378 7 10 190.72 0.019 0.306 1.0 0.3 1.606 8 10 673.08 0.009 0.279 1.0 0.3 1.579 8 13 39.82 0.81 0.443 1.0 - 1.443 9 10 361.35 0.26 0.111 1.0 - 1.111 9 11 752.93 0.004 0.335 1.0 0.3 1.635 9 14 108.71 0.50 0.347 1.0 0.3 1.347 10 11 645.72 0.0043 0.348 1.0 0.3 1.648 10 14 65.70 0.665 0.425 1.0 0.3 1.425 12 11 796.85 0.002 0.34 1.0 0.3 1.64 12 13 1667.57 0.004 0.2862 1.0 0.3 1.586 13 14 403.35 0.004 0.448 1.0 0.3 1.748 14 11 755.98 0.0024 0.403 1.0 0.3 1.703

6.2-114 STPEGS UFSAR STPEGS UFSAR Revision 18 TABLE 6.2.1.2-15 REGENERATIVE HEAT EXCHANGER SUBCOMPARTMENT NODAL DESCRIPTION*

Node Description Volume (ft

3) Peak Pressure Differential (psig)

Design Pressure (psig) Design Margin (%) 1 Northeast quadrant of El. 37 ft 3 in., between azimuth 0 and 270 , and between secondary and containment walls. (Room No. 307) 2,268.0 5.0 5.52 9.4 2 Balance of Reactor Containment Building 3.38 x10 6 N/A - -

• Initial conditions for all nodes are identical: Temp. = 110F, Press. = 14.7 psig, and humidity = 25 percent.

6.2-115 STPEGS UFSAR STPEGS UFSAR Revision 18 TABLE 6.2.1.2-16 REGENERATIVE HEAT EXCHANGER SUBCOMPARTMENT JUNCTION DESCRIPTION Description of Flow Turning and From To Flow Friction Obstruction Expansion ContractionTotal L/A Volume Volume Choked Unchoked Area (ft 2) (K) (K) (K) (K) (K t) (ft-1) 1 2 X 30.3 -- -- -- -- 1.85 0.27 Parallel Paths a) X 17.5 0.0 0.0 1.0 0.414 1.414 0.41 b) X 12.8 0.0 1.0 1.0 0.437 2.437 0.77

6.2-116 STPEGS UFSAR STPEGS UFSAR Revision 18 TABLE 6.2.1.2-17 RADIOACTIVE PIPE CHASE SUBCOMPARTMENT NODAL DESCRIPTION(1)

Node Description Net Free Volume (ft

3) Peak Pressure Differential (psig)

Design Pressure (psig)

Margin (%) 1 Space between floors at El. 29 ft and 37 ft-3 in. between the

secondary shield and the Containment, and between radial shield walls. 5,331 1.42 - Large Margin Exists 2 Space directly below node 1 on El. 29 ft between azimuth 6 and 43 (Room No. 210SE) 5,763 N/A N/A - 3 Balance of RCB 3.37 x10 6 N/A N/A -

1. Initial conditions all nodes are identical: Temp. = 110F, Press. = 14.7 psia, and humidity = 25%

6.2-117 STPEGS UFSAR STPEGS UFSAR Revision 18 TABLE 6.2.1.2-18 RADIOACTIVE PIPE CHASE SUBCOMPARTMENT JUNCTION DESCRIPTION Turning and From To Description of Flow Flow Friction Obstruction Expansion Contraction Total L/A Volume Volume Choked Unchoked Area (ft 2) (K) (K) (K) (K) (K t) (ft-1) 1 2 X 13.4 0.0 0.0 1.0 0.5 1.50 0.82 2 3 X 230.0 0.0 0.0 1.0 0.23 1.23 0.90

6.2-118 STPEGS UFSAR STPEGS UFSAR Revision 18 TABLE 6.2.1.2-19 RHR1A VALVE ROOM SUBCOMPARTMENT NORMAL DESCRIPTION Net Free Peak Pressure Design Node Description Volume (ft

3) Differential (psig) Pressure (psig) Margin (%) 1 Northeast quadrant at El. 19 ft adjacent to SIS Accumulator tank (Room no. 209) 1,877 1.58 - Large Margin Exists 2 Balance of RCB 3.38 x 10 6 N/A - -

6.2-119 STPEGS UFSAR STPEGS UFSAR Revision 18 TABLE 6.2.1.2-20 RHR 1A VALVE ROOM SUBCOMPARTMENT JUNCTION DESCRIPTION Turning and From To Description of Flow Flow Friction Obstruction Expansion Contraction Total L/A Volume Volume Choked Unchoked Area (ft 2) (K) (K) (K) (K) (K t) (ft-1) 1 2 X 17.1 0.0 1.0 1.0 0.43 2.43 0.35

STPEGS UFSAR 6.2-120 Revision 18 TABLE 6.2.1.3-1 SYSTEM PARAMETER INITIAL CONDITIONS (LOCA MASS AND ENERGY ANALYSIS)

Parameter Value Core Thermal Power (MWt) (with uncertainty) 3,876 Reactor Coolant System Total Flowrate (lbm/sec) [1] 40,366 Vessel Outlet Temperature (°F) [1] 629.9 Core Inlet Temperature (°F) [1] 565.4 Vessel Average Temperature (°F) 597.7 Initial Steam Generator Steam Pressure (psia) 1102.0 Steam Generator Design 94 Steam Generator Tube Plugging (%) 0 Initial Steam Generator Secondary Side Mass (lbm) [1] 178,761 Assumed Maximum Containment Backpressure (psia) 71.2 Accumulator Water Volume (ft

3) per accumulator N 2 Cover Gas Pressure for liquid release (psia) Temperature (°F)

RWST Temperature (°F) 1,200 600.0 120 130 Safety Injection Delay, total (s ec) from beginning of event Two Trains of SI Three Trains of SI Flow:

Minimum SI Maximum SI Time to cold leg recircula tion (switchover to sump) (sec) 30 24.1

Table 6.2.1.3-2

Table 6.2.1.3-3

Tables 6.2.1.3-2, 6.2.1.3-3

[1] Includes appropriate uncertainty and/or allowance. CN-3136 STPEGS UFSAR 6.2-121 Revision 18 TABLE 6.2.1.3-2 LOCA-TOTAL PUMPED ECCS FLOW RATE FOR TWO TRAINS OF SI OPERATING INJECTION MODE (REFLOOD PHASE)

RCS Pressure (psia) Total Flow (lbm/sec) 14.7 1049.5 114.7 871.9

214.7 601.0 RECIRCULATION MODE Time (sec) Enthalpy (BTU/lbm)

Flow 1465 239.0 656.69 lbm/sec 3600 239.0 659.96 lbm/sec >3600 At transient 5062 gpm Sump temperature Figures 6.2.1.1-31 and 6.2.1.1-37 (2 LHSI) CN-3136 STPEGS UFSAR 6.2-122 Revision 18 TABLE 6.2.1.3-3 LOCA-TOTAL PUMPED ECCS FLOW RATE FOR THREE TRAINS OF SI OPERATING INJECTION MODE (REFLOOD PHASE)

RCS Pressure (psia) Total Flow (lbm/sec) 14.7 1757.0 114.7 1479.0

214.7 1152.0

314.7 664.0 RECIRCULATION MODE Time (sec) Enthalpy (BTU/lbm)

Flow 1000 239.0 1649.8 lbm/sec 3600 239.0 1649.8 lbm/sec >3600 At transient 5062 gpm Sump temperature Figures 6.2.1.1-31 and 6.2.1.1-37 (2 LHSI) CN-3136 CN-3136 STPEGS UFSAR 6.2-123 Revision 18 TABLE 6.2.1.3-4 DOUBLE-ENDED HOT LEG BREAK MASS AND ENERGY RELEASES Time Break Path No. 1 Flow (SG Side) Break Path No. 2 Flow (Reactor Side) Total Mass From Both Sides Total Energy From Both Sides (seconds) (lbm/sec) Thousand (Btu/sec) Enthalpy (Btu/lbm) (lbm/sec) Thousand (Btu/sec) Enthalpy (Btu/lbm) (lbm/sec) Thousand (Btu/sec) 0.00 0.0 0.0 0 0.0 0.0 0 0.0 0.0 0.001118 48,161.3 31,617.2 656.5 48,159.3 31,614.5 656.5 96,320.5 63,231.7 0.10 43,479.9 29,082.3 668.9 29,157.0 19,106.3 655.3 72,636.9 48,188.6 0.20 37,455.1 25,208.7 673.0 25,850.5 16,855.8 652.0 63,305.5 42,064.4 0.30 36,887.7 24,896.8 674.9 23,217.8 14,996.2 645.9 60,105.5 39,893.0 0.40 36,127.8 24,441.2 676.5 21,962.5 14,004.1 637.6 58,090.3 38,445.3 0.50 35,740.4 24,222.2 677.7 21,260.8 13,380.2 629.3 57,001.2 37,602.4 0.60 35,453.0 24,065.9 678.8 20,731.5 12,888.5 621.7 56,184.5 36,954.4 0.70 35,161.5 23,906.5 679.9 20,406.3 12,547.9 614.9 55,567.9 36,454.4 0.80 34,748.6 23,669.2 681.2 20,121.9 12,255.4 609.1 54,870.4 35,924.6 0.90 34,219.4 23,358.1 682.6 19,942.1 12,047.4 604.1 54,161.5 35,405.5 1.00 33,679.8 23,043.6 684.2 19,785.1 11,869.8 599.9 53,464.9 34,913.4 1.10 33,229.5 22,793.8 686.0 19,657.1 11,721.9 596.3 52,886.7 34,515.7 1.20 32,837.3 22,585.7 687.8 19,557.7 11,601.1 593.2 52,395.0 34,186.8 1.30 32,452.0 22,382.2 689.7 19,500.8 11,513.3 590.4 51,952.7 33,895.5 1.40 32,124.8 22,222.2 691.7 19,424.8 11,421.7 588.0 51,549.5 33,643.9 1.50 31,704.0 21,986.7 693.5 19,394.0 11,361.1 585.8 51,098.0 33,347.7 1.60 31,296.5 21,742.6 694.7 19,379.8 11,314.3 583.8 50,676.3 33,056.9 1.70 30,973.2 21,544.3 695.6 19,383.7 11,281.8 582.0 50,356.9 32,826.2 1.80 30,711.6 21,381.6 696.2 19,409.1 11,264.8 580.4 50,120.8 32,646.4 1.90 30,428.7 21,200.4 696.7 19,447.4 11,257.6 578.9 49,876.1 32,458.0 2.00 30,068.4 20,959.8 697.1 19,487.0 11,253.3 577.5 49,555.4 32,213.1 2.10 29,694.8 20,706.8 697.3 19,526.6 11,251.5 576.2 49,221.3 31,958.3 2.20 29,351.0 20,476.2 697.6 19,564.8 11,250.5 575.0 48,915.8 31,726.7 2.30 29,043.3 20,273.0 698.0 19,601.0 11,250.4 574.0 48,644.3 31,523.4 2.40 28,724.0 20,060.4 698.4 19,633.2 11,250.0 573.0 48,357.2 31,310.3 2.50 28,351.9 19,804.0 698.5 19,659.7 11,248.0 572.1 48,011.6 31,052.0 2.60 27,968.5 19,534.0 698.4 19,678.6 11,243.3 571.3 47,647.1 30,777.2 2.70 27,656.0 19,316.2 698.4 19,693.5 11,238.0 570.6 47,349.6 30,554.2 2.80 27,390.1 19,133.3 698.5 19,706.0 11,232.6 570.0 47,096.1 30,365.9 2.90 27,113.3 18,937.3 698.4 19,712.2 11,225.3 569.5 46,825.5 30,162.5 3.00 26,805.4 18,709.1 698.0 19,710.9 11,214.9 569.0 46,516.3 29,924.0 3.10 26,516.3 18,486.9 697.2 19,701.3 11,201.1 568.5 46,217.6 29,688.0 3.20 26,294.9 18,313.2 696.5 19,687.1 11,185.8 568.2 45,982.0 29,499.0 3.30 26,110.3 18,163.1 695.6 19,667.6 11,168.6 567.9 45,777.9 29,331.7 3.40 25,929.1 18,007.0 694.5 19,641.3 11,148.5 567.6 45,570.4 29,155.5 3.50 25,776.7 17,863.0 693.0 19,607.4 11,125.1 567.4 45,384.1 28,988.1 3.60 25,674.9 17,749.9 691.3 19,567.1 11,098.9 567.2 45,242.0 28,848.8 3.70 25,610.1 17,656.4 689.4 19,521.5 11,070.6 567.1 45,131.7 28,727.0 3.80 25,578.7 17,575.2 687.1 19,467.7 11,038.3 567.0 45,046.4 28,613.5 3.90 25,622.7 17,541.6 684.6 19,406.9 11,002.8 567.0 45,029.6 28,544.5 4.00 25,749.0 17,557.1 681.9 19,339.6 10,964.3 566.9 45,088.6 28,521.4 4.20 15,546.7 12,991.0 835.6 19,174.3 10,871.7 567.0 34,721.0 23,862.7 4.40 17,784.1 13,682.5 769.4 18,983.0 10,766.5 567.2 36,767.1 24,449.0 4.60 18,349.4 13,806.4 752.4 18,734.9 10,631.0 567.4 37,084.3 24,437.5 4.80 18,984.7 14,075.3 741.4 18,476.4 10,491.6 567.8 37,461.0 24,566.9 5.20 20,896.6 14,901.7 713.1 17,886.4 10,175.7 568.9 38,783.1 25,077.4 5.40 30,394.4 21,316.2 701.3 17,575.3 10,010.1 569.6 47,969.7 31,326.3 5.60 28,621.1 19,694.3 688.1 17,236.0 9,829.6 570.3 45,857.1 29,523.9 5.80 28,594.7 19,284.6 674.4 16,890.6 9,646.5 571.1 45,485.3 28,931.1 6.00 29,735.9 19,668.9 661.5 16,513.4 9,445.8 572.0 46,249.3 29,114.8 6.20 30,986.6 20,173.2 651.0 16,084.4 9,216.2 573.0 47,071.0 29,389.4 6.40 31,918.1 20,547.4 643.8 15,686.5 9,006.3 574.1 47,604.5 29,553.7 6.60 32,569.4 20,827.6 639.5 15,287.0 8,796.6 575.4 47,856.4 29,624.2 6.80 33,008.1 21,013.7 636.6 14,851.0 8,566.6 576.8 47,859.1 29,580.3 7.00 33,293.7 21,127.3 634.6 14,399.0 8,328.4 578.4 47,692.6 29,455.7 CN-3136 STPEGS UFSAR 6.2-124 Revision 18 TABLE 6.2.1.3-4 Continued) DOUBLE-ENDED HOT LEG BREAK MASS AND ENERGY RELEASES Time Break Path No. 1 Flow (SG Side) Break Path No. 2 Flow (Reactor Side) Total Mass From Both Sides Total Energy From Both Sides (seconds) (lbm/sec) Thousand (Btu/sec) Enthalpy (Btu/lbm) (lbm/sec) Thousand (Btu/sec) Enthalpy (Btu/lbm) (lbm/sec) Thousand (Btu/sec) 7.20 33,488.8 21,200.7 633.1 13,913.6 8,072.0 580.2 47,402.4 29,272.7 7.40 33,619.0 21,247.0 632.0 13,421.4 7,812.7 582.1 47,040.4 29,059.6 7.60 33,707.9 21,276.7 631.2 12,936.2 7,558.3 584.3 46,644.1 28,835.0 7.80 33,784.6 21,303.1 630.6 12,451.8 7,305.0 586.7 46,236.4 28,608.1 8.00 33,808.6 21,288.7 629.7 11,977.4 7,057.9 589.3 45,786.0 28,346.6 8.20 33,810.8 21,260.6 628.8 11,515.8 6,818.4 592.1 45,326.6 28,079.0 8.40 33,756.0 21,200.4 628.0 11,061.1 6,582.7 595.1 44,817.1 27,783.0 8.60 33,627.1 21,098.1 627.4 10,628.3 6,359.3 598.3 44,255.4 27,457.3 8.80 33,420.0 20,951.7 626.9 10,218.8 6,148.9 601.7 43,638.8 27,100.5 9.00 33,138.5 20,766.5 626.7 9,833.6 5,951.9 605.3 42,972.2 26,718.4 9.20 32,795.4 20,541.2 626.3 9,472.0 5,767.8 608.9 42,267.4 26,308.9 9.40 32,398.9 20,291.1 626.3 9,130.6 5,594.8 612.8 41,529.5 25,885.9 9.60 31,594.2 19,778.5 626.0 8,807.7 5,431.9 616.7 40,401.9 25,210.4 9.80 30,463.6 19,042.9 625.1 8,502.2 5,278.5 620.8 38,965.8 24,321.4 10.00 28,855.6 17,997.2 623.7 8,219.2 5,137.1 625.0 37,074.8 23,134.3 10.20 18,648.6 11,318.0 606.9 7,962.3 5,010.9 629.3 26,611.0 16,328.9 10.40 12,416.3 8,786.5 707.7 7,701.0 4,881.2 633.8 20,117.3 13,667.7 10.60 12,484.2 8,797.3 704.7 7,490.3 4,782.1 638.4 19,974.5 13,579.3 10.80 11,600.1 8,643.0 745.1 7,337.4 4,713.9 642.5 18,937.4 13,356.9 11.00 11,834.8 8,691.0 734.4 7,195.4 4,643.8 645.4 19,030.2 13,334.8 11.20 11,727.9 8,617.7 734.8 7,095.2 4,593.2 647.4 18,823.1 13,211.0 11.40 12,284.0 8,821.4 718.1 7,022.3 4,551.3 648.1 19,306.3 13,372.7 11.60 12,771.6 9,043.4 708.1 6,967.7 4,514.7 647.9 19,739.3 13,558.1 11.80 13,273.6 9,307.5 701.2 6,928.1 4,484.0 647.2 20,201.7 13,791.5 12.00 14,145.7 9,806.5 693.3 6,889.6 4,452.4 646.2 21,035.3 14,258.9 12.20 16,007.3 11,129.5 695.3 6,848.6 4,420.1 645.4 22,855.9 15,549.6 12.40 16,333.8 11,425.4 699.5 6,791.0 4,379.7 644.9 23,124.7 15,805.1 12.60 15,926.3 11,101.4 697.0 6,713.8 4,330.8 645.1 22,640.1 15,432.3 12.80 15,838.9 11,001.4 694.6 6,604.6 4,267.3 646.1 22,443.5 15,268.7 13.00 15,794.9 10,945.5 693.0 6,473.3 4,197.5 648.4 22,268.2 15,143.0 13.20 15,712.7 10,885.1 692.8 6,323.2 4,123.3 652.1 22,035.9 15,008.4 13.40 15,563.5 10,802.0 694.1 6,157.0 4,045.7 657.1 21,720.5 14,847.8 13.60 15,352.0 10,705.7 697.4 5,982.5 3,967.6 663.2 21,334.4 14,673.3 13.80 12,307.7 8,493.9 690.1 5,799.4 3,887.6 670.3 18,107.0 12,381.5 14.00 12,898.5 8,570.7 664.5 5,617.3 3,810.0 678.3 18,515.8 12,380.7 14.20 13,470.2 8,706.0 646.3 5,439.4 3,735.5 686.7 18,909.6 12,441.5 14.40 8,500.2 6,722.1 790.8 5,278.5 3,670.0 695.3 13,778.8 10,392.1 14.60 9,004.6 6,938.0 770.5 5,143.5 3,616.5 703.1 14,148.1 10,554.5 14.80 9,205.6 7,102.4 771.5 5,035.0 3,572.8 709.6 14,240.6 10,675.3 15.00 9,310.4 7,258.9 779.7 4,948.3 3,530.3 713.4 14,258.6 10,789.2 15.20 9,706.9 7,649.1 788.0 4,887.4 3,494.2 714.9 14,594.3 11,143.3 15.40 10,793.8 8,776.6 813.1 4,839.4 3,458.4 714.6 15,633.2 12,235.0 15.60 9,215.3 8,085.6 877.4 4,795.6 3,423.1 713.8 14,010.9 11,508.7 15.80 8,411.9 7,691.3 914.3 4,739.7 3,382.2 713.6 13,151.6 11,073.6 16.00 8,048.6 7,393.2 918.6 4,657.0 3,330.9 715.2 12,705.5 10,724.1 16.20 5,900.9 5,600.4 949.1 4,534.7 3,266.5 720.3 10,435.6 8,866.8 16.40 5,260.1 5,189.5 986.6 4,375.5 3,195.4 730.3 9,635.7 8,384.9 16.60 5,018.9 5,046.9 1,005.6 4,181.0 3,121.5 746.6 9,199.9 8,168.4 16.80 4,775.4 4,887.3 1,023.4 3,965.9 3,052.8 769.8 8,741.3 7,940.1 17.00 4,529.6 4,704.8 1,038.7 3,735.6 2,982.4 798.4 8,265.2 7,687.2 17.20 4,256.9 4,491.0 1,055.0 3,492.3 2,904.4 831.7 7,749.2 7,395.4 17.40 3,964.5 4,297.9 1,084.1 3,245.9 2,820.1 868.8 7,210.3 7,118.0 17.60 3,686.5 4,123.6 1,118.6 3,004.0 2,736.4 910.9 6,690.4 6,860.0 17.80 3,445.5 3,960.7 1,149.5 2,775.3 2,662.3 959.3 6,220.7 6,622.9 18.00 3,272.4 3,824.7 1,168.8 2,544.4 2,589.7 1,017.8 5,816.8 6,414.4 18.20 3,120.2 3,667.9 1,175.5 2,323.7 2,515.5 1,082.6 5,443.9 6,183.4 18.40 2,955.1 3,489.4 1,180.8 2,123.1 2,430.4 1,144.8 5,078.2 5,919.9 18.60 2,775.9 3,294.8 1,186.9 1,931.4 2,302.7 1,192.2 4,707.3 5,597.4 18.80 2,581.4 3,074.8 1,191.1 1,771.9 2,165.7 1,222.2 4,353.4 5,240.5 19.00 2,412.6 2,884.0 1,195.4 1,613.8 1,992.1 1,234.4 4,026.4 4,876.1 19.20 2,298.2 2,757.9 1,200.0 1,461.9 1,813.1 1,240.2 3,760.1 4,571.0 19.40 2,225.1 2,690.2 1,209.0 1,329.7 1,654.9 1,244.6 3,554.8 4,345.1 CN-3136 STPEGS UFSAR 6.2-125 Revision 18 TABLE 6.2.1.3-4 Continued) DOUBLE-ENDED HOT LEG BREAK MASS AND ENERGY RELEASES Time Break Path No. 1 Flow (SG Side) Break Path No. 2 Flow (Reactor Side) Total Mass From Both Sides Total Energy From Both Sides (seconds) (lbm/sec) Thousand (Btu/sec) Enthalpy (Btu/lbm) (lbm/sec) Thousand (Btu/sec) Enthalpy (Btu/lbm) (lbm/sec) Thousand (Btu/sec) 19.60 2,043.1 2,466.3 1,207.1 1,228.1 1,532.9 1,248.2 3,271.2 3,999.1 19.80 1,942.8 2,363.9 1,216.7 1,160.4 1,451.8 1,251.2 3,103.2 3,815.8 20.00 1,853.2 2,264.2 1,221.8 1,109.3 1,390.0 1,253.1 2,962.4 3,654.2 20.20 1,770.0 2,177.2 1,230.0 1,065.0 1,336.2 1,254.7 2,835.0 3,513.4 20.40 1,646.3 2,032.5 1,234.6 1,022.2 1,284.3 1,256.3 2,668.6 3,316.8 20.60 1,511.6 1,865.7 1,234.3 985.1 1,239.0 1,257.8 2,496.7 3,104.8 20.80 1,369.3 1,686.9 1,231.9 949.0 1,194.7 1,259.0 2,318.3 2,881.6 21.00 1,235.6 1,517.5 1,228.1 914.0 1,151.7 1,260.1 2,149.6 2,669.2 21.20 1,137.2 1,394.5 1,226.2 883.9 1,114.7 1,261.1 2,021.1 2,509.2 21.40 1,054.6 1,294.2 1,227.1 855.3 1,079.5 1,262.2 1,909.9 2,373.7 21.60 922.8 1,131.9 1,226.5 827.3 1,045.0 1,263.1 1,750.1 2,176.9 21.80 796.1 975.2 1,225.1 800.6 1,011.9 1,263.9 1,596.6 1,987.1 22.00 692.5 849.2 1,226.2 766.3 969.1 1,264.6 1,458.9 1,818.3 22.20 584.4 716.9 1,226.7 723.8 915.9 1,265.3 1,308.2 1,632.8 22.40 454.9 555.6 1,221.5 680.2 861.5 1,266.5 1,135.1 1,417.1 22.60 375.7 460.1 1,224.9 654.4 830.0 1,268.4 1,030.1 1,290.2 22.80 270.6 330.1 1,220.1 642.8 815.5 1,268.6 913.4 1,145.6 23.00 201.7 245.1 1,215.1 625.0 793.3 1,269.3 826.7 1,038.4 23.20 70.2 84.0 1,196.7 600.3 762.2 1,269.6 670.5 846.1 23.40 0.0 0.0 0 555.7 705.7 1,270.0 555.7 705.7 23.60 0.0 0.0 0 506.3 643.5 1,271.1 506.3 643.5 23.80 0.0 0.0 0 457.1 581.7 1,272.4 457.1 581.7 24.00 0.0 0.0 0 405.4 516.3 1,273.6 405.4 516.3 24.20 0.0 0.0 0 339.3 432.6 1,275.0 339.3 432.6 24.40 0.0 0.0 0 260.4 332.6 1,277.3 260.4 332.6 24.60 0.0 0.0 0 185.2 237.2 1,280.5 185.2 237.2 24.80 0.0 0.0 0 77.7 100.1 1,287.8 77.7 100.1 24.84 0.0 0.0 0 66.4 85.7 1,290.2 66.4 85.7 End of Blowdown [2, 3, 4, 5] NOTES: 1. Hot Leg Break Area = 4.587 ft2, Pipe inside diameter = 2.42 ft 2 The blowdown phase mass and energy releases are the same for Minimum and Maximum SI cases. 3. For DEHL Minimum SI post-blowdown phase, the DEPS Min. SI post-blowdown M&E releases are used (Table 6.2.1.3-5A), as discussed in Section 6.2.1.3.2. 4. For DEHL Maximum SI post-blowdown phase, the DEPS Max. SI post-blowdown M&E releases are used (Table 6.2.1.3-5B), as discussed in Section 6.2.1.3.2. 5 After 3600 seconds, the revised post recirculation methodology is used, as discussed in Section 6.2.1.3.4.5.

CN-3136 STPEGS UFSAR 6.2-126 Revision 18 TABLE 6.2.1.3-5A DOUBLE-ENDED PUMP SUCTION BR EAK MASS AND ENERGY RELEASES (Minimum SI)

Time Break Path No. 1 Flow (SG Side) Break Path No. 2 Flow (Pump Side)

Total Mass From Both Sides Total Energy From Both Sides(seconds) (lbm/sec)

Thousand (Btu/sec)

Enthalpy (Btu/lbm) (lbm/sec)

Thousand (Btu/sec)

Enthalpy (Btu/lbm) (lbm/sec)

Thousand (Btu/sec) 0.00 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.00114 97,158.3 54,746.8 563.5 43,339.6 24,348.1 561.8 140,497.9 79,094.8 0.10 43,480.5 24,471.9 562.8 21,547.8 12,088.3 561.0 65,028.3 36,560.2 0.20 51,982.9 29,373.7 565.1 24,528.6 13,777.6 561.7 76,511.5 43,151.3 0.30 51,633.9 29,319.5 567.8 25,873.5 14,546.5 562.2 77,507.4 43,866.0 0.40 51,282.7 29,294.9 571.2 25,649.9 14,432.9 562.7 76,932.6 43,727.8 0.50 50,920.4 29,294.0 575.3 24,960.9 14,057.0 563.2 75,881.3 43,351.0 0.60 50,714.3 29,407.1 579.9 24,416.8 13,760.3 563.6 75,131.1 43,167.3 0.70 49,896.9 29,180.0 584.8 24,052.4 13,561.7 563.8 73,949.4 42,741.7 0.80 48,045.5 28,330.9 589.7 23,753.6 13,396.9 564.0 71,799.1 41,727.8 0.90 47,471.7 28,211.3 594.3 23,440.1 13,222.0 564.1 70,911.8 41,433.3 1.00 47,553.0 28,462.2 598.5 23,099.6 13,030.6 564.1 70,652.7 41,492.8 1.10 47,301.6 28,504.7 602.6 22,771.3 12,845.1 564.1 70,072.9 41,349.8 1.20 46,713.0 28,337.7 606.6 22,488.7 12,685.9 564.1 69,201.7 41,023.6 1.30 45,879.3 28,014.4 610.6 22,307.8 12,584.1 564.1 68,187.1 40,598.6 1.40 44,977.2 27,652.8 614.8 22,153.8 12,497.8 564.1 67,131.0 40,150.5 1.50 44,069.3 27,288.9 619.2 22,023.9 12,425.0 564.2 66,093.2 39,713.9 1.60 43,087.0 26,882.9 623.9 21,910.8 12,361.3 564.2 64,997.8 39,244.1 1.70 42,038.7 26,434.8 628.8 21,829.6 12,315.5 564.2 63,868.3 38,750.3 1.80 40,932.5 25,950.6 634.0 21,785.3 12,290.8 564.2 62,717.8 38,241.4 1.90 39,839.5 25,469.8 639.3 21,742.5 12,267.2 564.2 61,582.0 37,737.0 2.00 38,715.4 24,965.0 644.8 21,660.5 12,221.1 564.2 60,375.9 37,186.1 2.10 37,556.9 24,426.6 650.4 21,545.6 12,156.0 564.2 59,102.4 36,582.6 2.20 36,371.7 23,856.7 655.9 21,371.8 12,057.1 564.2 57,743.5 35,913.8 2.30 35,147.2 23,250.1 661.5 21,088.3 11,896.7 564.1 56,235.5 35,146.8 2.40 34,060.0 22,718.5 667.0 20,894.6 11,787.9 564.2 54,954.6 34,506.4 2.50 32,996.1 22,186.4 672.4 20,712.4 11,685.5 564.2 53,708.6 33,871.9 2.60 31,939.8 21,643.1 677.6 20,514.2 11,573.9 564.2 52,454.0 33,217.0 2.70 30,932.3 21,118.9 682.7 20,313.0 11,460.6 564.2 51,245.3 32,579.6 2.80 29,765.0 20,472.0 687.8 20,113.0 11,348.2 564.2 49,878.0 31,820.2 2.90 27,445.6 18,995.3 692.1 19,902.8 11,230.2 564.2 47,348.4 30,225.5 3.00 25,766.4 17,965.5 697.2 19,688.4 11,109.8 564.3 45,454.8 29,075.2 3.10 24,813.9 17,434.4 702.6 19,480.3 10,993.1 564.3 44,294.2 28,427.6 3.20 23,807.7 16,826.2 706.8 19,276.4 10,879.0 564.4 43,084.1 27,705.1 3.30 22,807.1 16,193.0 710.0 19,070.0 10,763.4 564.4 41,877.1 26,956.4 3.40 22,078.1 15,737.9 712.8 18,852.2 10,641.4 564.5 40,930.3 26,379.3 3.50 21,448.8 15,339.9 715.2 18,643.2 10,524.4 564.5 40,092.0 25,864.3 3.60 20,878.1 14,972.0 717.1 18,453.8 10,418.7 564.6 39,331.9 25,390.8 3.70 20,389.7 14,654.9 718.7 18,266.8 10,314.4 564.7 38,656.5 24,969.4 3.80 19,938.4 14,356.3 720.0 18,076.3 10,208.1 564.7 38,014.7 24,564.4 3.90 19,505.0 14,064.6 721.1 17,883.0 10,100.1 564.8 37,388.1 24,164.7 4.00 19,114.4 13,799.7 722.0 17,705.0 10,000.9 564.9 36,819.4 23,800.6 4.20 18,464.4 13,353.2 723.2 17,375.2 9,817.4 565.0 35,839.6 23,170.6 4.40 17,903.6 12,954.7 723.6 17,046.4 9,634.3 565.2 34,950.0 22,589.0 4.60 17,483.5 12,645.2 723.3 16,753.7 9,471.7 565.3 34,237.2 22,116.9 4.80 17,144.9 12,380.3 722.1 16,458.5 9,307.4 565.5 33,603.4 21,687.7 5.20 17,002.0 12,201.1 717.6 15,778.8 8,926.8 565.7 32,780.7 21,127.8 CN-3136 STPEGS UFSAR 6.2-127 Revision 18 TABLE 6.2.1.3-5A (continued) DOUBLE-ENDED PUMP SUCTION BR EAK MASS AND ENERGY RELEASES (Minimum SI)

Time Break Path No. 1 Flow (SG Side) Break Path No. 2 Flow (Pump Side)

Total Mass From Both Sides Total Energy From Both Sides(seconds) (lbm/sec)

Thousand (Btu/sec)

Enthalpy (Btu/lbm) (lbm/sec)

Thousand (Btu/sec)

Enthalpy (Btu/lbm) (lbm/sec)

Thousand (Btu/sec) 5.40 17,031.9 12,141.1 712.8 15,592.9 8,826.8 566.1 32,624.8 20,967.8 5.60 16,900.2 12,240.9 724.3 15,241.3 8,629.2 566.2 32,141.5 20,870.0 5.80 15,466.8 11,897.2 769.2 15,053.8 8,528.0 566.5 30,520.6 20,425.2 6.00 14,376.0 11,430.7 795.1 16,196.3 9,180.7 566.8 30,572.3 20,611.4 6.20 14,657.9 11,492.0 784.0 15,895.2 9,009.6 566.8 30,553.2 20,501.7 6.40 15,346.8 11,800.3 768.9 15,813.2 8,967.1 567.1 31,160.1 20,767.5 6.60 15,997.4 12,107.9 756.9 15,629.5 8,865.9 567.3 31,626.9 20,973.8 6.80 16,544.7 12,356.4 746.9 15,430.6 8,756.7 567.5 31,975.3 21,113.1 7.00 16,993.7 12,521.2 736.8 15,310.6 8,692.4 567.7 32,304.3 21,213.6 7.20 17,301.2 12,567.4 726.4 15,127.2 8,590.1 567.9 32,428.4 21,157.5 7.40 17,454.4 12,526.1 717.6 14,903.7 8,463.6 567.9 32,358.1 20,989.7 7.60 17,610.0 12,526.9 711.4 14,723.3 8,361.1 567.9 32,333.3 20,888.0 7.80 17,829.7 12,592.3 706.3 14,506.8 8,237.2 567.8 32,336.4 20,829.6 8.00 17,924.5 12,575.6 701.6 14,289.4 8,113.0 567.8 32,213.9 20,688.6 8.20 17,836.0 12,454.6 698.3 14,107.1 8,009.0 567.7 31,943.1 20,463.6 8.40 17,825.2 12,420.5 696.8 13,922.3 7,903.6 567.7 31,747.5 20,324.1 8.60 17,956.9 12,483.5 695.2 13,698.3 7,775.5 567.6 31,655.2 20,259.0 8.80 17,676.8 12,241.5 692.5 13,487.0 7,655.0 567.6 31,163.8 19,896.5 9.00 17,077.6 11,811.4 691.6 13,366.6 7,586.8 567.6 30,444.2 19,398.2 9.20 16,898.6 11,709.6 692.9 13,192.2 7,486.7 567.5 30,090.8 19,196.3 9.40 17,090.6 11,826.0 692.0 12,944.4 7,344.6 567.4 30,035.1 19,170.6 9.60 16,910.7 11,644.8 688.6 12,758.2 7,238.8 567.4 29,668.9 18,883.5 9.80 14,830.5 10,196.8 687.6 12,709.0 7,211.9 567.5 27,539.5 17,408.8 10.00 12,649.1 8,828.0 697.9 13,118.2 7,446.2 567.6 25,767.3 16,274.2 10.20 12,658.6 9,020.5 712.6 12,514.9 7,092.9 566.8 25,173.5 16,113.4 10.40 12,797.8 9,094.0 710.6 12,318.5 6,983.1 566.9 25,116.3 16,077.1 10.60 11,922.0 8,448.1 708.6 12,796.2 7,260.6 567.4 24,718.1 15,708.6 10.80 11,736.9 8,446.7 719.7 12,339.2 6,994.1 566.8 24,076.0 15,440.8 11.00 12,081.0 8,773.4 726.2 12,043.5 6,825.4 566.7 24,124.5 15,598.8 11.20 11,784.2 8,497.8 721.1 12,135.5 6,881.3 567.0 23,919.7 15,379.1 11.40 11,410.1 8,242.3 722.4 12,060.5 6,838.9 567.1 23,470.5 15,081.3 11.60 12,022.0 8,705.2 724.1 11,676.4 6,616.5 566.7 23,698.5 15,321.8 11.80 12,800.0 9,129.8 713.3 11,454.4 6,491.8 566.7 24,254.4 15,621.5 12.00 11,778.0 8,305.9 705.2 11,582.3 6,569.0 567.2 23,360.3 14,874.9 12.20 10,425.1 7,479.6 717.5 11,903.4 6,749.6 567.0 22,328.4 14,229.3 12.40 10,397.9 7,613.8 732.2 11,064.1 6,264.2 566.2 21,462.1 13,877.9 12.60 10,018.5 7,345.8 733.2 11,629.6 6,594.0 567.0 21,648.1 13,939.8 12.80 9,733.9 7,184.7 738.1 11,276.7 6,388.8 566.5 21,010.6 13,573.5 13.00 9,876.1 7,359.2 745.2 11,100.7 6,292.2 566.8 20,976.8 13,651.4 13.20 9,734.1 7,235.4 743.3 11,058.9 6,270.0 567.0 20,792.9 13,505.4 13.40 9,607.8 7,128.7 742.0 10,975.5 6,225.1 567.2 20,583.3 13,353.7 13.60 9,972.8 7,373.1 739.3 10,604.9 6,014.2 567.1 20,577.6 13,387.3 13.80 9,909.5 7,230.9 729.7 10,672.5 6,057.1 567.5 20,582.0 13,288.1 14.00 9,207.4 6,740.9 732.1 10,751.1 6,104.7 567.8 19,958.5 12,845.6 14.20 9,198.0 6,827.9 742.3 10,242.6 5,817.7 568.0 19,440.7 12,645.5 14.40 8,859.7 6,572.9 741.9 10,609.9 6,035.7 568.9 19,469.6 12,608.5 14.60 8,566.4 6,402.9 747.4 10,296.8 5,861.4 569.2 18,863.2 12,264.3 14.80 8,533.4 6,474.8 758.8 10,211.7 5,827.7 570.7 18,745.1 12,302.5 15.00 8,216.2 6,319.6 769.2 10,063.9 5,745.5 570.9 18,280.1 12,065.1 15.20 8,116.9 6,272.4 772.8 9,886.0 5,654.2 571.9 18,002.9 11,926.6 15.40 8,111.4 6,214.1 766.1 9,718.4 5,562.7 572.4 17,829.8 11,776.8 15.60 7,997.5 6,067.5 758.7 9,736.5 5,583.5 573.5 17,734.0 11,651.0 15.80 7,981.8 6,028.7 755.3 9,444.5 5,428.5 574.8 17,426.2 11,457.2 CN-3136 STPEGS UFSAR 6.2-128 Revision 18 TABLE 6.2.1.3-5A (continued) DOUBLE-ENDED PUMP SUCTION BR EAK MASS AND ENERGY RELEASES (Minimum SI)

Time Break Path No. 1 Flow (SG Side) Break Path No. 2 Flow (Pump Side)

Total Mass From Both Sides Total Energy From Both Sides(seconds) (lbm/sec)

Thousand (Btu/sec)

Enthalpy (Btu/lbm) (lbm/sec)

Thousand (Btu/sec)

Enthalpy (Btu/lbm) (lbm/sec)

Thousand (Btu/sec) 16.00 7,827.7 5,894.1 753.0 9,559.1 5,508.9 576.3 17,386.9 11,403.1 16.20 7,670.7 5,794.8 755.4 9,331.2 5,405.3 579.3 17,001.9 11,200.0 16.40 7,560.1 5,759.4 761.8 9,310.0 5,419.4 582.1 16,870.1 11,178.8 16.60 7,435.8 5,732.5 770.9 9,144.5 5,356.4 585.8 16,580.2 11,088.9 16.80 7,286.3 5,686.3 780.4 8,976.1 5,287.4 589.0 16,262.4 10,973.6 17.00 7,157.4 5,633.2 787.0 8,762.9 5,196.7 593.0 15,920.4 10,829.9 17.20 7,050.4 5,571.8 790.3 8,538.6 5,097.8 597.0 15,589.0 10,669.6 17.40 6,958.0 5,516.4 792.8 8,327.4 5,015.3 602.3 15,285.4 10,531.7 17.60 6,849.1 5,460.8 797.3 8,119.3 4,942.0 608.7 14,968.4 10,402.8 17.80 6,723.1 5,414.2 805.3 7,902.6 4,875.6 617.0 14,625.7 10,289.8 18.00 6,585.5 5,382.0 817.3 7,668.1 4,807.5 626.9 14,253.6 10,189.5 18.20 6,430.2 5,356.2 833.0 7,441.3 4,749.7 638.3 13,871.6 10,105.9 18.40 6,261.9 5,327.1 850.7 7,187.1 4,681.0 651.3 13,448.9 10,008.0 18.60 6,107.3 5,301.0 868.0 6,981.9 4,661.7 667.7 13,089.2 9,962.7 18.80 5,941.4 5,251.4 883.9 6,470.9 4,522.9 699.0 12,412.3 9,774.3 19.00 5,702.7 5,205.0 912.7 5,996.7 4,374.5 729.5 11,699.4 9,579.5 19.20 5,251.8 5,128.4 976.5 5,581.4 4,262.8 763.7 10,833.1 9,391.1 19.40 4,598.8 4,953.8 1,077.2 5,082.1 4,145.8 815.8 9,680.9 9,099.6 19.60 3,926.3 4,649.5 1,184.2 4,413.1 4,052.0 918.2 8,339.4 8,701.5 19.80 3,408.6 4,188.7 1,228.9 2,536.6 2,869.1 1,131.1 5,945.1 7,057.8 20.00 3,024.3 3,747.2 1,239.0 1,724.2 2,095.5 1,215.3 4,748.5 5,842.7 20.20 2,731.6 3,399.5 1,244.5 1,504.4 1,859.6 1,236.2 4,236.0 5,259.1 20.40 2,468.3 3,081.6 1,248.5 1,351.9 1,681.7 1,243.9 3,820.2 4,763.3 20.60 2,239.0 2,803.8 1,252.3 1,229.0 1,535.2 1,249.1 3,468.0 4,339.0 20.80 2,048.2 2,571.6 1,255.6 1,110.7 1,392.9 1,254.1 3,158.9 3,964.5 21.00 1,892.3 2,381.5 1,258.5 1,480.9 1,611.7 1,088.4 3,373.2 3,993.2 21.20 1,796.6 2,265.5 1,261.0 2,572.9 1,432.5 556.7 4,369.5 3,698.0 21.40 1,711.4 2,160.7 1,262.5 2,837.4 1,364.0 480.7 4,548.9 3,524.7 21.60 1,619.6 2,046.9 1,263.8 3,167.8 1,406.2 443.9 4,787.4 3,453.0 21.80 1,501.7 1,899.3 1,264.8 3,156.0 1,336.7 423.5 4,657.7 3,236.0 22.00 1,388.1 1,758.3 1,266.8 2,799.3 1,149.5 410.6 4,187.4 2,907.8 22.20 1,275.2 1,617.3 1,268.2 2,433.4 977.0 401.5 3,708.6 2,594.3 22.40 1,171.6 1,487.4 1,269.6 2,162.1 850.7 393.5 3,333.7 2,338.2 22.60 1,045.0 1,328.9 1,271.7 1,952.0 751.4 385.0 2,996.9 2,080.3 22.80 946.3 1,204.8 1,273.1 1,774.9 666.0 375.2 2,721.2 1,870.8 23.00 877.3 1,118.2 1,274.7 1,635.9 597.7 365.3 2,513.1 1,715.9 23.20 831.5 1,060.7 1,275.6 1,731.5 613.6 354.4 2,563.0 1,674.3 23.40 802.0 1,023.6 1,276.4 2,058.5 696.1 338.2 2,860.5 1,719.8 23.60 775.7 990.4 1,276.9 2,539.4 819.5 322.7 3,315.1 1,810.0 23.80 727.1 928.6 1,277.1 3,217.9 995.9 309.5 3,945.1 1,924.5 24.00 557.7 712.0 1,276.5 3,471.3 1,035.2 298.2 4,029.0 1,747.1 24.20 453.5 579.7 1,278.3 2,353.0 685.2 291.2 2,806.5 1,264.9 24.40 375.8 480.8 1,279.4 1,269.5 365.6 288.0 1,645.3 846.4 24.60 279.1 357.3 1,280.4 543.6 156.0 286.9 822.6 513.3 24.80 168.9 216.5 1,281.9 91.9 26.4 287.1 260.8 242.9 25.00 37.6 48.4 1,285.8 0.0 0.0 0.0 37.6 48.4 25.20 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 End of Blowdown 25.65 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 25.75 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 25.85 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 25.95 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 CN-3136 STPEGS UFSAR 6.2-129 Revision 18 TABLE 6.2.1.3-5A (continued) DOUBLE-ENDED PUMP SUCTION BR EAK MASS AND ENERGY RELEASES (Minimum SI)

Time Break Path No. 1 Flow (SG Side) Break Path No. 2 Flow (Pump Side)

Total Mass From Both Sides Total Energy From Both Sides(seconds) (lbm/sec)

Thousand (Btu/sec)

Enthalpy (Btu/lbm) (lbm/sec)

Thousand (Btu/sec)

Enthalpy (Btu/lbm) (lbm/sec)

Thousand (Btu/sec) 26.05 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 26.28 56.5 66.7 1,180.8 0.0 0.0 0.0 56.5 66.7 26.38 58.3 68.9 1,180.8 0.0 0.0 0.0 58.3 68.9 26.48 66.1 78.0 1,180.9 0.0 0.0 0.0 66.1 78.0 26.58 73.8 87.2 1,180.9 0.0 0.0 0.0 73.8 87.2 26.68 81.1 95.8 1,180.9 0.0 0.0 0.0 81.1 95.8 26.78 88.1 104.0 1,181.0 0.0 0.0 0.0 88.1 104.0 26.85 93.1 109.9 1,181.0 0.0 0.0 0.0 93.1 109.9 26.88 94.7 111.8 1,181.0 0.0 0.0 0.0 94.7 111.8 26.98 101.0 119.2 1,181.1 0.0 0.0 0.0 101.0 119.2 27.08 107.0 126.3 1,181.1 0.0 0.0 0.0 107.0 126.3 27.18 112.7 133.1 1,181.1 0.0 0.0 0.0 112.7 133.1 27.28 118.2 139.7 1,181.2 0.0 0.0 0.0 118.2 139.7 27.38 123.6 146.0 1,181.2 0.0 0.0 0.0 123.6 146.0 27.48 128.7 152.1 1,181.3 0.0 0.0 0.0 128.7 152.1 27.58 133.7 158.0 1,181.3 0.0 0.0 0.0 133.7 158.0 27.68 138.6 163.7 1,181.3 0.0 0.0 0.0 138.6 163.7 27.78 143.3 169.2 1,181.4 0.0 0.0 0.0 143.3 169.2 27.88 147.8 174.6 1,181.4 0.0 0.0 0.0 147.8 174.6 27.98 152.3 179.9 1,181.5 0.0 0.0 0.0 152.3 179.9 28.08 156.6 185.0 1,181.5 0.0 0.0 0.0 156.6 185.0 28.18 160.9 190.1 1,181.5 0.0 0.0 0.0 160.9 190.1 28.28 165.0 195.0 1,181.6 0.0 0.0 0.0 165.0 195.0 29.28 202.1 238.9 1,182.0 0.0 0.0 0.0 202.1 238.9 30.00 768.7 915.4 1,190.8 6,636.7 910.3 137.2 7,405.4 1,825.7 30.30 808.8 963.9 1,191.8 6,942.3 988.6 142.4 7,751.1 1,952.5 31.30 806.1 960.8 1,191.9 6,925.2 997.7 144.1 7,731.3 1,958.5 32.30 795.6 948.1 1,191.7 6,828.4 986.0 144.4 7,624.0 1,934.1 32.70 790.1 941.4 1,191.6 6,786.0 980.9 144.5 7,576.1 1,922.3 33.30 847.2 1,010.1 1,192.3 7,265.8 1,044.6 143.8 8,113.0 2,054.7 34.30 826.4 985.3 1,192.3 7,140.1 1,026.7 143.8 7,966.5 2,012.0 35.30 815.3 971.9 1,192.1 7,034.1 1,013.3 144.1 7,849.4 1,985.2 35.90 808.9 964.1 1,191.9 6,971.1 1,005.3 144.2 7,780.0 1,969.5 36.30 804.7 959.1 1,191.9 6,929.5 1,000.1 144.3 7,734.2 1,959.1 37.30 794.1 946.3 1,191.6 6,827.9 987.4 144.6 7,622.0 1,933.6 38.30 782.1 931.9 1,191.4 6,730.7 975.5 144.9 7,512.8 1,907.4 39.30 770.7 918.1 1,191.2 6,636.5 964.1 145.3 7,407.2 1,882.2 39.50 768.5 915.4 1,191.2 6,618.0 961.8 145.3 7,386.5 1,877.2 40.30 759.7 904.9 1,191.1 6,545.4 953.1 145.6 7,305.1 1,858.0 41.30 749.2 892.2 1,190.9 6,457.2 942.5 146.0 7,206.4 1,834.7 42.30 739.2 880.1 1,190.7 6,371.9 932.3 146.3 7,111.1 1,812.4 43.30 729.5 868.5 1,190.5 6,289.4 922.5 146.7 7,018.9 1,791.0 43.40 728.6 867.4 1,190.5 6,281.3 921.5 146.7 7,009.9 1,788.9 44.30 720.2 857.3 1,190.4 6,209.6 913.0 147.0 6,929.8 1,770.3 45.30 711.3 846.6 1,190.2 6,132.3 903.8 147.4 6,843.6 1,750.4 46.30 702.7 836.3 1,190.1 6,057.5 894.9 147.7 6,760.2 1,731.2 47.30 409.3 485.0 1,184.9 220.8 198.5 899.3 630.1 683.5 48.30 409.9 485.7 1,185.0 218.8 199.2 910.6 628.6 684.9 49.30 409.6 485.3 1,185.0 219.9 198.8 903.9 629.5 684.1 50.30 409.4 485.1 1,184.9 221.1 198.4 897.2 630.5 683.4 51.30 409.2 484.9 1,184.9 222.3 198.0 890.4 631.5 682.8 52.30 409.0 484.7 1,184.9 223.6 197.6 883.8 632.6 682.2 53.30 408.9 484.5 1,184.9 224.8 197.2 877.2 633.7 681.7 CN-3136 STPEGS UFSAR 6.2-130 Revision 18 TABLE 6.2.1.3-5A (continued) DOUBLE-ENDED PUMP SUCTION BR EAK MASS AND ENERGY RELEASES (Minimum SI)

Time Break Path No. 1 Flow (SG Side) Break Path No. 2 Flow (Pump Side)

Total Mass From Both Sides Total Energy From Both Sides(seconds) (lbm/sec)

Thousand (Btu/sec)

Enthalpy (Btu/lbm) (lbm/sec)

Thousand (Btu/sec)

Enthalpy (Btu/lbm) (lbm/sec)

Thousand (Btu/sec) 53.90 408.8 484.4 1,184.9 225.6 197.0 873.2 634.3 681.3 54.30 408.7 484.3 1,184.9 226.1 196.8 870.6 634.8 681.1 55.30 408.6 484.1 1,184.9 227.3 196.4 864.1 635.9 680.5 56.30 408.4 483.9 1,184.9 228.6 196.1 857.7 637.0 680.0 57.30 408.3 483.8 1,184.9 229.9 195.7 851.2 638.2 679.5 58.30 408.1 483.6 1,184.9 231.2 195.3 844.8 639.3 678.9 59.30 408.0 483.4 1,184.9 232.6 195.0 838.4 640.5 678.4 60.30 407.8 483.3 1,184.9 233.9 194.6 832.1 641.7 677.9 61.30 407.7 483.1 1,184.9 235.3 194.3 825.6 643.0 677.3 62.30 407.5 482.9 1,184.9 236.7 193.9 819.2 644.2 676.8 63.30 407.4 482.7 1,184.9 238.2 193.6 812.8 645.5 676.3 64.30 407.2 482.5 1,184.9 239.6 193.2 806.3 646.8 675.7 65.30 407.0 482.3 1,184.9 241.1 192.9 799.9 648.1 675.1 66.30 406.8 482.0 1,184.9 242.7 192.5 793.4 649.5 674.6 66.40 406.8 482.0 1,184.9 242.8 192.5 792.8 649.6 674.5 67.30 406.6 481.8 1,184.9 244.2 192.2 786.9 650.8 674.0 68.30 406.4 481.6 1,184.9 245.8 191.8 780.4 652.2 673.4 69.30 406.2 481.3 1,184.9 247.4 191.5 773.9 653.6 672.8 70.30 406.0 481.1 1,184.9 249.1 191.1 767.4 655.1 672.2 71.30 405.8 480.8 1,184.9 250.8 190.8 760.8 656.5 671.6 72.30 405.5 480.5 1,184.9 252.5 190.5 754.3 658.0 671.0 73.30 405.3 480.2 1,184.9 254.3 190.1 747.7 659.5 670.3 74.30 405.0 479.9 1,184.9 256.1 189.8 741.1 661.1 669.7 75.30 404.8 479.6 1,184.9 257.9 189.4 734.6 662.6 669.0 76.30 404.5 479.2 1,184.9 259.7 189.1 728.0 664.2 668.3 77.30 404.2 478.9 1,184.9 261.7 188.8 721.5 665.8 667.7 78.30 403.9 478.5 1,184.9 263.6 188.4 714.9 667.5 667.0 79.30 403.5 478.1 1,184.9 265.5 188.1 708.4 669.1 666.2 79.70 403.4 478.0 1,184.8 266.3 188.0 705.8 669.7 665.9 80.30 403.2 477.7 1,184.8 267.5 187.8 701.9 670.7 665.5 81.30 402.8 477.2 1,184.8 269.5 187.4 695.4 672.3 664.7 82.30 402.4 476.8 1,184.8 271.6 187.1 689.0 673.9 663.9 83.30 402.0 476.2 1,184.8 273.6 186.8 682.6 675.6 663.0 84.30 401.5 475.7 1,184.8 275.7 186.4 676.2 677.2 662.1 85.30 401.0 475.1 1,184.8 277.8 186.1 669.9 678.8 661.2 86.30 400.5 474.6 1,184.8 279.9 185.7 663.7 680.4 660.3 88.30 399.5 473.3 1,184.8 284.1 185.1 651.3 683.6 658.3 90.30 398.3 471.9 1,184.8 288.5 184.4 639.1 686.8 656.3 92.30 397.1 470.5 1,184.7 292.9 183.7 627.1 690.0 654.2 94.20 395.9 469.0 1,184.7 297.2 183.1 616.0 693.0 652.0 94.30 395.8 468.9 1,184.7 297.4 183.0 615.4 693.2 651.9 96.30 394.4 467.3 1,184.7 302.0 182.4 603.9 696.4 649.6 98.30 393.0 465.5 1,184.7 306.6 181.7 592.6 699.6 647.2 100.30 391.4 463.7 1,184.7 311.3 181.1 581.6 702.7 644.8 102.30 389.8 461.7 1,184.6 316.1 180.4 570.8 705.9 642.2 104.30 388.1 459.7 1,184.6 320.9 179.8 560.3 709.0 639.5 106.30 386.3 457.6 1,184.6 325.9 179.2 550.0 712.2 636.8 108.30 384.5 455.4 1,184.5 330.9 178.6 539.9 715.3 634.0 110.00 382.8 453.5 1,184.5 335.1 178.2 531.6 718.0 631.6 110.30 382.5 453.1 1,184.5 335.9 178.1 530.2 718.4 631.2 112.30 380.6 450.8 1,184.5 341.0 177.5 520.6 721.6 628.3 114.30 378.5 448.3 1,184.4 346.2 177.0 511.4 724.7 625.4 116.30 376.4 445.8 1,184.4 351.4 176.5 502.4 727.8 622.3 CN-3136 STPEGS UFSAR 6.2-131 Revision 18 TABLE 6.2.1.3-5A (continued) DOUBLE-ENDED PUMP SUCTION BR EAK MASS AND ENERGY RELEASES (Minimum SI)

Time Break Path No. 1 Flow (SG Side) Break Path No. 2 Flow (Pump Side)

Total Mass From Both Sides Total Energy From Both Sides(seconds) (lbm/sec)

Thousand (Btu/sec)

Enthalpy (Btu/lbm) (lbm/sec)

Thousand (Btu/sec)

Enthalpy (Btu/lbm) (lbm/sec)

Thousand (Btu/sec) 118.30 374.2 443.2 1,184.4 356.7 176.1 493.7 730.9 619.3 120.30 372.0 440.6 1,184.3 362.0 175.6 485.2 734.0 616.2 122.30 369.7 437.8 1,184.3 367.4 175.2 476.9 737.1 613.1 124.30 367.3 435.0 1,184.3 372.9 174.8 468.9 740.2 609.9 126.30 364.9 432.1 1,184.2 378.4 174.5 461.2 743.3 606.6 127.70 363.2 430.1 1,184.2 382.3 174.3 455.9 745.5 604.3 128.30 362.4 429.2 1,184.2 384.0 174.2 453.6 746.4 603.4 130.30 359.9 426.2 1,184.2 389.6 173.9 446.3 749.5 600.0 132.30 357.3 423.1 1,184.1 395.3 173.6 439.2 752.6 596.7 134.30 354.6 419.9 1,184.1 401.1 173.4 432.3 755.7 593.3 136.30 351.9 416.6 1,184.0 406.9 173.2 425.7 758.8 589.9 138.30 349.1 413.3 1,184.0 412.9 173.1 419.2 762.0 586.4 140.30 346.2 409.9 1,183.9 418.9 173.0 412.9 765.1 582.9 142.30 343.3 406.4 1,183.9 424.9 172.9 406.8 768.2 579.3 144.30 340.3 402.9 1,183.8 431.1 172.8 400.9 771.4 575.7 146.30 337.3 399.3 1,183.8 437.3 172.8 395.2 774.6 572.1 148.20 334.3 395.7 1,183.8 443.4 172.9 389.9 777.7 568.6 148.30 334.2 395.6 1,183.8 443.7 172.9 389.6 777.8 568.4 150.30 331.0 391.8 1,183.7 450.1 173.0 384.3 781.1 564.7 152.30 327.7 387.9 1,183.7 456.7 173.1 379.0 784.4 560.9 154.30 324.3 383.9 1,183.6 463.4 173.3 373.9 787.7 557.1 156.30 320.9 379.8 1,183.6 470.2 173.5 369.0 791.0 553.3 158.30 317.4 375.6 1,183.5 477.1 173.7 364.2 794.5 549.4 160.30 313.8 371.4 1,183.5 484.1 174.1 359.6 797.9 545.4 162.30 309.9 366.8 1,183.4 491.0 174.3 355.0 801.0 541.1 164.30 305.8 361.9 1,183.3 497.1 174.4 350.8 802.9 536.3 166.30 301.7 357.0 1,183.3 503.2 174.5 346.8 804.9 531.5 168.30 297.6 352.1 1,183.2 509.3 174.7 342.9 806.9 526.8 170.30 293.2 346.9 1,183.2 515.5 174.8 339.1 808.8 521.7 172.30 288.6 341.5 1,183.1 521.0 174.8 335.5 809.7 516.3 173.10 286.8 339.3 1,183.1 523.3 174.8 334.1 810.1 514.1 End of Reflood 173.20 324.5 404.1 1,245.4 622.7 204.6 328.6 947.1 608.7 178.20 300.8 374.5 1,245.4 646.4 202.7 313.7 947.1 577.3 183.20 300.1 373.7 1,245.4 647.1 202.7 313.2 947.1 576.4 188.20 298.2 371.3 1,245.4 649.0 202.9 312.7 947.1 574.2 193.20 297.4 370.4 1,245.4 649.7 202.9 312.2 947.1 573.3 198.20 296.7 369.5 1,245.4 650.5 202.8 311.8 947.1 572.3 203.20 296.1 368.8 1,245.4 651.0 202.7 311.4 947.1 571.5 208.20 295.6 368.1 1,245.4 651.5 202.6 311.0 947.1 570.7 213.20 293.8 365.9 1,245.4 653.3 202.8 310.5 947.1 568.8 218.20 293.3 365.2 1,245.4 653.9 202.8 310.1 947.1 568.0 223.20 292.7 364.5 1,245.4 654.5 202.7 309.7 947.1 567.1 228.20 292.0 363.6 1,245.4 655.2 202.6 309.3 947.1 566.2 233.20 291.3 362.8 1,245.4 655.9 202.6 308.8 947.1 565.3 238.20 289.4 360.4 1,245.4 657.8 202.8 308.4 947.1 563.2 243.20 288.6 359.4 1,245.4 658.5 202.8 307.9 947.1 562.2 248.20 287.8 358.4 1,245.4 659.4 202.8 307.5 947.1 561.2 253.20 286.9 357.3 1,245.4 660.2 202.8 307.1 947.1 560.1 258.20 286.0 356.1 1,245.4 661.2 202.8 306.7 947.1 558.9 263.20 285.0 354.9 1,245.4 662.1 202.8 306.3 947.1 557.7 268.20 284.0 353.7 1,245.4 663.2 202.8 305.8 947.1 556.5 CN-3136 STPEGS UFSAR 6.2-132 Revision 18 TABLE 6.2.1.3-5A (continued) DOUBLE-ENDED PUMP SUCTION BR EAK MASS AND ENERGY RELEASES (Minimum SI)

Time Break Path No. 1 Flow (SG Side) Break Path No. 2 Flow (Pump Side)

Total Mass From Both Sides Total Energy From Both Sides(seconds) (lbm/sec)

Thousand (Btu/sec)

Enthalpy (Btu/lbm) (lbm/sec)

Thousand (Btu/sec)

Enthalpy (Btu/lbm) (lbm/sec)

Thousand (Btu/sec) 273.20 284.0 353.6 1,245.4 663.2 202.6 305.4 947.1 556.2 278.20 282.8 352.2 1,245.4 664.3 202.6 305.0 947.1 554.8 283.20 281.6 350.7 1,245.4 665.6 202.7 304.6 947.1 553.4 288.20 280.3 349.1 1,245.4 666.9 202.8 304.1 947.1 551.9 293.20 280.0 348.7 1,245.4 667.2 202.7 303.7 947.1 551.3 298.20 278.5 346.9 1,245.4 668.6 202.8 303.3 947.1 549.7 303.20 278.0 346.2 1,245.4 669.1 202.7 302.9 947.1 548.9 308.20 276.4 344.2 1,245.4 670.8 202.9 302.4 947.1 547.1 313.20 275.7 343.3 1,245.4 671.5 202.8 302.0 947.1 546.1 318.20 274.9 342.3 1,245.4 672.3 202.8 301.6 947.1 545.1 323.20 273.9 341.1 1,245.4 673.3 202.8 301.2 947.1 543.9 328.20 272.8 339.7 1,245.4 674.3 202.8 300.8 947.1 542.6 333.20 271.6 338.2 1,245.4 675.6 202.9 300.3 947.1 541.1 338.20 271.1 337.6 1,245.4 676.0 202.8 300.0 947.1 540.4 343.20 269.6 335.7 1,245.4 677.6 202.9 299.5 947.1 538.6 348.20 268.7 334.6 1,245.4 678.4 202.9 299.1 947.1 537.6 353.20 267.6 333.3 1,245.4 679.5 203.0 298.7 947.1 536.3 358.20 266.3 331.7 1,245.4 680.8 203.1 298.2 947.1 534.7 363.20 265.6 330.7 1,245.4 681.6 203.0 297.8 947.1 533.7 368.20 264.5 329.4 1,245.4 682.7 203.0 297.4 947.1 532.4 373.20 263.8 328.5 1,245.4 683.4 203.0 297.0 947.1 531.5 378.20 262.7 327.1 1,245.4 684.5 203.0 296.6 947.1 530.1 383.20 261.0 325.1 1,245.4 686.1 203.2 296.2 947.1 528.3 388.20 260.2 324.1 1,245.4 686.9 203.2 295.8 947.1 527.3 393.20 258.7 322.2 1,245.4 688.4 203.3 295.3 947.1 525.5 398.20 257.6 320.8 1,245.4 689.6 203.4 294.9 947.1 524.2 403.20 256.6 319.6 1,245.4 690.5 203.4 294.5 947.1 523.0 408.20 255.3 317.9 1,245.4 691.9 203.5 294.1 947.1 521.4 413.20 254.0 316.3 1,245.4 693.2 203.6 293.7 947.1 519.9 639.85 254.0 316.3 1,245.4 693.2 203.6 293.7 947.1 519.9 639.95 106.3 131.2 1,235.2 840.9 239.7 285.1 947.1 371.0 643.20 106.2 131.1 1,235.2 841.0 239.6 284.8 947.1 370.7 1,464.90 106.2 131.1 1,235.2 841.0 239.6 284.8 947.1 370.7 Start of sump recirculation 1,465.00 89.1 109.9 1,233.3567.6295.3520.3656.7 405.21,613.06 89.1 109.9 1,233.3 567.6 295.3 520.3 656.7 405.2 1,613.16 85.5 98.3 1,150.6 571.2 175.3 306.9 656.7 273.6 3,600.00 70.0 80.6 1,150.6 586.6 178.1 303.6 656.7 258.7 Start of revised post-recirculation methodology [4] NOTES: 1. Pump Suction Break Area = 5.24 ft

2. Pipe inside diameter = 2.58 ft. 2. The blowdown phase mass and energy releases are the same for Minimum and Maximum SI cases. 3. Blowdown ends at 25.2 seconds. Reflood ends at 173.1 seconds. Sump recirculation begins at 1465 seconds. All SGs depressurized to atmospheric pressure at 3600 seconds. 4. After 3600 seconds, the revised post recirculation methodology is used, as discussed in Section 6.2.1.3.4.5.

CN-3136 STPEGS UFSAR 6.2-133 Revision 18 TABLE 6.2.1.3-5B DOUBLE-ENDED PUMP SUCTION BR EAK MASS AND ENERGY RELEASES (Maximum SI)

Time Break Path No. 1 Flow (SG Side) Break Path No. 2 Flow (Pump Side) Total Mass From Both Sides Total Energy From Both Sides (seconds) (lbm/sec) Thousand (Btu/sec) Enthalpy (Btu/lbm) (lbm/sec) Thousand (Btu/sec) Enthalpy (Btu/lbm) (lbm/sec) Thousand (Btu/sec) 0.00 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.00114 97,158.3 54,746.8 563.5 43,339.6 24,348.1 561.8 140,497.9 79,094.8 0.10 43,480.5 24,471.9 562.8 21,547.8 12,088.3 561.0 65,028.3 36,560.2 0.20 51,982.9 29,373.7 565.1 24,528.6 13,777.6 561.7 76,511.5 43,151.3 0.30 51,633.9 29,319.5 567.8 25,873.5 14,546.5 562.2 77,507.4 43,866.0 0.40 51,282.7 29,294.9 571.2 25,649.9 14,432.9 562.7 76,932.6 43,727.8 0.50 50,920.4 29,294.0 575.3 24,960.9 14,057.0 563.2 75,881.3 43,351.0 0.60 50,714.3 29,407.1 579.9 24,416.8 13,760.3 563.6 75,131.1 43,167.3 0.70 49,896.9 29,180.0 584.8 24,052.4 13,561.7 563.8 73,949.4 42,741.7 0.80 48,045.5 28,330.9 589.7 23,753.6 13,396.9 564.0 71,799.1 41,727.8 0.90 47,471.7 28,211.3 594.3 23,440.1 13,222.0 564.1 70,911.8 41,433.3 1.00 47,553.0 28,462.2 598.5 23,099.6 13,030.6 564.1 70,652.7 41,492.8 1.10 47,301.6 28,504.7 602.6 22,771.3 12,845.1 564.1 70,072.9 41,349.8 1.20 46,713.0 28,337.7 606.6 22,488.7 12,685.9 564.1 69,201.7 41,023.6 1.30 45,879.3 28,014.4 610.6 22,307.8 12,584.1 564.1 68,187.1 40,598.6 1.40 44,977.2 27,652.8 614.8 22,153.8 12,497.8 564.1 67,131.0 40,150.5 1.50 44,069.3 27,288.9 619.2 22,023.9 12,425.0 564.2 66,093.2 39,713.9 1.60 43,087.0 26,882.9 623.9 21,910.8 12,361.3 564.2 64,997.8 39,244.1 1.70 42,038.7 26,434.8 628.8 21,829.6 12,315.5 564.2 63,868.3 38,750.3 1.80 40,932.5 25,950.6 634.0 21,785.3 12,290.8 564.2 62,717.8 38,241.4 1.90 39,839.5 25,469.8 639.3 21,742.5 12,267.2 564.2 61,582.0 37,737.0 2.00 38,715.4 24,965.0 644.8 21,660.5 12,221.1 564.2 60,375.9 37,186.1 2.10 37,556.9 24,426.6 650.4 21,545.6 12,156.0 564.2 59,102.4 36,582.6 2.20 36,371.7 23,856.7 655.9 21,371.8 12,057.1 564.2 57,743.5 35,913.8 2.30 35,147.2 23,250.1 661.5 21,088.3 11,896.7 564.1 56,235.5 35,146.8 2.40 34,060.0 22,718.5 667.0 20,894.6 11,787.9 564.2 54,954.6 34,506.4 2.50 32,996.1 22,186.4 672.4 20,712.4 11,685.5 564.2 53,708.6 33,871.9 2.60 31,939.8 21,643.1 677.6 20,514.2 11,573.9 564.2 52,454.0 33,217.0 2.70 30,932.3 21,118.9 682.7 20,313.0 11,460.6 564.2 51,245.3 32,579.6 2.80 29,765.0 20,472.0 687.8 20,113.0 11,348.2 564.2 49,878.0 31,820.2 2.90 27,445.6 18,995.3 692.1 19,902.8 11,230.2 564.2 47,348.4 30,225.5 3.00 25,766.4 17,965.5 697.2 19,688.4 11,109.8 564.3 45,454.8 29,075.2 3.10 24,813.9 17,434.4 702.6 19,480.3 10,993.1 564.3 44,294.2 28,427.6 3.20 23,807.7 16,826.2 706.8 19,276.4 10,879.0 564.4 43,084.1 27,705.1 3.30 22,807.1 16,193.0 710.0 19,070.0 10,763.4 564.4 41,877.1 26,956.4 3.40 22,078.1 15,737.9 712.8 18,852.2 10,641.4 564.5 40,930.3 26,379.3 3.50 21,448.8 15,339.9 715.2 18,643.2 10,524.4 564.5 40,092.0 25,864.3 3.60 20,878.1 14,972.0 717.1 18,453.8 10,418.7 564.6 39,331.9 25,390.8 3.70 20,389.7 14,654.9 718.7 18,266.8 10,314.4 564.7 38,656.5 24,969.4 3.80 19,938.4 14,356.3 720.0 18,076.3 10,208.1 564.7 38,014.7 24,564.4 3.90 19,505.0 14,064.6 721.1 17,883.0 10,100.1 564.8 37,388.1 24,164.7 4.00 19,114.4 13,799.7 722.0 17,705.0 10,000.9 564.9 36,819.4 23,800.6 4.20 18,464.4 13,353.2 723.2 17,375.2 9,817.4 565.0 35,839.6 23,170.6 4.40 17,903.6 12,954.7 723.6 17,046.4 9,634.3 565.2 34,950.0 22,589.0 4.60 17,483.5 12,645.2 723.3 16,753.7 9,471.7 565.3 34,237.2 22,116.9 CN-3136 STPEGS UFSAR 6.2-134 Revision 18 TABLE 6.2.1.3-5B (continued) DOUBLE-ENDED PUMP SUCTION BR EAK MASS AND ENERGY RELEASES (Maximum SI)

Time Break Path No. 1 Flow (SG Side) Break Path No. 2 Flow (Pump Side) Total Mass From Both Sides Total Energy From Both Sides (seconds) (lbm/sec) Thousand (Btu/sec) Enthalpy (Btu/lbm) (lbm/sec) Thousand (Btu/sec) Enthalpy (Btu/lbm) (lbm/sec) Thousand (Btu/sec) 4.80 17,144.9 12,380.3 722.1 16,458.5 9,307.4 565.5 33,603.4 21,687.7 5.20 17,002.0 12,201.1 717.6 15,778.8 8,926.8 565.7 32,780.7 21,127.8 5.40 17,031.9 12,141.1 712.8 15,592.9 8,826.8 566.1 32,624.8 20,967.8 5.60 16,900.2 12,240.9 724.3 15,241.3 8,629.2 566.2 32,141.5 20,870.0 5.80 15,466.8 11,897.2 769.2 15,053.8 8,528.0 566.5 30,520.6 20,425.2 6.00 14,376.0 11,430.7 795.1 16,196.3 9,180.7 566.8 30,572.3 20,611.4 6.20 14,657.9 11,492.0 784.0 15,895.2 9,009.6 566.8 30,553.2 20,501.7 6.40 15,346.8 11,800.3 768.9 15,813.2 8,967.1 567.1 31,160.1 20,767.5 6.60 15,997.4 12,107.9 756.9 15,629.5 8,865.9 567.3 31,626.9 20,973.8 6.80 16,544.7 12,356.4 746.9 15,430.6 8,756.7 567.5 31,975.3 21,113.1 7.00 16,993.7 12,521.2 736.8 15,310.6 8,692.4 567.7 32,304.3 21,213.6 7.20 17,301.2 12,567.4 726.4 15,127.2 8,590.1 567.9 32,428.4 21,157.5 7.40 17,454.4 12,526.1 717.6 14,903.7 8,463.6 567.9 32,358.1 20,989.7 7.60 17,610.0 12,526.9 711.4 14,723.3 8,361.1 567.9 32,333.3 20,888.0 7.80 17,829.7 12,592.3 706.3 14,506.8 8,237.2 567.8 32,336.4 20,829.6 8.00 17,924.5 12,575.6 701.6 14,289.4 8,113.0 567.8 32,213.9 20,688.6 8.20 17,836.0 12,454.6 698.3 14,107.1 8,009.0 567.7 31,943.1 20,463.6 8.40 17,825.2 12,420.5 696.8 13,922.3 7,903.6 567.7 31,747.5 20,324.1 8.60 17,956.9 12,483.5 695.2 13,698.3 7,775.5 567.6 31,655.2 20,259.0 8.80 17,676.8 12,241.5 692.5 13,487.0 7,655.0 567.6 31,163.8 19,896.5 9.00 17,077.6 11,811.4 691.6 13,366.6 7,586.8 567.6 30,444.2 19,398.2 9.20 16,898.6 11,709.6 692.9 13,192.2 7,486.7 567.5 30,090.8 19,196.3 9.40 17,090.6 11,826.0 692.0 12,944.4 7,344.6 567.4 30,035.1 19,170.6 9.60 16,910.7 11,644.8 688.6 12,758.2 7,238.8 567.4 29,668.9 18,883.5 9.80 14,830.5 10,196.8 687.6 12,709.0 7,211.9 567.5 27,539.5 17,408.8 10.00 12,649.1 8,828.0 697.9 13,118.2 7,446.2 567.6 25,767.3 16,274.2 10.20 12,658.6 9,020.5 712.6 12,514.9 7,092.9 566.8 25,173.5 16,113.4 10.40 12,797.8 9,094.0 710.6 12,318.5 6,983.1 566.9 25,116.3 16,077.1 10.60 11,922.0 8,448.1 708.6 12,796.2 7,260.6 567.4 24,718.1 15,708.6 10.80 11,736.9 8,446.7 719.7 12,339.2 6,994.1 566.8 24,076.0 15,440.8 11.00 12,081.0 8,773.4 726.2 12,043.5 6,825.4 566.7 24,124.5 15,598.8 11.20 11,784.2 8,497.8 721.1 12,135.5 6,881.3 567.0 23,919.7 15,379.1 11.40 11,410.1 8,242.3 722.4 12,060.5 6,838.9 567.1 23,470.5 15,081.3 11.60 12,022.0 8,705.2 724.1 11,676.4 6,616.5 566.7 23,698.5 15,321.8 11.80 12,800.0 9,129.8 713.3 11,454.4 6,491.8 566.7 24,254.4 15,621.5 12.00 11,778.0 8,305.9 705.2 11,582.3 6,569.0 567.2 23,360.3 14,874.9 12.20 10,425.1 7,479.6 717.5 11,903.4 6,749.6 567.0 22,328.4 14,229.3 12.40 10,397.9 7,613.8 732.2 11,064.1 6,264.2 566.2 21,462.1 13,877.9 12.60 10,018.5 7,345.8 733.2 11,629.6 6,594.0 567.0 21,648.1 13,939.8 12.80 9,733.9 7,184.7 738.1 11,276.7 6,388.8 566.5 21,010.6 13,573.5 13.00 9,876.1 7,359.2 745.2 11,100.7 6,292.2 566.8 20,976.8 13,651.4 13.20 9,734.1 7,235.4 743.3 11,058.9 6,270.0 567.0 20,792.9 13,505.4 13.40 9,607.8 7,128.7 742.0 10,975.5 6,225.1 567.2 20,583.3 13,353.7 13.60 9,972.8 7,373.1 739.3 10,604.9 6,014.2 567.1 20,577.6 13,387.3 13.80 9,909.5 7,230.9 729.7 10,672.5 6,057.1 567.5 20,582.0 13,288.1 14.00 9,207.4 6,740.9 732.1 10,751.1 6,104.7 567.8 19,958.5 12,845.6 14.20 9,198.0 6,827.9 742.3 10,242.6 5,817.7 568.0 19,440.7 12,645.5 14.40 8,859.7 6,572.9 741.9 10,609.9 6,035.7 568.9 19,469.6 12,608.5 14.60 8,566.4 6,402.9 747.4 10,296.8 5,861.4 569.2 18,863.2 12,264.3 14.80 8,533.4 6,474.8 758.8 10,211.7 5,827.7 570.7 18,745.1 12,302.5 CN-3136 STPEGS UFSAR 6.2-135 Revision 18 TABLE 6.2.1.3-5B (continued) DOUBLE-ENDED PUMP SUCTION BR EAK MASS AND ENERGY RELEASES (Maximum SI)

Time Break Path No. 1 Flow (SG Side) Break Path No. 2 Flow (Pump Side) Total Mass From Both Sides Total Energy From Both Sides (seconds) (lbm/sec) Thousand (Btu/sec) Enthalpy (Btu/lbm) (lbm/sec) Thousand (Btu/sec) Enthalpy (Btu/lbm) (lbm/sec) Thousand (Btu/sec) 15.00 8,216.2 6,319.6 769.2 10,063.9 5,745.5 570.9 18,280.1 12,065.1 15.20 8,116.9 6,272.4 772.8 9,886.0 5,654.2 571.9 18,002.9 11,926.6 15.40 8,111.4 6,214.1 766.1 9,718.4 5,562.7 572.4 17,829.8 11,776.8 15.60 7,997.5 6,067.5 758.7 9,736.5 5,583.5 573.5 17,734.0 11,651.0 15.80 7,981.8 6,028.7 755.3 9,444.5 5,428.5 574.8 17,426.2 11,457.2 16.00 7,827.7 5,894.1 753.0 9,559.1 5,508.9 576.3 17,386.9 11,403.1 16.20 7,670.7 5,794.8 755.4 9,331.2 5,405.3 579.3 17,001.9 11,200.0 16.40 7,560.1 5,759.4 761.8 9,310.0 5,419.4 582.1 16,870.1 11,178.8 16.60 7,435.8 5,732.5 770.9 9,144.5 5,356.4 585.8 16,580.2 11,088.9 16.80 7,286.3 5,686.3 780.4 8,976.1 5,287.4 589.0 16,262.4 10,973.6 17.00 7,157.4 5,633.2 787.0 8,762.9 5,196.7 593.0 15,920.4 10,829.9 17.20 7,050.4 5,571.8 790.3 8,538.6 5,097.8 597.0 15,589.0 10,669.6 17.40 6,958.0 5,516.4 792.8 8,327.4 5,015.3 602.3 15,285.4 10,531.7 17.60 6,849.1 5,460.8 797.3 8,119.3 4,942.0 608.7 14,968.4 10,402.8 17.80 6,723.1 5,414.2 805.3 7,902.6 4,875.6 617.0 14,625.7 10,289.8 18.00 6,585.5 5,382.0 817.3 7,668.1 4,807.5 626.9 14,253.6 10,189.5 18.20 6,430.2 5,356.2 833.0 7,441.3 4,749.7 638.3 13,871.6 10,105.9 18.40 6,261.9 5,327.1 850.7 7,187.1 4,681.0 651.3 13,448.9 10,008.0 18.60 6,107.3 5,301.0 868.0 6,981.9 4,661.7 667.7 13,089.2 9,962.7 18.80 5,941.4 5,251.4 883.9 6,470.9 4,522.9 699.0 12,412.3 9,774.3 19.00 5,702.7 5,205.0 912.7 5,996.7 4,374.5 729.5 11,699.4 9,579.5 19.20 5,251.8 5,128.4 976.5 5,581.4 4,262.8 763.7 10,833.1 9,391.1 19.40 4,598.8 4,953.8 1,077.2 5,082.1 4,145.8 815.8 9,680.9 9,099.6 19.60 3,926.3 4,649.5 1,184.2 4,413.1 4,052.0 918.2 8,339.4 8,701.5 19.80 3,408.6 4,188.7 1,228.9 2,536.6 2,869.1 1,131.1 5,945.1 7,057.8 20.00 3,024.3 3,747.2 1,239.0 1,724.2 2,095.5 1,215.3 4,748.5 5,842.7 20.20 2,731.6 3,399.5 1,244.5 1,504.4 1,859.6 1,236.2 4,236.0 5,259.1 20.40 2,468.3 3,081.6 1,248.5 1,351.9 1,681.7 1,243.9 3,820.2 4,763.3 20.60 2,239.0 2,803.8 1,252.3 1,229.0 1,535.2 1,249.1 3,468.0 4,339.0 20.80 2,048.2 2,571.6 1,255.6 1,110.7 1,392.9 1,254.1 3,158.9 3,964.5 21.00 1,892.3 2,381.5 1,258.5 1,480.9 1,611.7 1,088.4 3,373.2 3,993.2 21.20 1,796.6 2,265.5 1,261.0 2,572.9 1,432.5 556.7 4,369.5 3,698.0 21.40 1,711.4 2,160.7 1,262.5 2,837.4 1,364.0 480.7 4,548.9 3,524.7 21.60 1,619.6 2,046.9 1,263.8 3,167.8 1,406.2 443.9 4,787.4 3,453.0 21.80 1,501.7 1,899.3 1,264.8 3,156.0 1,336.7 423.5 4,657.7 3,236.0 22.00 1,388.1 1,758.3 1,266.8 2,799.3 1,149.5 410.6 4,187.4 2,907.8 22.20 1,275.2 1,617.3 1,268.2 2,433.4 977.0 401.5 3,708.6 2,594.3 22.40 1,171.6 1,487.4 1,269.6 2,162.1 850.7 393.5 3,333.7 2,338.2 22.60 1,045.0 1,328.9 1,271.7 1,952.0 751.4 385.0 2,996.9 2,080.3 22.80 946.3 1,204.8 1,273.1 1,774.9 666.0 375.2 2,721.2 1,870.8 23.00 877.3 1,118.2 1,274.7 1,635.9 597.7 365.3 2,513.1 1,715.9 23.20 831.5 1,060.7 1,275.6 1,731.5 613.6 354.4 2,563.0 1,674.3 23.40 802.0 1,023.6 1,276.4 2,058.5 696.1 338.2 2,860.5 1,719.8 23.60 775.7 990.4 1,276.9 2,539.4 819.5 322.7 3,315.1 1,810.0 23.80 727.1 928.6 1,277.1 3,217.9 995.9 309.5 3,945.1 1,924.5 24.00 557.7 712.0 1,276.5 3,471.3 1,035.2 298.2 4,029.0 1,747.1 24.20 453.5 579.7 1,278.3 2,353.0 685.2 291.2 2,806.5 1,264.9 24.40 375.8 480.8 1,279.4 1,269.5 365.6 288.0 1,645.3 846.4 24.60 279.1 357.3 1,280.4 543.6 156.0 286.9 822.6 513.3 24.80 168.9 216.5 1,281.9 91.9 26.4 287.1 260.8 242.9 25.00 37.6 48.4 1,285.8 0.0 0.0 0.0 37.6 48.4 25.20 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 CN-3136 STPEGS UFSAR 6.2-136 Revision 18 TABLE 6.2.1.3-5B (continued) DOUBLE-ENDED PUMP SUCTION BR EAK MASS AND ENERGY RELEASES (Maximum SI)

Time Break Path No. 1 Flow (SG Side) Break Path No. 2 Flow (Pump Side) Total Mass From Both Sides Total Energy From Both Sides (seconds) (lbm/sec) Thousand (Btu/sec) Enthalpy (Btu/lbm) (lbm/sec) Thousand (Btu/sec) Enthalpy (Btu/lbm) (lbm/sec) Thousand (Btu/sec)

End of Blowdown 25.65 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 25.75 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 25.85 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 25.95 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 26.05 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 26.28 56.5 66.7 1,180.8 0.0 0.0 0.0 56.5 66.7 26.38 58.3 68.9 1,180.8 0.0 0.0 0.0 58.3 68.9 26.48 66.1 78.0 1,180.9 0.0 0.0 0.0 66.1 78.0 26.58 73.8 87.2 1,180.9 0.0 0.0 0.0 73.8 87.2 26.68 81.1 95.8 1,180.9 0.0 0.0 0.0 81.1 95.8 26.78 88.1 104.0 1,181.0 0.0 0.0 0.0 88.1 104.0 26.85 93.1 109.9 1,181.0 0.0 0.0 0.0 93.1 109.9 26.88 94.7 111.8 1,181.0 0.0 0.0 0.0 94.7 111.8 26.98 101.0 119.2 1,181.1 0.0 0.0 0.0 101.0 119.2 27.08 107.0 126.3 1,181.1 0.0 0.0 0.0 107.0 126.3 27.18 112.7 133.1 1,181.1 0.0 0.0 0.0 112.7 133.1 27.28 118.2 139.7 1,181.2 0.0 0.0 0.0 118.2 139.7 27.38 123.6 146.0 1,181.2 0.0 0.0 0.0 123.6 146.0 27.48 128.7 152.1 1,181.3 0.0 0.0 0.0 128.7 152.1 27.58 133.7 158.0 1,181.3 0.0 0.0 0.0 133.7 158.0 27.68 138.6 163.7 1,181.3 0.0 0.0 0.0 138.6 163.7 27.78 143.3 169.2 1,181.4 0.0 0.0 0.0 143.3 169.2 27.88 147.8 174.6 1,181.4 0.0 0.0 0.0 147.8 174.6 27.98 152.3 179.9 1,181.5 0.0 0.0 0.0 152.3 179.9 28.08 156.6 185.0 1,181.5 0.0 0.0 0.0 156.6 185.0 28.18 160.9 190.1 1,181.5 0.0 0.0 0.0 160.9 190.1 28.28 165.0 195.0 1,181.6 0.0 0.0 0.0 165.0 195.0 29.28 202.1 238.9 1,182.0 0.0 0.0 0.0 202.1 238.9 30.00 768.7 915.4 1,190.8 6,636.7 910.3 137.2 7,405.4 1,825.7 30.30 808.8 963.9 1,191.8 6,942.3 988.6 142.4 7,751.1 1,952.5 31.30 806.1 960.8 1,191.9 6,925.2 997.7 144.1 7,731.3 1,958.5 32.30 795.6 948.1 1,191.76,828.4986.0144.47,624.0 1,934.1 32.70 790.1 941.4 1,191.6 6,786.0 980.9 144.5 7,576.1 1,922.3 33.30 895.8 1,068.6 1,192.9 7,651.0 1,096.6 143.3 8,546.8 2,165.2 34.30 865.2 1,032.2 1,193.1 7,506.6 1,074.0 143.1 8,371.8 2,106.3 35.30 854.0 1,018.7 1,192.9 7,404.2 1,061.0 143.3 8,258.2 2,079.7 35.80 848.6 1,012.1 1,192.8 7,353.3 1,054.6 143.4 8,201.8 2,066.7 36.30 843.2 1,005.7 1,192.7 7,302.8 1,048.2 143.5 8,146.0 2,053.9 37.30 832.9 993.2 1,192.4 7,203.6 1,035.8 143.8 8,036.5 2,029.0 38.30 823.1 981.3 1,192.2 7,107.1 1,023.7 144.0 7,930.2 2,005.1 39.30 813.8 970.1 1,192.0 7,013.3 1,012.1 144.3 7,827.1 1,982.2 40.30 805.0 959.4 1,191.9 6,922.5 1,001.0 144.6 7,727.5 1,960.4 41.30 796.6 949.2 1,191.7 6,834.6 990.3 144.9 7,631.1 1,939.5 42.30 786.7 937.3 1,191.5 6,751.1 980.3 145.2 7,537.8 1,917.6 43.00 780.0 929.3 1,191.4 6,694.3 973.6 145.4 7,474.2 1,902.9 43.30 777.2 925.9 1,191.3 6,670.3 970.8 145.5 7,447.4 1,896.6 44.30 768.0 914.9 1,191.2 6,592.0 961.5 145.9 7,360.1 1,876.4 45.30 759.3 904.3 1,191.0 6,516.2 952.6 146.2 7,275.5 1,856.9 46.30 750.8 894.1 1,190.9 6,442.8 943.9 146.5 7,193.6 1,838.0 47.30 562.3 669.5 1,190.8 1,683.5 491.7 292.1 2,245.7 1,161.2 48.30 346.6 410.4 1,184.0 953.2 280.8 294.5 1,299.8 691.1 CN-3136 STPEGS UFSAR 6.2-137 Revision 18 TABLE 6.2.1.3-5B (continued) DOUBLE-ENDED PUMP SUCTION BR EAK MASS AND ENERGY RELEASES (Maximum SI)

Time Break Path No. 1 Flow (SG Side) Break Path No. 2 Flow (Pump Side) Total Mass From Both Sides Total Energy From Both Sides (seconds) (lbm/sec) Thousand (Btu/sec) Enthalpy (Btu/lbm) (lbm/sec) Thousand (Btu/sec) Enthalpy (Btu/lbm) (lbm/sec) Thousand (Btu/sec) 49.30 326.1 386.0 1,183.7 986.4 285.7 289.6 1,312.5 671.7 50.30 315.5 373.4 1,183.5 1,003.5 288.4 287.4 1,319.0 661.7 51.30 306.6 362.9 1,183.4 1,017.8 290.7 285.6 1,324.4 653.5 52.30 297.9 352.4 1,183.2 1,031.9 293.0 284.0 1,329.7 645.5 53.30 288.7 341.5 1,183.1 1,046.6 295.5 282.4 1,335.2 637.1 53.40 287.7 340.4 1,183.1 1,048.1 295.8 282.2 1,335.8 636.2 54.30 278.9 329.9 1,183.0 1,062.1 298.2 280.8 1,341.0 628.1 55.30 268.3 317.4 1,182.8 1,078.8 301.2 279.2 1,347.1 618.6 56.30 256.8 303.7 1,182.7 1,096.7 304.5 277.7 1,353.5 608.2 57.30 244.4 289.0 1,182.5 1,116.9 308.4 276.1 1,361.3 597.4 58.30 234.3 277.1 1,182.4 1,132.4 311.5 275.0 1,366.8 588.5 59.30 227.1 268.5 1,182.3 1,143.9 313.4 274.0 1,371.0 581.9 60.30 226.1 267.3 1,182.3 1,145.9 313.5 273.6 1,372.0 580.8 61.30 225.7 266.8 1,182.3 1,147.1 313.4 273.2 1,372.7 580.2 62.30 225.3 266.3 1,182.3 1,148.2 313.3 272.9 1,373.5 579.6 63.30 224.8 265.8 1,182.2 1,149.4 313.2 272.5 1,374.2 579.0 64.30 224.4 265.3 1,182.2 1,150.6 313.1 272.1 1,375.0 578.5 65.30 224.0 264.9 1,182.2 1,151.8 313.0 271.8 1,375.8 577.9 66.30 223.6 264.4 1,182.2 1,153.0 312.9 271.4 1,376.6 577.3 67.30 223.2 263.9 1,182.2 1,154.1 312.9 271.1 1,377.4 576.8 68.30 222.8 263.4 1,182.2 1,155.3 312.8 270.7 1,378.2 576.2 69.30 222.4 263.0 1,182.2 1,156.6 312.7 270.4 1,379.0 575.7 69.60 222.3 262.8 1,182.2 1,156.9 312.7 270.3 1,379.2 575.5 70.30 222.0 262.5 1,182.2 1,157.8 312.6 270.0 1,379.8 575.1 71.30 221.6 262.0 1,182.2 1,159.0 312.5 269.7 1,380.6 574.6 72.30 221.3 261.6 1,182.2 1,160.2 312.5 269.3 1,381.5 574.0 73.30 220.9 261.1 1,182.2 1,161.5 312.4 269.0 1,382.3 573.5 74.30 220.5 260.7 1,182.2 1,162.7 312.3 268.6 1,383.2 573.0 75.30 220.1 260.2 1,182.2 1,163.9 312.2 268.3 1,384.0 572.4 76.30 219.7 259.7 1,182.2 1,165.2 312.2 267.9 1,384.9 571.9 77.30 219.3 259.3 1,182.2 1,166.4 312.1 267.5 1,385.8 571.4 78.30 219.0 258.8 1,182.2 1,167.7 312.0 267.2 1,386.7 570.9 79.30 218.6 258.4 1,182.2 1,169.0 311.9 266.8 1,387.6 570.3 80.30 218.2 258.0 1,182.2 1,170.3 311.9 266.5 1,388.5 569.8 81.30 217.8 257.5 1,182.2 1,171.5 311.8 266.1 1,389.4 569.3 82.30 217.5 257.1 1,182.2 1,172.8 311.7 265.8 1,390.3 568.8 83.30 217.1 256.6 1,182.2 1,174.1 311.7 265.4 1,391.2 568.3 84.30 216.7 256.2 1,182.2 1,175.5 311.6 265.1 1,392.2 567.8 85.30 216.3 255.7 1,182.1 1,176.8 311.5 264.7 1,393.1 567.3 86.30 216.0 255.3 1,182.1 1,178.1 311.5 264.4 1,394.1 566.7 87.40 215.6 254.8 1,182.1 1,179.6 311.4 264.0 1,395.1 566.2 88.30 215.2 254.4 1,182.1 1,180.8 311.3 263.7 1,396.0 565.7 90.30 214.5 253.5 1,182.1 1,183.4 311.2 263.0 1,397.9 564.7 92.30 213.8 252.7 1,182.1 1,186.0 311.0 262.3 1,399.7 563.7 94.30 213.0 251.8 1,182.1 1,188.6 310.9 261.5 1,401.6 562.7 96.30 212.3 251.0 1,182.1 1,191.1 310.7 260.8 1,403.4 561.7 98.30 211.6 250.1 1,182.1 1,193.7 310.5 260.1 1,405.3 560.6 100.30 210.9 249.3 1,182.1 1,196.2 310.4 259.4 1,407.1 559.6 102.30 210.2 248.4 1,182.1 1,198.7 310.2 258.7 1,408.9 558.6 104.30 209.5 247.6 1,182.1 1,201.2 310.0 258.0 1,410.7 557.6 106.30 208.8 246.8 1,182.1 1,203.7 309.8 257.3 1,412.5 556.5 106.90 208.6 246.5 1,182.1 1,204.4 309.7 257.1 1,413.0 556.2 108.30 208.1 245.9 1,182.0 1,206.2 309.6 256.6 1,414.2 555.5 CN-3136 STPEGS UFSAR 6.2-138 Revision 18 TABLE 6.2.1.3-5B (continued) DOUBLE-ENDED PUMP SUCTION BR EAK MASS AND ENERGY RELEASES (Maximum SI)

Time Break Path No. 1 Flow (SG Side) Break Path No. 2 Flow (Pump Side) Total Mass From Both Sides Total Energy From Both Sides (seconds) (lbm/sec) Thousand (Btu/sec) Enthalpy (Btu/lbm) (lbm/sec) Thousand (Btu/sec) Enthalpy (Btu/lbm) (lbm/sec) Thousand (Btu/sec) 110.30 207.4 245.1 1,182.0 1,208.6 309.4 256.0 1,416.0 554.5 112.30 206.7 244.3 1,182.0 1,211.0 309.1 255.3 1,417.8 553.5 114.30 206.0 243.5 1,182.0 1,213.5 308.9 254.6 1,419.5 552.5 116.30 205.4 242.8 1,182.0 1,215.9 308.7 253.9 1,421.2 551.5 118.30 204.7 242.0 1,182.0 1,218.2 308.5 253.2 1,423.0 550.5 120.30 204.1 241.2 1,182.0 1,220.6 308.2 252.5 1,424.7 549.5 122.30 203.4 240.5 1,182.0 1,222.9 308.0 251.9 1,426.4 548.5 124.30 202.8 239.7 1,182.0 1,225.3 307.8 251.2 1,428.1 547.5 126.30 202.2 239.0 1,182.0 1,227.6 307.5 250.5 1,429.8 546.5 128.30 201.6 238.3 1,182.0 1,229.9 307.3 249.9 1,431.5 545.6 128.70 201.5 238.1 1,182.0 1,230.4 307.3 249.7 1,431.8 545.4 130.30 201.0 237.6 1,182.0 1,232.2 307.1 249.2 1,433.2 544.6 132.30 200.4 236.9 1,182.0 1,234.5 306.8 248.6 1,434.9 543.7 134.30 199.8 236.2 1,182.0 1,236.8 306.6 247.9 1,436.6 542.8 136.30 199.3 235.5 1,181.9 1,239.0 306.4 247.3 1,438.3 541.9 138.30 198.7 234.8 1,181.9 1,241.3 306.1 246.6 1,440.0 541.0 140.30 198.1 234.2 1,181.9 1,243.6 305.9 246.0 1,441.7 540.1 142.30 197.6 233.5 1,181.9 1,245.8 305.7 245.4 1,443.4 539.2 144.30 197.1 232.9 1,181.9 1,248.0 305.4 244.7 1,445.1 538.3 146.30 196.5 232.3 1,181.9 1,250.3 305.2 244.1 1,446.8 537.5 148.30 196.0 231.7 1,181.9 1,252.5 305.0 243.5 1,448.5 536.7 150.30 195.5 231.1 1,181.9 1,254.8 304.7 242.9 1,450.3 535.8 152.30 195.0 230.5 1,181.9 1,257.0 304.5 242.3 1,452.0 535.0 153.60 194.7 230.1 1,181.9 1,258.5 304.4 241.9 1,453.2 534.5 154.30 194.5 229.9 1,181.9 1,259.3 304.3 241.6 1,453.8 534.2 156.30 194.0 229.3 1,181.9 1,261.5 304.1 241.0 1,455.6 533.4 158.30 193.6 228.8 1,181.9 1,263.8 303.9 240.4 1,457.3 532.6 160.30 193.1 228.2 1,181.9 1,266.1 303.7 239.8 1,459.2 531.9 162.30 192.6 227.7 1,181.9 1,268.4 303.5 239.2 1,461.0 531.1 164.30 192.2 227.1 1,181.9 1,270.7 303.3 238.7 1,462.8 530.4 166.30 191.8 226.6 1,181.9 1,273.0 303.1 238.1 1,464.7 529.7 168.30 191.3 226.1 1,181.9 1,275.3 302.9 237.5 1,466.6 529.0 170.30 190.9 225.6 1,181.9 1,277.7 302.7 236.9 1,468.6 528.4 172.30 190.5 225.2 1,181.9 1,280.0 302.6 236.4 1,470.6 527.7 174.30 190.1 224.7 1,181.8 1,282.4 302.4 235.8 1,472.6 527.1 176.30 189.7 224.3 1,181.8 1,284.9 302.3 235.3 1,474.6 526.5 178.30 189.4 223.8 1,181.8 1,287.4 302.2 234.7 1,476.8 526.0 180.30 189.0 223.4 1,181.8 1,289.9 302.1 234.2 1,478.9 525.5 182.30 188.7 223.0 1,181.8 1,292.5 302.0 233.6 1,481.2 525.0 183.80 188.5 222.7 1,181.8 1,294.5 301.9 233.3 1,482.9 524.7 184.30 188.4 222.6 1,181.8 1,295.1 301.9 233.1 1,483.5 524.6 186.30 188.1 222.3 1,181.8 1,297.9 301.9 232.6 1,485.9 524.2 188.30 187.8 221.9 1,181.8 1,300.7 301.9 232.1 1,488.5 523.8 190.30 187.5 221.6 1,181.8 1,303.6 301.9 231.6 1,491.1 523.5 192.30 187.1 221.1 1,181.8 1,304.2 301.3 231.1 1,491.2 522.4 194.30 186.6 220.6 1,181.8 1,304.7 300.8 230.6 1,491.4 521.4 196.30 186.2 220.1 1,181.8 1,305.3 300.3 230.1 1,491.5 520.4 198.30 185.8 219.6 1,181.8 1,305.8 299.8 229.6 1,491.6 519.4 200.30 185.3 219.0 1,181.8 1,305.4 299.0 229.0 1,490.7 518.0 202.30 184.8 218.4 1,181.8 1,304.0 298.0 228.5 1,488.8 516.4 204.30 184.2 217.7 1,181.8 1,303.0 297.1 228.0 1,487.2 514.9 206.30 183.7 217.1 1,181.8 1,302.2 296.3 227.5 1,486.0 513.4 208.30 183.3 216.6 1,181.8 1,301.7 295.5 227.0 1,485.0 512.1 CN-3136 STPEGS UFSAR 6.2-139 Revision 18 TABLE 6.2.1.3-5B (continued) DOUBLE-ENDED PUMP SUCTION BR EAK MASS AND ENERGY RELEASES (Maximum SI)

Time Break Path No. 1 Flow (SG Side) Break Path No. 2 Flow (Pump Side) Total Mass From Both Sides Total Energy From Both Sides (seconds) (lbm/sec) Thousand (Btu/sec) Enthalpy (Btu/lbm) (lbm/sec) Thousand (Btu/sec) Enthalpy (Btu/lbm) (lbm/sec) Thousand (Btu/sec) 210.30 182.8 216.0 1,181.8 1,301.4 294.8 226.5 1,484.1 510.8 212.30 182.3 215.4 1,181.8 1,301.2 294.0 226.0 1,483.5 509.5 214.30 181.8 214.9 1,181.8 1,301.2 293.3 225.4 1,483.0 508.2 216.30 181.4 214.3 1,181.8 1,301.3 292.7 224.9 1,482.7 507.0 218.30 180.9 213.8 1,181.8 1,301.6 292.0 224.4 1,482.5 505.8 220.00 180.5 213.3 1,181.7 1,301.9 291.5 223.9 1,482.5 504.9 End of Reflood 220.10 201.8 254.2 1,259.3 1,395.0 290.2 208.0 1,596.9 544.4 225.10 202.9 255.5 1,259.3 1,394.0 289.7 207.8 1,596.9 545.2 230.10 202.3 254.7 1,259.3 1,394.6 289.6 207.7 1,596.9 544.3 235.10 201.6 253.9 1,259.3 1,395.2 289.6 207.5 1,596.9 543.5 240.10 202.7 255.2 1,259.3 1,394.2 289.0 207.3 1,596.9 544.3 245.10 202.0 254.4 1,259.3 1,394.8 289.0 207.2 1,596.9 543.4 250.10 201.4 253.7 1,259.3 1,395.4 288.9 207.0 1,596.9 542.5 255.10 202.4 254.9 1,259.3 1,394.4 288.4 206.8 1,596.9 543.3 260.10 201.8 254.1 1,259.3 1,395.1 288.3 206.7 1,596.9 542.4 265.10 201.2 253.3 1,259.3 1,395.7 288.2 206.5 1,596.9 541.6 270.10 202.1 254.5 1,259.3 1,394.7 287.7 206.3 1,596.9 542.3 275.10 201.5 253.7 1,259.3 1,395.4 287.7 206.2 1,596.9 541.4 280.10 200.8 252.9 1,259.3 1,396.0 287.6 206.0 1,596.9 540.5 285.10 201.8 254.1 1,259.3 1,395.1 287.1 205.8 1,596.9 541.2 290.10 201.1 253.3 1,259.3 1,395.7 287.0 205.7 1,596.9 540.3 295.10 200.5 252.4 1,259.3 1,396.4 287.0 205.5 1,596.9 539.4 300.10 201.4 253.6 1,259.3 1,395.5 286.5 205.3 1,596.9 540.1 305.10 200.7 252.7 1,259.3 1,396.2 286.4 205.1 1,596.9 539.2 310.10 200.0 251.9 1,259.3 1,396.8 286.4 205.0 1,596.9 538.2 315.10 200.9 253.0 1,259.3 1,395.9 285.9 204.8 1,596.9 538.9 320.10 200.2 252.1 1,259.3 1,396.6 285.8 204.6 1,596.9 537.9 325.10 201.1 253.2 1,259.3 1,395.8 285.3 204.4 1,596.9 538.5 330.10 200.4 252.3 1,259.3 1,396.5 285.3 204.3 1,596.9 537.6 335.10 199.7 251.5 1,259.3 1,397.2 285.2 204.1 1,596.9 536.7 340.10 200.5 252.5 1,259.3 1,396.3 284.7 203.9 1,596.9 537.2 345.10 199.8 251.6 1,259.3 1,397.1 284.7 203.8 1,596.9 536.3 350.10 200.6 252.6 1,259.3 1,396.3 284.2 203.6 1,596.9 536.8 355.10 199.9 251.7 1,259.3 1,397.0 284.2 203.4 1,596.9 535.9 360.10 199.1 250.8 1,259.3 1,397.7 284.1 203.3 1,596.9 534.9 365.10 199.9 251.7 1,259.3 1,397.0 283.7 203.1 1,596.9 535.4 370.10 199.2 250.8 1,259.3 1,397.7 283.6 202.9 1,596.9 534.4 375.10 199.9 251.7 1,259.3 1,397.0 283.2 202.7 1,596.9 534.9 380.10 199.1 250.8 1,259.3 1,397.7 283.1 202.6 1,596.9 533.9 385.10 198.4 249.8 1,259.3 1,398.5 283.1 202.4 1,596.9 532.9 390.10 199.1 250.7 1,259.3 1,397.8 282.6 202.2 1,596.9 533.3 395.10 198.3 249.7 1,259.3 1,398.6 282.6 202.1 1,596.9 532.3 400.10 199.0 250.6 1,259.3 1,397.9 282.1 201.8 1,596.9 532.7 405.10 198.3 249.8 1,259.3 1,398.5 282.1 201.7 1,596.9 531.8 410.10 199.2 250.8 1,259.3 1,397.7 281.6 201.5 1,596.9 532.4 415.10 198.5 250.0 1,259.3 1,398.3 281.5 201.3 1,596.9 531.5 420.10 197.9 249.2 1,259.3 1,399.0 281.5 201.2 1,596.9 530.6 425.10 198.6 250.1 1,259.3 1,398.2 281.0 201.0 1,596.9 531.1 430.10 198.0 249.3 1,259.3 1,398.9 280.9 200.8 1,596.9 530.2 435.10 198.7 250.2 1,259.3 1,398.2 280.5 200.6 1,596.9 530.7 440.10 198.0 249.3 1,259.3 1,398.8 280.4 200.5 1,596.9 529.8 CN-3136 STPEGS UFSAR 6.2-140 Revision 18 TABLE 6.2.1.3-5B (continued) DOUBLE-ENDED PUMP SUCTION BR EAK MASS AND ENERGY RELEASES (Maximum SI)

Time Break Path No. 1 Flow (SG Side) Break Path No. 2 Flow (Pump Side) Total Mass From Both Sides Total Energy From Both Sides (seconds) (lbm/sec) Thousand (Btu/sec) Enthalpy (Btu/lbm) (lbm/sec) Thousand (Btu/sec) Enthalpy (Btu/lbm) (lbm/sec) Thousand (Btu/sec) 445.10 197.3 248.5 1,259.3 1,399.5 280.4 200.3 1,596.9 528.8 450.10 198.0 249.4 1,259.3 1,398.8 279.9 200.1 1,596.9 529.3 455.10 197.3 248.5 1,259.3 1,399.6 279.9 200.0 1,596.9 528.3 460.10 198.0 249.3 1,259.3 1,398.9 279.4 199.8 1,596.9 528.7 465.10 197.2 248.4 1,259.3 1,399.6 279.4 199.6 1,596.9 527.8 470.10 197.8 249.1 1,259.3 1,399.0 279.0 199.4 1,596.9 528.1 475.10 197.1 248.2 1,259.3 1,399.8 278.9 199.3 1,596.9 527.1 480.10 197.7 248.9 1,259.3 1,399.2 278.5 199.1 1,596.9 527.4 485.10 196.9 248.0 1,259.3 1,399.9 278.5 198.9 1,596.9 526.4 490.10 197.5 248.7 1,259.3 1,399.4 285.5 204.0 1,596.9 534.1 495.10 196.7 247.6 1,259.3 1,400.2 285.4 203.8 1,596.9 533.1 500.10 197.2 248.3 1,259.3 1,399.7 285.0 203.6 1,596.9 533.3 505.10 196.3 247.2 1,259.3 1,400.5 285.0 203.5 1,596.9 532.2 510.10 196.8 247.8 1,259.3 1,400.1 284.5 203.2 1,596.9 532.4 515.10 195.9 246.8 1,259.3 1,400.9 284.5 203.1 1,596.9 531.3 520.10 196.4 247.3 1,259.3 1,400.5 284.1 202.9 1,596.9 531.4 525.10 196.8 247.8 1,259.3 1,400.1 283.7 202.6 1,596.9 531.5 530.10 195.9 246.6 1,259.3 1,401.0 283.7 202.5 1,596.9 530.3 535.10 196.2 247.1 1,259.3 1,400.7 283.3 202.3 1,596.9 530.4 540.10 196.5 247.5 1,259.3 1,400.4 283.0 202.1 1,596.9 530.4 545.10 195.5 246.3 1,259.3 1,401.3 282.9 201.9 1,596.9 529.2 550.10 195.8 246.6 1,259.3 1,401.0 282.6 201.7 1,596.9 529.2 555.10 196.0 246.9 1,259.3 1,400.8 282.2 201.5 1,596.9 529.1 560.10 196.2 247.1 1,259.3 1,400.6 281.9 201.3 1,596.9 529.0 565.10 195.2 245.8 1,259.3 1,401.7 281.9 201.1 1,596.9 527.7 570.10 195.3 245.9 1,259.3 1,401.5 281.6 200.9 1,596.9 527.5 575.10 195.4 246.1 1,259.3 1,401.5 281.3 200.7 1,596.9 527.3 580.10 195.4 246.1 1,259.3 1,401.4 281.0 200.5 1,596.9 527.1 585.10 195.5 246.1 1,259.3 1,401.4 280.7 200.3 1,596.9 526.8 590.10 195.4 246.1 1,259.3 1,401.4 280.4 200.1 1,596.9 526.5 595.10 195.3 246.0 1,259.3 1,401.5 280.1 199.9 1,596.9 526.1 600.10 195.2 245.8 1,259.3 1,401.6 279.9 199.7 1,596.9 525.7 605.10 195.1 245.7 1,259.3 1,401.7 279.6 199.5 1,596.9 525.3 610.10 194.9 245.5 1,259.3 1,401.9 279.4 199.3 1,596.9 524.9 615.10 194.7 245.2 1,259.3 1,402.1 279.2 199.1 1,596.9 524.4 620.10 194.5 244.9 1,259.3 1,402.4 279.0 198.9 1,596.9 523.8 625.10 194.1 244.5 1,259.3 1,402.7 278.8 198.7 1,596.9 523.2 630.10 194.8 245.3 1,259.3 1,402.1 278.3 198.5 1,596.9 523.6 635.10 194.3 244.7 1,259.3 1,402.5 278.1 198.3 1,596.9 522.9 640.10 194.8 245.3 1,259.3 1,402.0 277.7 198.1 1,596.9 523.0 645.10 194.2 244.5 1,259.3 1,402.7 277.6 197.9 1,596.9 522.1 650.10 194.5 244.9 1,259.3 1,402.4 277.2 197.7 1,596.9 522.1 655.10 193.7 243.9 1,259.3 1,403.2 277.1 197.5 1,596.9 521.1 660.10 193.8 244.0 1,259.3 1,403.1 276.8 197.3 1,596.9 520.8 665.10 193.7 243.9 1,259.3 1,403.2 276.6 197.1 1,596.9 520.5 670.10 193.5 243.7 1,259.3 1,403.3 276.3 196.9 1,596.9 520.0 675.10 194.1 244.4 1,259.3 1,402.8 275.9 196.7 1,596.9 520.2 680.10 193.5 243.7 1,259.3 1,403.3 275.7 196.5 1,596.9 519.4 685.10 193.7 243.9 1,259.3 1,403.2 275.4 196.3 1,596.9 519.3 690.10 193.6 243.7 1,259.3 1,403.3 275.1 196.1 1,596.9 518.9 695.10 193.2 243.3 1,259.3 1,403.7 274.9 195.9 1,596.9 518.2 995.10 85.5 107.6 1,259.3 1,511.4 296.7 196.3 1,596.9 404.3 CN-3136 STPEGS UFSAR 6.2-141 Revision 18 TABLE 6.2.1.3-5B (continued) DOUBLE-ENDED PUMP SUCTION BR EAK MASS AND ENERGY RELEASES (Maximum SI)

Time Break Path No. 1 Flow (SG Side) Break Path No. 2 Flow (Pump Side) Total Mass From Both Sides Total Energy From Both Sides (seconds) (lbm/sec) Thousand (Btu/sec) Enthalpy (Btu/lbm) (lbm/sec) Thousand (Btu/sec) Enthalpy (Btu/lbm) (lbm/sec) Thousand (Btu/sec)

Start of sump recirculation 1,000.00 85.4 107.5 1,259.3 1,564.4 534.2 341.4 1,649.8 641.7 1,045.56 85.4 107.5 1,259.3 1,564.4 534.2 341.4 1,649.8 641.7 1,045.66 95.1 118.6 1,247.3 1,554.7 534.6 343.9 1,649.8 653.2 1,050.00 95.0 118.5 1,247.3 1,554.8 534.3 343.6 1,649.8 652.7 1,754.45 95.0 118.5 1,247.3 1,554.8 534.3 343.6 1,649.8 652.7 1,754.55 82.8 95.3 1,150.6 1,567.0 407.7 260.2 1,649.8 503.0 3,600.00 69.1 79.5 1,150.6 1,580.7 410.2 259.5 1,649.8 489.7 Start of revised post-recirculation methodology [4] NOTES: 1. Pump Suction Break Area = 5.24 ft

2. Pipe inside diameter = 2.58 ft. 2. The blowdown phase mass and energy releases are the same for Minimum and Maximum SI cases. 3. Blowdown ends at 25.2 seconds. Reflood ends at 220.0 seconds. Sump recirculation begins at 1000 seconds. All SGs depressurized to atmospheric pressure at 3600 seconds. 4. After 3600 seconds, the revised post recirculation methodology is used, as discussed in Section 6.2.1.3.4.5.

CN-3136 STPEGS UFSAR 6.2-142 Revision 18 TABLE 6.2.1.3-6 DECAY HEAT DATA BA SED ON ANS-5.1-1979, PLUS 2 SIGMA UNCERTAINTY Time (sec) Decay Heat Generation Rate (Btu/Btu)

(Fraction of Full Power) 1.00E+01 0.053876 1.50E+01 0.050401

2.00E+01 0.048018

4.00E+01 0.042401

6.00E+01 0.039244

8.00E+01 0.037065

1.00E+02 0.035466

1.50E+02 0.032724

2.00E+02 0.030936

4.00E+02 0.027078

6.00E+02 0.024931

8.00E+02 0.023389

1.00E+03 0.022156

1.50E+03 0.019921

2.00E+03 0.018315

4.00E+03 0.014781

6.00E+03 0.013040

8.00E+03 0.012000

1.00E+04 0.011262

1.50E+04 0.010097

2.00E+04 0.009350

4.00E+04 0.007778

6.00E+04 0.006958

8.00E+04 0.006424

1.00E+05 0.006021

1.50E+05 0.005323

4.00E+05 0.003770

6.00E+05 0.003201

8.00E+05 0.002834

1.00E+06 0.002580 CN-3136 STPEGS UFSAR 6.2-143 Revision 18 TABLE 6.2.1.3-6A DECAY HEAT DATA BASED ON STANDARD REVIEW PLAN ASB 9-2 CORRELATIONS Time (seconds) Decay Heat (Btu/hr) 9.0E+00 1.1E+02 5.0E+02 1.0E+03 2.0E+03 3.0E+03 3.6E+03 4.0E+03 5.0E+03 6.0E+03 7.0E+03 8.0E+03 9.0E+03 1.03E+09 5.80E+08 3.84E+08 3.06E+08 2.56E+08 2.24E+08 2.11E+08 2.03E+08 1.88E+08 1.78E+08 1.70E+08 1.64E+08 1.59E+08 1.0E+04 2.0E+04 3.0E+04 4.0E+04 5.0E+04 6.0E+04 7.0E+04 8.0E+04 9.0E+04 1.55E+08 1.29E+08 1.13E+08 1.02E+08 9.49E+07 8.96E+07 8.57E+07 8.25E+07 8.00E+07 1.0E+05 2.0E+05 3.0E+05 4.0E+05 5.0E+05 6.0E+05 7.0E+05 8.0E+05 9.0E+05 7.78E+07 6.33E+07 5.42E+07 4.81E+07 4.38E+07 4.06E+07 3.82E+07 3.63E+07 3.48E+07 1.0E+06 I.IE+06 1.2E+06 1.3E+06 1.4E+06 1.5E+06 1.6E+06 1.7E+06 1.8E+06 1.9E+06 2.0E+06 2.5E+06 3.0E+06 3.5E+06 4.0E+06 4.5E+06 5.0E+06 6.0E+06 7.0E+06 8.0E+06 9.0E+06 3.34E+07 3.23E+07 3.13E+07 3.04E+07 2.95E+07 2.87E+07 2.80E+07 2.73E+07 2.67E+07 2.61E+07 2.55E+07 2.30E+07 2.10E+07 1.94E+07 1.81E+07 1.70E+07 1.60E+07 1.46E+07 1.34E+07 1.25E+07 1.17E+07 CN-3136 STPEGS UFSAR 6.2-144 Revision 18 TABLE 6.2.1.3-6A (Continued) DECAY HEAT DATA BASED ON STANDARD REVIEW PLAN ASB 9-2 CORRELATIONS Time (seconds) Decay Heat (Btu/hr) 1.0E+07 2.0E+07 3.0E+07 4.0E+07 5.0E+07 6.0E+07 7.0E+07 8.0E+07 9.0E+07 1.10E+07 6.90E+06 4.99E+06 3.96E+06 3.32E+06 2.90E+06 2.60E+06 2.37E+06 2.21E+06 1.0E+08 2.08E+06 STPEGS UFSAR 6.2-145 Revision 18 TABLE 6.2.1.3-9 DOUBLE-ENDED PUMP SUCTION BREAK PRINCIPAL PARAMETERS DURING REFLOOD (Minimum SI)

Time (seconds)

Flooding Carryover Fraction Core Height (ft) Downcomer Height (ft) Flow Fraction Enthalpy(Btu/lbm) Temp (ûF) Rate (in/sec) Injection (lbm/sec) Total Accumulator Spill 25.2 196.5 0.000 0.000 0.00 0.00 0.250 0.0 0.0 0.0 0.0 25.9 192.4 26.017 0.000 0.60 2.29 0.000 11135.7 11135.7 0.0 89.5 26.1 189.7 31.875 0.000 1.08 2.37 0.000 11067.7 11067.7 0.0 89.5 26.9 187.8 3.653 0.307 1.50 5.59 0.324 10760.5 10760.5 0.0 89.5 27.8 187.5 3.423 0.456 1.67 9.88 0.360 10483.6 10483.6 0.0 89.5 30.0 186.9 7.415 0.630 2.00 18.29 0.654 8989.9 8989.9 0.0 89.5 30.3 186.7 7.529 0.649 2.07 18.31 0.646 8792.9 8792.9 0.0 89.5 31.3 186.1 7.102 0.686 2.27 18.31 0.644 8545.2 8545.2 0.0 89.5 32.7 185.7 6.719 0.712 2.51 18.31 0.645 8282.1 8282.1 0.0 89.5 33.3 185.6 6.980 0.719 2.60 18.31 0.653 8833.6 8017.3 0.0 90.28 35.9 185.7 6.603 0.735 3.00 18.31 0.651 8418.4 7592.6 0.0 90.33 39.5 186.8 6.233 0.744 3.50 18.31 0.648 7967.0 7125.2 0.0 90.40 43.4 188.9 5.927 0.749 4.00 18.31 0.642 7551.3 6695.0 0.0 90.46 47.3 191.5 3.964 0.747 4.46 18.31 0.543 922.4 0.0 0.0 97.98 48.3 192.3 3.957 0.747 4.54 18.31 0.542 922.0 0.0 0.0 97.98 53.9 198.3 3.915 0.750 5.01 18.31 0.545 922.0 0.0 0.0 97.98 60.3 207.7 3.867 0.753 5.52 18.31 0.548 921.9 0.0 0.0 97.98 66.4 218.3 3.818 0.756 6.00 18.31 0.552 921.8 0.0 0.0 97.98 73.3 231.1 3.757 0.760 6.53 18.31 0.556 921.8 0.0 0.0 97.98 79.7 243.0 3.693 0.765 7.00 18.31 0.559 921.8 0.0 0.0 97.98 88.3 256.6 3.599 0.771 7.61 18.31 0.564 921.9 0.0 0.0 97.98 94.2 264.2 3.530 0.775 8.01 18.31 0.567 922.1 0.0 0.0 97.98 102.3 273.0 3.431 0.780 8.53 18.31 0.570 922.5 0.0 0.0 97.98 110.0 279.8 3.332 0.784 9.00 18.31 0.573 923.1 0.0 0.0 97.98 120.3 287.1 3.195 0.790 9.60 18.31 0.576 924.1 0.0 0.0 97.98 127.7 291.4 3.094 0.795 10.00 18.31 0.578 924.9 0.0 0.0 97.98 138.3 296.3 2.945 0.801 10.54 18.31 0.579 926.3 0.0 0.0 97.98 148.2 300.0 2.800 0.808 11.00 18.31 0.578 927.9 0.0 0.0 97.98 160.3 303.5 2.613 0.817 11.51 18.31 0.575 930.1 0.0 0.0 97.98 173.1 303.3 2.427 0.818 12.00 18.31 0.566 932.9 0.0 0.0 97.98 CN-3136 STPEGS UFSAR 6.2-146 Revision 18 TABLE 6.2.1.3-10 DOUBLE-ENDED PUMP SUCTION BREAK PRINCIPAL PARAMETERS DURING REFLOOD (Maximum SI)

Time (seconds)

Flooding Carryover Fraction Core Height (ft) Downcomer Height (ft) Flow Fraction Enthalpy(Btu/lbm) Temp (ûF) Rate (in/sec) Injection (lbm/sec) Total Accumulator Spill 25.2 196.5 0.000 0.000 0.00 0.00 0.250 0.0 0.0 0.0 0.0 25.9 192.4 26.017 0.000 0.60 2.29 0.000 11135.7 11135.7 0.0 89.5 26.1 189.7 31.875 0.000 1.08 2.37 0.000 11067.7 11067.7 0.0 89.5 26.9 187.8 3.653 0.307 1.50 5.59 0.324 10760.5 10760.5 0.0 89.5 27.8 187.5 3.423 0.456 1.67 9.88 0.360 10483.6 10483.6 0.0 89.5 30.0 186.9 7.415 0.630 2.00 18.29 0.654 8989.9 8989.9 0.0 89.5 30.3 186.7 7.529 0.649 2.07 18.31 0.646 8792.9 8792.9 0.0 89.5 31.3 186.1 7.102 0.686 2.27 18.31 0.644 8545.2 8545.2 0.0 89.5 32.7 185.7 6.719 0.712 2.51 18.31 0.645 8282.1 8282.1 0.0 89.5 33.3 185.6 7.250 0.720 2.60 18.31 0.658 9299.3 7905.3 0.0 90.77 35.8 185.6 6.880 0.734 3.01 18.31 0.656 8869.0 7468.3 0.0 90.84 39.3 186.6 6.534 0.744 3.51 18.31 0.654 8436.8 7016.4 0.0 90.93 43.0 188.5 6.257 0.749 4.01 18.31 0.651 8046.5 6608.5 0.0 91.02 47.3 191.3 3.990 0.752 4.56 18.31 0.489 2673.6 1218.7 0.0 94.11 48.3 192.0 3.558 0.745 4.64 18.31 0.509 1570.7 0.0 0.0 97.98 53.4 196.7 3.198 0.743 5.00 18.31 0.473 1582.2 0.0 0.0 97.98 61.3 205.9 2.814 0.741 5.50 18.31 0.424 1592.1 0.0 0.0 97.98 69.6 216.9 2.752 0.744 6.00 18.31 0.425 1592.0 0.0 0.0 97.98 78.3 229.2 2.687 0.748 6.50 18.31 0.427 1592.0 0.0 0.0 97.98 87.4 242.0 2.617 0.753 7.00 18.31 0.428 1591.9 0.0 0.0 97.98 98.3 255.3 2.535 0.759 7.58 18.31 0.430 1591.8 0.0 0.0 97.98 106.9 263.9 2.472 0.764 8.00 18.31 0.432 1591.7 0.0 0.0 97.98 118.3 273.4 2.391 0.771 8.54 18.31 0.435 1591.6 0.0 0.0 97.98 128.7 280.4 2.320 0.777 9.00 18.31 0.437 1591.5 0.0 0.0 97.98 142.3 287.8 2.231 0.786 9.57 18.31 0.441 1591.3 0.0 0.0 97.98 153.6 292.8 2.160 0.794 10.00 18.31 0.444 1591.2 0.0 0.0 97.98 168.3 298.0 2.069 0.807 10.52 18.31 0.449 1591.1 0.0 0.0 97.98 183.8 302.4 1.973 0.824 11.00 18.31 0.454 1590.9 0.0 0.0 97.98 202.3 303.3 1.902 0.829 11.50 18.31 0.459 1590.9 0.0 0.0 97.98 220.0 301.7 1.865 0.818 12.00 18.31 0.463 1590.9 0.0 0.0 97.98 CN-3136 STPEGS UFSAR 6.2-147 Revision 18 TABLE 6.2.1.3-13 DOUBLE-ENDED PUMP SUCTION BREAK MASS BALANCE (Minimum SI)

Time (seconds) 0.00 25.20 25.20 173.10 639.95 1613.06 3600.0 Mass (Thousand lbm) Initial Mass In RCS and Accumulator 933.50 933.50 933.50 933.50 933.50 933.50 933.50 Added Mass Pumped Injection 0.00 .00 .00 128.39 570.47 1442.38 2753.95 Total Added 0.00 .00 .00 128.39 570.47 1442.38 2753.95 *** Total Available *** 933.50 933.50 933.50 1061.89 1503.98 2375.89 3687.45 Distribution Reactor Coolant 625.85 54.54 59.94 129.38 129.38 129.38 129.38 Accumulator 307.65 256.21 250.81 0.00 0.00 0.00 0.00 Total Contents 933.50 310.75 310.75 129.38 129.38 129.38 129.38 Effluent Break Flow 0.00 622.73 622.73 841.65 1283.74 2162.39 3467.20 ECCS Spill 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Total Effluent 0.00 622.73 622.73 841.65 1283.74 2162.39 3467.20 *** Total Available *** 933.50 933.48 933.48 971.04 1413.12 2291.78 3596.58 CN-3136 STPEGS UFSAR 6.2-148 Revision 18 TABLE 6.2.1.3-14 DOUBLE-ENDED PUMP SUCTION BREAK MASS BALANCE (Maximum SI)

Time (seconds) 0.00 25.20 25.20 220.0 1045.66 1754.45 3600.0 Mass (Thousand lbm) Initial Mass In RCS and Accumulator 933.50 933.50 933.50 933.50 933.50 933.50 933.50 Added Mass Pumped Injection 0.00 0.00 0.00 295.06 1615.78 2785.14 5829.93 Total Added 0.00 0.00 0.00 295.06 1615.78 2785.14 5829.93 *** Total Available *** 933.50 933.50 933.50 1228.57 2549.28 3718.64 6763.43 Distribution Reactor Coolant 625.85 54.54 59.94 131.30 131.30 131.309 131.30 Accumulator 307.65 256.21 250.81 0.00 0.00 0.00 0.00 Total Contents 933.50 310.75 310.75 131.30 131.30 131.30 131.30 Effluent Break Flow 0.00 622.73 622.73 1006.42 2327.13 3496.62 6541.41 ECCS Spill 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Total Effluent 0.00 622.73 622.73 1006.42 2327.13 3496.62 6541.41 *** Total Available *** 933.50 933.48 933.48 1137.71 2458.43 3627.92 6672.71 CN-3136 STPEGS UFSAR 6.2-149 Revision 18 TABLE 6.2.1.3-15 DOUBLE-ENDED HOT LEG BREAK MASS BALANCE Time (seconds) 0.00 24.8 24.8 Mass (Thousand lbm) Initial Mass In RCS and Accumulator 933.50 933.50 933.50 Added Mass Pumped Injection 0.00 0.00 0.00 Total Added 0.00 0.00 0.00 *** Total Available *** 933.50 933.50 933.50 Distribution Reactor Coolant 625.85 90.85 96.82 Accumulator 307.65 232.24 226.28 Total Contents 933.50 323.10 323.10 Effluent Break Flow 0.00 610.39 610.39 ECCS Spill 0.00 0.00 0.00 Total Effluent 0.00 610.39 610.39 *** Total Available *** 933.50 933.490 933.49 CN-3136 STPEGS UFSAR 6.2-150 Revision 18 TABLE 6.2.1.3-16 DOUBLE-ENDED PUMP SUCTION BREAK ENERGY BALANCE (Minimum SI)

Time (seconds) 0.00 25.20 25.20 173.10 639.95 1613.06 3600.0 Energy (Million Btu) Initial Energy In RCS, Accumulator, SG 1219.15 1219.15 1219.15 1219.15 1219.15 1219.15 1219.15 Added Energy Pumped Injection 0.00 0.00 0.00 12.58 55.90 157.19 467.55 Decay Heat 0.00 8.68 8.68 28.58 75.85 153.68 279.01 Heat From Secondary 0.00 8.76 8.76 8.76 20.06 26.30 26.30 Total Added 0.00 17.44 17.44 49.92 151.80 337.18 772.86 *** Total Available *** 1219.15 1236.58 1236.58 1269.06 1370.95 1556.32 1992.01 Distribution Reactor Coolant 375.72 12.28 12.76 36.52 36.52 36.52 36.52 Accumulator 27.53 22.93 22.45 0.00 0.00 0.00 0.00 Core Stored 31.45 15.37 15.37 5.87 5.36 4.87 3.88 Primary Metal 204.93 194.62 194.62 173.42 125.06 93.04 72.25 Secondary Metal 161.72 158.13 158.13 143.93 116.37 81.03 62.30 Steam Generator 417.80 431.42 431.42 386.36 315.58 222.96 174.42 Total Contents 1219.15 834.75 834.75 746.09 598.90 438.43 349.38 Effluent Break Flow 0.00 401.15 401.15 512.53 761.61 1128.39 1657.23 ECCS Spill 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Total Effluent 0.00 401.15 401.15 512.53 761.61 1128.39 1657.23 *** Total Available *** 1219.15 1235.90 1235.90 1258.63 1360.51 1566.82 2006.61 CN-3136 STPEGS UFSAR 6.2-151 Revision 18 TABLE 6.2.1.3-17 DOUBLE-ENDED PUMP SUCTION BREAK ENERGY BALANCE (Maximum SI)

Time (seconds) 0.00 25.20 25.20 220.0 1045.66 1754.45 3600.0 Energy (Million Btu) Initial Energy In RCS, Accumulator, SG 1219.15 1219.15 1219.15 1219.15 1219.15 1219.15 1219.15 Added Energy Pumped Injection 0.00 0.00 0.00 28.91 168.94 448.41 1176.12 Decay Heat 0.00 8.68 8.68 33.95 110.45 163.70 278.94 Heat From Secondary 0.00 8.76 8.76 8.76 26.30 26.30 26.30 Total Added 0.00 17.44 17.44 71.62 305.70 638.42 1481.37 *** Total Available *** 1219.15 1236.58 1236.58 1524.84 1857.56 2700.51 Distribution Reactor Coolant 375.72 12.76 12.76 36.86 36.86 36.86 36.86 Accumulator 27.53 22.45 22.45 0.00 0.00 0.00 0.00 Core Stored 31.45 15.37 15.37 5.87 5.06 4.73 3.88 Primary Metal 204.93 194.62 194.62 170.66 112.47 89.68 72.84 Secondary Metal 161.72 158.13 158.13 145.46 103.22 77.94 63.04 Steam Generator 417.80 431.42 431.42 390.48 283.11 214.76 176.32 Total Contents 1219.15 834.75 834.75 749.32 540.71 423.98 352.95 Effluent Break Flow 0.00 401.15 401.15 530.99 973.67 1416.40 2332.44 ECCS Spill 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Total Effluent 0.00 401.15 401.15 530.99 973.67 1416.4 2332.44 *** Total Available *** 1219.15 1235.90 1235.90 1280.31 1514.39 1840.38 2685.39 CN-3136 STPEGS UFSAR 6.2-152 Revision 18 TABLE 6.2.1.3-18 DOUBLE-ENDED HOT LEG BREAK ENERGY BALANCE Time (seconds) 0.00 24.84 24.84 Energy (Million Btu) Initial Energy In RCS, Accumulator, SG 1219.15 1219.15 1219.15 Added Energy Pumped Injection 0.00 0.00 0.00 Decay Heat 0.00 9.19 9.19 Heat From Secondary 0.00 -13.31 -13.31 Total Added 0.00 -4.12 -4.12 *** Total Available *** 1219.15 1215.03 1215.03 Distribution Reactor Coolant 375.72 19.01 19.54 Accumulator 27.53 20.79 20.25 Core Stored 31.45 13.70 13.70 Primary Metal 204.93 192.02 192.02 Secondary Metal 161.72 156.81 156.81 Steam Generator 417.80 401.73 401.73 Total Contents 1219.15 804.06 804.06 Effluent Break Flow 0.00 410.27 410.27 ECCS Spill 0.00 0.00 0.00 Total Effluent 0.00 410.27 410.27 *** Total Available *** 1219.15 1214.33 1214.33 CN-3136 STPEGS UFSAR 6.2-153 Revision 18 TABLE 6.2.1.4-1 MASS AND ENERGY RELEASES 1.4Ft 2 DER MSLB AT 30% POWER, MSIV FAILURE (Peak Pressure Case) Time (Sec) Forward Flow (lbm/sec) Forward Enthalpy (Btu/hr) Reverse Flow (lbm/sec) Reverse Enthalpy (Btu/lbm) 0.005 3462.0 1185.4 10031.0 1186.7 0.01 3459.4 1185.5 9882.2 1187.5 0.05 3440.0 1185.8 9142.9 1191.2 0.1 3419.4 1186.1 8662.1 1193.3 0.2 3396.6 1186.4 8165.5 1195.4 0.3 3376.9 1186.7 7882.8 1196.4 0.4 3357.6 1186.9 7697.1 1197.1 0.5 3337.4 1187.2 7568.8 1197.5 0.6 3317.4 1187.5 7475.0 1197.9 0.7 3297.9 1187.8 7401.9 1198.1 0.8 3278.2 1188.0 7341.8 1198.3 0.9 3258.0 1188.3 7290.5 1198.5 1 3237.2 1188.6 7245.5 1198.6 1.1 3216.0 1188.9 7204.9 1198.7 1.2 3194.7 1189.1 7167.6 1198.9 1.3 3173.6 1189.4 7132.4 1199.0 1.4 3152.8 1189.7 7098.6 1199.1 1.5 3132.5 1190.0 7065.7 1199.2 1.6 3112.7 1190.2 7033.3 1199.3 1.7 3093.2 1190.5 7001.5 1199.4 1.8 3073.9 1190.7 6970.1 1199.4 1.9 3054.8 1191.0 6939.3 1199.5 2 3035.9 1191.2 6909.1 1199.6 2.1 3017.1 1191.5 6891.4 1199.7 2.2 2998.5 1191.7 6896.0 1199.6 2.3 2980.3 1191.9 6902.0 1199.6 2.4 2962.3 1192.1 6904.1 1199.6 2.5 2944.5 1192.4 6901.3 1199.6 2.6 2927.1 1192.6 6894.0 1199.6 2.7 2909.9 1192.8 6883.1 1199.6 2.8 2893.0 1193.0 6869.5 1199.6 2.9 2876.2 1193.2 6853.9 1199.7 3 2859.7 1193.4 6836.9 1199.7 3.1 2843.4 1193.6 6819.0 1199.8 3.2 2827.4 1193.8 6800.4 1199.8 3.3 2811.5 1194.0 6781.6 1199.9 3.4 2795.9 1194.2 6762.5 1199.9 3.5 2780.4 1194.3 6743.4 1200.0 3.6 2765.2 1194.5 6724.3 1200.0 3.7 2750.1 1194.7 6705.3 1200.1 3.8 2735.3 1194.9 6686.4 1200.1 3.9 2720.5 1195.0 6667.5 1200.2 4 2706.0 1195.2 6648.8 1200.2 4.1 2691.0 1195.4 6630.2 1200.3 4.2 2676.7 1195.5 6611.8 1200.3 4.3 2662.6 1195.7 6593.5 1200.4 4.4 2648.7 1195.8 6575.3 1200.4 4.5 2635.3 1196.0 6557.2 1200.5 4.6 2621.9 1196.1 6539.3 1200.5 4.7 2608.5 1196.3 6521.6 1200.6 4.8 2595.4 1196.4 6503.9 1200.6 STPEGS UFSAR 6.2-154 Revision 18 TABLE 6.2.1.4-1 (Continued)

MASS AND ENERGY RELEASES 1.4Ft 2 DER MSLB AT 30% POWER, MSIV FAILURE (Peak Pressure Case) Time (Sec) Forward Flow (lbm/sec) Forward Enthalpy (Btu/hr) Reverse Flow (lbm/sec) Reverse Enthalpy (Btu/lbm) 4.9 2582.5 1196.6 6486.5 1200.7 5 2569.6 1196.7 6469.1 1200.7 5.1 2556.8 1196.8 6451.9 1200.8 5.2 2544.1 1197.06434.8 1200.8 5.3 2531.6 1197.1 6417.8 1200.8 5.4 2519.3 1197.2 6401.0 1200.9 55 2507.2 1197.4 6384.2 1200.9 5.6 2495.3 1197.5 6367.5 1201.0 5.7 2483.6 1197.6 6351.0 1201.0 5.8 2472.1 1197.7 6334.6 1201.1 5.9 2461.2 1197.8 6318.2 1201.1 6 2450.6 1197.9 6302.0 1201.1 6.1 2440.2 1198.0 6285.9 1201.2 6.2 2430.0 1198.1 6269.9 1201.2 6.3 2419.7 1198.2 6254.0 1201.3 6.4 2409.4 1198.3 6238.3 1201.3 6.5 2399.4 1198.4 6222.6 1201.3 6.6 2389.5 1198.5 6207.0 1201.4 6.7 2379.7 1198.6 6191.5 1201.4 6.8 2370.0 1198.7 6176.2 1201.5 6.9 2360.5 1198.8 6160.9 1201.5 7 2351.2 1198.9 6145.7 1201.5 7.1 2341.9 1199.0 6130.6 1201.6 7.2 2332.8 1199.1 6115.5 1201.6 7.3 2323.9 1199.2 6100.6 1201.7 7.4 2315.1 1199.3 6085.8 1201.7 7.5 2306.4 1199.3 6071.1 1201.7 7.6 2297.9 1199.4 6056.4 1201.8 7.7 2289.9 1199.5 6041.9 1201.8 7.8 2282.7 1199.6 6027.4 1201.8 7.9 2273.1 1199.6 6013.1 1201.9 8 2259.1 1199.8 5985.9 1201.9 8.1 2243.4 1199.9 5829.5 1202.3 8.2 2227.3 1200.1 5583.1 1202.9 8.3 2211.0 1200.2 5328.0 1203.5 8.4 2194.0 1200.4 5080.6 1203.9 8.5 2176.5 1200.5 4844.3 1204.3 8.6 2158.8 1200.7 4618.5 1204.5 8.7 2141.3 1200.8 4403.5 1204.7 8.8 2124.1 1201.0 4198.4 1204.8 8.85 2115.7 1201.0 4099.5 1204.8 8.9 2107.2 1201.1 4005.1 1204.8 9 2090.0 1201.2 3816.2 1204.7 9.1 2072.6 1201.4 3638.6 1204.6 9.2 2054.9 1201.5 3469.1 1204.4 9.3 2037.6 1201.6 3307.4 1204.1 9.4 2020.6 1201.8 3153.1 1203.8 9.5 2004.0 1201.9 3006.0 1203.4 9.6 1987.8 1202.0 2865.6 1203.0 9.7 1971.7 1202.1 2731.6 1202.6 9.8 1955.9 1202.2 2603.7 1202.1 STPEGS UFSAR 6.2-155 Revision 18 TABLE 6.2.1.4-1(Continued)

MASS AND ENERGY RELEASES 1.4Ft 2 DER MSLB AT 30% POWER, MSIV FAILURE (Peak Pressure Case)

Time (Sec) Forward Flow (lbm/sec) Forward Enthalpy (Btu/hr) Reverse Flow (lbm/sec) Reverse Enthalpy (Btu/lbm) 9.9 1940.4 1202.4 2481.6 1201.5 10 1925.2 1202.5 2365.0 1200.9 11 1795.3 1203.3 1476.2 1194.3 12 1790.8 1203.3 903.1 1184.9 13 1827.6 1203.1 571.3 1175.3 14 1819.4 1203.1 357.6 1165.5 15 1787.8 1203.3 222.2 1156.4 15.5 1767.6 1203.4 178.4 1152.0 16 1746.5 1203.5 0.0 1152.0 17 1704.1 1203.8 N/A N/A 18 1664.1 1203.9 N/A N/A 19 1626.9 1204.1 N/A N/A 20 1592.0 1204.2 N/A N/A 22 1527.4 1204.4 N/A N/A 24 1468.5 1204.6 N/A N/A 26 1414.6 1204.7 N/A N/A 28 1374.5 1204.8 N/A N/A 30 1337.1 1204.8 N/A N/A 35 1255.7 1204.8 N/A N/A 40 1177.0 1204.7 N/A N/A 45 1120.6 1204.6 N/A N/A 50 1078.7 1204.4 N/A N/A 55 1051.1 1204.3 N/A N/A 60 1030.6 1204.2 N/A N/A 65 1013.2 1204.1 N/A N/A 70 1001.4 1204.1 N/A N/A 75 991.0 1204.0 N/A N/A 80 982.0 1204.0 N/A N/A 85 976.9 1203.9 N/A N/A 90 970.0 1203.9 N/A N/A 100 962.1 1203.9 N/A N/A 110 957.0 1203.8 N/A N/A 120 953.6 1203.8 N/A N/A 130 951.4 1203.8 N/A N/A 140 934.2 1203.7 N/A N/A 150 942.1 1203.7 N/A N/A 160 940.4 1203.7 N/A N/A 170 952.1 1203.8 N/A N/A 180 952.1 1203.8 N/A N/A 190 949.0 1203.8 N/A N/A 200 943.9 1203.7 N/A N/A 220 918.0 1203.6 N/A N/A 240 700.1 1201.3 N/A N/A 260 443.3 1194.9 N/A N/A 280 240.6 1184.4 N/A N/A 300 279:7 1187.2 N/A N/A 400 224.5 1183.2 N/A N/A 500 183.9 1179.2 N/A N/A 600 162.1 1176.6 N/A N/A STPEGS UFSAR 6.2-156 Revision 18 TABLE 6.2.1.4-1 (Continued)

MASS AND ENERGY RELEASES 1.4Ft 2 DER MSLB AT 30% POWER, MSIV FAILURE (Peak Pressure Case)

Time (Sec) Forward Flow (lbm/hr) Forward Enthalpy (Btu/hr) Reverse Flow (lbm/hr) Reverse Enthalpy (Btu/lbm) 700 159.1 1176.2 N/A N/A 800 158.8 1176.2 N/A N/A 900 158.8 1176.1 N/A N/A 1000 158.8 1176.1 N/A N/A 1200 158.8 1176.1 N/A N/A 1400 158.8 1176.1 N/A N/A 1600 158.8 1176.1 N/A N/A 1700 158.8 1176.1 N/A N/A 1800 158.8 1176.1 N/A N/A 1810 157.6 1176.0 N/A N/A 1820 128.8 1171.3 N/A N/A 1830 92.9 1165.1 N/A N/A 1840 56.5 1155.9 N/A N/A 1850 46.2 1152.0 N/A N/A 2000 0.1 1150.4 N/A N/A STPEGS UFSAR 6.2-157 Revision 18 TABLE 6.2.1.4-2 MASS AND ENERGY RELEASES -

1.4 Ft 2 DER MSLB @ 0% POWER MSIV FAILURE (Peak Temperature Case) (Peak Temperature Case)

Time (Sec) Forward Flow (lbm/sec) Forward Enthalpy (Btu/lbm)

Reverse Flow (lbm/sec) Reverse Enthalpy (Btu/lbm) 0.005 3449.2 1185.6 10005.9 1186.8 0.01 446.3 1185.7 9858.8 1187.6 0.05 3423.9 1186.0 9136.4 1191.2 0.1 3402.3 1186.3 8664.4 1193.3 0.2 3373.1 1186.7 8175.1 1195.3 0.3 3351.5 1187.0 7906.1 1196.3 0.4 3333.1 1187.3 7738.5 1196.9 0.5 3316.3 1187.5 7629.6 1197.3 0.6 3299.9 1187.7 7554.0 1197.5 0.7 3282.2 1188.0 7496.8 1197.7 0.8 3263.4 1188.2 7449.8 1197.9 0.9 3244.5 1188.5 7409.0 1198.0 1 3225.5 1188.8 7372.6 1198.1 1.1 3206.4 1189.0 7339.1 1198.3 1.2 3187.6 1189.2 7307.6 1198.4

1.3 3169.0 1189.5 7277.5 1198.5 1.4 3151.1 1189.7 7248.4 1198.5 1.5 3133.5 1189.9 7220.0 1198.6 1.6 3116.1 1190.2 7192.0 1198.7 1.7 3098.8 1190.4 7164.3 1198.8 1.8 3081.7 1190.6 7137.0 1198.9 1.9 3064.7 1190.8 7110.0 1199.0 2 3048.0 1191.0 7083.4 1199.1 2.1 3031.7 1191.3 7057.9 1199.1 2.2 3015.5 1191.5 7033.9 1199.2 2.3 2999.5 1191.7 7010.0 1199.3 2.4 2983.7 1191.9 6986.0 1199.3 2.5 2968.1 1192.0 6961.8 1199.4 2.6. 2952.8 1192.2 6937.5 1199.5 2.7 2937.6 1192.4 6913.3 1199.6 2.8 2922.7 1192.6 2889.1 1199.6 2.9 2907.8 1192.8 6865.0 1199.7 3 2893.1 1193.0 6841.0 1199.8 3.1 2878.6 1193.1 6817.0 1199.8 3.2 2864.3 1193.3 6793.2 1199.9 3.3 2850.2 1193.5 6769.6 1200.0 3.4 2836.3 1193.6 6746.1 1200.0 3.5 2822.6 1193.8 6722.8 1200.1 3.6 2809.1 1194.0 6699.7 1200.2 3.7 2795.9 1194.1 6676.8 1200.2 3.8 2782.8 1194.3 6654.1 1200.3 3.9 2769.8 1194.4 6631.6 1200.3 4 2757.1 1194.6 6609.2 1200.4 4.1 2744.5 1194.7 6587.1 1200.5 4.2 2732.0 1194.9 6565.1 1200.5 4.3 2719.7 1195.0 6543.3 1200.6 4.4 2707.5 1195.1 6521.7 1200.6 4.5 2694.8 1195.3 6500.3 1200.7 STPEGS UFSAR 6.2-158 Revision 18 TABLE 6.2.1.4-2 (Continued)

MASS AND ENERGY RELEASES -

1.4 Ft 2 DER MSLB @ 0% POWER MSIV FAILURE (Peak Temperature Case)

Time (Sec) Forward Flow (lbm/sec) Forward Enthalpy (Btu/lbm)

Reverse Flow (lbm/sec) Reverse Enthalpy (Btu/lbm) 4.6 2682.9 1195.4 6479.1 1200.7 4.7 2671.1 1195.6 6458.1 1200.8 4.8 2659.4 1195.7 6437.3 1200.9 4.9 2647.8 1195.8 6416.6 1200.9 5 2636.4 1195.9 6396.1 1201.0 5.1 2625.2 1196.1 6375.8 1201.0 5.2 2614.0 1196.2 6355.6 1201.1 5.3 2603.0 1196.3 6335.6 1201.1 5.4 2592.1 1196.4 6315.8 1201.2 5.5 2581.4 1196.5 6296.1 1201.2 5.6 2570.7 1196.7 6276.5 1201.3 5.7 2560.2 196.8 6257.1 1201.3 5.8 2549.7 1196.9 6237.9 1201.4 5.9 2539.4 1197.0 6218.8 1201.4 6 2529.2 1197.1 6199.9 1201.5 6.1 2519.0 1197.2 6181.2 1201.5 6.2 2509.0 1197.3 6162.5 1201.5 6.3 2499.1 1197.4 6144.1 1201.6 6.4 2489.2 1197.5 6125.7 1201.6 6.5 2479.7 1197.6 6107.6 1201.7 6.6 2470.3 1197.7 6089.5 1201.7 6.7 2460.9 1197.8 6071.6 1201.8 6.8 2451.6 1197.9 6053.9 1201.8 6.9 2442.4 1198.0 6036.3 1201.9 7 2433.4 1198.1 6018.8 1201.9 7.1 " 2424.4 1198.2 6001.4 1201.9" 7.2 24155 1198.3 5984.2 1202.0 7.3 2406.6 1198.4 5967.1 1202.0 7.4 2397.8 1198.4 5950.2 1202.1 7.5 2389.1 1198.5 5933.4 1202.1 7.6 2380.4 1198.6 5916.7 1202.1 7.7 2371.8 1198.7 5900.1 1202.2 7.8 2363.2 1198.8 5883.6 1202.2 7.9 2354.7 1198.9 5867.2 1202.2 8 2346.2 1198.9 5838.1 1202.3 8.1 2337.8 1199.0 5683.7 1202.7 8.2 2329.7 1199.1 5442.7 1203.2 8.3 2321.9 1199.2 5194.0 1203.7 8.4 2314.2 1199.2 4952.9 1204.1 8.5 2306.5 1199.3 4722.3 1204.4 8.6 2299.0 1199.4 4502.3 1204.6 , 8.7 2291.5 1199.5 4292.2 1204.8 8.8 2284.1 1199.5 4092.4 1204.8 8.85 2280.5 1199.6 3995.9 1204.8 8.9 2276.8 1199.6 3901.7 1204.8 9 2269.5 1199.7 3719.7 1204.7 9.1 2262.2 1199.7 3546.5 1204.5 STPEGS UFSAR 6.2-159 Revision 18 TABLE 6.2.1.4-2 (Continued)

MASS AND ENERGY RELEASES -

1.4 Ft 2 DER MSLB @ 0% POWER MSIV FAILURE (Peak Temperature Case)

Time (Sec) Forward Flow (lbm/sec) Forward Enthalpy (Btu/lbm)

Reverse Flow (lbm/sec) Reverse Enthalpy (Btu/lbm) 9.2 2254.9 1199.8 3381.1 1204.3 9.3 2247.5 1199.9 3223.5 1204.0 9.4 2240.1 1199.9 3073.1 1203.6 9.5 2232.7 1200.0 2929.6 1203.2 9.6 2225.2 1200.1 2792.6 1202.8 9.7 2217.6 1200.1 2662.0 1202.3 9.8 2210.0 1200.2 2537.2 1201.8 9.9 2202.2 1200.3 2418.2 1201.2 10 2194.4 1200.3 2304.4 1200.6 11 2111.7 1201.0 1466.4 1193.7 12 2034.9 1201.6 878.1 1184.4 13 1978.1 1202.1 557.4 1174.8 14 1934.1 1202.4 348.1 1165.0 15 1893.0 1202.7 216.7 1155.9 15.5 1871.1 1202.8 174.3 1151.5 16 1848.8 1203.0 0.0 1151.5 17 1803.2 1203.2 N/A N/A 18 1758.0 1203.5 N/A N/A 19 1713.0 1203.7 N/A N/A 20 1668.8 1203.9 N/A N/A 25 1483.4 1204.6 N/A N/A 30 1343.3 1204.8 N/A N/A 35 1236.7 1204.8 N/A N/A 40 1160.8 1204.7 N/A N/A 45 1103.7 1204.5 N/A N/A 50 1060.0 1204.3 N/A N/A 55 1027.3 1204.2 N/A N/A 60 1003.0 1204.1 N/A N/A 65 985.1 1204.0 N/A N/A 70 972.0 1203.9 N/A N/A 75 9624 1203.9 N/A N/A 80 955.3 1203.8 N/A N/A 85 950.1 1203.8 N/A N/A 90 946.4 1203.8 N/A N/A 95 943.7 1203.7 N/A N/A 100 941.8 1203.7 N/A N/A 110 939.6 1203.7 N/A N/A 120 938.6 1203.7 N/A N/A 130 938.3 1203.7 N/A N/A 140 938.2 1203.7 N/A N/A 150 938.3 1203.7 N/A N/A 160 938.5 1203.7 N/A N/A 170 938.7 1203.7 N/A N/A 180 92.1.9 1203.6 N/A N/A 190 938.6 1203.7 N/A N/A 200 946.1 1203.8 N/A N/A 220 911.3 1203.5 N/A N/A 240 450.7 1195.4 N/A N/A 260 197.0 1180.5 N/A N/A STPEGS UFSAR 6.2-160 Revision 18 TABLE 6.2.1.4-2 (Continued)

MASS AND ENERGY RELEASES -

1.4 Ft 2 DER MSLB @ 0% POWER MSIV FAILURE (Peak Temperature Case)

Time (Sec) Forward Flow (lbm/sec) Forward Enthalpy (Btu/lbm)

Reverse Flow (lbm/sec) Reverse Enthalpy (Btu/lbm) 280 162.7 1176.7 N/A N/A 3.00 159.0 1176.3 N/A N/A 400 158.8 1176.1 N/A N/A 500 158.8 1176.1 N/A N/A 600 158.8 1176.1 N/A N/A 700 158.8 1176.1 N/A N/A 800 158.8 1176.1 N/A N/A 900 158.8 1176.1 N/A N/A 1000 158.8 1176.1 N/A N/A 1100 158.8 1176.1 N/A N/A 1200 158.8 1176.1 N/A N/A 1300 158.8 1176.1 N/A N/A 1400 158.8 1176.1 N/A N/A 1500 158.8 1176.1 N/A N/A 1600 158.8 1176.1 N/A N/A 1700 158.8 1176.1 N/A N/A 1800 158.8 1176.1 N/A N/A 1900 164.2 1176.7 N/A N/A 1950 87.5 1164.0 N/A N/A 2000 0.0 1151.0 N/A N/A STPEGS UFSAR 6.2-161 Revision 18 TABLE 6.2.1.5-1 BLOWDOWN MASS AND ENERGY RELEASES (DECLG, C D = 0.8, Min. SI, High T AVG) Time (sec) Mass Flow Rate (lbm/sec)

Energy Flow Rate (Btu/sec) 0.0 0 0 1.0 76,524 43,327,052 2.0 65,297 37,896,832 3.0 52,831 31,245,812 4.0 43,754 26,445,336 5.0 40,003 24,933,400 6.0 37,034 23,747,274 7.0 31,955 21,105,676 8.0 27,333 18,646,950 9.0 22,270 15,946,700 10.0 17,929 13,725,611 11.0 14,610 11,993,951 12.0 12,271 10,642,712 13.0 10,626 9,623,101 14.0 8,191 7,771,218 15.0 6,507 6,040,223 16.0 4,219 4,238,667 17.0 4,213 3,437,627 18.0 5,354 3,170,841 19.0 6,036 2,815,177 20.0 6,883 2,601,243 21.0 6,164 1,989,770 22.0 5,313 1,476,441 23.0 5,307 1,297,294 24.0 2,692 612,425 24.86 853 194,466 STPEGS UFSAR 6.2-162 Revision 18 TABLE 6.2.1.5-1a BROKEN LOOP INJECTION SPILL DURING BLOWDOWN (DECLG, C D = 0.8, Min. SI, High T AVG) Time (sec) Mass Flow Rate (lbm/sec)

Energy Flow Rate (BTU/sec) Specific Enthalpy (BTU/lbm) . 0.0 0.0 0.0 0.0 1.0 4,280.09 255,007.76 59.580 2.0 4,121.84 245,579.23 59.580 3.0 3,983.51 237,337.53 59.580 4.0 3,860.23 229,992.50 59.580 5.0 3,748.18 223,316.56 59.580 6.0 3,645.23 217,182.80 59.580 7.0 3,549.61 211,485.76 59.580 8.0 3,461.92 206,261.19 59.580 9.0 3,380.45 201,407.21 59.580 10.0 3,304.92 196,907.13 59.580 11.0 3,234.51 192,712.11 59.580 12.0 3,168.13 188,757.19 59.580 13.0 3,106.39 185,078.72 59.580 14.0 3,047.72 181,583.16 59.580 15.0 2,993.48 178,351.54 59.580 16.0 2,942.36 175,305.81 59.580 17.0 2,894.26 172,440.01 59.580 18.0 2,848.82 169,732.70 59.580 19.0 2,805.73 167,165.39 59.580 20.0 2,764.81 164,727.38 59.580 21.0 2,725.89 162,408.53 59.580 22.0 2,688.86 160,202.28 59.580 23.0 0.0 0.0 0.0 24.0 0.0 0.0 0.0 STPEGS UFSAR 6.2-163 Revision 18 TABLE 6.2.1.5-2 REFLOOD MASS AND ENERGY RELEASES (DECLG, C D = 0.8, Min. SI, High T AVG) Time (sec) Mass Flow Rate (lbm/sec)

Energy Flow Rate (Btu/sec) 32.0 0 0 33.0 3.621 4,753.1 34.0 13.307 17,457.9 35.0 13.667 17,938.6 36.0 14.326 18,797.4 37.0 16.485 21,611.9 38.0 16.894 22,137.5 39.0 17.544 22,986.0 40.0 24.886 32,653.5 41.0 37.390 49,285.6 42.0 37.039 48,705.0 43.0 44.381 58,677.4 44.0 437.606 119,239.5 45.0 7,491.397 702,691.8 46.0 8,650.349 727,911.0 47.0 292.294 270,218.3 48.0 1,548.652 283,854.1 49.0 567.037 141,318.0 54.0 487.505 184,286.0 59.0 181.046 216,100.1 64.0 163.899 199,390.9 69.0 130.554 143,661.9 74.0 161.953 197,030.5 79.0 220.414 138,584.0 84.0 225.474 158,355.1 89.0 697.930 179,017.3 94.0 523.194 179,799.0 99.0 464.675 175,726.7 109.0 464.903 209,166.5 119.0 400.056 205,160.8 129.0 654.246 232,322.7 139.0 352.418 239,641.0 149.0 266.631 150,074.3 159.0 920.713 268,357.4 169.0 238.294 138,193.5 179.0 804.151 259,842.7 189.0 232.595 191,229.8 199.0 924.525 233,390.0 219.0 301.313 233,315.8 239.0 501.192 157,940.4 259.0 1,007.706 278,484.8 279.0 549.935 275,078.3 STPEGS UFSAR 6.2-164 Revision 18 TABLE 6.2.1.5-3 ACTIVE HEAT SINK DATA FOR MINIMUM POST-LOCA CONTAINMENT PRESSURE Containment Spray System Parameters

Maximum spray system flow, total 8,700 gal/min

Fastest post-LOCA initiation of spray system, assuming offsite power loss at start of LOCA 58.6 sec Reactor Containment Fan Coolers

Maximum number of fan coolers operating 6

Fastest post-LOCA initiation, assuming offsite

power loss at start of LOCA 25 sec Performance data - see Figure 6.2.1.5-2 for fan cooler atmosphere heat removal rate

STPEGS UFSAR Revision 18 6.2-165 TABLE 6.2.1.5-4 PASSIVE HEAT SINK DATA FOR MINIMUM POST-LOCA CONTAINMENT PRESSURE Heat Sink No.

Description

Materials*

Thickness (in.)

Total Surface Area (ft 2)(1) 1 Containment shell Carbon Steel Concrete Paint 0.477 48.0 0.008 84,520 2 Containment dome Carbon Steel Concrete Paint 0.375 36.0 0.008 38,877 3 Personnel lock and equipment hatch Carbon Steel Paint 1.0 0.007 811 4 Sump concrete and liner Stainless Steel Concrete 0.250 144.0 182 5 CS mat liner and concrete in contact with ground Carbon Steel Concrete Paint 0.375 24.0 0.010 15,207 6 Mat liner, fill slab and misc. steel in contact with ground Carbon Steel Concrete Paint 0.875 240.0 0.006 4,244 7 Painted concrete walls 6 inches or less Concrete Paint 6.0 0.010 8,037 8 Painted concrete greater than 6 inches Concrete Paint 72.0 0.010 148,935 9 Galvanized carbon steel less than 0.1 ft thick Carbon Steel Zinc 0.026 0.003 2,246,199 10 Galvanized carbon steel greater than 0.1 ft thick Carbon Steel Zinc 2.76 0.003 45,048 11 Painted carbon steel Carbon Steel Paint 0.063 0.003 2,260,009 12 Stainless steel Stainless Steel 0.002 869,637 13 Painted carbon steel over concrete Carbon Steel Concrete Paint 0.250 60.0 0.006 48,720 *Thermophysical Properties

STPEGS UFSAR Revision 18 6.2-166 TABLE 6.2.1.5-4 (Continued)

PASSIVE HEAT SINK DATA FOR MINIMUM POST-LOCA CONTAINMENT PRESSURE ANALYSIS Heat Sink No. Description Materials*

Thickness (in.) Total Surface Area (ft 2)(1) 14 Stainless steel over concrete Stainless Steel Concrete 0.250 52.5 11,098 15 Copper tubing Copper 0.025 843 16 Unpainted carbon steel piping with 60 F water Carbon Steel 0.200 8,334 17 Unpainted carbon steel piping with 105 F water Carbon Steel 0.300 33,668 18 Stainless steel piping with 105 F water Stainless Steel 0.280 13,146 19 Unpainted carbon steel Carbon Steel 0.026 168,836 20 Unpainted carbon steel over concrete Carbon Steel Concrete 0.250 24.0 7,275 NOTE:

(1) All heat sink areas include a 10% margin.

Material Thermal Conductivity (Btu/hr-ft- F) Volumetric Heat Capacity (Btu/ft 3- F) Carbon steel 25.0 54.0 Stainless steel 9.4 54.0 Concrete 0.8 30.0 Paint (inorganic primer) 0.633 21.7 Paint (organic topcoat) 0.4 49.9 Paint (concrete paint) 0.13 28.3 Copper 200.0 51.3 Zinc coating 66.4 41.3

• Thermophysical Properties STPEGS UFSAR 6.2-167 Revision 18 TABLE 6.2.2-1 CONTAINMENT SPRAY SYSTEM - DESIGN PARAMETERS Containment Spray Pump

Type Vertical centrifugal

Quantity 3

Design pressure, psig 495

Design temperature, F 300 Design flow rate, gal/min 1,900

Design head, ft 560

STPEGS UFSAR 6.2-168 Revision 18 TABLE 6.2.2-2 DESIGN DATA FOR THE REACTOR CONTAINMENT FAN COOLER (RCFC) SYSTEM There are six RCFC units and each unit consists of:

Fan Quantity 1

Fan type Vane axial

Bearing monitors Vibration and temperature

Flow adjustment mechanism Manual fan blade adjustment Normal Mode Operation Accident Mode Operation Nominal speed (rpm) 1,770 1,770 Capacity (ft 3/min) 53,500 53,500 Containment atmosphere pressure (psig) 0 See Section 6.2.1.1 Containment atmosphere temperature ( F) 110 See Section 6.2.1.1 Fan inlet temperature ( F) 51* 270 Containment atmosphere density (lb/ft

3) 0.072* 0.172

Motor Quantity 1

Enclosure Totally Enclosed Air Over

Type 460V, 3-Phase, 60 Hz, single-speed

Bearing monitors Vibration and temperature Winding monitors RTDs

Service factor 1.15

Space heater (volt, watts) 120 volts, 264 watts

• The data is based on an air mixture inlet temperature of 93F and 15 percent relative humidity STPEGS UFSAR 6.2-169 Revision 18 TABLE 6.2.2-2 (Continued)

DESIGN DATA FOR THE REACTOR CONTAINMENT FAN COOLER (RCFC) SYSTEM Normal Mode Operation Accident Mode Operation Motor (Continued) Speed (rpm) 1,800 1,800

Horsepower 150 150

Cooling Coil Assembly

Number of coil sections 10

Nominal face area for all coil sections (ft 2/section) 19 Type Finned tube

Tube material Copper, ASME SB-75, Type 122

Fin material Copper, ASTM B-152, Alloy 110

Fins per inch 6

Tube nominal OD (in.) .625 Nominal tube length (in.) 114

Assembly frame material Carbon steel, ASTM A 570

Drain pan material Galvanized ASTM A 446 Normal Mode Operation Accident Mode Operation Heat removal capability (Btu/hr) 2.6 x 10 6* 95.1 x 10 6 Mixture inlet temperature ( F) 120 275 Mixture outlet temperature ( F) 51* 270

• The data is based on an air mixture inlet temperature of 93F and 15 percent relative humidity STPEGS UFSAR 6.2-170 Revision 18 TABLE 6.2.2-2 (Continued)

DESIGN DATA FOR THE REACTOR CONTAINMENT FAN COOLER (RCFC) SYSTEM

Normal Mode Operation Accident Mode Operation Cooling Coil Assembly (Continued)

Steam-air density entering coil (lb/ft

3) 0.072 0.170 Steam-air density leaving coil (lb/ft

3) 0.0776 0.177 Relative humidity entering coil (%) 20-60 100 Relative humidity leaving coil (%) 63 100 Cooling water flow (gal/min) 450 1,800

Cooling water inlet temperature ( F) 45 125 Cooling water outlet temperature ( F) 56 235 Coil tube side fouling factor .0005 .0005

Backdraft Damper

Maximum backpressure across damper (approx., psi) N/A 15 Operating time (approx.) N/A less than 1 second Maximum flow (ft 3/min) 53,500 53,500

Housing Differential pressure (psi) 0 5 Temperature ( F) 120 275 6.2-171 STPEGS UFSAR Revision 18 TABLE 6.2.2-3 FAILURE MODES AND EFFECT ANALYSIS - CONTAINMENT HEAT REMOVAL ACTIVE FAILURE Plant Method Failure Effect Description Safety Operating Failure of Failure on System Safety of Component Function Mode* Mode(s) Detection Function Capability General Remarks CSS Pump A (Pumps B and C analogous) Delivers spray flow to RCB 1-4 Pump fails to start Flow indicator at main control board (MCB)

CSS pump low discharge flow alarm at MCB.

Indicator lights and ESF status monitoring at MCB None - 3 CSS Trains Failure of one train leaves the system 100% capacity via the redundant trains 1-4 Pump fails to deliver adequate flow. Flow indicator and low discharge flow alarm at

MCB Each of 3 trains provides 50% of system requirements Spray Pump A Discharge Isolation Valve XCS0001A (Valves XCS0001B and XCS0001C analogous))

Opens to allow spray flow to be delivered

Remains open for spraying 1-4 1-4 Valve fails to open fully

Spurious closure Position indicator and ESF monitoring at MCB

Position indicator and ESF status monitoring, and low flow alarm at MCB None - Failure of one train leaves the system with 100% capacity via the redundant trains Check valve XCS0002 None - valve failure (Valve XCS0006 analogous) Open to allow spray flow to be delivered 1-4 Fails to open Flow indication and alarm at MCB Leaves system with 100% capacity via redundant

trains

• Plant Modes

1. Power Operation 4. Hot Shutdown

2. Startup 5. Cold Shutdown 3. Hot Standby 6. Refueling 6.2-172 STPEGS UFSAR Revision 18 TABLE 6.2.2-3 (Continued)

FAILURE MODES AND EFFECT ANALYSIS - CONTAINMENT HEAT REMOVAL ACTIVE FAILURE Plant Method Failure Effect Description Safety Operating Failure of Failure on System Safety of Component Function Mode* Mode(s) Detection Function Capability General Remarks Check valve XCS0004 (Valve XCS0005 analogous) Open to allow spray flow to be delivered 1-4 Fails to open None None - Flow from affected train delivered to spray header via valve XCS0005, system maintains capacity in excess of 100%

Pressure Transmitter 0810, 0820, or 0830 Alarm on low alarm pressure 1-4 Fails to alarm low pressure Remaining two pressure transmitters would indicate

pressure None - Remaining two pressure transmitters generate low alarm Pressure low setpoint is high enough that system can perform its safety function Channel I DC Power (Train A) Provide DC power to channel I components 1-4 Loss of DC power ESF monitoring on UPS failure, DC trouble alarm, ESF monitoring for pump (not running, no control power) None - Redundant trains provide system safety

capability Pump status lights off Channels III & IV (Trains B & C analogous) RCFC Fan VFN001 (RCFC Fans VFN002, VFN003, VFN004, VFN005 or VFN006 analogous)

Operates to provide air circulation in the Containment for cooling and mixing 1-4 Fan fails to operate or trips Low differential pressure is alarmed in the main control room fan status indicating lights. ESF status monitoring input to ERF computer None - Failure of RCFC fan leaves the system with over 100% capacity Each RCFC fan is of 33-1/3% capacity

Each train of RCFCs is of 66-2/3% capacity

• Plant Modes

1. Power Operation 4. Hot Shutdown 2. Startup 5. Cold Shutdown 3. Hot Standby 6. Refueling 6.2-173 STPEGS UFSAR Revision 18 TABLE 6.2.2-3 (Continued)

FAILURE MODES AND EFFECT ANALYSIS - CONTAINMENT HEAT REMOVAL ACTIVE FAILURE Plant Method Failure Effect Description Safety Operating Failure of Failure on System Safety of Component Function Mode* Mode(s) Detection Function Capability General Remarks Cooling Coil VHX001

and associated supply and return pipes (Cooling Coil VHX002, VHX003, VHX004, VHX005 or VHX006 analogous) Provides cooling by transferring heat from Containment air to component cooling water 1-4 Tube rupture or pipe leak Flow indication in the control room downstream of cooling coil temperature and flow of cooling water input to ERF computer

High air temperature indication downstream of

the cooling coil in the control room None - Failure of cooling coil leaves the system with over 100% capacity Back Draft Damper VXV001 (Dampers VXV002, VXV003, VXV004, VXV005 or VXV006 analogous) Close to provide isolation of RCFC enclosure and ring duct against DBA

pressure 1-4 Remains open resulting in enclosure or ring duct rupture None None - Three remaining units, one from each train, are adequate for cooling Worst Case: One RCFC unit is on extended maintenance and two units are operable in the other sector, rupture of enclosure or ring duct as a result of back draft damper failure in the open position Partial short circuiting will result but leaves the system with over 100%

capacity

• Plant Modes

1. Power Operation 4. Hot Shutdown 2. Startup 5. Cold Shutdown 3. Hot Standby 6. Refueling 6.2-174 STPEGS UFSAR Revision 18 TABLE 6.2.2-3 (Continued)

FAILURE MODES AND EFFECT ANALYSIS - CONTAINMENT HEAT REMOVAL ACTIVE FAILURE Plant Method Failure Effect Description Safety Operating Failure of Failure on System Safety of Component Function Mode* Mode(s) Detection Function Capability General Remarks Back Draft Damper VXV001 (Dampers VXV002, VXV003 VXV004, VXV005 or VXV006 analogous)

Open to allow air flow through the RCFC unit. 1-4 Remains closed when the associated RCFC fan starts None None - Failure of back draft damper leaves the system with over 100%

capacity Class 1E AC Power Train A (Trains B and C analogous) Provides power to Train A AC components 1-4 Loss of power on bus Bus undervoltage alarms. ESF Status monitoring for ESF Diesel Generator System and components

ESF monitoring for systems and AC components None - Trains B and C available to provide system

safety capability Channels I DC Power (Train A Channels III and IV (Trains B and C analogous) Provide DC Power to Channel I components 1-4 Loss of DC power ESF monitoring on UPS failure, DC trouble alarm, ESF monitoring for pump (not running no control power) None - Redundant trains provide system safety

capability Pump status lights off

• Plant Modes

1. Power Operation 4. Hot Shutdown 2. Startup 5. Cold Shutdown 3. Hot Standby 6. Refueling STPEGS UFSAR 6.2-175 Revision 18 TABLE 6.2.2-4 CSS PUMP NPSH PARAMETERS

Required NPSH at Max Flow Rate, ft (max) 1.4

Available NPSH, ft (from RWST) 41.4 (From RCB Emergency Sump) 7.0

Note:

The Available NPSH from RCB excludes any debris head loss and any strainer head loss (which will be submitted in a future Licensing Amendment Request to address GSI-191).

NPSH values are based upon a reference elevation of the center line of the pump suction nozzle rather than the first stage impeller. CN-3143 CN-3143 STPEGS UFSAR 6.2-176 Revision 18 TABLE 6.2.2-5 ESTIMATE OF CSS SPRAY MASS FLOW RATES FOR VARIOUS REGIONS The spray mass flow rates for the various regions are as follows:

1. Containment Dome Area 29,840 lb/min

2. From operating floor (El. 68 ft) to the springline (El. 153ft) 29,840 lb/min

3. Inside the secondary shield wall below El.

19 ft 304 lb/min

4. Inside the secondary shield wall between El. 19 ft and El. 68 ft including the refueling cavity 9,730 lb/min

5. Outside Secondary Shield Wall

a. El. 52 ft to El. 68 ft 6,280 lb/min

b. El. 19 ft to El. 52 ft 6,270 lb/min

c. El. (-) 2 ft to El. 19 ft 2,300 lb/min d. Below El. (-)2 ft 1,770 lb/min 6.2-177 STPEGS UFSAR Revision 18 TABLE 6.2.4-1 CONTAINMENT ISOLATION SYSTEM FAILURE MODES AND EFFECT ANALYSIS Plant Method Failure Effect Description Safety Operating Failure of Failure on System Safety of Component Function Mode* Mode(s) Detection Function Capability General Remarks Isolation valves: Main Steam System M-1,2,3,4 Main Steam FMEA Tables 10.3-1 and 10.3-1A Isolation valves:

Feedwater System M-5,6,7,8 Feedwater System FMEA Tables 10.4-8 and 10.4-8A Isolation valves Containment Spray System M-9,13,17 Containment Heat Removal System FMEA Table 6.2.2-3 Isolation valves: Safety Injection System M-10,11,14,15,18,19,20,21, 22 Emergency Core Cooling System FMEA Table 6.3-10 Isolation valves: Steam Generator Blowdown System M-62,63,64,65,86 Steam Generator Blowdown System FMEA Tables 10.4-9 and 10.4-9A Isolation valves: Component Cooling Water System M-23,24,25,26,27,28,33,34, 35,36,37,38,39,40 CCW System FMEA Table 9.2.2-3

• Plant Modes

1. Power Operation 4. Hot Shutdown

2. Startup 5. Cold Shutdown 3. Hot Standby 6. Refueling 6.2-178 STPEGS UFSAR Revision 18 TABLE 6.2.4-1 (Continued)

CONTAINMENT ISOLATION SYSTEM FAILURE MODES AND EFFECT ANALYSIS Plant Method Failure Effect Description Safety Operating Failure of Failure on System Safety of Component Function Mode* Mode(s) Detection Function Capability General Remarks Isolation valves: CVCS M-46,47,48,51,52,53 CVCS FMEA Table 9.3-12 Isolation valves: RCB instrument Air FV8565 (normally open). IA0541 (normally open). M-58 Containment Isolation 1-4 One fails to close ESF status monitoring, position indication (none for check valve) None - Redundant valve available Isolation valves: RCB Normal Purge SubSystem M-41,42 RCB HVAC FMEA Table 9.4-5.5 Isolation valves: RCB Supplementary Purge SubSystem M-43,44 RCB HVAC FMEA Table 9.4-5.5 Isolation valves:

Auxiliary Feedwater System M-83,84,94,95 AFWS FMEA Table 10.4-3 Isolation Valves: Radioactive Vent & Drain System FV-7800 (Normally Open), ED-0064 (Normally Open), FV-2453 (Normally Closed) M-72 Containment Isolation 1-4 Failure to close ESF status monitoring, position indication None - Redundant valve available

• Plant Modes

1. Power Operation 4. Hot Shutdown

2. Startup 5. Cold Shutdown 3. Hot Standby 6. Refueling 6.2-179 STPEGS UFSAR Revision 18 TABLE 6.2.4-1 (Continued)

CONTAINMENT ISOLATION SYSTEM FAILURE MODES AND EFFECT ANALYSIS Plant Method Failure Effect Description Safety Operating Failure of Failure on System Safety of Component Function Mode* Mode(s) Detection Function Capability General Remarks Isolation Valves:

Sampling System FV-4461, FV-2454, FV-4823 (Normally Closed) M-86 Containment Isolation 1-4 Fails to stay closed ESF status monitoring, position indication None - Redundant valve available Isolation Valves: Sampling System FV-4824, FV-4466 (Normally closed) M-29 Containment Isolation 1-4 Fails to stay closed ESF status monitoring, position indication None - Redundant valve available Isolation Valves:

Containment Hydrogen Monitoring System FV-4101, FV-4135, FV-4127, FV-4128 (Normally closed) M-80 Containment Isolation 1-4 Fails to stay closed ESF status monitoring, position indication None - Redundant valve available Isolation Valves: Containment Hydrogen Monitoring System FV-4104, FV-4136, FV-2456, FV-4133, FV-4134, FV-2457 (Normally Closed)

M-82 Containment Isolation 1-4 Fails to stay closed ESF status monitoring, position indication None - Redundant valve available

• Plant Modes

1. Power Operation 4. Hot Shutdown

2. Startup 5. Cold Shutdown 3. Hot Standby 6. Refueling 6.2-180 STPEGS UFSAR Revision 18 TABLE 6.2.4-1 (Continued)

CONTAINMENT ISOLATION SYSTEM FAILURE MODES AND EFFECT ANALYSIS Plant Method Failure Effect Description Safety Operating Failure of Failure on System Safety of Component Function Mode* Mode(s) Detection Function Capability General Remarks Isolation Valves: Sampling System FV-4450, FV-4451, FV-4452, FV-4451B (Normally closed) M-85 Containment Isolation 1-4 Fails to stay closed ESF status monitoring, position indication None - Redundant valve available Isolation Valves: Sampling System FV-4454, FV-4455, FV-4456, FV-2455, FV-2455A (Normally closed) M-85 Containment Isolation 1-4 Fails to stay closed ESF status monitoring, position indication None - Redundant valve available Isolation Valves: Fire Protection System Fire Protection System FMEA Table 9.5-1 Isolation Valves: Liquid Waste Processing System FV-4919, FV-4920 (Normally Open) M-30 FV-4913, WL-0312 (Normally Open) M-56 Containment Isolation 1-4 Valves fail to close ESF status monitoring, position indication None - Redundant valve available

Isolation Valves: Reactor Coolant System FV-3651 (Normally Open), FV-2458 (Normally Closed),

XRC0046 (Check Valve) M-45 Containment Isolation 1-4 Fails to close ESF status monitoring, position indication (none for check valve) None - Redundant valve available

• Plant Modes

1. Power Operation 4. Hot Shutdown

2. Startup 5. Cold Shutdown 3. Hot Standby 6. Refueling 6.2-181 STPEGS UFSAR Revision 18 TABLE 6.2.4-1 (Continued)

CONTAINMENT ISOLATION SYSTEM FAILURE MODES AND EFFECT ANALYSIS Plant Method Failure Effect Description Safety Operating Failure of Failure on System Safety of Component Function Mode* Mode(s) Detection Function Capability General Remarks Isolation Valves: PRT Vent/Nitrogen Supply FV-3652, FV-3653 (Normally Closed) M-68 Containment Isolation 1-4 Fails to remain closed ESF status monitoring, position indication None - Redundant valve available Isolation Valves: Safety Injection Test Line FV-3970, FV-3971 (Normally Closed) M-68 Containment Isolation 1-4 Fails to remain closed ESF status monitoring, position indication None - Redundant valve available Nitrogen Supply to Accumulators FV-3983 (Normally Closed) SI0058 (check valve) Containment Isolation 1-4 Fails to remain closed ESF status monitoring, position indication (none for check valve) None - Redundant valve available

• Plant Modes

1. Power Operation 4. Hot Shutdown

2. Startup 5. Cold Shutdown 3. Hot Standby 6. Refueling 6.2-182 STPEGS UFSAR Revision 18 TABLE 6.2.4-1 (Continued)

CONTAINMENT ISOLATION SYSTEM FAILURE MODES AND EFFECT ANALYSIS Plant Method Failure Effect Description Safety Operating Failure of Failure on System Safety of Component Function Mode* Mode(s) Detection Function Capability General Remarks

Isolation Valves: Radiation Monitoring System RA-0001, RA-0003, RA-0004, RA-0006 (Normally Open) M-80 Containment Isolation 1-4 One fails to close ESF status monitoring, position indication None - Redundant valve available ESF Actuation System Train A (Analogous for Trains B & C). Provide actuation signals as required to safety-related components 1-4 Fails to generate and send actuation signals Loss of power or actuation train in test is alarmed by ESF status monitoring.

Individual bistables used to generate actuation signals are individually provided with lights and computer inputs. These inputs combined with other similar inputs (for same signal) are alarmed on annunciator, which is located on the main control board None - Redundant valve in series powered and actuated from different train (or inside Containment check valve depending on system

design, except in the case of hydrogen monitoring system which powers and actuates from a single train and will not actuate on a loss of single train actuation signal.) See General Remarks Operator is expected to see that one train has not actuated. Manual action is

then possible to actuate (isolate) systems

• Plant Modes

1. Power Operation 4. Hot Shutdown 2. Startup 5. Cold Shutdown 3. Hot Standby 6. Refueling 6.2-183 STPEGS UFSAR Revision 18 TABLE 6.2.4-1 (Continued)

CONTAINMENT ISOLATION SYSTEM FAILURE MODES AND EFFECT ANALYSIS Plant Method Failure Effect Description Safety Operating Failure of Failure on System Safety of Component Function Mode* Mode(s) Detection Function Capability General Remarks Channel I DC Power (Train A). Provide DC power to Channel I Components 1-4 Loss of DC power ESF status monitoring on UPS failure, DC Trouble alarm None - All Train A air-operated and solenoid-operated valves fail closed Channel III DC Power (Train B). Provide DC Power to Channel III Components 1-4 Loss of DC power ESF status monitoring on UPS failure, DC Trouble alarm None - All Train B air-operated and solenoid-operated valves fail closed Channel IV Power (Train C). Provide DC Power To Channel IV Components 1-4 Loss of DC power ESF status monitoring on UPS failure, DC Trouble alarm None - All Train C air-operated and solenoid-operated valves fail closed Instrument Air (Non-Safety). None 1-4 Instrument air lost Header pressure indication and alarms None - Loss of instrument air causes air-operated

valves to go to their safety position (Closed)

Class 1E AC Power Train A. Provides power to Train A AC Components 1-4 Loss of power on bus Bus undervoltage alarms, ESF status monitoring for ESF diesel generator system and components Train A Fail motive power to WL-0312. None - Isolation function provided by Train B air-operated valve FV-4913

• Plant Modes

1. Power Operation 4. Hot Shutdown

2. Startup 5. Cold Shutdown 3. Hot Standby 6. Refueling 6.2-184 STPEGS UFSAR Revision 18 TABLE 6.2.4-1 (Continued)

CONTAINMENT ISOLATION SYSTEM FAILURE MODES AND EFFECT ANALYSIS Plant Method Failure Effect Description Safety Operating Failure of Failure on System Safety of Component Function Mode* Mode(s) Detection Function Capability General Remarks

Class 1E AC Power Train

B Provide power to Train B AC components 1-4 Loss of power on bus Same as Train A Train B Fail motive power to ED-0064. None - Isolation function provided by Train A air-operated valve FV-7800 and Train A solenoid-operated valve FV-2453 Class 1E AC Power Train C Provide power to Train C AC components 1-4 Loss of power on bus Same as Train A Train C Fail motive power to FP-0756, None - Isolation provided by check valve

• Plant Modes

1. Power Operation 4. Hot Shutdown

2. Startup 5. Cold Shutdown 3. Hot Standby 6. Refueling STPEGS UFSAR 6.2-185 Revision 18 TABLE 6.2.6-1 SYSTEMS WHICH NEED NOT BE VENTED DURING TYPE A TESTING System Penetration No.* Justification High Head Safety Injection 10, 14, 18 The system is normally filled with water and operating under post-

accident conditions. (Drain up to two

of the High Head Safety Injection penetrations)

Chemical and Volume Control 46, 48, 53 The system maintains the plant in a safe condition during testing.

Low Head Safety Injection 11, 15, 19 The system is normally filled with water and operating under post-

accident conditions. (Drain up to two of the Low Head Safety Injection penetrations)

Refueling cavity drainage to RWST 55, 76 The piping inside the Containment is connected to RHR system by two locked closed manual valves and is used only during refueling. The system is filled with water during normal and post-accident conditions.

(Drain penetration M-76 if desired)

Component Cooling Water to Reactor Containment Fan Coolers 23, 24, 25, 26, 27, 28 This is a closed system inside the Containment which is normally filled

with water and operating under post-

accident conditions. (Drain up to six of the Component Cooling Water Supply/Return Reactor Containment

Fan Cooler penetrations)

• See Figure 6.2.4-1 for further description.

STPEGS UFSAR 6.2-186 Revision 18 TABLE 6.2.6-1 (Continued)

SYSTEMS WHICH NEED NOT BE VENTED DURING TYPE A TESTING

System Penetration No.* Justification Component Cooling Water to RHR

Heat Exchanger and Pump 33, 34, 35, 36, 37, 38 This is a closed system inside the Containment which is normally filled

with water and operating under post-

accident conditions. (Drain up to two of the same train of the Component Cooling Water Supply/Return RCP penetrations)

CCW to and from RCPs 39, 40 This is a closed system inside the Containment which is normally filled

with water and operating under normal and post-accident conditions.

Automatic isolation occurs upon reaching the Containment pressure

HI-3 setpoint (see Section 7.3).

(Drain up to two of the CCW

Supply/Return RCP penetrations)

• See Figure 6.2.4-1 for further description.

Revision 18 6.2-187 STPEGS UFSAR TABLE 6.2.6-3 CONTAINMENT ISOLATION VALVES TO BE LEAK TESTED IN OPPOSITE DIRECTION Penetration Number System Function Type of Valve Valve Identification Location M-41 RCB Normal Purge Subsystem Butterfly HC-0009 Inside Containment M-42 RCB Normal Purge Subsystem Butterfly HC-0008 Inside Containment M-43 RCB Supplementary Purge Subsystem Butterfly HC-0003 Inside Containment M-44 RCB Supplementary Purge Subsystem Butterfly HC-0005 Inside Containment M-80 Containment Hydrogen Monitoring System Globe FV-4128 Inside Containment M-82 Containment Hydrogen Monitoring System Globe FV-4134 Inside Containment M-80 Radiation Monitoring System Ball RA-0001 Inside Containment M-80 Radiation Monitoring System Ball RA-0003 Inside Containment

STPEGS UFSAR 6.3-1 Revision 1 8 6.3 EMERGENCY CORE COOLING SYSTEM

6.3.1 Design

Bases The Emergency Core Cooling System (ECCS) is designed to cool the reactor core and provide shutdown capability subsequent to the following accident conditions:

1. Pipe breaks in the Reactor Coolant System (RCS) which cause a discharge larger than that which can be made up by the normal makeup system, up to and including the instantaneous circumferential rupture of the largest pipe in the RCS.

2. Rupture of a control rod drive mechanism (CDRM) causing a rod cluster control assembly (RCCA) ejection accident.

3. Pipe breaks in the steam system, up to and including the instantaneous circumferential rupture of the largest pipe in the steam system.

4. A steam generator tube rupture.

The primary function of the ECCS is to remove the stored and fission product decay heat from the reactor core and to provide shutdown capability during accident conditions.

The ECCS provides shutdown capability for the accidents above by means of boron injection. It is designed to tolerate a single active failure in the short term or a single active or passive failure in the long term. The system meets its minimum required performance level with onsite or offsite electrical power.

The ECCS consists of the high head safety injection (HHSI) and low head safety injection (LHSI) pumps, Safety Injection System (SIS) accumulators, residual heat removal (RHR) heat exchangers (HXs), the refueling water storage tank (RWST) along with the associated piping, valves, instrumentation, and other related equipment.

The design bases for selecting the functional requirements of the ECCS, such as peak fuel cladding temperature, etc., are derived from Appendix K limits as delineated in 10CFR50.46. The subsystem functional parameters are integrated so that the Appendix K requirements are met over the range of anticipated accidents and single failure assumptions.

Reliability of the ECCS has been considered in selection of the functional requirements, selections of the particular components, and location of components and connected piping. Redundant components are provided where the loss of one component would impair reliability. Valves are provided in series where isolation is desired. Redundant sources of the ECCS actuation signal are available so that the proper and timely operation of the ECCS is not inhibited. Sufficient instrumentation is available so that a failure of an instrument does not impair readiness of the system.

The active components of the ECCS are powered from separate buses which are energized from offsite power supplies.

STPEGS UFSAR 6.3-2 Revision 1 8 In addition, the standby diesel generators (DGs) assure that adequate redundant sources of auxiliary onsite power are available to meet all ECCS power requirements. Each diesel is capable of driving all pumps, valves, and necessary instruments associated with one train of the ECCS.

In response to the Nuclear Regulatory Commission (NRC) Branch Technical Position (BTP) ICSB

-18, protection against spurious movement by power lockout has been included in the design of certain motor

-operated valves (MOVs) as described in Sections 6.3.2.2 and 6.3.5.5.

The elevated temperature of the sump solution during recirculation is well within the design temperature of all ECCS components. In addition, consideration has been given to the potential for corrosion of various types of metals exposed to the fluid conditions prevalent immediately after the accident or during long

-term recirculation operations.

Environmental qualification of ECCS equipment which is required to operate following a Loss

-of-Coolant Accident (LOCA) is discussed in Section 3.11.

6.3.2 System

Design The ECCS components are designed such that a minimum of two accumulators delivering to two unaffected loops, and one HHSI and one LHSI pump delivering to an unaffected loop, will assure adequate core cooling in the event of a design basis LOCA. The redundant onsite standby DGs assure adequate emergency power to all electrically

-operated components in the event a loss

-of-offsite power (LOOP) occurs simultaneously with a LOCA, even assuming a single failure in the emergency power system such as the failure of one DG to start.

6.3.2.1 Schematic Piping and Instrumentation Diagrams. Flow diagrams of the ECCS are shown on Figure 6.3

-1 through 6.3

-5. Pertinent design and operating parameters for the components of the ECCS are given in Table 6.3

-1. The codes and standards to which the individual components of the ECCS are designed are listed in Section 3.2.

The component interlocks used in different modes of ECCS operation are listed below.

1. The safety injection (SI) signal is interlocked with the following components and initiates the indicated action:

a. HHSI pumps start (through the Engineered Safety Feature [ESF] load sequencer signal)

b. LHSI pumps start (through the ESF load sequencer signal)

c. Any closed accumulator isolation valves open

d. RWST discharge isolation valves to Spent Fuel Pool Cooling and Cleanup System (SFPCCS) close

e. The component cooling water system (CCWS) valves for the RHR HXs open STPEGS UFSAR 6.3-3 Revision 1 8 As indicated in Section 7.3.1, the standby DGs, ESF load sequencers, heating ventilating, and air-conditioning (HVAC) equipment, cooling water systems and other components required to support the ECCS equipment are also actuated by the SI signal

. 2. Switchover of a train from injection mode to recirculation mode involves an interlock where the HHSI and LHSI pump mini

-flow valves (which are normally open) close and the suction valves from the sump open when the level transmitter indicates a low

-low level in the RWST, coincident with an SI signal.

3. Additionally, the system includes an interlock which prevents the RWST isolation valves from being opened unless the corresponding recirculation sump valves are closed.

6.3.2.2 Equipment and Component Descriptions. The component design and operating conditions are specified as the most severe conditions to which each respective component is exposed during either normal plant operation or during operation of the ECCS. For each component, these conditions are considered in relation to the code to which it is designed. By designing the components in accordance with applicable codes, and with due consideration for the design and operating conditions, the fundamental assurance of structural integrity of the ECCS components is maintained. Components of the ECCS are designed to withstand the appropriate seismic loadings in accordance with their safety class as given in Section 3.2. Active, powered components required for ECCS operation are listed in Table 6.3-12.

The major mechanical components of the ECCS follow. ECCS component parameters are provided in Table 6.3

-1.

Accumulators

The accumulators are pressure vessels partially filled with borated water and pressurized with nitrogen gas. During normal operation each accumulator is isolated from the RCS by two check valves in series. Should the RCS pressure fall below the accumulator pressure, the check valves open and borated water is forced into the RCS. One accumulator is attached to each of the cold legs of loops 1, 2 and 3 of the RCS. Mechanical operation of the swing

-disc check valves is the only action required to open the injection path from the accumulators to the core via the cold leg.

Connections are provided for remotely adjusting the level and boron concentration of the borated water in each accumulator during normal plant operation as required. Accumulator water level may be adjusted by pumping borated water from the RWST to the accumulator. Samples of the solution in the accumulators are taken periodically for checks of boron concentration.

Accumulator pressure is provided by a supply of nitrogen gas, and can be adjusted as required during normal plant operation; however, the accumulators are normally isolated from this nitrogen supply.

Gas relief valves on the accumulators provide protection from pressures in excess of design pressure.

The accumulators are located within the Containment but outside of the secondary shield wall thus providing missile protection.

STPEGS UFSAR 6.3-4 Revision 1 8 Accumulator gas pressure is monitored by indicators and alarms. The operator can take action as required to maintain plant operation within the requirements of the Technical Specification addressing accumulator operability.

Refueling Water Storage Tank The RWST is used to provide a sufficient supply of borated water to the LHSI, HHSI, and the Containment spray pumps for the injection mode of ECCS operation. All valves between the RWST and the SIS are normally open to assure an immediate supply of water to the safeguards equipment when required. Three level transmitters and alarms are provided with readouts on the main control board to (1) prevent overflow, (2) maintain a nominal operating level, (3) initiate automatic switchover from the injection to recirculation phase, and (4) indicate when the tank is empty. A further discussion of RWST level indication is provided in Section 6.3.5.4.

The RWST also provides borated water for filling the refueling cavity for refueling operations and a source of borated water to the charging pump suction header if a low

-low level exists in the volume control tank during normal operation.

The nominal RWST volumes and minimum required volumes are given as follows. Note that the volumes below have been rounded to the nearest one

-thousand gallons. (See Figure 6.3

-8 for elevations of the tank outlet nozzle and overflow nozzle and the various tank level setpoints):

Nominal Volume (gal)

Required Volume (gal)

Volume Above High Alarm 22,000 >0 Working Allowance 55,000 >0 Injection Volume 398,000 360,000 Transfer Allowance 43,000 12,000 Volume at Empty Alarm 32,000 16,000 RWST Total Volume 550,000 Instrument system error is a combination of errors applicable for each setpoint. The error for the Lo

-Lo Setpoint (which actuates switchover) includes a combination of errors that include allowances for instrument uncertainties plus additional margin for a total minimum allowance of 5 percent of instrument span. The instrument span is 388 inches. The volume corresponding to 5 percent is approximately 27,000 gallons.

Evaluations have been performed on the remainder of the tank settings to ensure functional requirements are met when considering instrument uncertainty.

The working allowance is the volume between the high level alarm and the low level alarm which is used during normal plant operation as makeup to the spent fuel pool and as an alternate source of water for the charging pump suction.

The transfer allowance is the amount of water allowed for the completion of the switchover from the injection mode of operation to the recirculation mode. The switchover is automatically initiated at the low-low alarm setpoint. The changeover from the injection mode to recirculation mode is STPEGS UFSAR 6.3-5 Revision 1 8 completed automatically with manual operator action from the control room required only to secure the RWST to prevent backflow leakage across the check valve into the RWST.

Assuming that the 3 LHSI, 3 HHSI, and the 3 Containment Spray System (CSS) pumps are operating at maximum flow (total flow rate = 19,500 gal/min), the HHSI and LHSI mini

-glow recirculation valves close, and that the emergency sump isolation valves open in 38 seconds, volume of approximately 12,000 gallons is required to complete the switchover.

Any single failure of the ECCS would not result in larger volumes of water being needed for the transfer process. There is no operator action required to recover from a single failure. The failure of one sump isolation valve to open on receipt of the switchover does not impair the safety function of the safety injection or CSS. The potential failure of an RWST isolation valve to close will not required operator action since the elevation difference between the RWST and the Containment recirculation sump (even neglecting Containment pressurization) is sufficient to preclude unacceptable air entrainment in the ECCS pumps.

An unusable volume exists at the bottom of the tank. The suction nozzle of the tank is an internal elbow which terminates about one foot above the tank bottom. This one foot of volume is considered unavailable to any of the pumps which take suction from the tank. Additionally, some amount of water above velocity and submergence considerations (vortex tendencies). A vortex breaker is provided for the nozzle. The vortex breaker is two feet tall and establishes the minimum practical water level for suction for the ECCS pumps in the post

-DBA mode of operation.

As mentioned above, the only operator action required is the manual closure of the RWST isolation valve at the completion of the switchover to prevent backflow leakage across the check valve into the RWST. Low Head Safety Injection Pumps

In the event of an accident, the three LHSI pumps are started automatically upon receipt of an SI signal and a load sequencer start permissive. The LHSI pumps deliver borated water to the RCS cold legs from the RWST during the injection phase and from the Containment sump to the RCS hot legs or cold legs during the recirculation phase. Each LHSI pump is multi

-stage vertical motor drive n centrifugal pump. A pump performance curve is provided on Figure 6.3

-6.

A minimum flow bypass line is provided for the pumps to recirculate and return the pump discharge fluid to the RWST should these pumps be started with their normal flow paths blocked. This line prevents deadheading of the pumps and permits pump testing during normal plant operation. At the initiation of the recirculation phase of ECCS operation the bypass line isolation valves are automatically closed upon receipt of a low

-low RWST level signal coincident with an SI signal. The portion of the minimum flow bypass line downstream of the second isolation valve is classified as

non-nuclear safety since its failure would not degrade ECCS performance or result in a radioactive leakage path to the environment. Should a rupture occur in one or more of these lines, pump minimum flow during the injection mode of operation is limited by a flow orifice in the bypass line upstream of the bypass line isolation valves. Since the minimum flow bypass lines are isolated at the initiation of the recirculation phase, a failure in the non

-nuclear safety portion would have no effect on pump performance and would not result in radioactive leakage to the environment during long

-term recirculation.

STPEGS UFSAR 6.3-6 Revision 1 8 The LHSI pumps contain an internal bearing system which utilizes the pumpage for lubrication and requires no external cooling medium. The pump suction bowl and column support bearings are carbon steel. The pump shaft which forms the journal for the carbon bearings is constructed from the American Society of Testing and Materials (ASTM) A276 GR410 stainless steel which is heat treated to a hardness of 250

-300 Brinell. The pump discharge head and impeller bowl bearings are constructed of ASTM A276 GR440A stainless steel with heat treatment to achieve a minimum hardness of 450 Brinell, and operate outside shaft journal sleeves which are ASTM A276 GR 420 stainless steel heat treated to a hardness of 430

-450 Brinell. Qualification tests were performed to verify the ability of these pumps to successfully operate through a thermal transient, which postulated the switchovers from injection to recirculation, concurrently with reactor building debris in the pumpage. This bearing system and configuration are utilized on numerous condensate and heater drain pumps manufactured by the same pump supplier.

Each LHSI pump contains a Type 1B (balanced) mechanical seal which is installed inside the pump discharge head. The sealing surfaces consist of a rotating carbon primary ring which seals against a stationary tungsten carbide mating ring. The secondary seals (bellows, O

-rings) are constructed of a radiation and chemically resistant elastomeric compound. The seal also contains a disaster bushing which is a spring

-loaded packing which rides near the shaft diameter to form a very tight leakage clearance to seal against catastrophic failure of the primary or secondary seals.

The pump does not contain mechanical seal coolers since the seal is cooled by the pumpage.

Extensive qualification testing has been performed by both the seal and pump suppliers to include tests at various conditions of temperatures, pressure, radiation, and boric acid concentrations. The same seal design is common to most of the safety

-related auxiliary pumps used in nuclear plant applications.

High Head Safety Injection Pumps

In the event of an accident, the three HHSI pumps are started automatically on receipt of an SI signal and a load sequencer start permissive.

These pumps deliver water to the RCS from the RWST during the injection phase and from the containment sump during the recircualtion phase. Each HHSI pump is a multi

-stage, vertical, motor

-driven centrifugal pump. A pump performance curve is shown on Figure 6.3

-7.

A minimum flow bypass line is provided on each pump discharge line to recirculate flow to the RWST in the event the pumps are started with the normal flow paths blocked. This line also permits pump testing during normal plant operation. Two valves in series are provided in this line. These valves are automatically closed during the initiation of the recirculation phase of ECCS operation, upon receipt of a low

-low RWST level signal coincident with an SI signal. The portion of the minimum flow bypass line downstream of the second isolation valve is classified as non

-nuclear safety since its failure would not degrade ECCS performance or result in a radioactive leakage path to the environment. Justification for this is the same as that given for the LHSI pump minimum flow bypass valve.

Residual Heat Removal Heat Exchangers

STPEGS UFSAR 6.3-7 Revision 1 8 The RHR HXs are conventional shell and U

-tube type units. During normal cooldown operation, the RHR pumps recirculate reactor coolant through the tube side while component cooling water (CCW) flows through the shell side. During ECCS operation, water from either the RWST or the containment sump flows, via the LHSI pumps, through the tube side while component cooling water flows through the shell side. Credit is taken for cooling provided by the RHR HXs only during long

-term recirculation operation. The tubes are seal welded to the tubesheet.

A further discussion of the RHR HXs is found in Section 5.4.7. Design parameters appear in Table 5.4-8. It should be noted the parameters are based on normal cooldown rather than the recirculation phase of ECCS operation following a LOCA. This is due to the relatively small T that exists on the tube side of the HX during the latter part of normal cooldown.

Valves Closing times for MOVs used in the ECCS are given in Table 6.3-1.

Design features employed to minimize valve leakage include:

1. Where possible, packless valves are used.

2. Other valves which are normally open, except check valves and those which perform a control function, are provided with backseats to limit stem leakage.

3. Normally closed globe valves are installed with recirculation fluid pressure under the seat to prevent stem leakage of recirculated (radioactive)water.

4. Relief valves are enclosed, i.e., they are provided with a closed bonnet.

Motor-Operated Gate Valves

The seating design of all MOVs is of the flexible wedge design. This design releases the mechanical holding force during the first increment of travel so that the motor operator works only against the frictional component of the hydraulic unbalance on the disc and the packing box friction. The disc is guided throughout the full disc travel to prevent chattering and to provide ease of gate movement.

The seating surfaces are hard faced to prevent galling and to reduce wear.

Where a gasket is employed for the body to bonnet joint, it is either a fully trapped, controlled compression, spiral wound gasket with provisions for seal welding, or it is of the pressure seal design with provisions for seal welding.

The motor operator incorporates a "hammer blow" feature that allows the motor to impact the discs away from the backseat upon opening or closing. This "hammer blow' feature not only impacts the disc but allows the motor to attain its operational speed prior to impact. Valves which must function against system pressure are designed such that they function with a pressure drop expected on these valves during both normal and abnormal events within the design basis.

Manual Globe, Gate, and Check Valves

STPEGS UFSAR 6.3-8 Revision 1 8 Gate valves employ a wedge design and are straight through. The wedge is either split or solid. All gate valves have backseat and outside screw and yoke.

Globe valves, "T" and "Y" style, are full ported with outside screw and yoke construction.

Check valves are spring

-loaded lift piston types for sizes 2 in. and smaller, and swing type for size 2

-1/2 in. and larger. Stainless steel check valves have no penetration welds other than the inlet, outlet, and bonnet. The check hinge is serviced through the bonnet.

Folding disc type check valves are also used in size 2

-1/2 in. and larger non

-safety related piping.

The stem packing and gasket of the stainless steel manual globe and gate valves are similar to those described above for MOVs. Carbon steel manual valves are employed to pass nonradioactive fluids only and therefore do not contain the double packing and seal weld provisions.

Accumulator Check Valves (Swing

-disc)

The accumulator check valve is designed with a low pressure drop configuration with all operating parts contained within the body.

Design considerations and analyses which assure that leakage across the check valves located in each accumulator injection line do not impair accumulator availability are as follows:

1. During normal operation the check valves are in the closed position. Since the valves remain in this position except for testing or when called upon to open following an accident, and are therefore not subject to the abuse of flowing operation or impact loads caused by sudden flow reversal and seating, they do not experience significant wear of the moving parts, and are expected to function with minimal back

-leakage. This back

-leakage can be checked via the test connection as described in Section 6.3.4.

2. When the RCS is being pressurized during the normal plant heatup operation, the check valves are tested for leakage in accordance with Technical Specifications. Any required testing is performed prior to the plant entering Mode 2. This test confirms the seating of the disc and whether or not there has been an increase in the leakage since the last test.

3. The experience derived from the check valves employed in the emergency injection systems indicate that the system is reliable and effective; check valve leakage has not been a problem.

This is substantiated by the satisfactory experience obtained from operation of the Robert Emmett Ginna and subsequent plants where the usage of check valves is identical to this application.

4. The accumulators can accept some in

-leakage from the RCS without affecting availability. Continuous in leakage would require, however, that the accumulator water volume be adjusted according to Technical Specification requirements.

Relief Valves

STPEGS UFSAR 6.3-9 Revision 1 8 Relief valves are installed in various sections of the ECCS to protect lines which have a lower design pressure than the RCS. The valve stem and spring adjustment assembly are isolated from the system fluids by a bellows seal between the valve disc and spindle. The closed bonnet provides an additional barrier for enclosure of the relief valves. The accumulator relief valves are sized to pass nitrogen gas at a rate in excess of the accumulator gas fill line delivery rate. The case of maximum nitrogen filling of the accumulator is the design transient for accumulator relief valve sizing and a coincident water

-fill operation would have no significant effect on the transient. The relief valves will also pass water in excess of the expected accumulator in

-leakage rate, but this is not considered to be necessary, because the time required to fill the gas space gives the operator ample opportunity to correct the situation. Table 6.3

-2 lists the system relief valves with their capacities and setpoints.

System Filling, Venting, and Availability

The HHSI subsystem is gravity filled from the RWST. The subsystem is manually vented utilizing high point vents on the subsystem piping. Once the HHSI subsystem has been filled and vented, it is kept in this condition by the head of the RWST which is the high point of the subsystem.

The LHSI subsystem is initially filled utilizing the LHSI pumps. Subsystem piping is manually vented. The RHR HX tubes which are the subsystem high points are purged by the LHSI pump flow which is sufficient to sweep out entrapped air. The seal standpipes for reactor coolant pumps (RCPs) A, B, and C are used to maintain a static head on the RHR HXs and keep the HX tubes filled. A line is routed from each of the seal standpipes to the corresponding inlet line of the RHR HXs. This maintains the LHSI subsystem in a filled condition. Makeup to the seal standpipe is from the Reactor Makeup Water System (RMWS), as discussed in Section 9.3.4.

Butterfly Valves

Each RHR HX discharge line has an air

-operated butterfly valve which is normally open and is designed to fail in the open position. The air line to the valve contains a Class 1E solenoid to allow manual venting to its design failure position. The actuator is arranged such that air pressure on the diaphragm overcomes the spring force, causing the linkage to move the butterfly to the closed position. Upon loss of air pressure, the spring returns the butterfly to the open position. These valves are left in the fully open position during normal plant operation to maximize flow from this system to the RCS during the injection mode of ECCS operation. These valves are used during normal Residual Heat Removal System (RHRS) operation to control cooldown flowrate.

Each RHR HX bypass line has an air

-operated butterfly valve which is normally closed and is designed to fail closed. The air line to the valve contains a Class 1E solenoid to allow manual venting to its design failure position. The butterfly valves are used during normal cooldown to maintain a uniform return flow to the RCS. They are left in the fully closed position during normal plant operation.

Net Positive Suction Head Available and required net positive suction head (NPSH) for ECCS pumps are shown in Table 6.3

-1. The safety intent of Regulatory Guide (RG) 1.1 is met by the design of the ECCS such that adequate NPSH is provided to system pumps.

STPEGS UFSAR 6.3-10 Revision 1 8 The NPSH available for the injection mode is determined from the elevation head and the vapor pressure (atmospheric) of the water in the RWST, and the pressure drop in the suction piping from the tanks to the pumps. The NPSH evaluation is based on all pumps operating at maximum flow rate with no credit taken for the elevation head in the tank and full penalty assumed for head loss in the suction lines.

In addition to considering the static head and suction line pressure drop, the calculation of available NPSH in the recirculation mode assumes that the vapor pressure of the liquid in the sump is equal to the Containment ambient pressure. This assures that the actual available NPSH is always greater than the calculated NPSH.

Accumulator Motor

-Operated Valve Controls

As part of the plant shutdown administrative procedures, the operator is required to close these valves. This prevents a loss of accumulator water inventory to the RCS and is done after the RCS has been depressurized below the P

-11 setpoint (Table 7.3

-4) and prior to the time RCS pressure reaches accumulator discharge pressure. The redundant pressure and level alarms on each accumulator would remind the operator to close these valves, if any were inadvertently left open. Power is disconnected after the valves are closed.

During plant startup, the operator is instructed via procedures to energize and open these valves after the RCS pressure reaches accumulator discharge pressure and prior to th e P-11 setpoint. Monitoring lights in conjunction with an audible alarm will alert the operator should any of these valves be left inadvertently closed once the RCS pressure increases beyond the safety injection unblock setpoint.

The accumulator isolation valves are not required to move during power operation or in a post

-accident situation. A discussion of limiting conditions for operation and surveillance requirements of these valves will be provided in the Technical Specifications.

The control circuit for the accumulator motor

-operated isolation valve provides protection against inadvertent closure of that valve due to safety signal override logic. In addition, the electric power source is removed from the valve motor operator. Although the valve is normally open, automatic opening is provided whenever RCS pressure exceeds the P

-11 setpoint. It is necessary with automatic opening of these valves with reactor coolant pressure to include an administratively controlled manual bypass circuit which must be actuated to allow for periodic testing of the check valves. This manual bypass is overridden by an SI signal or a manual opening signal. Therefore, in the event a valve is closed for accumulator maintenance or testing for check valve leakage at the time the injection is required, an SI signal from one train will open the valve, overriding the test closure.

For further discussions of the controls and instrumentation associated with these valves, refer to Sections 6.3.5.5 and 7.6.3.

Safety Injection Hot and Cold Leg Recirculation Isolation Valves

The MOVs in the hot leg recirculation line of each high head and low head safety injection pump are normally closed valves. The valves may be opened by operator action to provide recirculation flow to the corresponding hot leg during the switchover from cold leg to hot leg recirculation, post

-accident. They are also opened during periodic SIS testing operations.

STPEGS UFSAR 6.3-11 Revision 1 8 The MOVs in the cold leg recirculation line of each high head and low head safety injection pump are normally open valves. The valves may be closed by operator action to provide recirculation flow to the corresponding hot leg during the switchover from cold leg to hot leg recirculation, post

-accident. They are also closed during periodic SIS testing operations.

The testing procedures instruct the operator to energize and open/close these valves when required during testing, and to energize and close/open the valves again after the testing is complete. Monitoring lights in conjunction with an audible alarm will alert the operator when any of these valves are opened/closed.

During normal operations, the electric power source is removed from the valve motor operator by power lockout capability from a control switch located at the main control panel. During normal operations, the electric power source is also removed from the LHSI pumps cold leg isolation valves by opening the breaker at the motor control center (MCC). For further discussion of the controls and instrumentation associated with these valves, refer to Sections 6.3.5.5. and 7.6.7.

Motor-Operated Valves and Controls

Remotely operated valves for the injection mode which are under manual control are in their ready position and do not require an SI signal. The valve positions are indicated on a common portion of the control board. If a component is out of its proper position, its monitoring light will indicate this on the control panel. At any time during operation when one of these valves is not in the ready position for injection, this condition is shown visually on the board, and an audible alarm is sounded in the control room.

Table 6.3-3 is a listing of MOVs in the ECCS showing interlocks, automatic features, and position indications.

The ECCS delivery lag times are given in Chapter

15. The accumulator injection time varies as the size of the assumed break varies since the RCS pressure drop will vary proportionately to the break size.

6.3.2.3 Applicable Codes and Classifications. Applicable industry codes and classifications for the ECCS are discussed in Sections 3.9.3 and 6.3.2.2.

6.3.2.4 Material Specifications and Compatibility. Materials employed for components of the ECCS are given in Section 6.1 and Table 6.3

-4. Materials are selected to meet the applicable material requirements of the codes in Section 3.2 and the following additional requirements:

1. All parts of components in contact with borated water are fabricated of or clad with austenitic stainless steel or equivalent corrosion resistant material.

2. All parts of components in contact (internal) with sump solution during recirculation are fabricated of austenitic stainless steel or equivalent corrosion resistant material.

3. Valve seating surfaces are hard faced with Stellite number 6 or equivalent to prevent galling and to reduce wear.

STPEGS UFSAR 6.3-12 Revision 1 8 4. Valve stem materials are selected for their corrosion resistance, high tensile properties, and resistance to surface scoring by the packing.

6.3.2.5 System Reliability. Reliability of the ECCS is considered in all aspects of the system from initial design to periodic testing of the components during plant operation. The ECCS consists of three separate subsystems and fully redundant standby safeguard features. The system has been designed and proven by analysis to withstand any single credible active failure during injection or active or passive failure during recirculation and maintain the performance objectives required by Section 6.3.1. This capability is demonstrated by the failure mode and effects analysis presented in Table 6.3-10 for train A of the ECCS (results for trains B and C are analogous). The three subsystems of pumps, accumulators, and flow paths are provided to assure redundancy as only one subsystem and a second accumulator delivering to the vessel are required to satisfy the performance requirements. The initiating signals for the ECCS are derived from independent sources as measured from process (e.g., low pressurizer pressure) or environmental variables (e.g., Containment pressure).

Redundant as well as functionally independent variables are measured to initiate the safeguards signals. Each subsystem is physically separated and protected where necessary so that a single event cannot initiate a common failure. Power sources for the ECCS are divided into independent trains supplied from the emergency buses from offsite power. Sufficient diesel generating capacity is maintained onsite to provide required power to each subsystem. The DGs and their auxiliary systems are completely independent and each supplies power to one of the three ECCS subsystems.

The reliability program extends to the procurement of the ECCS components such that only designs which have been proven by past use in similar applications are acceptable for use. The quality assurance program as described in the Operations Quality Assurance Plan assures receipt of components only after manufacture and testing to the applicable codes and standards.

The preoperational testing program assures that the system as designed and constructed will meet the functional design requirements.

The ECCS is designed with the ability for on

-line testing of most components so the availability and operational status can be readily determined.

In addition to the above, the integrity of the ECCS is assured through examination of critical components during the routine inservice inspection in accordance with the quality assurance program and American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel (B&PV) Code,Section XI (Section 6.3.4).

1. Active Failure Criteria

The ECCS is designed to accept a single failure following the incident without loss of its protective function. The system design will tolerate the failure of any single active component in the ECCS itself or in the necessary associated service systems at any time during the period of required system operations following the incident.

A single active failure analysis is presented in Table 6.3

-5 and demonstrates that the ECCS can sustain the failure of any single active component in either the short

-or long-term and still meet the required level of performance for core cooling.

STPEGS UFSAR 6.3-13 Revision 1 8 Since the operation of the active components of the ECCS following a steam line rupture is identical to that following a LOCA, the same analysis is applicable and demonstrates that the ECCS can sustain the failure of any single active component and still meet the required level of performance for the addition of shutdown reactivity.

2. Passive Failure Criteria

The following philosophy provides for necessary redundancy in component and system arrangement to meet the intent of the General Design Criterion on single failure as it specifically applies to failure of passive components in the ECCS. Thus, for the long term, the system design is based on accepting either a passive or an active failure.

Redundancy of Flow Paths and Components for Long

-Term Emergency Core Cooling

In design of the ECCS, Westinghouse utilizes the following criteria.

a. During the long

-term cooling period following a LOCA, the emergency core cooling flow paths shall be separable into three subsystems, any of which can provide minimum core cooling functions and return spilled water from the floor of the Containment back to the RCS.

b. Any of the subsystems can be isolated and removed from service in the event of a leak outside the Containment.

c. Adequate redundancy of check valves is provided to tolerate failure of a check valve during the long term as a passive component.

d. Should one of the subsystems be isolated in this long

-term period, the other subsystems remain operable.

e. Provisions are also made in the design to detect and collect leakage from components outside the Containment.

Thus, for the long

-term emergency core cooling function, adequate core cooling capacity exists with one flow path removed from service.

Subsequent Leakage From Components in Safeguards Systems

With respect to piping and mechanical equipment outside the Containment, considering the provisions for visual inspection and leak detection, leaks would be detected before they propagate to major proportions. A review of the equipment in the system indicates that the largest sudden leak potential would be the sudden failure of a pump shaft seal. Evaluation of leak rate assuming only the presence of a seal retention ring around the pump shaft showed flows less than 50 gal/min would result. Piping leaks, valve packing leaks, or flange gasket leaks have been of a nature to build up slowly with time and are considered less severe than the pump seal failure.

Larger leaks in the ECCS are prevented by the following:

STPEGS UFSAR 6.3-14 Revision 1 8 1. The piping is classified safety class 2 and therefore must comply with the corresponding quality assurance program requirements associated with this safety class.

2. The piping, equipment, and supports are designed to seismic Category I classification permitting no loss of function resulting from the design basis earthquake.

3. The system piping is located within an area to which access is controlled.

4. The piping system receives periodic pressure tests and is accessible for periodic visual inspection.

5. The piping is austenitic stainless steel which, due to its ductility, can withstand severe distortion without failure.

The SI pump cubicle sumps are provided with safety class leak detection instrumentation that alarms in the main control room such that operator action can be taken to isolate the leak.

A single passive failure analysis is presented in Table 6.3

-6. It demonstrates that the ECCS can sustain a single passive failure during the lo ng-term phase and still retain an intact flow path. The intact flow path supplies sufficient flow to assure the core remains covered and effects the removal of decay heat. The procedure followed to establish the alternate flow path also calls for isolation of the failed component.

Figure 6.3

-5 is simplified illustration of the ECCS. The notes provided with Figure 6.3

-5 contain information relative to the operation of the ECCS in its various modes. The modes of operation illustrated are full operation of all ECCS components, cold leg recirculation, and hot leg recirculation. These are representative of the operation of the ECCS during accident conditions.

Lag times for initiation and operation of the ECCS are dependent upon pump startup time and the

sequential loading of these motors onto the safeguard buses. Most valves are normally in the position conductive to safety and therefore valve opening time is not considered for these valves. If there is no power blackout, all pump motors and valve motors are started sequentially upon receipt of the SI signal and a load sequencer start permissive. In the event of a loss of offsite power (LOOP), a

10-second delay is assumed for DG startup followed by the loading of pumps and valves on the ESF buses according to the sequencer. The MOVs are applied to the buses immediately, the HHSI pumps start in 5 seconds, and the LHSI pumps in 10 seconds. These times refer to time after the DGs attain rated speed. Accumulator injection occurs immediately upon the RCS pressure decreasing to the operating pressure of the accumulators regardless of whether a LOOP has occurred.

Potential Boron Precipitation

Boron precipitation in the reactor vessel can be prevented by a backflush of cooling water through the core to reduce boil-off and the resulting increase in concentration of boric acid in the water remaining in the reactor vessel. This can be accomplished by initiation of hot leg recirculation at about 5.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> following a LOCA.

Six flow paths are available for hot leg recirculation of sump water. Three high and three low head SI pumps can discharge to three hot legs with suction taken from the containment sump. Normal hot STPEGS UFSAR 6.3-15 Revision 1 8 leg recirculation procedures (i.e., with all safety injection pumps available) provide for two high head and two low head pumps injecting water into the hot legs. Loss of one pump or one flow path will not prevent hot leg recirculation since redundant flow paths are available for use. The remaining HHSI and LHSI pumps are aligned for cold leg recirculation. The initiation time for hot leg switchover is a function of core decay heat and the initial RCS soluble boron concentration. To ensure the time for switchover initiation is bounding for all modes of operation in which a DBA LOCA could be postulated, the RCS boron concentration is limited to 2500 ppm boron during power operation and during the first hour after shutdown. After one hour following shutdown, the decay heat content of the core has sufficiently decreased to allow the RCS boron concentration to be increased to a maximum of 3500 ppm boron. This boration would usually be performed in anticipation of proceeding to cold shutdown or refueling conditions.

The above restriction does not apply during the initial ascent to criticality after a refueling outage. This is because of the low level of decay heat, such that the 5.5 hour5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> hot leg switchover time would remain bounding, even assuming the RCS boron concentration is at a maximum of 3500 ppm.

The pH of the post

-LOCA sump fluid will be maintained within the proper range, assuming a maximum RCS boron concentration of 3500 ppm, as discussed in Section 6.5.2.

6.3.2.6 Protection Provisions. The provisions taken to protect the system from damage that might result from dynamic effects are discussed in Section 3.6. The provisions taken to protect the system from missiles are discussed in Section 3.5. The provisions to protect the system from seismic damage are discussed in Sections 3.7, 3.9, and 3.10. Thermal stresses on the RCS are discussed in Section 5.2.

6.3.2.7 Provisions For Performance Testing. Test lines are provided for performance testing of the ECCS system as well as individual components. These test lines and instrumentation are shown on Figure 6.3

-1 through 6.3

-4. All pumps have miniflow lines for use in testing operability. Additional information on testing can be found in Section 6.3.4.2.

6.3.2.8 Manual Actions. No manual actions are required of the operator for proper operation of the ECCS during the injection mode of operation. No manual actions are required by the operator to realign the system for the cold leg recirculation mode of operation. After approximately 5.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br />, only limited manual actions are required by the operator to realign the system for the hot leg recirculation mode of operation. These actions are delineated in Table 6.3

-7.

The changeover from the injection mode to recirculation mode is completed automatically with manual operator action from the main control room required only to secure the RWST to prevent backflow leakage across the check valve into the RWST. Protection logic is provided to automatically open the safety injection recirculation sump isolation valves when (1) the RWST level channels indicate a level less than the low

-low level setpoint coincident with the engineered safeguards actuation signal (SI signal), and (2) the corresponding miniflow valves are closed. These miniflow valves are closed automatically on low

-low RWST level coincident with an SI signal. This automatic action would align the three LHSI and three HHSI pumps to take suction from the containment sump and deliver directly to the RCS. The SI pumps would continue to operate during this changeover from injection mode to recirculation mode.

CN-3157 STPEGS UFSAR 6.3-16 Revision 1 8 The RWST low level protection logic consists of three level transmitters, each of which provides a level signal to one of three normally deenergized level channel bistables. Each level channel is assigned to a separate process control protection set with each of these protection sets powered by one of the three independent emergency electrical power trains.

The level channel bistables would be energized on receipt of a RWST level signal less than the low

-low level setpoint. The signal generated by a given level channel bistable would be used to provide actuation signals only to those valves which were assigned to the same electrical power train as that of the corresponding level channel.

Therefore, the low

-low level signal generated by each level bistable, in conjunction with a corresponding safeguard actuation signal, would automatically close the two LHSI pump miniflow isolation valves and the two HHSI pump miniflow isolation valves, and open the one recirculation sump isolation valve in the corresponding ECCS subsystem.

In addition, the level channel bistable would provide an alarm in the main control room to notify the operator that the automatic switchover from injection to recirculation has commenced. On receipt of this low-low level alarm, the operator should verify the completion of the automatic switchover operation to assure that the individual components have been properly realigned to establish the recirculation configuration of the ECCS. The operator should also close the three motor

-operated RWST isolation valves at the SIS pump suction to secure the RWST, as this suction source is not required for recirculation.

In the unlikely event that a level channel would generate a low

-low level signal prematurely, the subsequent opening of the corresponding sump valve could result in a loss of suction to the pumps of one ECCS subsystem. Since the loss of one ECCS subsystem is assumed under the single failure criterion, this failure can be accepted without loss of the capability of the ECCS to perform its design funciton.

See Section 7.5 for process information available to the operator in the control room following an accident.

Failure of the operator to act will cause no adverse effects since switchover is automatic.

Each normally closed containment sump isolation valve is interlocked with the RWST isolation valve in its train. This interlock prevents the sump isolation valves from being opened by operator action from the main control board unless the corresponding RWST isolation valves are closed and either the redundant isolation valves in both the HHSI and LHSI miniflow lines are closed. It also prevents the sump isolation valves from being opened during periodic testing unless the corresponding RWST valves are closed. Likewise, an interlock on the RWST discharge isolation valve prevents it from being opened during testing, unless the sump isolation valve is closed. In the absence of an SI signal, no single instrument failure, component failure, or operator action can cause the sump valve to open unless the RWST isolation valve is already closed, nor can a spurious SI signal, by itself, cause the valve to open.

6.3.3 Performance

Evaluation

STPEGS UFSAR 6.3-17 Revision 1 8 6.3.3.1 Accidents Requiring ECCS Operation. Accidents which require ECCS operation are as follows:

1. The accidental depressurization of the main steam system

2. A loss of reactor coolant from small ruptured pipes or from cracks in large pipes

3. A major primary system pipe rupture (LOCA)

4. A major secondary system pipe rupture

5. A steam generator tube rupture

6. RCCA ejection A discussion of the RCCA ejection accident and post accident ECCS operation is discussed in Section 15.4.

Accidental Depressurization of the Main Steam System

The most severe core conditions resulting from an accidental depressurization of the main steam system are associated with an inadvertent opening of a single steam dump, relief, or safety valve.

Should more than one valve open and fail to close, the resulting depressurization transient would be enveloped by the major secondary system pipe break analysis. The results of this analysis indicate that no departure from nucleate boiling (DNB) occurs for any secondary system rupture even assuming that the most reactive RCCA is stuck in its fully withdrawn position.

ECCS actuation would result from any of the following:

1. Low pressurizer pressure signal

2. Low steam line pressure signal in one steam line

3. High Containment pressure

4. Manual actuation

Upon receipt of the SI signal, the LHSI and HHSI pumps start. At such time as the RCS pressur e decreases to less than the shutoff head of the HHSI pump, the HHSI pumps would inject water from the RWST into the RCS. SI termination criteria are identified in the Plant Emergency Operating Procedures (EOPs).

Results and Conclusions of Accidental Depressurization of Main Steam System

The assumed steam release is typical of the capacity of any single steam dump, relief, or safety valve.

The boron solution provides sufficient negative reactivity to maintain the reactor in a safe condition.

The cooldown for the analysis case is more rapid than an actual transient involving steam release from all steam generators through one steam dump, relief, or safety valve. The analysis is quite STPEGS UFSAR 6.3-18 Revision 1 8 conservative with respect to cooldown, since no credit is taken for the energy stored in the system metal other than that of the fuel elements or the energy stored in the steam generators. Since the transient occurs over a period of about five minutes, the neglected stored energy is likely to have a significant effect in slowing the cooldown. The analysis shows that the core is protected assuming a stuck RCCA, with offsite power available, and assuming a single failure in the ESFs.

Loss of Reactor Coolant from Small Ruptured Pipes or from Cracks in Large Pipes Which Acuate Emergency Core Cooling System

A LOCA is defined as a rupture of the RCS piping or of any line connected to the system. Ruptures of a small cross section will cause expulsion of the coolant at a rate which can be accommodated by the charging pumps which would maintain an operataional water level in the pressurizer permitting the operator to execute an orderly shutdown.

For small breaks (less than 1.0 ft2) causing a discharge rate greater than can be compensated by normal makeup, a safety injection signal will be generated. The SI signal will start the safety injection pumps, properly align valves which receive SI signals, stop normal feedwater flow by closing feedwater isolation valves and initiate emergency feedwater flow by starting auxiliary feedwater pumps. Analyses demonstrate that the HHSI pumps play an important role in the initial core recovery because of the slower depressurization of the RCS than would have occurred from a larger break.

The analysis of the RCS depressurization and water level transients further shows that for a break of approximately 4.0 in. equivalent diameter, the transient is turned around and the core is recovering prior to accumulator injection. For a 4.5

-in. equivalent diameter break, the core remains uncovered with a decreasing level until accumulator action. Thus, the maximum break size showing core recovery prior to accumulator injection is approximately 4.0 in. equivalent diameter. Accumulator injection commences when pressure reaches approximately 600 psig; i.e., approximately 1,100 seconds from the time of the break for the 4.0

-inch-break size.

Results and Conclusions from Analysis of Small Break LOCA

The analysis of this break has shown that the high head portion of the ECCS, together with the accumulators, provides sufficient core flooding to keep the calculated peak clad temperature below the required limits of 10CFR50.46. Hence, adequate protection is afforded by the ECCS in the event of a small break LOCA.

Major Reactor Coolant System Pipe Rupture (LOCA)

A major LOCA is defined as a rupture of the RCS piping with a total cross sectional area equal or greater than 1.0 ft2 including the double

-ended rupture of the largest pipe in the RCS or of any line connected to that system. The boundary considered for LOCAs as related to connecting piping is defined in Section 3.6.

Should a major break occur, depressurization of the RCS results in a pressure decrease in the pressurizer. Reactor trip occurs when the pressurizer low pressure trip setpoint is reached. Th e ECCS is actuated when the pressurizer low pressure setpoint is reached. ECCS actuation is also STPEGS UFSAR 6.3-19 Revision 1 8 provided by a high Containment pressure signal. These counter

-measures limit the consequences of the accident in two ways:

1. Reactor trip and borated water injection provide additional negative reactivity insertion to supplement void formation in causing rapid reduction of power to a residual level corresponding to fission product decay heat.

2. Injection of borated water ensures sufficient flooding of the core to prevent excessive clad temperatures.

When the pressure falls below approximately 600 psig, the accumulators begin to inject borated water. The conservative assumption is made that accumulator water injected bypasses the core and goes out through the break until the termination of the blowdown phase. This conservatism is consistent with the Acceptance Criteria (10CFR50.46).

The pressure transient in the Containment during a LOCA affects ECCS performance in the following ways. The time at which end of blowdown occurs is determined by zero break flow which is a result of achieving pressure equilibrium between the RCS and the Containment. In this way the amount of accumulator water bypass is also affected by the Containment pressure, since the amount of accumulator water discharged during blowdown is dependent upon the length of the blowdown phase and RCS pressure at end of blowdown. During the reflood phase of the transient, the density of the steam generated in the core is dependent upon the existing Containment pressure. The density of this steam affects the amount of steam which can be vented from the core to the break for a given downcomer head, the core reflooding process, and thus the ECCS performance. It is through these effects that Containment pressure affects ECCS performance.

For breaks up to and including the double

-ended severance of a reactor coolant pipe, the ECCS will limit the clad temperature to well below the limit specified in 10CFR50.46 and assure that the core will remain in place and substantially intact with its essential heat transfer geometry preserved. See Section 15.6 for ECCS sequence of events.

Results and Conclusions for Major Reactor Coolant System Pipe Rupture

Conclusions

- Thermal Analysis

For breaks up to and including the double

-ended severance of a reactor coolant pipe, the ECCS meets the Acceptance Criteria as presented in 10CFR50.46, namely:

1. The calculated peak fuel element clad temperature provides margin to the limit of 2,200 F. 2. The amount of fuel element cladding that reacts chemically with water or steam does not exceed one percent of the total amount of Zircaloy in the active fuel cladding.

3. The clad temperature transient is terminated at a time when the core geometry is still amenable to cooling.

4. The cladding oxidation limits of 17 percent are not exceeded during or after quenching.

STPEGS UFSAR 6.3-20 Revision 1 8 5. The core temperature is reduced and decay heat is removed for an extended period of time, as required by the long

-lived radioactivity remaining in the core. Major Secondary System Pipe Rupture

The steam release arising from a rupture of a main steam pipe would result in increased energy removal from the RCS causing a reduction of coolant temperature and pressure. In the presence of a negative moderator temperature coefficient, the cooldown results in an insertion of positive reactivity. There is, therefore, an increased potential for the core to become critical and return to power. Following a steam pipe rupture, boric acid injection delivered by the ECCS will effectively shut down the core.

Minimum capability for injection of boric acid solution is assumed corresponding to the most restrictive single failure in the ECCS.

For the cases where offsite power is assumed, the sequence of events in the SIS is as follows. After the generation of the SI signal (appropriate delays for instrumentation, logic, and signal transport included), the appropriate valves begin to operate and the safety injection pumps start. In 12 seconds, the valves are assumed to be in their final position and the pumps are assumed to be at full speed.

In cases where offsite power is not available, additional delays are assumed to start the DGs and to load the necessary safety injection equipment onto them.

Results and Conclusions of Major Secondary System Pipe Rupture

The analysis has shown that even assuming a stuck RCCA with or without offsite power, and assuming a single failure in the engineered safeguard systems, the core remains in place and intact.

Furthermore, radiation doses will not exceed 10CFR100 guidelines.

Although DNB and possible clad perforation following a steam pipe rupture are not necessarily unacceptable and not precluded in the criterion, the above analysis, in fact, shows that no DNB occurs for any rupture assuming the most reactive RCCA stuck in its fully withdrawn position.

Steam Generator Tube Rupture

The accident examined is the complete severance of a single steam generator (SG) tube; the accident is assumed to take place at power.

Assuming normal operation of the various plant control systems, the following sequence of events is initiated by a tube rupture.

1. The condenser vacuum pump radiation monitor will alarm, indicating a sharp increase in radioactivity in the secondary system. In addition indication will be available from the steam line and SG blowdown monitors.

2. Pressurizer low pressure and low level alarms are actuated and charging pump flow increases in an attempt to maintain pressurizer level. On the secondary side there is a steam STPEGS UFSAR 6.3-21 Revision 1 8 flow/feedwater flow mismatch before the trip as feedwater flow to the affected steam generator is reduced due to the additional break flow which is now being supplied to that unit.

3. Continued loss of reactor coolant inventory leads to a reactor trip signal generated by low pressurizer pressure. Resultant plant cooldown following reactor trip leads to a rapid change of pressurizer level, followed shortly by the generation of an SI signal, initiated by low pressurizer pressure. The SI signal automatically terminates normal feedwater supply and initiates auxiliary feedwater addition. After reactor trip the break flow reaches equilibrium at the point where incoming SI flow is balanced by out going break flow. The resultant break flow persists from plant trip for a period of time (dependent upon break size and here assumed to be 30 minutes) during which the recovery procedure to isolate the affected SG is implemented.

4. The reactor trip automatically trips the turbine and if offsite power is available, the steam dump valves would open to allow steam blowdown to the condenser. In the event of a coincident LOOP, the steam dump valves would automatically close to protect the condenser. The SG pressure would rapidly increase, resulting in steam discharge to the atmosphere through the SG safety

- and/or power

-operated relief valves (PORVs).

5. Following reactor trip, the continued action of auxiliary feedwater supply and borated safety injection flow (supplied from the RWST) provide a heat sink which absorbs some of the decay heat. Thus, steam bypass to the condenser, or in the case of loss of offsite power, steam relief to atmosphere, is attenuated during the period in which the recovery procedure leading to isolation is being carried out.

6. Safety injection flow results in increasing pressuizer water level. The time after trip at which the operator can clearly see returning level in the pressurizer is dependent upon the amount of operating auxiliary equipment and operator actions to cool down and depressurize the RCS.

Results and Conclusions of Steam Generator Tube Rupture

A steam generator tube rupture (SGTR) will cause no subsequent damage to the RCS or the reactor core. An orderly recovery from the accident can be completed even assuming simultaneous loss of offsite power.

Criteria Used to Judge the Adequacy of the ECCS

10CFR50.46 provides the following criteria to judge the adequacy of the ECCS.

1. Peak clad temperature calculated shall not exceed 2,200 F. 2. The calculated total oxidation of the clad shall nowhere exceed 0.17 times the total clad thickness before oxidation.

3. The calculated total amount of hydrogen generated from the chemical reaction of the clad with water or steam shall not exceed 0.01 times the hypothetical amount that would be generated if all of the metal in the clad cylinders surrounding the fuel, excluding the clad around the plenum volume, were to react.

STPEGS UFSAR 6.3-22 Revision 1 8 4. Calculated changes in core geometry shall be such that the core remains amenable to cooling.

5. After any calculated successful initial operation of the ECCS, the calculated core temperature shall be maintained at an acceptably low value and decay heat shall be removed for the extended period of time required by long

-lived radioactivity remaining in the core.

In addition to and as an extension of the Acceptance Criteria, two accidents have more specific criteria as shown below.

In the case of the accidental depressurization of the Main Steam System an additional Westinghouse

-imposed criterion for adequacy of the ECCS is: Assuming a stuck RCCA with offsite power available, and assuming a single failure in the ESF, there is no consequential damage to the core or RCS for a steam release equivalent to the spurious opening, with failure to close, of the larger of any single steam dump, relief, or safety valve.

For a major secondary pipe rupture the added criterion is: Assuming a stuck RCCA with or without offsite power, and assuming a single failure in the engineered safeguards, the core remains in place and intact. An evaluation of boron precipitation and single failure is provided in Section 6.3.2.5.

More detailed descriptions of above accidents, including analysis methods, assumptions, and results are provided in Chapter 15.

Analysis shows that ECCS MOV motors are above the maximum post

-accident water level therby preventing any submerged valve motors.

Use of Dual Function Components

The ECCS contains components which have no other operating function as well as components which are shared with other systems. Components in each category are as follows:

1. Components of the ECCS which perform no other function are:

a. One accumulator for each of three loops which discharges borated water into its respective cold leg of the reactor coolant loop piping

b. Three HHSI pumps, which supply borated water for core cooling to the RCS (may be used during check valve testing also)

c. Associated piping, valves, and instrumentation

2. Components which also have a normal operating function are:

a. The LHSI pumps are used to transfer water from the RWST to the refueling cavity during refueling. At all other times, they remain aligned to deliver RWST water during ECCS operation.

STPEGS UFSAR 6.3-23 Revision 1 8 b. The RHR HXs are normally used during the latter stages of normal reactor cooldown and when the reactor is held at cold shutdown for core decay heat removal. However, during all other plant operating periods, they are aligned for ECCS injection.

c. The RWST is used to fill the refueling canal for refueling operations. However, during all other plant operating periods it is aligned to the suction of the LHSI and HHSI pumps.

An evaluation of all components required for operation of the ECCS demonstrates that either:

1. The component is not shared with other systems, or

2. If the component is shared with other systems, it is aligned during normal plant operation to perform its accident function.

Table 6.3-8 indicates the alignment of shared components during normal operation, and the realignment required to perform the accident function.

In all cases of component operation, safety injection has the priority usage such that an SI signal will override all other signals and start or align systems for injection.

Limits on System Parameters

The analyses show that the design basis performance characteristics of the ECCS are adequate to meet the requirements for core cooling following a LOCA with the minimum ESF equipment operating. Technical Specifications for reactor operation are established in order to ensure this capability in the event of the simultaneous failure of any single active component.

Normal operating status of ECCS components is given in Table 6.3

-1.

The ECCS components are available whenever the coolant energy is high and the reactor is critical.

During low temperature physics tests there is a negligible amount of stored energy in the coolant and low decay heat; therefore, an accident comparable in severity to accidents occurring at operating conditions is not possible and ECCS components are not required.

The principal system parameters and the number of components which may be out of operation in test, quantities and concentrations of coolant available, and allowable time in a degraded status are discussed in the Technical Specifications. If efforts to repair the faulty component are not successful the plant is placed into a lower operational status; i.e., hot standby to hot shutdown, hot shutdown to cold shutdown, etc.

6.3.4 Test and Inspections 6.3.4.1 ECCS Performance Tests

.

Preoperational Test Program at Ambient Conditions

STPEGS UFSAR 6.3-24 Revision 1 8 Preliminary operational testing of the ECCS system was conducted during the testing following flushing and hydrostatic testing, with the system cold and the reactor vessel head removed. Provision was made for excess water to drain into the refueling canal. The ECCS was aligned for normal power operation. Simultaneously, the SI block switch was reset and the breakers on the lines supplying offsite power were tripped manually so that operation of the standby DGs was tested in conjunction with the SIS. This test provided information including the following facets:

1. Satisfactory SI signal generation and transmission

2. Proper operation of the standby DGs, including sequential load pickup

3. Valve operating times

4. Pump starting times

5. Pump delivery rates at runout conditions (one point on the operating curve)

The preoperational test program on the ECCS and its components was performed in accordance with RG 1.79 (with the exception of in situ emergency sump recirculation testing) to provide assurance that the ECCS will accomplish its intended function when required.

The emergency sump design was evaluated in accordance with Appendix A to RG 1.82 proposed Revision 1, May 1983, to verify vortex control and acceptable pressure drops across screening, suction lines and valves.

Components

1. Pumps Separate flow tests of the pumps in the ECCS systems were conducted during the operational startup testing (with the reactor vessel head off) to check capability for sustained operation. The HHSI and LHSI pumps discharge into the reactor vessel through the injection lines, with overflow from the reactor vessel passing into the refueling canal. Each pump was tested separately with water drawn from the RWST. Data was taken to determine pump head and flow at this time. Pumps were then run on miniflow circuits and data taken to determine a second point on the head flow characteristic curve.

2. Accumulators

Each accumulator was filled with water from the RWST and pressurized with the MOV on the discharge line closed. The valve was then opened and the accumulator allowed to discharge into the reactor vessel as part of the operational startup testing with the reactor cold and the vessel head off.

6.3.4.2 Reliability Tests and Inspections

.

6.3.4.2.1 Description of Tests Planned: Routine periodic testing of the ECCS components and all necessary support systems at power is planned. Valves which operate after a LOCA are STPEGS UFSAR 6.3-25 Revision 1 8 operated through a complete cycle, and pumps are operated individually in their miniflow lines. If such testing indicates a need for corrective maintenance, the redundancy of equipment in these systems permits such maintenance to be performed under certain conditions such as the period within which the component should be restored to service and the capability of remaining equipment to provide the minimum required level of performance during such a period.

The operation of the isolation valve and the check valve in each accumulator tank discharge line may be tested by opening the test line valves just downstream of the isolation valve and check valve, respectively. Flow through the test line can be observed on instruments and the opening and closing of the discharge line isolation valves can be sensed on this instrumentation.

The check valves on the discharge side of the HHSI, LHSI, and RHR systems which perform an isolation function in protecting low pressure systems from full RCS pressure are identified in Table 6.3-11. These valves are classified ASME IWV

-2000 category AC and will be lea k-tested in accordance with the frequency specified by the Inservice Testing Program for this category valve.

Testing of these valves will be discussed in the Technical Specifications.

The check valves on the discharge side of the charging pumps, at the Chemical and Volume Control System (CVCS) tie to the RCS, are not part of a high pressure to low pressure interface. As a result, failure of these valves will not initiate an overpressure condition on CVCS equipment or piping.

Therefore, these check valves are not required to be classified as ASME IWV

-2000 category AC and are not required to be leak

-tested according to those specifications.

The SIS Test Line Subsystem provides the test line necessary to leak

-test each of the valves identified in Table 6.

3-11.

Section XI of the ASME B&PV Code established the leakage criteria for ASME IWV

-2000 category AC valves. This section of the ASME Code is established, by the Technical Specifications, as the basis for inservice inspection and testing of ASME Code Class 1, 2, and 3 components.

During periodic system testing, a visual inspection of pump seals, valve packings, flanged connections, and relief valves is made to detect leakage. Inservice inspection provides further confirmation that no significant deterioration is occurring in the ECCS fluid boundary.

Design measures have been taken to assure that the following testing can be performed:

1. Active components may be tested periodically for operability (e.g., pumps on miniflow, certain valves, etc.).

2. An integrated system actuation test can be performed when the plant is cooled down and the RHRS is in operation. The ECCS will be arranged so that no flow will be introduced into the RCS for this test.

3. An initial flow test of the full operational sequence can be performed.

Details of the testing of the sensors and logic circuits associated with the generation of an SI signal, together with the application of this signal to the operation of each active component, are given in Section 7.3.

STPEGS UFSAR 6.3-26 Revision 1 8 The design features which assure this test capability are specifically:

1. Power sources are provided to permit individual actuation of each active component of the ECCS. 2. The SI pumps can be tested periodically during plant operation using the minimum flow recirculation lines provided.

3. Remote-operated valves can be exercised during routine plant maintenance.

4. Level and pressure instrumentation is provided for each accumulator tank for continuous monitoring of these parameters during plant operation.

5. Flow from each accumulator tank can be directed at any time through a test line to determine check valve leakage and to demonstrate operation of the accumulator MOVs.

6. A flow indicator is provided in the LHSI and HHSI pump headers. Pressure instrumentation is also provided in these lines.

7. An integrated system test can be performed when the plant is cooled down and the RHRS is in operation. This test does not introduce flow into the RCS but does demonstrate the operation of the valves, pump circuit breakers, and automatic circuitry including diesel starting and the automatic loading of ECCS components on the diesels (by simultaneously simulating a loss of offsite power to the vital electrical buses).

The Technical Specifications identify the test frequency, acceptability of testing, and measured parameters. A description of the inservice inspection program is also included in the Technical Specifications. ECCS components and system are designed to meet the intent

of ASME Code Section XI for inservice inspection.

6.3.5 Instrumentation

Requirements

Instrumentation and associated analog and logic channels employed for initiation of ECCS operation is discussed in Section 7.3. This section describes the instrumentation employed for monitoring ECCS components during normal plant operation and also ECCS post accident operation.

6.3.5.1 Temperature Indication.

Residual Heat Removal Heat Exchanger Outlet Temperature

The fluid temperature at the inlet and outlet of each RHR HX is recorded in the control room.

6.3.5.2 Pressure Indication

.

Safety Injection Pump Discharge Header Pressure

LHSI and HHSI pump discharge pressures are indicated in the control room.

STPEGS UFSAR 6.3-27 Revision 1 8 Safety Injection Pump Suction Pressure

Pressure indicators are installed in the suction line of the HHSI and LHSI lines.

Accumulator Pressure

Duplicate pressure channels are installed on each accumulator. Pressure indication and high and low pressure alarms are provided in the control room for each accumulator.

Test Line Pressure

A local pressure indicator used to check for proper seating of the accumulator check valves between the injection lines and the RCS is installed on the leakage test line.

6.3.5.3 Flow Indication

.

Safety Injection Pump Flow

Flow rates from the HHSI and LHSI pumps are indicated in the control room. Indication is provided for both injection and hot and cold leg recirculation.

Test Line Flow Local indication of the leakage test line flow is provided to check for proper seating of th e accumulator check valves between the injection lines and the RCS.

Safety Injection Pump Bypass Flow

A local flow indicator is installed in the HHSI and LHSI pump miniflow lines.

6.3.5.4 Level Indication

.

Refueling Water Storage Tank Level

Three water level indicator channels, which indicate in the control room, are provided for the RWST.

Each channel is powered by one of the three corresponding electrical power trains and provided with high, low, low

-low, and empty level alarms. The high level alarm is provided to protect against possible overflow of the RWST. The low level alarm is provided to assure that a sufficient volume of water is always available in the RWST in conformance with the Technical Specifications. The low

-low level alarm alerts the operator that the changeover from injection to recirculation is automatically being accomplished. The empty alarm indicates that the useable volume of the RWST has been exhausted.

Accumulator Water Level

Duplicate water level channels are provided for each accumulator. Both channels provide indication in the control room and actuate high and low water level alarms.

STPEGS UFSAR 6.3-28 Revision 1 8 Containment Emergency Sump Level

Each containment emergency sump is provided with a level transmitter, which gives control room indication through the qualified display processing system.

6.3.5.5 Valve Position Indication. Valve positions are indicated on the main control board for all MOVs, air

-operated valves (AOVs) and solenoid

-operated valves (SOVs) by means of red (open) and green (closed) position indicating lights. Tables 6.3

-3, 6.3-13, and 6.3

-14 list the ECCS MOVs and AOVs which could degrade performance If left open, and SOVs respectively. These lights are located at the control switch for each valve. They are powered by valve control power and actuated by valve motor operator limit switches (for MOVs) or valve

-stem-mounted limit switches (for AOVs and SOVs). Positions for these valves (all MOVs and AOVs) are also indicated (in the ESF Status Monitoring System described in Section 7.5.4) by a "normal off" system. Should the valve not be in its proper position, thus disabling safeguards operations, a bright white light will be lit and will thus give a highly visible indication to the operator. This light is energized from a separate monitor light supply and actuated by a valve motor operator limit switch or, for AOVs and SOVs, a stem-mounted limit switch. A window light and alarm are provided at the system level to further alert the operator should any valve in the ECCS be improperly aligned during operation.

Certain ECCS valves are provided with more extensive control features, as described in Section 6.3.5.5.1 and 6.3.5.5.2.

The following valves do not have control room position indication and could degrade the performance of the ECCS:

1. XRH0063 B, C, and XRH0064 B, C located in the RHRS return line to the RWST. However, as shown in Figure 5.4

-6, both valves in series would have to be left open in order to degrade ECCS performance.

2. SI0206 A, B, C and SI0207 A, B, C, could degrade ECCS performance if one were left closed. The SI0206 series are in the high head injection lines downstream from the check valve in order to facilitate leak testing. The SI0207 series are similarly located in the low head injection lin es.

Accumulator gas pressure is monitored by indicators and alarms, and therefore no discussion has been provided for manual valves that could affect pressurization of the accumulators.

For the manual valves listed above, administrative controls, procedures, and checklists are employed to assure they are always restored and locked in their correct position for operation. The ECCS design precludes the degradation of more than one train as a result of mispositioning any manual valve. The above mentioned design and administrative provisions are adequate to ensure ECCS valves are maintained in the correct position.

6.3.5.5.1 Accumulator Isolation Valve Position Indication and Power Lockout: These valves are required to remain in their aligned positions during certain phases of a LOCA or during plant shutdown, as described in Section 7.6.3. To ensure that no spurious movements of these valves can occur, the valves will be power

-locked-out from a control switch located at the main control panel or STPEGS UFSAR 6.3-29 Revision 1 8 auxiliary shutdown panel (ASP). Indication is provided at the main control panel and ASP to monitor the position of the power lockout breakers for these valves: red (power on) and green (power off).

Redundant valve position indication is also provided (as required by BTP Instrumentation and Controls Systems Branch [BTP ICSB] 18) at the main control panel and ASP to supplement the normal valve position indicators when the power lock

-out is in operation. These redundant valve position indicating lights are powered independently of the valve operator control power, and are operated by valve stem

-mounted limit switches to ensure complete independence from the normal valve position indication system.

An annunciator alarm point is activated by both a valve motor operator limit switch and by a valve position limit switch activated by stem travel whenever an accumulator valve is not fully open, for any reason, with the system at pressure (the pressure at which the safety injection block is unblocked is approximately 1900 psig). A separate annunciator point is used for each accumulator valve. This alarm is recycled at approximately one

-hour intervals to remind the operator of the improper valve lineup.

6.3.5.5.2 Hot and Cold Leg Recirculation Isolation Valve Position Indication and Power Lockout: The hot leg recirculation isolation valves for each LHSI pump and each HHSI pump are required to remain in the closed position during the injection and recirculation phases of a LOCA, until operator action is taken to switch to hot leg recirculation in two of the safety injection trains. To ensure that no spurious movement of these valves can occur, the power for these valves is locked

-out from a control switch located at the main control panel. Indication is provided at the main control panel to monitor the position of the power lockout breakers for each valve: red (power on) and green (power off).

Redundant valve position indication is also provided (as required by BTP ICSB 18) at the main control panel to supplement the normal valve position indicators when the power lock

-out is in operation. These redundant valve position indicating lights are powered independently of the valve operator control power, and are operated by valve

-stem-mounted limit switches to ensure complete independence from the normal valve position indication system.

The cold leg recirculation isolation valves for each LHSI pump and each HHSI pump are required to remain in the open position during the injection and recirculation phases of a LOCA, until operator action is taken to switch to hot leg recirculation in two of the safety injection trains. To ensure that no spurious movement of the LHSI pump valves can occur, the power for these valves is locked out by opening the breaker at the valve MCCs. Indication of the power lockout of the valves is provided by tags affixed to the main control panel.

STPEGS UFSAR 6.3-30 Revision 1 8 TABLE 6.3-1 EMERGENCY CORE COOLING SYSTEM COMPONENT PARAMETERS Accumulators Number 3 Design pressure, psig 700 Design temperature, F 300 Operating temperature, F 90 Maximum operating pressure, psig 670 Minimum operating pressure, psig 590 Total volume, ft 3 2,500 each Nominal water volume, ft 3 1,200 N 2 volume, f t 3 1,300 Boron concentration (as boric acid), ppm 2,700-3,000 Relief valve setpoint, psig 700 High Head Safety Injection Pumps Number 3 Design pressure, psig 1,750 Design temperature, F 300 Design flow rate*, gal/min 800 Design head, ft 2,8 50 Max. flow rate, gal/min 1,600 Head at max. flow rate, ft 1,000 Differential head at shutoff, ft (max) 3,700 Motor rating, hp 1,000 Required NPSH at max. flow rate, ft (max)

1.1 Available

NPSH, ft (From RWST) 41.1 (From RCB Emergency Sump) 7.2 Low Head Safety Injection Pumps Number 3 Design pressure, psig 495 Design temperature, F 300 Design flow rate, gal/min 1,900 Design head, ft 560 Max. flow rate, gal/min 2,900 Head at max. flow rate, ft 400 Differential head at shutoff, ft 7 00 Motor rating, hp 400 Required NPSH, ft (max)

1.5 Available

NPSH, ft (From RWST) 40.8 (From RCB Emergency Sump) 7.3

• Includes miniflow Note: - The Available NPSH from RCB excludes any debris head loss and any strainer head loss (which will be submitted in a future Licensing Amendment Request to address GSI

-191). - NPSH values are based upon a reference elevation of the center line of the pump suction nozzle rather than the first stage impeller. CN-3143 CN-3143 CN-3143 STPEGS UFSAR 6.3-31 Revision 1 8 TABLE 6.3-1 (Continued)

EMERGENCY CORE COOLING SYSTEM COMPONENT PARAMETERS Residual Heat Exchangers (See Section 5.4.7 for design parameters)

Refueling Water Storage Tank Number 1 Full tank volume, gal 550,000* Minimum volume (Technical Specification), gal 458,000* Normal pressure, psig Atmospheric Operating temperature, F 50 F Design pressure, psig Atmospheric Design temperature, F 120 Boron concentration (as boric acid), ppm 2,800-3,000 Motor-Operated Valves Maximum Opening or Closing Time

a. Up to and including 8 inches except SI 4A, B and C 15 sec b. Over 8 inches Nom. Size (in.)

49 in./min

c. SI 4A, B and C 18 sec.

• Volumes include unuseable volume.

6.3-32 STPEGS UFSAR Revision 1 8 TABLE 6.3-2 ECCS RELIEF VALVE DATA Fluid Inlet Set Back Fluid Temperature Pressure Pressure Psig Description Valve I.D.

Discharge Normal ( F) (psig) (psig) Buildup Capacity N 2 Supply to Accumulators PSV-3978 N2 120 700 0 0 2,743 sc fm High Head Safety Injection Pump Discharge PSV-3938 PSV-3940 PSV-3942 Water 104 1,750 0 50 20 gal/min Low Head Safety Injection Pump Discharge PSV-3934 PSV-3943 PSV-3944 Water 104 600 0 50 20 gal/min LHSI & HHSI Pumps Common Suction Line Relief PSV-3935 PSV-3939 PSV-3941 Water 104 220 0 50 25 gal/min Accumulator to Containment PSV-3977 PSV-3980 PSV-3981 Water or N 2 Gas 120 700 0 0 1,500 scfm

6.3-33 STPEGS UFSAR Revision 1 8 TABLE 6.3-3 MOTOR-OPERATED VALVES IN ECCS Automatic Position Location Valve I.D.

Interlocks Features Indication Alarms Accumulator Isolation XSI00 39 A,B,C SI, RCS Press. > Unblock Opens on SI, RCS Press. > Unblock MCB Out of Position SI Pumps Suction From RWST XSI0001 A,B,C Prevents opening unless sump isolation valve is closed, must be closed prior to manual opening of sump isolation valve.

None MCB Out of Position LHSI Pump Discharge Isolation XSI0018 A,B,C None None MCB Out of Position HHSI Pump Discharge Isolation XSI0004 A,B,C None None MCB Out of Position Containment Sump Suction XSI0016 A,B,C Opens on RWST Lo

-Lo Level With SI Signal and LHSI & HHSI miniflow isolation. Prevents opening by operator action unless RWST isolation valve is closed and LHSI and HHSI miniflows are isolated. Opens on RWST Lo-Lo Level with SI Signal and LHSI & HHSI miniflow isolation.

MCB Out of Position HHSI Cold Leg Isolation XSI0006 A,B,C None None MCB Out of Position 6.3-34 STPEGS UFSAR Revision 1 8 TABLE 6.3-3 (Continued)

MOTOR-OPERATED VALVES IN ECCS Automatic Position Location Valve I.D.

Interlocks Features Indication Alarms HHSI Hot Leg Isolation XSI0008 A,B,C None None MCB Out of Position LHSI Cold Leg Isolation XRH 0031 A,B,C None None MCB Out of Position LHSI Hot Leg Isolation XRH0019 A,B,C None None MCB Out of Position HHSI Pump Miniflow SI0011 A,B,C and SI0012

A,B,C Closes on RWST Lo

-Lo Level with SI signal, prevents manual opening unless sump isolation valve is closed Closes on RWST Lo-Lo Level with SI signal MCB Out of Position LHSI Pump Miniflow SI0013 A,B,C SI0014 A,B,C Closes on RWST Lo

-Lo Level with SI signal, prevents manual opening unless sump isolation valve is closed Closes on RWST Lo-Lo Level with SI signal MCB Out of Position

STPEGS UFSAR 6.3-35 Revision 1 8 TABLE 6.3-4 MATERIALS EMPLOYED FOR EMERGENCY CORE COOLING SYSTEM COMPONENTS Component Material Accumulators Carbon Steel, Clad with Austenitic Stainless Steel Pumps High Head Safety Injection Austenitic Stainless Steel Low Head Safety Injection Austenitic Stainless Steel Residual Heat Removal Heat Exchangers

Shell Carbon Steel Shell End Cap Carbon Steel Tubes Austenitic Stainless Steel Channel Austenitic Stainless Steel Channel Cover Austenitic Stainless Steel Tube Sheet Austenitic Stainless Steel Valves Motor-Operated Valves Containing Radioactive Fluids Pressure - Containing Parts Austenitic Stainless Steel or Equivalent Body-to-Bonnet Bolts & Nuts Low Alloy Steel Seating Surfaces Stellate No. 6 or Equivalent Stems Austenitic Stainless Steel or 17

-4PH Stainless

STPEGS UFSAR 6.3-36 Revision 1 8 TABLE 6.3-4 (Continued)

MATERIALS EMPLOYED FOR EMERGENCY CORE COOLING SYSTEM COMPONENTS Component Material Motor-Operated Valves Containing Nonradioactive, Boron

-Free Fluids Body, Bonnet and Flange Carbon Steel Stems Corrosion resistant Steel Diaphragm Valves Austenitic Stainless Steel Accumulator Check Valves Parts Contacting Borated Water Austenitic Stainless Steel Clapper Arm Shaft 17-4PH Stainless Relief Valves Stainless Steel Bodies Stainless Steel Carbon Steel Bodies Carbon Steel All Nozzles, Discs, Spindles, and Guides Austenitic Stainless Steel Bonnets for Stainless Steel Valves Without a Balancing Bellows Stainless Steel or Plated Carbon Steel All Other Bonnets Carbon Steel Piping All Piping in Contact with Borated Water Austenitic Stainless Steel

6.3-37 STPEGS UFSAR Revision 1 8 TABLE 6.3-5 SINGLE ACTIVE FAILURE ANALYSIS FOR EMERGENCY CORE COOLING SYSTEM COMPONENTS SHORT TERM PHASE Component Malfunction Comments 1. Pumps

a. High Head Safety Injection Fails to start Three provided, evaluation based on operation of two.

b. Low Head Safety Injectio n Fails to start Three provided, evaluation based on operation of two.

2. Automatically Operated Valves

a. LH & HH Safety Injection pumps suction line from containment sump Fails to open Three parallel lines; only two valves in any of three lines are required to open.

b. High Head Safety Injection pump miniflow line Fails to close Two valves in series; only one valve required to close.

c. Low Head Safety Injection pump miniflow line Fails to close Two valves in series; only one valves required to close. 3. Valves Operated Manually from the Control Room a. HHSI & LHSI pump common suction line to refueling water storage tank Fails to close Check valve in series with gate valve; operation of only one valve required.

b. HHSI or LHSI hot leg isolation valve Fails to open Three flow paths available. Adequate flow to core is assured by any two.

c. HHSI or LHSI cold leg isolation valve Fails to close Three flow paths available. Adequate flow to core is assured by any two.

6.3-38 STPEGS UFSAR Revision 1 8 TABLE 6.3-6 EMERGENCY CORE COOLING SYSTEM RECIRCULATION PIPING PASSIVE FAILURE ANALYSIS LONG-TERM PHASE Flow Path Indication of Loss of Flow Path Alternate Flow Path Low Head Recirculation From containment sump to LHSI pump Accumulation of water in a LHSI pump compartment of Fuel Handling Building sump Via the independent, identical low head flow paths utilizing the two remaining RHR HXs and LHSI pumps.

High Head Recirculation From containment sump to the HHSI pumps Accumulation of water in the Fuel Handling Building sump or HHSI pump compartments Via the independent identical high head flow paths from containment sump to the two remaining HHSI pumps.

STPEGS UFSAR 6.3-39 Revision 1 8 TABLE 6.3-7 MANUAL ACTIONS REQUIRED FOR SAFETY INJECTION MODES OF OPERATION Injection Mode No manual actions are required.

Cold Leg Recirculation Mode

No manual actions are required to realign the system for the cold leg recirculation mode. The operator is required to close the RWST isolation valves to prevent backflow leakage acros s the check valves into the RWST.

Hot Leg Recirculation Mode

1. Open the HHSI hot let isolation valve in the first train.

2. Close the HHSI cold leg isolation valve in the first train.

3. Monitor valve position indicators and flow indicators.

4. Open the LHSI hot leg isolation valve in the first train.

5. a. Close breaker at LHSI cold leg isolation valve MCC in the first train.

b. Close the LHSI cold leg isolation valve in the first train.

6. Monitor valve position indicators and flow indicators.

7. Open the HHSI hot leg isolation valve in the second train.

8. Close the HHSI cold leg isolation valve in the second train.

9. Monitor valve position indicators and flow indicators.

10. a. Close breaker at cold leg isolation valve MCC in the second train.

b. Open the LHSI hot leg isolation valve in the second train.

11. Close the LHSI cold leg isolation valve in the second train.

12. Monitor valve position indicators and flow indicators.

6.3-40 STPEGS UFSAR Revision 1 8 TABLE 6.3-8 EMERGENCY CORE COOLING SYSTEM SHARED FUNCTIONS EVALUATION

Component Normal Operating Arrangement Accident Arrangement Refueling Water Storage Tank Lined up to suction of the safety injection pumps Lined up to suction of safety injection pumps RHR Heat Exchangers Lined up to cold legs of reactor coolant piping Lined up to cold legs of reactor coolant piping Low Head SI pumps Lined up to cold legs of reactor coolant piping Lined up to cold legs of reactor coolant piping

6.3-41 STPEGS UFSAR Revision 1 8 TABLE 6.3-10 EMERGENCY CORE COOLING SYSTEM

- SAFEGUARDS OPERATIONS FAILURE MODES AND EFFECTS ANALYSIS Effect on System Failure Detection Component Failure Mode Function Operation Method Comments 1. HHSI pump 1A (pumps 1B and 1C analogous)

Fails to deliver working fluid Provides high pressure injection flow during injection and recirculation phases Failure reduces quantity of injection flow. Adequate injection flow is provided by redundant high head pumps and, for lower RCS pressures, by low head pumps Hot leg and cold leg flow indication Pump discharge pressure indication and ESF monitoring are provided at MCB for both injection and recirculation phases

2. Motor

-operated gate valve XSH0001A (valves XSI0001B and XSI0001C analogous)

Fails to close on demand Provides RWST isolation during recirculation phases Failure reduces redundancy of isolating RWST. Isolation of RWST will be provided by check valve XSI0002A (XSI0002B and C) Valve position indication and ESF monitoring at MCB Valve is closed by the operator following switchover to recirculation

3. Motor

-operated gate valve XSI0004A (valves XSI0004B and XSI0004C analogous)

Fails to close on demand Provides outside containment isolation capability for HHSI pump discharge line Failure reduces redundancy of providing containment isolation. Isolation will be provided by inside containment check valve XSI0005A (XSI0005B and C) Valve position indication at MCB Valve is closed by the operator for HHSI pump operational tests, maintenance or containment isolation, if required

4. Motor

-operated gate valve XSI0006A (valves XSI0006B and XSI0006C analogous)

Fails to close on demand provides isolation of HHSI line to cold leg Failure prevents use of specific HHSI pump for hot leg recirculation. Hot leg recirculation will be provided by redundant HHSI pumps (see Section 6.3.2.5)

Valve position indication, cold leg flow indication, and ESF monitoring at MCB

5. Motor

-operated gate valve XSI0008A (valves XSI0008B and XSI0008C analogous)

Fails to open on demand Provides isolation of HHSI line to hot leg Failure prevents use of specific HHSI pump for hot leg recirculation. Hot leg recirculation will be provided by redundant HHSI pumps (see Section 6.3.2.5)

Valve position indication, hot leg flow indication, and ESF monitoring at MCB Valve is normally closed and has its power removed, Power is restored and the valve opened during the switchover from cold leg to hot leg recirculation

6.3-42 STPEGS UFSAR Revision 1 8 TABLE 6.3-10 (Continued)

EMERGENCY CORE COOLING SYSTEM

- SAFEGUARDS OPERATIONS FAILURE MODES AND EFFECTS ANALYSIS Effect on System Failure Detection Component Failure Mode Function Operation Method Comments 6. LHSI pump 1A (pumps 1B and 1C analogous)

Fails to deliver working fluid Provides low pressure injection flow during injection and recirculation phases Failure reduces quantity of injection flow. Adequate injection flow is provided by redundant low head pumps and by 3 high head pumps Hot leg and cold leg flow indication and, pump discharge pressure indication, and ESF monitoring are provided at MCB for both injection and recirculation phases

7. Motor

-operated gate valve XSI0018A (valves XSI0018B and XSI0018C analogous)

Fails to close on demand Provides outside Containment isolation capability for LHSI pump discharge line Failure reduces redundancy of providing containment isolation. Isolation will be provided by inside Containment check valve XSI0030A, (XSI0030B and C) Valve position indication and ESF monitoring at MCB Valve is closed by the operator for LHSI pump maintenance, operational tests, RHR operations, or containment isolation, if required 8. Motor

-operated gate valve XRH0019A (valves XRH0019B and XRH0019C analogous)

Fails to open on demand Provides isolation of LHSI line to hot leg Failure prevents use of specific LHSI pump for hot leg recirculation. Hot leg recirculation will be provided by redundant LHSI pumps (see Section 6.3.2.5)

Valve position indication hot leg flow indication and ESF monitoring at MCB Valve is normally closed and has its power removed.

Power is restored and the valve opened during the switchover from cold leg to hot leg recirculation

9. Motor

-operated gate valve XRH0031A (valves XRH0031B and XRH0031C analogous)

Fails to close on demand Provides isolation of LHSI line to cold leg Failure prevents use of specific LHSI pump for hot leg recirculation. Hot leg recirculation will be provided by redundant LHSI pumps (see Section 6.3.2.5)

Valve position indication, cold leg flow indication and ESF monitoring at MCB

6.3-43 STPEGS UFSAR Revision 1 8 TABLE 6.3-10 (Continued)

EMERGENCY CORE COOLING SYSTEM

- SAFEGUARDS OPERATIONS FAILURE MODES AND EFFECTS ANALYSIS Effect on System Failure Detection Component Failure Mode Function Operation Method Comments 10. Motor

-operated gate valve XSI0016A (valves XSI0016B and XSI0016C analogous)

Fails to open on demand Provides isolation of recircultion line from containment sump to suction of LHSI and HHSI pumps Failure prevents use of specific LHSI and HHSI train for recirculation phases. Adequate sump water recirculation will be provided by redundant LHSI and HHSI trains Valve position indication and ESF monitoring at MCB Protection logic is provided to automatically open the valve when an RWST low

-low level signal occurs coincident with SI signal and the corresponding miniflow valves are closed (see Section 6.3.2.8 and logic diagram Figure 7.6

-5). 11. Motor

-operated gate valve XSI0039A (valves XSI0039B and XSI0039C analogous)

Fails to open on demand Provides isolation of accumulator discharge line to cold leg Valve is normally open and not required to function during either injection or recirculation phases Failure prevents discharge of accumulator contents to cold leg during reflood phase Valve position indication and ESF monitoring at MCB Valve is normally open with power removed. Protection logic is provided to automatically open the valve on an SI signal or if RCS pressure is greater than SI unblock pressure (see Sections 6.3.2.2 and 7.6.3 and logic diagram Figure 7.6-3) 12. Motor

-operated PMD valve SI0011A (valves SI0011B and SI0011C analogous)

Fails to close on demand Provides isolation of HHSI pump miniflow line to RWST Failure reduces redundancy of providing miniflow line isolation during recirculation phases. Isolation will be provided by redundant valve SI0012A9(SI0012B and C)

Valve position indication and ESF monitoring at MCB Valve is automatically closed during switchover from injection to recirculation (see Sections 6.3.2.2 and logic diagram Figure 7.6

-4) 13. Motor

-operated PMD valve SI012A (valves SI012B and SI012C analogous)

Fails to close on demand provides isolation of HHSI pump miniflow line to RWST Failure reduces redundancy of providing miniflow line isolation during recirculation phases. Isolation will be provided by redundant valve SI0011A (SI0011B and C)

Valve position indication and ESF monitoring at MCB Valve is automatically closed during switchover from injection to recirculation (see Section 6.3.2.2 and logic diagram Figure 7.6

-4) 6.3-44 STPEGS UFSAR Revision 1 8 TABLE 6.3-10 (Continued)

EMERGENCY CORE COOLING SYSTEM

- SAFEGUARDS OPERATIONS FAILURE MODES AND EFFECTS ANALYSIS Effect on System Failure Detection Component Failure Mode Function Operation Method Comments 14. Motor

-operated PMD valve SI0013A (valves SI00013B and SI0013C Fails to close on demand Provides isolation of LHSI pump miniflow line to RWST Failure reduces redundancy of providing miniflow line isolation during recirculation phases. Isolation will be provided by redundant valve SI0014A (SI0014B and C)

Valve position indication and ESF monitoring at MCB Valve is automatically closed during switchover from injection to recirculation (see Section 6.3.2.2 and logic diagram Figure 7.6

-4) 15. Motor

-operated PMD valve SI0014A (valves SI0014B and SI0014C analogous)

Fails to close on demand Provides isolation of LHSI pump miniflow line to RWST Failure reduces redundancy of providing miniflow line isolation during recirculation phases. Isolation will be provided by redundant valve SI0013A (SI0013B and C)

Valve position indication and ESF monitoring at MCB Valve is automatically closed during switchover from injection to recirculation (see Section 6.3.2.2 and logic diagram Figure 7.6

-4) 16. Air-operated butterfly valve HCV-864 (valves HCV

-865 and HCV-866 analogous)

Fails closed Provides throttling capability for LHSI pump flow through RHR heat exchanger Failure prevents flow from LHSI pump through RHR heat exchanger. Adequate injection flow is provided by redundant low head pumps and by three high head pumps Valve position indication and ESF monitoring at MCB Valve is normally open, fail open 17. Air-operated butterfly valve FCV-851 (valves FCV

-852 and FCV-853 analogous)

Fails open Provides RHR heat exchanger bypass capability and is used in conjunction with valve HCV-864 (HCV-865 and HCV

-866) Failure reduces LHSI pump flow through RHR heat exchanger and results in higher coolant temperature during recirculation phases. Adequate recirculation fluid heat removal is provided by the reduced flow through the heat exchanger plus the flow provided by the redundant LHSI pumps through their associated heat exchangers Valve position indication and ESF monitoring at MCB Valve is normally closed, fail closed

6.3-45 STPEGS UFSAR Revision 1 8 TABLE 6.3-10 (Continued)

EMERGENCY CORE COOLING SYSTEM - SAFEGUARDS OPERATIONS FAILURE MODES AND EFFECTS ANALYSIS Effect on System Failure Detection Component Failure Mode Function Operation Method Comments 18. Air-operated valve FV3936 (FV3937 analogous)

Fails to close on demand Provides isolation of line from RWST to SFPCCS Failure reduces redundancy of providing isolation.

Isolation will be provided by redundant valve in series Valve position indication and ESF monitoring at MCB Valve is normally closed, fail closed. Line is periodically opened to permit clean

-up of RWST water by means of the SFPCCS 19. Solenoid

-operated globe valve PV3976 (valves PV3979 and PV3982 analogous)

Fails to close on demand Provides isolation of nitrogen fill/vent line to accumulator Failure reduces redundancy of isolating nitrogen fill/vent line. Isolation will be provided by redundant valves SI0058 and FV3983 in nitrogen fill line and valve HCV-900 and HV

-899 in nitrogen vent line Valve position indication, accumulator pressure pressure indication, and low pressure alarm at MCB Valves are normally closed, fail closed

20. Air-operated globe valve FV3983 Fails to close on demand Provides outside containment isolation capability for accumulator nitrogen fill line Failure reduces redundancy of providing containment isolation. Isolation will be provided by inside containment check valve SI0058 Valve position indication and ESF monitoring at MCB Valve is normally closed, fail closed, and receives confirmatory containment isolation signal

21. Air-operated globe valve FV3970 (valve FV3971 analogous)

Fails to close on demand Provides inside (out

-side) containment isolation capability for SIS test line Failure reduces redundancy of providing containment isolation. Isolation will be provided by redundant containment valve FV3971 (FV3970) Valve position indication and ESF monitoring at MCB Valve in normally closed, fail closed, and receives confirmatory containment isolation signal

Check valves are not listed in that a failure of a check valve to function results in the same effect on system operation as a failure of a powered component in the associated line. Consequently, the ECCS has adequate redundancy should a check valve fail to function. An exception to the single failure criterion is assumed for the accumulator discharge check valves (XSI0038A,B,C and XSI0046A, B, C) as permitted by Section 4.1 of ANSI 58.9 1981. See Sections 6.3.2.2 and 6.3.1.5 and the response to NRC Question 211.05

.

STPEGS UFSAR 6.3-46 Revision 1 8 TABLE 6.3-11 ECCS CHECK VALVES TO BE LEAK TESTED Valve Number Drawing Number Location on Drawing Train A XSI0007A 9-F-05013 E-7 XSI0009A 9-F-05013 F-7 XSI0010A 9-F-05013 F-8 XRH0020A 9-F-20000 C-2 XRH0032A 9-F-2 0000 B-2 XSI0038A 9-F-05016 E-7 XSI0046A 9-F-05016 E-6 Train B XSI0007B 9-F-05014 F-7 XSI0009B 9-F-05014 G-7 XSI0010B 9-F-05014 G-8 XRH0020B 9-F-20000 E-2 XRH0032B 9-F-20000 D-2 XSI0038B 9-F-05016 C-7 XSI0046B 9-F-05016 C-7 Trai n C XSI0007C 9-F-05015 E-7 XSI0009C 9-F-05015 F-7 XSI0010C 9-F-05015 G-7 XRH0020C 9-F-20000 H-2 XRH0032C 9-F-20000 G-2 XSI0038C 9-F-05016 A-7 XSI0046C 9-F-05016 A-7 STPEGS UFSAR 6.3-47 Revision 1 8 TABLE 6.3-12 ECCS ACTIVE POWERED COMPONENTS Safety Seismic Actuated Electrical Valve Number Type Class Class by Train Services XSI0039 A, B, C Gate 2 I Motor A, B, C XSI0008 A, B, C Gate 2 I Motor A, B, C XSI0006 A, B, C Gate 2 I Motor A, B, C XSI0004 A, B, C Gate 2 I Motor A, B, C XRH0019 A, B, C Gate 2 I Motor A, B, C XRH0031 A, B, C Gate 2 I Motor A, B, C XSI0018 A, B, C Gate 2 I Motor A, B, C SI0011 A, B, C PMD 2 I Motor A, B, C SI0012 A, B, C PMD 2 I Motor A, B, C SI0013 A, B, C PMD 2 I Motor A, B, C SI0014 A, B, C PMD 2 I Motor A, B, C XSI0001 A, B, C Gate 2 I Motor A, B, C XSI0016 A, B, C Gate 2 I Motor A, B, C FV-3936, 3937 Globe 2 I Air A, B FV-3970 Globe 2 I Air B FV-3971 Globe 2 I Air A PV-3928, 3930,3929 Globe 2 I Solenoid A, B, C FV-3983 Globe 2 I Air A HV-899 Globe 2 I Solenoid B HCV-900 Globe 2 I Solenoid A STPEGS UFSAR 6.3-48 Revision 1 8 TABLE 6.3-12 (Continued)

ECCS ACTIVE POWERED COMPONENTS

Safety Seismic Electrical Pumps Class Class Train Services High Head Safety Injection (A, B, C) 2 I A, B, C Bearing oil Low Head Safety Injection (A, B, C) 2 I A, B, C Bearing oil

STPEGS UFSAR 6.3-49 Revision 1 8 TABLE 6.3-13 AIR-OPERATED VALVES IN THE ECCS

Valve No. UFSAR Figure No.

FV-3950 6.3-1 FV-3951 6.3-1 FV-3952 6.3-1 FV-3953 6.3-1 FV-3954 6.3-1 FV-3955 6.3-2 FV-3956 6.3-2 FV-3957 6.3-2 FV-3958 6.3-2 FV-3959 6.3-2 FV-3960 6.3-3 FV-3964 6.3-4 FV-3967 6.3-4 FV-3968 6.3-4 FV-3969 6.3-4 FV-3970 6.3-4 FV-3971 6.3-4 FV-3972 6.3-4 FV-3973 6.3-4 FV-3974 6.3-4 FV-3975 6.3-4 FV-3936 6.3-1 FV-3937 6.3-1 FV-3983 6.3-4 HCV-864 5.4-6 HCV-865 5.4-6 HCV-866 5.4-6 FCV-851 5.4-6 FCV-852 5.4-6 FCV-853 5.4-6 STPEGS UFSAR 6.3-50 Revision 1 8 TABLE 6.3-14 SOLENOID-OPERATED VALVES IN THE ECCS

Valve No. UFSAR Figure No.

HCV-900 6.3-4 HV-899 6.3-4 PV-3928 6.3-4 PV-3929 6.3-4 PV-3930 6.3-4 STPEGS UFSAR 6.4-1 Revision 15 6.4 HABITABILITY SYSTEMS The habitability systems for the control room envelope are designed in accordance with the design bases described in Section 6.4.1 so that habitability of the control room envelope can be maintained under normal and accident conditions. The habitability systems and provisions include:

1. Shielding

2. Control room air purification and pressurization (includes makeup and cleanup filtration units)

3. Kitchen and sanitary facilities

The general guidance contained in General Desi gn Criterion (GDC) 19 of 10CFR50, Appendix A, is reflected throughout this section. 6.4.1 Design Bases.

The functional design of the habitability systems and their features are established by the following

design bases:

6.4.1.1 Control Room Envelope. The control room envelope is located at El. 35 ft and in two heating, ventilating, and air conditioning (HVAC) rooms at El. 10 ft and 60 ft. in the Electrical

Auxiliary Building (EAB) as shown in Figure 6.4-1.

The control room envelope is provided with HVAC equipment, fire protection equipment, adequate lighting, communication equipment, kitchen, sanitary, administrative and storage facilities, and spaces required for normal plant operation and for maintaining the plant in a safe condition following

an accident.

6.4.1.2 Habitability. The control room envelope is equipped to maintain the control room atmosphere at environmental conditions suitable for occupancy per GDC 19.

6.4.1.3 Capacity. The normal occupancy level of the control room envelope is 10 persons.

6.4.1.4 Food, Water, Medical Supplies, and Sanitary Facilities. Food, water, basic medical supplies, and first-aid equipment are provided by the Emergency Response Organization in the event of an emergency. Kitchen and sanitary facilities including toilets, washrooms, and lockers are provided within the control room envelope. If emergency conditions require confinement, food is brought onsite in protected containers. Site accessibility is determined by the Radiological Services.

Potable water required for toilet, kitchen, and lavatory is provided by a storage tank during plant emergency. One gallon of water per person per da y is provided for drinking, food preparation, and medical needs. The Potable and Sanitary Water System is described in Section 9.2.4. Should this system become unavailable during an emergency period, bottled water could be brought into the control room envelope if required.

Normal sanitation facilities are available as described in Section 9.2.4 STPEGS UFSAR 6.4-2 Revision 15 6.4.1.5 Radiation Protection. Radiation protection as required by GDC 19 of 10CFR50, Appendix A, is provided by shield walls, shield slabs at floor and ceiling, radiation monitoring equipment, and emergency filtering units. Assumptions and analyses regarding sources and amounts of radioactivity which may surround or leak into the control room envelope are discussed in Sections 15.6.5 and 15.D.2.2. Related shielding requirements are discussed in Sections 12.3.2. The Radiation Monitoring System (RMS) is discussed in Sections 11.5 and 12.3.4. CN-2897 6.4.1.6 Noxious Gas Protection. Smoke detectors located in the control room envelope return air duct actuate alarms and display them to the operators in the control room to indicate the presence of smoke in the control room envelope. Additionally, the control room envelope can be purged of smoke by outside air if required as described in Section 9.4.1.

Refer to Section 2.2.3 for an evaluation of Hazardous Chemicals located on and off-site.

6.4.1.7 Respiratory Apparatus for Emergencies. A 6-hour supply of breathing air and self-contained breathing apparatus (including require d redundant apparatus) will be provided for the emergency team with provision for obtaining additional air beyond the 6-hour limit. A minimum of 1-hour supply with redundancy will be provided within the control room envelope. A portion of the total 6-hour supply may be stored elsewhere in the EAB in locations easily accessible to the emergency team, if required due to storage limitations within the envelope.

6.4.1.8 Habitability Systems Operation During Emergencies. Operation of the habitability systems during emergencies is discussed in Section 9.4.1. Fire protection for the control room

envelope is discussed in Section 9.5.1.

6.4.1.9 Radiation Monitors. Radiation monitors are discussed in Sections 11.5 and 12.3.4. 6.4.2 System Design

6.4.2.1 Definition of Control Room Envelope. The areas included in the control room envelope are presented in Figures 6.4-1 and 6.4-2. The occupancy assumptions for the control room

envelope are presented in Table 6.4-2.

The equipment to which control room operators could require access during an emergency is listed in

Table 6.4-1.

6.4.2.2 Ventilation System Design. The control room envelope HVAC system is designed to maintain the control room envelope area at room design temperature and relative humidity conditions given in Table 9.4-1. The HVAC system is also designed to maintain the control room envelope at a minimum of 0.125-inch water gauge (wg) positive pressure relative to the surrounding area, following postulated accidents other than hazardous chemical/smoke releases and/or Loss-of-Offsite Power (LOOP), by introducing makeup air equi valent to the expected exfiltration air during plant emergency conditions (Engineered Safety Features [ESF] signal and/or high radiation in outside air). The design outside makeup air is 2,000 ft 3/min and drawn from a single intake on the east side of the EAB at El. 80 ft-0 in. (Figure 9.4.1-2). This arrangement minimizes any possibility of

STPEGS UFSAR 6.4-3 Revision 15 contaminants infiltrating the control room envelope from the surrounding areas. Additionally, during postulated accident conditions, on detection of high radi ation in the outside air or safety injection (SI) signal, outside makeup air for the control room envelope is automatically routed through makeup air units and cleanup units containing charcoal filters. The control room air is also automatically

recirculated partially (i.e., 10,000 ft 3/min) through control room air cleanup units containing charcoal filters. This arrangement provides cleanup of the control room air. A LOOP event by itself does not start the makeup air units, but it does isolate the control room envelope and start cleanup units.

The design features, fission product removal capability, and protection capability of the control room envelope HVAC system are as follows:

1. Normal and emergency ventilation of the control room envelope area are discussed in Section 9.4.1. The system configuration is shown on Figure 9.4.1-2. Principal components, ducts, dampers, instrumentation, and airflows for normal and emergency modes are indicated in the above-mentioned figure.

2. Design parameters and data for major system components are listed and described in Table 9.4-2.1.

3. Control room envelope HVAC system components, essential instrumentation, ducting, and outside air intake are designed in accordance with seismic Category I requirements. The components are not subject to the effects of floods, hurricane, tornado, internal or external missiles, pipe whip, or jet impingement. Tornado damper and missile shielding is provided at the outside air intake to protect the system components from tornado and external missiles.

Figure 12.3.1-9 presents layout drawings of the control room envelope showing doors, corridors, stairwells, shielded walls, and the placement and type of equipment within the control room envelope. A description of the emergency filter trains, their filtration capability, and the extent of their compliance with Regulatory Guide (RG) 1.52 are presented in Section 6.5.1.

6.4.2.3 Leaktightness. The HVAC system is designed to maintain the control room envelope at 0.125-in. wg positive pressure relative to the surrounding area during emergency conditions. The control room envelope HVAC system operates on a continuous basis. During the plant emergency operation mode, the following potential paths of air infiltration to the control room

envelope exist.

1. Outside air normal intake isolation dampers, return air smoke relief dampers and exhaust air dampers in the control room envelope HVAC system. These dampers are used for isolating the control room envelope.

2. Penetration space around supply air, return air and exhaust air ducts in the control room envelope and chase wall and floors.

3. Penetration space around electrical conduits and cables in the control room envelope and chase walls and floors.

STPEGS UFSAR 6.4-4 Revision 15 4. Penetration spaces around chilled water piping for HVAC equipment, piping to plumbing fixtures, drains, and potable water piping in the control room envelope and chase walls and floors are sealed airtight. 4. Penetration space around piping in the control room envelope and chase walls and floors.

5. Space around doors.

6. Makeup filter units and associated ductwork outside the envelope.

A review of these leak paths, as summarized below, indicates that infiltration through these paths during the plant emergency mode is minimal.

1. In the control room envelope HVAC system, the outside air normal intake dampers, return air smoke relief dampers, and exhaust air dampers are designed leak-tight.

2. Supply air, return, air and exhaust air duct penetrations in the control room envelope walls and floors are sealed airtight (seal-welded).

3. Penetration space around electrical and control conduits and cables in the control room envelope and chase walls and floors are sealed airtight.

5. Doors leading from the control room envelope at El. 35 ft to the EAB and the Mechanical Auxiliary Building (MAB) are 3-hour-fire rated automatic closures. The doors leading from the control room envelope to the electrical penetration area, the MAB, and the Diesel Generator Building (DGB) are provided with air locks. None of the control room envelope

doors leads directly to the outside. All doors lead to closed chase spaces, closed stairwells, or

closed corridors and are designed for low leakage.

Thus, the effect of outside wind or other adjoining building ventilation systems on infiltration or leakage into the control room envelope is insignificant. The elevator door at elevation 35 ft is a potential leak path and

therefore is provided with an air lock.

6. Makeup filter units and associated ductwork downstream of the unit are pressurized to prevent inleakage and are designed for low leakage.

6.4.2.4 Interaction with Other Zones and Pressure-containing Equipment. The control room envelope HVAC system is not connected to other areas or HVAC systems where the potential for radioactivity exists, except for sharing common air intake and exhaust with the remaining EAB.

The computer and relay rooms are provided with fire protection by a total flooding halon system. In the event of fire in these areas, these rooms are flooded with Halon 1301. The supply and return air ducts of the ventilation system for these areas are automatically sealed with isolation dampers preventing the escape of Halon 1301 to the remaining control room envelope. Any leakage of halon around the 3-hour-rated fire doors of the computer room and the relay room is diluted by the volume of control room envelope. The other rooms in the control room envelope are provided with portable fire extinguishers or deluge water spray fire protec tion. All HVAC ducts penetrating fire walls in the STPEGS UFSAR 6.4-5 Revision 15 control room envelope are provided with quick-acting fire dampers which isolate the fire affected room from adjoining rooms.

As described in Section 6.4.2.3 above, the control room envelope is maintained at 0.125-in. wg positive pressure relative to the surroundings during emergency conditions. Additionally, as

described in Section 6.4.2.2, above, upon detection of an unacceptable level of airborne radioactivity in the outside makeup air of the control room envelope HVAC system or receipt of an SI signal, the makeup air and part of control room envelope recirculation air are filtered by makeup air units and control room air cleanup units containing charcoal filters.

There are no pressure-containing tanks, pipes, or equipment containing hazardous materials in the control room envelope. In the event of an inadvertent release of hazardous materials from outside of the control room, the low-leakage fire-rated doors of the control room envelope will prevent a significant transfer of such materials into the control room envelope.

6.4.2.5 Shielding Design. The control room envelope radiation shielding design is discussed in Section 12.3.2. 6.4.3 System Operational Procedures The method of operation of the control room envelope HVAC system during normal plant and emergency conditions is described in Section 9.4.1. 6.4.4 Design Evaluation Each of the operating systems which ensures control room envelope habitability is discussed in detail in other sections. These systems and the sections in which they are discussed are:

CN-2910 Essential Chilled Water System

9.4.1 Electrical

Auxiliary Building HVAC Systems 9.4.1 Fire Protection System

9.5.1 Communication

System

9.5.2 Lighting

System

9.5.3 Offsite

Power System

8.2 Radiation

Monitoring System 11.5, 12.3.4 Onsite Power System

8.3 STPEGS

UFSAR 6.4-6 Revision 15 6.4.4.1 Radiological Protection. The control room envelope HVAC system has been designed to limit the dose equivalent to the plant operators from airborn radioactivity after a Design Basis Accident (DBA).

CN-2910 Air flow through the cleanup filters is maintained below 70% relative humidity to ensure the assumed filter efficiencies for iodine removal used in the postulated Chapter 15 accidents (see Appendix l5D). The humidity is maintained by the cooling provided by the Essential Chilled Water System supply to the main CRE AHUs. Operation of the heaters in the CRE HVAC Makeup filters is not necessary to maintain the proper humidity over the charcoal beds, even assuming the pressurization air is at 100% RH.

CN-2897 The radiological effects of the accidents postulated in Chapter 15 on Control Room personnel have been determined and are documented in the discussions of the respective accidents in Chapter 15 (except for the sample line break and small line break outside containment). These analyses were performed using the assumptions of RG 1.183.

The emergency HVAC for the control room envelope is discussed in Section 9.4.1. The system configuration is shown on Figure 9.4.1-2. The mathematical model used to represent the system and the system parameters are described in Section 15.D. This model is used in all of the Chapter 15 control room analyses. CN-2897 Control Room doses for the accidents are provided in the dose summary table in Chapter 15 for each accident. The control room envelope HVAC System design meets the dose requirements of GDC 19

of 10CFR50, Appendix A.

6.4.4.2 Toxic Gas Protection. The general guidance contained in RG 1.78, has been considered in the design of the control room envelope HVAC system, as described in Section 9.4.1.

The habitability of the control room was evaluated using the procedures described in Regulatory

Guide 1.78. As indicated in Section 2.2, no offsite storage or transport of chemicals is considered a hazard to the plant based on the Offsite Toxic Gas Analysis (Ref. 2.2-3). There are no onsite chemicals that pose a credible hazard based on the Onsite Toxic Gas Analysis (Ref. 2.2-3).

Therefore, special provisions for protection against toxic gases are not required. In accordance with the plant emergency plans and procedures, self-contained breathing apparatus is provided for assurance of control room habitability.

Toxic gases which are handled onsite are kept to a minimum. During normal operation small amounts of chlorine are handled within the site boundary at the Training facility. The amount of chlorine (<300 lbs) will not impact the control room envelope. A detailed evaluation of potential hazardous chemical accidents and their impact on control room habitability is provided in Section

2.2.3. 6.4.5 Testing and Inspection Systems and their components, listed in Section 6.4.4 above, which maintain control room envelope habitability are subjected to documented preoperational testing and inservice surveillance to ensure

STPEGS UFSAR 6.4-7 Revision 15 continued integrity. The tests conducted verify the following for both normal and emergency conditions.

1. System integrity and leaktightness

2. Inplace testing of emergency filter plenums to establish leaktightness of plenums and design parameters of the high-efficiency particulate air and charcoal filters

3. Proper functioning of system components and control devices

4. Proper electrical and control wiring

5. System balance for design airflow, water flow and operational pressures

6.4.5.1 Control Room Envelope HVAC System Integrity and Leaktightness Test. The control room envelope is leak tested prior to plant startup and subsequently in accordance with the

Technical Specifications.

6.4.5.1.1 Considerations Leading to the Selected Test Frequency

The frequency of performing this test is determined by the following condsiderations:

1. Preoperational test data

2. Normal control room envelope HVAC system performance data, as correlated to the cleanup cycle performance data

3. Periodic monitoring of the control room envelope HVAC system, which gives an indication of building tightness and system performance

6.4.5.1.2 Test methods

The test is conducted by closing all the access points to the control room envelope including doors, temporary openings, etc.

Control room envelope pressure is established by setting the return air volume to less than the supply air volume such that the design pressure is achieved. Tests are repeated as often as necessary until the acceptance criteria are met. Control room envelope pressure and outside makeup airflow rate are measured by the portable pressure gauges and/or permanently installed flow monitors in the

ductwork.

6.4.5.1.3 Acceptability Requirements

The result of the final leak test is accepted if the control room envelope makeup airflow does not exceed 2,000 ft 3/min at a positive envelope pressure of 0.125-in wg. This criterion is based on a measuring accuracy of 1 percent of full scale on pressure reading and 5 percent of full scale on airflow reading.

6.4.5.2 In-Place Testing of Emergency Filter units. In-place testing of control room envelope HVAC system emergency filter units is performed prior to system startup and thereafter in STPEGS UFSAR 6.4-8 Revision 15 accordance with the guidelines contained in RG 1.52. This testing is described in Section 9.4.1.4.

6.4.5.3 Other Tests. Tests to verify proper functioning of control room envelope HVAC system components and control devices, proper electrical and control wiring, and system design air

and water flow are described in Section 9.4.1.4.

6.4.5.4 Inspection. After control room envelope HVAC system testing, balancing, and startup procedures have been completed, the system is periodically and routinely inspected as per the

Technical Specifications. 6.4.6 Instrumentation Requirement The control logic and the instrumentation required to actuate the control room envelope HVAC system are described in Section 7.3. Instruments for monitoring the makeup and cleanup air filter units are described in Section 6.5.1.5. The instrumentation and controls provided to ensure the habitability of the control room envelope are discussed in Section 9.4.1.

Control room envelope radiation monitoring instruments are discussed in Section 11.5 and 12.3.4.

STPEGS UFSAR 6.4-9 Revision 15 REFERENCES Section 6.4

6.4-1 Not Used

6.4-2 Not Used 6.4-3 Department of Defense, Office of Ci vil Defense, Shelter Design and Analysis , Vol.3, Chapter 9.

CN-2897 STPEGS UFSAR 6.4-10 Revision 15 TABLE 6.4-1 EQUIPMENT TO WHICH THE CONTORL ROOM OPERATORS COULD REQUIRE ACCESS DURING AN EMERGENCY Location Within Control Item or Equipment Room Area Control and monitoring panels See Figure 6.4-2

Portable radiation measuring instruments Storeroom

Emergency procedures, manuals, and

drawings Storage space

Self-contained breathing apparatus See Section 6.4.1.7

Communications equipment Operator's desk

Fire-extinguishing equipment All rooms

Control room cleanup filter units Control Room Envelope HVAC Equipment Rooms

STPEGS UFSAR 6.5-1 Revision 1 8 6.5 FISSION PRODUCT REMOVAL AND CONTROL SYSTEMS

6.5.1 Engineered

Safety Feature Filter Systems The following systems are designed as Engineered Safety Feature (ESF) filter systems:

1. Fuel Handling Building (FHB) Exhaust Subsystem (part of the Heating, Ventilating, and Air Conditioning [HVAC] System).

2. Main Control Room HVAC makeup and cleanup units.

6.5.1.1 Design Bases

.

6.5.1.1.1 FHB Exhaust Subsystem: The subsystem is designed:

To mitigate the consequences of the fuel handling accident or Design Basis Accident (DBA) (considering Emergency Core Cooling System [ECCS] leakage) by removing the airborne iodine radioactivity from the FHB exhaust air prior to releasing to the atmosphere.

However, no credit is taken for the FHB Exhaust Subsystem filtration in the Chapter 15 LOCA or Fuel Handling accident analyses.

To satisfy all applicable requirements of General Design Criterion (GDC) 61 of 10CFR50, Appendix A.

As a seismic Category I, safety class (SC) 3 system and is protected against tornadoes, missiles, pipe rupture, and flooding.

Redundant filter units and active components are provided to meet the requirements of the single

-failure criterion.

The components of the subsystem are designed and sized in accordance with the applicable sections of Oak Ridge National Laboratory report ORNL

-NSIC-65 (Ref. 6.5.1

-1) and Regulatory Guide (RG) 1.52, with the exceptions listed in Table 6.5

-1.

The fission product removal capacity of the filters is based on the requirements of RG 1.52 (although ,

no credit is taken for the FHB Exhaust Subsystem filtration in the Chapter 15 LOCA or Fuel Handling accident analyses).

6.5.1.1.2 Main Control Room HVAC Makeup and Cleanup Units: The units are designed:

To maintain, during and after a postulated design basis accident, the habitability of the control room envelope by limiting the radiation exposure to control room personnel to within the guidelines of GDC 19 of 10CFR50, Appendix A and 10CFR50.67.

STPEGS UFSAR 6.5-2 Revision 1 8 As seismic Category I and SC 3 components and are protected against tornadoes, missiles, pipe rupture, and flooding.

Redundant filter units and active components are provided to meet the requirements of the single

-failure criterion.

The components of the units are designed and sized in accordance with the applicable sections of ORNL-NSIC-65 and RG 1.52, with the exceptions listed in Table 6.5

-1.

The fission product removal capacity of the filters is based on the requirements of RG 1.52.

(although, no credit is taken for the Control Room makeup filtration in the Chapter 15 radiological accident analyses).

6.5.1.2 System Design

.

6.5.1.2.1 FHB Exhaust Subsystem: Descriptive and detailed information about the Exhaust Subsystem is presented in the following sections:

1. Design Bases

- Section 9.4.2.1

2. System Description

- Section 9.4.2.2

Comparison of the design features and fission product removal capability of the system to each position detailed in RG 1.52 is presented in Table 6.5

-1.

6.5.1.2.2 Main Control Room HVAC Makeup and Cleanup Units: Descriptive and detailed information about the makeup and cleanup units is presented in the following sections:

1. Design Bases

- Section 9.4.1.1

2. System Description

- Section 9.4.1.2

Comparison of the design features and fission product removal capability of the units to each position detailed in RG 1.52 is presented in Table 6.5

-1.

6.5.1.3 Design Evaluation

.

6.5.1.3.1 FHB Exhaust Subsystem: Evaluation of the subsystem is discussed in Section 9.4.2.3. 6.5.1.3.2 Main Control Room HVAC Makeup and Cleanup Units: Evaluation of the makeup and cleanup units is discussed in Section 9.4.1.3.

6.5.1.4 Tests and Inspections

.

STPEGS UFSAR 6.5-3 Revision 1 8 6.5.1.4.1 FHB Exhaust Subsystem: Tests and inspections of the Exhaust Subsystem are described in Section 9.4.2.4.

6.5.1.4.2 Main Control Room HVAC Makeup and Cleanup Units: Tests and inspections of the makeup and cleanup units are described in Section 9.4.1.4.

6.5.1.5 Instrumentation Requirements. Actuation instrumentation for the ESF filter systems is designed in accordance with Institute of Electrical and Electronics Engineers (IEEE) 279

-1971 and 338

-1971. ESF actuation instruments are classified seismic Category I as per RG 1.29 and are inspected and tested under the requirements of RG 1.30.

6.5.1.5.1 Fuel Handling Building Exhaust Subsystem: The control logic and the instrumentation required for actuating the FHB Exhaust Subsystem filter trains are described in Section 7.3.

Pressure differential transmitters across the high

-efficiency particulate air (HEPA) filters provide signals to control room indicators and alarms to indicate the amount of filter loading. Upstream HEPA filter pressure drops are recorded at the main control room. Local pressure differential indicators are provided across the prefilters, HEPA filters, and the entire filter unit. Each carbon adsorber cell electric heater is automatically controlled by exhaust booster fan operation.

Overtemperature protection for the electric heaters is provided by temperature switches and low

-flow switches. A temperature sensor at each carbon adsorber cell signals an alarm in the control room to indicate high carbon bed temperatures.

6.5.1.5.2 Control Room Makeup and Cleanup Filtration: The control logic and instrumentation required for actuating the control room makeup and cleanup filter trains is described in Section 7.3.

The HEPA filters on the makeup and cleanup filter trains are equipped with pressure differential indicating transmitters to signal indicators and alarms in the control room of the amount of filter loading. Upstream HEPA filter pressure drops are recorded at the main control room. Local pressure differential indicators are provided across the prefilters, HEPA filters, and the entire filter unit with high differential pressure alarm in the main control room for filter loading. The makeup filter train contains an electric heater which is automatically controlled by the makeup filter unit fan operation.

The electric heater controls are interlocked with signals from a low

-flow switch and provided with thermal cutout for heater overtemperature protection. A temperature sensor at each carbon adsorber cell signals an alarm in the control room to indicate high carbon bed temperatures.

6.5.1.6 Materials.

6.5.1.6.1 Fuel Handling Building Exhaust Subsystem: The filter unit housing is fabricated from 3/16-in. hot-rolled steel sheet. Materials for each filter component are as follows.

Each pre-filter is nominally 24 in. square and 12 in. deep.

The filter medium consists of waterproof glass fiber with aluminum separators and galvanized steel frames. Each HEPA filter is also 24 in. square and 12 in. deep. The filter medium consists of waterproof, fire

-retardant glass fiber with STPEGS UFSAR 6.5-4 Revision 1 8 aluminum separators. Frame material is cadmium

-plated steel. The charcoal adsorber is made of activated carbon. The mechanical structure and framing for the adsorber is welded stainless steel, type304, American Society for Testing and Materials (ASTM) A240.

6.5.1.6.2 Control Room Makeup and Cleanup Units: The materials for these units are the same as those outlined in Section 6.5.1.6.1, above.

6.5.2 Containment

Spray System

- Iodine Removal The Containment Spray System (CSS) (Section 6.2.2) provides water spray to the Containment during the unlikely event of DBA to depressurize the Containment and minimize the release of radioactive iodine to the environment. This section describes the iodine removal capability of the CSS. The analysis of the radiological consequences of the Loss

-of Coolant Accident (LOCA) is given in Section 15.6.5.

6.5.2.1 Design Bases. The design bases of the CSS for removing iodine from the Containment atmosphere are:

1. GDC 41, as related to Containment atmosphere cleanup.

2. GDC 42, as related to inspection of Containment atmosphere cleanup systems.

3. GDC 43, as related to testing of Containment atmosphere cleanup systems.

4. The CSS is capable of functioning effectively with the single failure of any active component in the system, any of its subsystems, or any of its support systems.

5. The CSS is designed to obtain adequate coverage of the Containment volume in order to limit (in conjunction with other safeguards systems) the offsite TEDE doses to a limit less than that established by 10CFR50.67, using the assumptions in RG 1.183.

6. The spray nozzles are designed to minimize the possibility of clogging and to produce droplet sizes effective for iodine absorption.

7. The equilibrium pH of the Containment sump is 6.8 to 9.5 due to the addition of trisodium phosphate.

6.5.2.2 System Design. The CSS design is discussed in detail in Section 6.2.2.

Trisodium phosphate is located at strategic points in the post

-LOCA flooded regions of the Containment and dissolves during initial spray and recirculation which, consistent with design basis

1. 7, assures iodine retention in the sump solution.

Before the refueling water storage tank (RWST) is emptied, the Containment spray pump suctions are switched automatically to the Containment emergency sumps.

STPEGS UFSAR 6.5-5 Revision 1 8 The number of nozzles and the nozzle spacing on each header is given in Section 6.2.2. A schematic of the headers illustrating the nozzle orientations is given on Figure 6.2.2

-3. The input parameters and results of the spray iodine analysis are given in Table 6.5

-2. The regions covered by the Containment spray are addressed in Section 6.2.2.3.4.

The system meets the redundancy requirements of an ESF system and satisfies the system performance requirements despite the most limiting single active failure. Included in the performance requirements is consideration of maximum concentration and volumes for the post

-LOCA Containment sump water sources.

The chronology of events for system operation is discussed in Section 6.2.2.

6.5.2.3 Design Evaluation. The CSS is an ESF system employed to reduce pressure and temperature in the Containment following a postulated LOCA. For this purpose, subcooled water is sprayed into the Containment atmosphere through a large number of nozzles from spray headers located in the Containment dome. The spray drop size distribution based on the Sprayco 1713A nozzle for a 40 psi pressure drop is shown in Figure 6.5.

-2.

The large spray drop surface to Containment volume ratio enables the spray to effectively remove fission products postulated to have been dispersed in the Containment atmosphere. (Radioiodine in its various forms is the fission product of primary concern in the evaluation of a LOCA.) The major benefit of the CSS is its capacity to remove iodine from the Containment atmosphere.

Values for the spray removal half

-life of the elemental iodine in a typical Containment are on the order of minutes or less. Most of the iodine released to the Containment is assumed to be the particulate form. The remainder is assumed to be in the organic and the elemental forms.

The Containment spray is very effective in removing airborne elemental iodine. No credit is taken for spray removal of the organic form of iodine. However, the particulate iodine is removed by the spray, but at a rate much lower than for elemental iodine. Credit is also taken for elemental iodine removal by surface deposition.

The iodine removal analysis is based on the conservative CSS parameters outlined in Table 6.5

-2. The total Containment volume and sprayed volume are consistent with those values used for the LOCA offsite dose analysis described in Section 15.6.5. The Containment temperature and pressure used for this analysis are consistent with the design values outlined in Section 6.2.

At the beginning of the injection phase, the sump contains borated water which has a pH of approximately 4.5. As the initial spray solution and subsequently the recirculation solution comes in contact with the trisodium phosphate, stored in baskets in the Containment post

-LOCA flooded region, the trisodium phosphate dissolves raising the pH of the sump solution to an equilibrium value of 6.8 to 9.5. This is based on the input parameters given in Table 6.5

-3 and Table 6.5

-4. Refer. to Figure 6.5

-1 for a graph of sump pH as a function of time.

STPEGS UFSAR 6.5-6 Revision 1 8 The boron concentration of the RCS is an input parameter to the sump pH analysis. However, the limiting analysis in determining the maximum RCS boron concentration is the determination of the hot leg switchover time, and not the sump pH analysis. The RCS boron concentration is used, along with the decay heat content of the core, to determine the time at which the hot leg switchover occurs to prevent boron precipitation in the core. Therefore, the maximum RCS boron concentration for Mode 3 one hour after exiting Modes 1 or 2 is 3500 ppm for a switchover time of 5.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br />, per Section 6.3.2.5.

The limitation on the sump pH is only applicable during the operational modes where DBA LOCA or a small break LOCA is postulated to occur. Therefore, the maximum RCS concentration is of concern during power operation, startup, hot standby, and hot shutdown. There is no operational limit, due to sump pH concerns, during cold shutdown and refueling.

The sump pH analysis was re

-performed using the guidance in RG 1.183 for the Alternative Source Term LOCA analysis and is described in Section 15.6.5. Specifically, the consideration of radiolysis of electrical cable insulation was considered. This analysis indicates the sump pH will drop to 6.8 by the end of the 30

-day period. This analysis and its impact on iodine re-evolution from the containment sump and from ESF leakage are discussed in Sections 15.6.5.3.1.2 and 15.6.5.3.2.2. The spray removal constants used in the LOCA analysis are presented in Table 15.6

-14.

6.5.2.3.1 Containment Spray Elemental Iodine Removal Coefficient: Containment spray iodine removal performance was determined using the spray model presented in Standard Review Plan 6.5.2, Revision 2 (Ref. 6.5 1). The methodology for the determination of the spray removal of elemental iodine presented is independent of the use of spray additive. The removal rate constant is determined by:

D V TF K 6 g s where s = Removal rate constant due to spray removal, hr

-1 K g = Gas phase mass transfer coefficient, ft/min

T = Time of fall of the spray drops, min

F = Volume flow rate of sprays, ft 3/hr V = Containment volume, ft 3

D = Mass-mean diameter of the spray drops, ft

Using the appropriate parameters from Table 6.5

-2, the spray removal rate was calculated to be 25.4 hr-1 which was reduced to 20 hr

-1 since this is the upper limit specified by this model. Details of the model, additional justification for its use, and the parameters used are presented in WCAP

-12477 (Ref. 6.5.2

-2).

STPEGS UFSAR 6.5-7 Revision 1 8 Determination of spray performance factors of drop size and drop fall time was made using the spray model developed by Westinghouse (Ref. 6.5.2

-3). This model includes consideration of the effects of: - Initial drop size distribution

- Condensation of steam onto spray drops

- Post-LOCA Containment pressure and temperature

- Drop coalescence

A DF of 60, corresponding to a pH of 6.8 was determined to be appropriate and is used in the dose analysis, even though the calculated value of pH at 30 days is just below 6.85. At a pH of 7.0, the DF approaches 150. The calculation is very conservative in that (1) the highest sump temperature is used and (2) the lowest pH is assumed throughout the duration of the accident. The DF of 60 will be exceeded at all times since early in the accident the sump pH is greater than 6.8 and later the sump temperature is much less than the maximum value. After a DF of 60 is attained

, it is assumed that there is no additional removal of elemental iodine by the sprays (Ref. 6.5.2

-2).

6.5.2.3.2 Containment Spray Particulate Iodine Removal Coefficient: The model used for particulate iodine removal by spray was also taken from Reference 6.5.2

-1. The first order spray removal rate constant for particulates is given as follows:

d E V 2 hF 3 p where h = Drop fall heig ht F = Spray flow rate

V = Volume sprayed

E = Single drop collection efficiency

d = Drop diameter

Values for h, F, and V are listed in Table 6.5

-2. The E/d term depends on the particle size distribution and spray drop size. The model presented in Reference 6.5.2

-1 conservatively uses:

d E = 0.1 cm

-1 for C o / C t 50 where C o / C t =

Ratio of the initial aerosol aerosol concentration to the concentration at the time t.

STPEGS UFSAR 6.5-8 Revision 1 8 d E = 0.01 cm

-1 for C o / C t > 50 With these values, the particulate removal constants are determined to be: p = 6.9 hr-1 for C o / C t 50 p = 0.7 hr-1 for C o / C t > 50 Although it would be expected that spray removal of particulate iodine would continue indefinitely, it is assumed that there is no additional removal once a DF of 1000 is reached. Additional details for the use of this model are presented in Reference 6.5.2

-2. 6.5.2.3.3 Elemental Iodine Deposition Removal Coefficient: Reference 6.5.2

-1 also presents a model for removal of elemental iodine by deposition onto Containment surfaces. The deposition removal rate constant is written as:

V A k g d where d = Removal rate constant due to surface deposition (hr

-1) k g = Average mass transfer coefficient (m/hr)

(deposition velocity)

A = Surface area for wall deposition (m

2)

V = Volume of contained gas (m

3)

From Reference 6.5.2

-1, the mass transfer coefficient k g is taken to be 4.9 meters per hour which comes from NUREG/CR

-0009 (Ref. 6.5.2

-4) and conservatively envelopes all experimental data. Including other values from Table 6.5

-2 results in a deposition removal coefficient of 4.5 hr

-1. As discussed in Reference 6.5.2

-2, this initial deposition removal rate is assumed to continue until a DF of 100 is achieved at which time the removal rate is assumed to be reduced to five percent of its initial value. Deposition of elemental iodine onto surfaces is assumed to continue until a DF of 200 is reached and is then conservatively assumed to stop. Additional details and justification for the use of this model are presented in Reference 6.5.2

-2.

6.5.2.4 Tests and Inspections. The tests and inspections of the CSS are described in Section 6.2.2.4.

6.5.2.5 Instrumentation Requirements. The instrumentation application of the CSS is given in Section 6.2.2.5.

6.5.2.6 Materials. The materials used in the CSS are discussed in Section 6.1.1.

STPEGS UFSAR 6.5-9 Revision 1 8 6.5.3 Fission Product Control Systems Refer to Sections 6.2.2 and 6.5.2 for a discussion of the CSS. Credit is taken for the CSS as a fission product removal system.

6.5.3.1 Primary Containment. For discussion of the primary Containment structural and functional design and of the Containment systems, refer to the following sections:

Concrete Containment

3.8.1 Containment

Functional Design

6.2.1 Containment

Heat Removal Systems

6.2.2 Containment

Isolation System

6.2.4 Containment

Leakage Testing

6.2.6 Containment

Ventilation Systems 9.4.5 For a summary of the primary Containment's capability to control fission product releases following a DBA see Section 15.6.5.3. The Containment Supplementary Purge Subsystem provides the capability to purge the Containment during normal reactor operation. The subsystem is designed for a smaller flow rate than the normal purge, thus requiring smaller penetration isolation valves.

Layouts of the primary Containment are shown on the general arrangement drawings listed as Figures

1.2-12 through 1.2

-19 in Table 1.2

-1.

6.5.3.2 Secondary Containment. The South Texas Project Electric Generating Station (STPEGS) does not utilize a Secondary Containment System.

STPEGS UFSAR 6.5-10 Revision 1 8 REFERENCES Section 6.5

6.5.1-1 Burchsted, C. A., and A. B. Fuller, "Design, Construction, and Testing of High Efficiency Air Filtration Systems for Nuclear Application", Oak Ridge National Laboratory Report No. ORNL

-NSIC-65 (1970).

6.5.2-1 NRC Staff, "Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants", NUREG

-0800, Section 6.5.2., Revision 2 (Dec. 1988).

6.5.2-2 Westinghouse, "Spray Additive Elimination Analysis for the South Texas Project", WCAP-12477, December 1989.

6.5.2-3 Sanford, M. O. and E. V. Somers, "Iodine Removal by Spray in the Joseph M. Farley Station Containment", Westinghouse Electric Report No. WCAP

-8376 (1974).

6.5.2-4 NUREG/CR-0009, "Technological Bases for Models of Spray Washout of Airborne Contaminants in Containment Vessels".

STPEGS UFSAR 6.5-11 Revision 1 8 TABLE 6.5-1 COMPARISION OF ENGINEERED SAFETY FEATURE FILTER SYSTEMS WITH REGULATORY GUIDE 1.52, REV. 2 REQUIREMENTS Regulatory Guide 1.52(1) Item Fuel Handling Building Exhaust Subsystem Units Main Control Room HVAC Makeup and Cleanup Units 1-a The system complies with this requirement.

The system complies with this requirement.

1-b,c The system complies with these requirements.

The system complies with this requirements.

1-d The systems complies with this requirement.

Not applicable.

1-e The system complies with this requirement. The system complies with this requirement.

2-a Demisters and cooling coils are not included. Makeup units do not include demisters and cooling coils. Cleanup units do not include demisters, cooling coils, and heaters.

2-b The system meets the intent of this requirement. Separation for fire protection is discussed in Section 9.5.1. The system complies with this requirement.

2-c The system complies with this requirement.

The system complies with this requirement.

2-d Not applicable.

Not applicable 2-e,f The system complies with this requirement.

The system complies with this requirement.

2-g The system complies with this requirement for pressure drop monitoring only. Flows are indicated and alarmed in the control room, but not recorded. Recorders are not required since the system is operated only during test and accent conditions The system complies with this requirement for pressure monitoring only. For the makeup unit, flows are indicated and alarmed in the control room, but not recorded. For the cleanup unit, flows are indicated locally.

STPEGS UFSAR 6.5-12 Revision 1 8 TABLE 6.5-1 (Continued)

COMPARISION OF ENGINEERED SAFETY FEATURE FILTER SYSTEMS WITH REGULATORY GUIDE 1.52, REV. 2 REQUIREMENTS Regulatory Guide 1.52(1) Item Fuel Handling Building Exhaust Subsystem Units Main Control Room HVAC Makeup and Cleanup Units 2-g (Continued) alarmed in the control room, but not recorded. Flow Recorders are not required since the system is operated only during test or accident conditions.

2-h See Table 3.12

-1 for RG compliance and UFSAR discussion references.

See Table 3.12

-1 for RG compliance and UFSAR discussion references.

2-i The system complies with this requirement.

The system complies with this requirement.

2-j The system complies with the intent of this requirement, however it is not designed to be removed as an intact unit or in segments. (Carbon filters are rechargeable.

Recharging and maintenance facilities are provided.)

The system complies with this requirement, however it is not designed to be removed as an intact unit or in segments.

2-k,l The system complies with these requirements.

The system complies with these requirements.

3-a Not applicable.

Not applicable since there is no possibility of carryover of water particles in the filter unit inlet air stream. 3-b,c,d,e,f,g,h The system complies with these requirements.

The system complies with these requirements.

3-i Adsorber material complies with this requirement.

Adsorber material complies with thi s requirement.

3-j,k,l,m,n,o The system complies with these requirements.

The system complies with these requirements.

STPEGS UFSAR 6.5-13 Revision 1 8 TABLE 6.5-1 (Continued)

COMPARISION OF ENGINEERED SAFETY FEATURE FILTER SYSTEMS WITH REGULATORY GUIDE 1.52, REV. 2 REQUIREMENTS Regulatory Guide 1.52(1) Item Fuel Handling Building Exhaust Subsystem Units Main Control Room HVAC Makeup and Cleanup Units 3-p Not Applicable Not Applicable 4-a The system complies with this requirement.

The system complies with this requirement. 4-b The system complies with this requirement.

The system complies with this requirement, however the distance between banks is less than the length of component to be replaced plus 3 feet. 4-c The system complies with this requirement.

The system complies with this requirements.

4-d,e, 5-a,b,c,d The system complies with these requirements.

The system complies with these requirements.

5-d This system complies with this requirement, except allowable bypass leakage is 0.1%.

The system complies with this requirement, except allowable bypass leakage is 0.1%.

6-a,b The system complies with these requirements.

The system complies with these requirements.

1. ANSI N509-1980 (Nuclear Power Plant Air Cleaning Units and Components for design, construction and testing) and ANSI N510

-1980 (Testing of Nuclear Air

-Cleaning Systems

- for field testing) and ASTM D3803

-1989 (Standard Test Methods of Nuclear

- Grade Gas Phase Adsorbents

-for laboratory testing) are used in conjunction with RG 1.52 in lieu of ANSI N509-1976 and ANSI N510

-1975, respectively (for testing requirements only).

STPEGS UFSAR 6.5-14 Revision 1 8 TABLE 6.5-2 INPUT PARAMETERS FOR DETERMINING IODINE REMOVAL COEFFICIENTS Containment pressure 37.5 psig*

Containment temperature 307 F* Total Containment free volume 3.41 x 10 6 ft 3 Unsprayed Containment free volume 20% Spray fall height 143 ft Net spray flow (2 pumps) 3,600 gal/min Gas Phase Mass Transfer Coefficient for Spray Removal of Elemental Iodine 9.84 ft/min Mass-Mean Diameter of Spray Drops 0.0044 ft Average Spray Drop Fall Time 0.233 min Containment Surface Area Available for Deposition of Iodine 1.0 x 10 6 ft 2

• These values of the containment pressure and temperature were used in the calculation of iodine removal coefficients. The revised values due to the VANTAGE 5H fuel upgrade are 41.2 psig and 313F. an engineering evaluation of the effects of the changes on the removal coefficient results determined that the pressure and temperature effects are second order effects and the current calculation is valid. Also, since a maximum value of 20 hr

-1 is used in the dose analysis, the current calculation remains bounding.

STPEGS UFSAR 6.5-15 Revision 1 8 TABLE 6.5-3 INPUT PARAMETERS TO DETERMINE MINIMUM pH FOR SUMP SOLUTION

RWST deliverable water mass, lb 4,505,980 RWST boron concentration, ppm 3,000 Accumulator water , mass, lb 228,015 Accumulator boron concentration, ppm 3,000 Reactor coolant system water mass, lb 631,700 Reactor coolant boron concentration, ppm 3,500 Trisodium Phosphate, lb (1) 11,500 Resultant Solution pH 7.0

1. Na 3 PO 4 12 H 2O which contains a minimum of 43% Na 3 PO 4. CN-3151 CN-3151 CN-3151 CN-3151 STPEGS UFSAR 6.5-16 Revision 1 8 TABLE 6.5-4 INPUT PARAMETERS TO DETERMINE MAXIMUM pH FOR SUMP SOLUTION RWST deliverable water mass, lb 2,988,450 RWST boron concentration, ppm 2,800 Accumulator water mass, lb 218,182 Accumulator boron concentration, ppm 2,700 Reactor coolant system water mass, lb(2) 534,400 Reactor coolant boron concentration, ppm 0 Trisodium Phosphate, lb(1) 15,100 Resulting Solution pH 7.5

1. Assumes that each of 6 Trisodium Phosphate basket (42 ft

3) is filled with TSP to the maximum level. The maximum TSP density is 60 lb/ft

3. The specified mass of TSP is based upon Na 3 PO 4 12H 2O which contains a minimum of 43% Na 3 PO 4. 2. Bounding case for maximum pH is with E

-2 steam generators, with maximum tube plugging..

CN-3151 CN-3151 CN-3151 STPEGS UFSAR 6.6-1 Revision 15 6.6 INSERVICE INSPECTION OF ASME C ODE CLASS 2 AND CLASS 3 COMPONENTS Preservice and inservice inspections of American Society of Mech anical Engineers (ASME) Code Class 2 and 3 components will be performed in accord ance with Section XI of the ASME Boiler and Pressure Vessel Code (B&PV) of the applicable Edition/Addenda as approved by 10CFR50.55a (b)

and required by 10CFR50.55a (g).

The preservice examination of ASME Section III, Class 2 and 3 components of South Texas Project Electric Generating Station (STPEGS) Unit 1 and Unit 2 was conducted in accordance with the ASME Section XI of the 1980 Edition with Addenda through Winter 1981, except that the extent of examination of piping welds in Residual Heat Removal (RHR), Safety Injection (SI), and Containment Spray Systems (CSSs) was determined in accordance with paragraph IWC-1220, Table IWC-2520 Category C-F and C-G, and paragraph IWC-2411 of the ASME Section XI of the 1974 Edition with Addenda through Summer 1975, as required by 10CFR50.55a (b) (2) (iv). CN-2969 CN-2969 The first 10 years of inservice examination and inservice testing was performed to the requirements of the 1983 edition of Section XI with addenda through the Summer 1983 Addenda. The inservice examination and inservice testing programs are upgrad ed to later editions a nd addenda of the Section XI Code at the start of each 10-year inspection interval in accord ance with 10CFR50.55a (g) (4) (ii). CN-2969 6.6.1 Components Subject to Inspection The Safety Class 2 and 3 components are classified in accordance with the criteria of Regulatory Guide (RG) 1.26, "Quality Group Classifications and Standards for Water-, Steam-, and Radioactive-Waste-Containing Components of Nuclear Power Pl ants", Revision 3. All Code Class 2 and 3 components will be subjected to an inservice inspection (ISI) program which meets the requirements of Subsection IWC and IWD, resp ectively, of ASME Section XI.

The identification of components to be examined, the methods of examination, and the extent and frequency of examinations will be as specified in the preservice inspection (PSI) and ISI examination plans. 6.6.2 Accessibility Access to the Class 2 and 3 system pressure bounda ries have been designed to provide compliance with the provisions for access as required by Subarticle IWA-1500 of the 1974 Edition,Section XI, with addenda through the Summer 1975 Addenda. Access for some systems and parts thereof is designed in accordance with the requirements of later editions and addenda up to the Code used for preservice examination. During the design of components, equipment layout, weld joint configuration, support structures, etc

., consideration has been given to assure that the Class 2 and 3 systems will be examinable to the applicable requirements of Section XI.

Access for the purpose of ISI is defined as the design of the plant with th e proper clearances for examination personnel and equipment to perform inservice examinations. Access to welds requiring visual surface or volumetric examination has been provided by means of removable insulation and/or STPEGS UFSAR 6.6-2 Revision 15 removable shielding. The provisions for suitable access for ISI examinations will minimize the time required for performing these examinations, thereby minimizing the amount of radiation exposure to both plant and examination personnel. Work platforms will be provided at strategic locations in the plant to permit ready access to those areas of the Class 2 and 3 preser vice boundaries which are designated as inspection poi nts in the ISI program. 6.6.3 Examination Techniques and Procedures Examination techniques and procedures for Class 2 components will be in accordance with Articles IWA-2000 and IWC-2000 of ASME Section XI. Manua l ultrasonic examinati on techniques will be used for most, if not all, volumetric examinations of Class 2 components. All reportable indications will be mapped, and records will be made of the recordable signal amplitude, depth below the scanning surface, and length of the reflector. The data compilation format will be such as to provide for comparison of data with data from subsequent examination. Radiographic techniques may be used where ultrasonic techniques are not practicable. For areas where manual surface examinations or direct visual examinations are to be performed, all reportable indications are to be mapped with respect to size and location in a manner to allow comparison of data with data from subsequent examinations.

Examination techniques and procedures for Class 3 components will be in accordance with Articles IWA-2000 and IWD-2000 of ASME Section XI. The visual examinations will be conducted during system pressure testing and during op eration without removing insulation. 6.6.4 Inspection Intervals The ISI Examination Plan for Class 2 and Class 3 components is developed in accordance with the requirements of Section XI, Articles IWC-2000 and IWD-2000, respectively. The initial ISI Examination Plan was based on an inspection interv al of 10 years beginning with placement of the unit into commercial service. Additional ISI Exam ination Plans are developed for subsequent 10-year inspection intervals throughout commercial service. The inservice examinations and tests required by Section XI are completed within each inspection interval. The fr equency and extent of the examinations within each examination category are provided in the ISI Examination Plan for each interval. CN-2969 CN -29696.6.5 Examination Categories and Requirements Examination categories and requirements for Class 2 and 3 components will be in agreement with Articles IWC-2000 and IWD-2000, respec tively, of ASME Section XI. 6.6.6 Evaluation of Examination Results CN-2969 The evaluation of examination results for Class 2 and 3 components are performed in accordance with Articles IWA-3000, IWB-3000, IWC-3000 and IWD-3000.

CN-2969 Repairs/Replacement of Class 2 and 3 components containing defects will be in accordance with the requirements of Article IWA-4000.

STPEGS UFSAR 6.6-3 Revision 15 6.6.7 System Pressure Tests Class 2 systems subject to system pressure tests will be tested in accordance with Articles IWA-5000 and IWC-5000 of Section XI. Class 3 systems subject to system pressure tests will be tested in accordance with the requirements of Articles IWA-5000 and IWD-5000 of Section XI. 6.6.8 Augmented Inservice Inspection High-energy piping (as defined by Standard Review Plan Section 3.6.1 and 3.6.2) will be included under an augmented ISI program when appropriate.

All welds located in appropriate high-energy piping for which no breaks are postulated will be examined using volumetric examination techniques. This examination will apply to all piping circumferential butt welds and longitudinal butt welds. Under this augmented scope, 100 percent volumetric examination will be performed during the PSI and once in each 10-year interval or as required per the Risk-Informed process for piping outlined in EPRI Topical Report TR-1006937. CN-2894

STPEGS UFSAR 6.7-1 Revision 136.7 MAIN STEAM ISOLATION VALVE LEAKAGE CONTROL SYSTEM This section does not apply to the South Texas Project.