Text

Enclosure, TS Amendment Mc 2225, Reactor Coolant System Pressure Temperature Limits Report
	ML050910029
Person / Time
Site:	Vogtle
Issue date:	03/28/2005
From:	Gratton C; NRC/NRR/DLPM/LPD2
To:	Grissette D; Southern Nuclear Operating Co
	Gratton C, NRR/DLPM, 415-1055
Shared Package
ML050690228	List: ML050690216; ML050840305; ML050910029;
References
	TAC MC2225, TAC MC2226, TAC MC2227, TAC MC2228, TAC MC3090, TAC MC3091
	Download: ML050910029 (31)
	v • d • e

e 1.1 Definitions PHYSICS TESTS (continued)

a.

Described in Chapter 14 of the FSAR;

b.

Authorized under the provisions of 10 CFR 50.59; or

c.

Otherwise approved by the Nuclear Regulatory Commission.

PRESSURE AND TEMPERATURE LIMITS REPORT (PTLR)

QUADRANT POWER TILT RATIO (QPTR)

RATED THERMAL POWER (RTP)

REACTOR TRIP SYSTEM (RTS) RESPONSE TIME The PTLR is the unit specific document that provides the reactor vessel pressure and temperature limits, including heatup and cooldown rates, Cold Overpressure Protection System (COPS) arming temperature and the nominal PORV setpoints for the COPS, for the current reactor vessel fluence period. These pressure and temperature limits shall be determined for each fluence period in accordance with Specification 5.6.6. Unit operation within these operating limits is addressed in individual specifications.

QPTR shall be the ratio of the maximum upper excore detector calibrated output to the average of the upper excore detector calibrated outputs, or the ratio of the maximum lower excore detector calibrated output to the average of the lower excore detector calibrated outputs, whichever is greater.

RTP shall be a total reactor core heat transfer rate to the reactor coolant of 3565 MWt.

The RTS RESPONSE TIME shall be that time interval from when the monitored parameter exceeds its RTS trip setpoint at the channel sensor until loss of stationary gripper coil voltage. The response time may be measured by means of any series of sequential, overlapping, or total steps so that the entire response time is measured. In lieu of measurement, response time may be verified for selected components provided that the components and the methodology for verification have been previously reviewed and approved by the NRC.

I (continued)

Vogtle Units 1 and 2 1.1-5 Amendment No. 136 (Unit 1)

Amendment No. 115 (Unit 2)

RCS Loops -

MODE 4 3.4.6 3.4 REACTOR COOLANT SYSTEM (RCS) 3.4.6 RCS Loops - MODE 4 LCO 3.4.6 Two loops consisting of any combination of RCS loops and residual heat removal (RHR) loops shall be OPERABLE, and one loop shall be in operation.

----------NOTES-----------------------------

1.

All reactor coolant pumps (RCPs) and RHR pumps may be de-energized for < 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months per 8 hour9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months period provided:

a.

No operations are permitted that would cause reduction of the RCS boron concentration; and

b.

Core outlet temperature is maintained at least 1 0F below saturation temperature.

2.

An RCP shall not be started with any RCS cold leg temperature < the Cold Overpressure Protection System (COPS) arming temperature specified in the PTLR, unless the secondary side water temperature of each steam generator (SG) is < 500F above each of the RCS cold leg temperatures. With the RHR suction isolation valves open, this value is reduced to 250F at an RCS temperature of 3500F and varies linearly to 500F at an RCS temperature of 2000F.

I APPLICABILITY:

MODE 4.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A.

One required RCS loop A.1 Initiate action to restore a Immediately inoperable.

second loop to OPERABLE status.

AND Two RHR loops inoperable.

(continued)

Vogtle Units 1 and 2 3.4.6-1 Amendment No.136(Unit 1)

Amendment No.11 5(Unit 2)

Pressurizer Safety Valves 3.4.10 3.4 REACTOR COOLANT SYSTEM (RCS) 3.4.10 Pressurizer Safety Valves LCO 3.4.10 APPLICABILITY:

Three pressurizer safety valves shall be OPERABLE with lift settings 2 2410 psig and < 2510 psig.

MODES 1, 2, and 3.

MODE 4 with all RCS cold leg temperatures > the COPS arming temperature specified in the PTLR.

I' K Icaser aj I t---

The lift settings are not required to be within the LCO limits during MODE 3 and MODE 4 with all RCS cold leg temperatures > the COPS arming temperature specified in the PTLR for the purpose of setting the pressurizer safety valves under ambient (hot) conditions. This exception is allowed for 54 hours6.25e-4 days 0.015 hours 8.928571e-5 weeks 2.0547e-5 months following entry into MODE 3 provided a preliminary cold setting was made prior to heatup.

-v--

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A.

One pressurizer safety A.1 Restore valve to 15 minutes valve inoperable.

OPERABLE status.

B.

Required Action and B.1 Be in MODE 3.

6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months associated Completion Time not met.

AND OR B.2 Be in MODE 4 with any 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months RCS cold leg temperature Two or more pressurizer

the COPS arming safety valves inoperable.

temperature specified in the PTLR.

Vogtle Units 1 and 2 3.4.1 0-1 Amendment No.136 (Unit 1)

Amendment No.1 15 (Unit 2)

COPS 3.4.12 3.4 REACTOR COOLANT SYSTEM (RCS) 3.4.12 Cold Overpressure Protection Systems (COPS)

LCO 3.4.12 A COPS shall be OPERABLE with all safety injection pumps incapable of injecting into the RCS and the accumulators isolated and either a or b below.

a.

Two RCS relief valves, as follows:

1.

Two power operated relief valves (PORVs) with lift settings within the limits specified in the PTLR, or

2.

Two residual heat removal (RHR) suction relief valves with setpoints 2 440 psig and < 460 psig, or

3.

One PORV with a lift setting within the limits specified in the PTLR and one RHR suction relief valve with a setpoint within specified limits.

b.

The RCS depressurized and an RCS vent of 2 1.5 square inches (based on an equivalent length of 10 feet of pipe).

I APPLICABILITY:

MODE 4 with any RCS cold leg temperature s the COPS arming temperature specified in the PTLR, MODE 5, MODE 6 when the reactor vessel head is on.

I klATU LI t

Accumulator isolation is only required when accumulator pressure is greater than or equal to the maximum RCS pressure for the existing RCS cold leg temperature allowed by the P/T limit curves provided in the PTLR.

I I

Vogtle Units 1 and 2 3.4.12-1 Amendment No.136 (Uniti )

Amendment No.1 15 (Unit 2)

I COPS 3.4.12 ACTIONS

.1 Ir%1r I.

I--

While this LCO is not met, entry into MODE 6 with the reactor vessel head on from MODE 6, and entry into MODE 5 from MODE 6 with the reactor vessel head on is not permitted.

I II CONDITION REQUIRED ACTION COMPLETION TIME A.

One or more safety A.1 Render all safety injection 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months injection pumps capable pumps incapable of injecting of injecting into the RCS.

into the RCS.

B.

An accumulator not B.1 Isolate affected accumulator.

1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months isolated when the accumulator pressure is greater than or equal to the maximum RCS pressure for existing cold leg temperature allowed in the PTLR.

C.

Required Action and C.1 Increase RCS cold leg 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months associated Completion temperature to > the COPS Time of Condition B not arming temperature specified met.

in the PTLR.

OR C.2 Depressurize affected 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months accumulator to less than the maximum RCS pressure for existing cold leg temperature allowed in the PTLR.

D.

One required RCS relief D.1 Restore required RCS relief 7 days valve inoperable in valve to OPERABLE status.

MODE 4 with any RCS cold leg temperature <

the COPS arming temperature specified in the PTLR.

(continued)

Vogtle Units 1 and 2 3.4.12-2 Amendment No. 136 (Unit 1)

Amendment No. 1 15 (Unit 2)

COPS 3.4.12 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.4.12.1 Verify both safety injection pumps are incapable 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months of injecting into the RCS.

SR 3.4.12.2 Verify each accumulator is isolated.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months SR 3.4.12.3 Verify RHR suction valves are open for each 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months required RHR suction relief valve.

SR 3.4.12.4 NOTE-Only required to be performed when complying with LCO 3.4.12.b.

Verify RCS vent size within specified limits.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months for unlocked open vent valve(s)

AND 31 days for locked open vent valve(s)

(continued)

Vogtle Units 1 and 2 3.4.12-4 Amendment No.1 36(Unit 1)

Amendment No.11 5(Unit 2)

I COPS 3.4.12 SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY SR 3.4.12.5 Verify PORV block valve is open for each 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months required PORV.

SR 3.4.12.6

NOTE---------------------------

Not required to be performed until 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months after decreasing RCS cold leg temperature to < the COPS arming temperature specified in the PTLR.

Perform a COT on each required PORV, 31 days excluding actuation.

SR 3.4.12.7 Perform CHANNEL CALIBRATION for each 18 months required PORV actuation channel.

I Vogtle Units 1 and 2 3.4.12-5 Amendment No.136(Unit 1)

Amendment No.11 5(Unit 2)

ECCS - Operating 3.5.2 3.5 EMERGENCY CORE COOLING SYSTEMS (ECCS) 3.5.2 ECCS - Operating LCO 3.5.2 APPLICABILITY:

Two ECCS trains shall be OPERABLE.

MODES 1, 2, and 3.

NOTE----------------------

In MODE 3, either residual heat removal pump to cold legs injection flow path may be isolated by closing the isolation valve to perform pressure isolation valve testing per SR 3.4.14.1.

I I

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A.

One or more trains A.1 Restore train(s) to 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months inoperable.

OPERABLE status.

AND At least 100% of the ECCS flow equivalent to a single OPERABLE ECCS train available.

B.

Required Action and B.1 Be in MODE 3.

6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months associated Completion Time not met.

AND B.2 Be in MODE 4.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months Vogtle Units 1 and 2 3.5.2-1 Amendment No.1 36(Unit 1)

Amendment No. 11 5(Unit 2)

Reporting Requirements 5.6 5.6 Reporting Requirements (continued) 5.6.5 Core Operating Limits Report (COLR) (continued)

d.

The COLR, including any midcycle revisions or supplements, shall be provided upon issuance for each reload cycle to the NRC.

5.6.6 Reactor Coolant System (RCS) PRESSURE AND TEMPERATURE LIMITS REPORT (PTLR)

a.

RCS pressure and temperature limits for heatup, cooldown, operation, criticality, and hydrostatic testing as well as heatup and cooldown rates shall be established and documented in the PTLR for the following:

LCO 3.4.3 "RCS Pressure and Temperature (P/T) Limits"

b.

The power operated relief valve lift settings required to support the Cold Overpressure Protection Systems (COPS) and the COPS arming temperature shall be established and documented in the PTLR for the following:

LCO 3.4.12 "Cold Overpressure Protection Systems"

c.

The analytical methods used to determine the RCS pressure and temperature limits shall be those previously reviewed and approved by the NRC, specifically those described in the following documents:

1.

WCAP-14040-A, Rev. 4, "Methodology Used to Develop Cold Overpressure Mitigating System Setpoints and RCS Heatup and Cooldown Limit Curves."

2.

WCAP-1 6142-P, Rev. 1, 'Reactor Vessel Closure Head/essel Flange Requirements Evaluation for Vogtle Units 1 and 2."

3.

The PTLR will contain the complete identification for each of the TS reference Topical Reports used to prepare the PTLR (i.e.,

report number, title, revision, date, and any supplements).

(continued)

Vogtle Units 1 and 2 5.6-4 Amendment No.1 36(Unit 1)

Amendment No.1 1 5(Unit 2)

I Reporting Requirements 5.6 5.6 Reporting Requirements

' 5.6.6 5.6.7 5.6.8 Reactor Coolant SVstem (RCS) PRESSURE AND TEMPERATURE LIMITS REPORT (PTLR) (continued)

d.

The PTLR shall be provided to the NRC upon issuance for each reactor vessel fluence period and for any revision or supplement thereto.

EDG Failure Report If an individual emergency diesel generator (EDG) experiences four or more valid failures in the last 25 demands, these failures and any nonvalid failures experienced by that EDG in that time period shall be reported within 30 days.

Reports on EDG failures shall include the information recommended in Regulatory Guide 1.9, Revision 3, Regulatory Position C.4, or existing Regulatory Guide 1.108 reporting requirement.

PAM Report When a Report is required by Condition G or K of LCO 3.3.3, 'Post Accident Monitoring (PAM) Instrumentation," a report shall be submitted within the following 14 days. The report shall outline the preplanned alternate method of monitoring, the cause of the inoperability, and the plans and schedule for restoring the instrumentation channels of the Function to OPERABLE status.

(continued)

Vogtle Units 1 and 2 5.6-5 Amendment No.1 36(Unit 1)

Amendment No.1 1 5(Unit 2)

RCS P/T Limits B 3.4.3 B 3.4 REACTOR COOLANT SYSTEM (RCS)

B 3.4.3 RCS Pressure arid Temperature (P/T) Limits BASES BACKGROUND All components of the RCS are designed to withstand effects of cyclic loads due to system pressure and temperature changes. These loads are introduced by startup (heatup) and shutdown (cooldown) operations, power transients, and reactor trips. This LCO limits the pressure and temperature changes during RCS heatup and cooldown, within the design assumptions and the stress limits for cyclic operation.

The PTLR contains P/T limit curves for heatup, cooldown, inservice leak and hydrostatic (ISLH) testing, and data for the maximum rate of change of reactor coolant temperature.

Each P/T limit curve defines an acceptable region for normal operation. The usual use of the curves is operational guidance during heatup or cooldown maneuvering, when pressure and temperature indications are monitored and compared to the applicable curve to determine that operation is within the allowable region.

The LCO establishes operating limits that provide a margin to brittle failure of the reactor vessel and piping of the reactor coolant pressure boundary (RCPB). The vessel is the component most subject to brittle failure, and the LCO limits apply mainly to the vessel. The limits do not apply to the pressurizer, which has different design characteristics and operating functions.

10 CFR 50, Appendix G (Ref. 1), requires the establishment of P/T limits for specific material fracture toughness requirements of the RCPB materials. Reference 1 requires an adequate margin to brittle failure during normal operation, anticipated operational occurrences, and system hydrostatic tests. It mandates the use of the American Society of Mechanical Engineers (ASME) Code, Section Xl, Appendix G (Ref. 2).

The neutron embrittlement effect on the material toughness is reflected by increasing the nil ductility reference temperature (RTNDT) as exposure to neutron fluence increases.

(continued)

Vogtle Units 1 and 2 B 3.4.3-1 Revision No.

1

I RCS P/T Limits B 3.4.3 BASES ACTIONS C.1 and C.2 (continued)"

Condition C is modified by a Note requiring Required Action C.2 to be completed whenever the Condition is entered. The Note emphasizes the need to perform the evaluation of the effects of the excursion outside the allowable limits. Restoration alone per Required Action C.1 is insufficient because higher than analyzed stresses may have occurred and may have affected the RCPB integrity.

SURVEILLANCE SR 3.4.3.1 REQUIREMENTS Verification that operation is within the PTLR limits is required every 30 minutes when RCS pressure and temperature conditions are undergoing planned changes. This Frequency is considered reasonable in view of the control room indication available to monitor RCS status. Also, since temperature rate of change limits are specified in hourly increments, 30 minutes permits assessment and correction for minor deviations within a reasonable time.

Surveillance for heatup, cooldown, or ISLH testing may be discontinued when the definition given in the relevant plant procedure for ending the activity is satisfied.

This SR is modified by a Note that only requires this SR to be performed during system heatup, cooldown, and ISLH testing. No SR is given for criticality operations because LCO 3.4.2 contains a more restrictive requirement.

REFERENCES

1.

10 CFR 50, Appendix G.

2.

ASME, Boiler and Pressure Vessel Code, Section Xl, Appendix G.

3.

ASTM E 185-82, July 1982.

4.

10 CFR 50, Appendix H.

5.

Regulatory Guide 1.99, Revision 2, May 1988.

(continued)

I Vogtle Units 1 and 2 B 3.4.3-7 Revi si on No. 1

I RCS PiT Limits B 3.4.3 BASES REFERENCES

6.

ASME, Boiler and Pressure Vessel Code,Section XI, (continued)

Appendix E.

7.

WCAP-14040-A, Revision 4.

I Vogtle Units 1 and 2 B 3.4.3-8 Revi sion No. l

I RCS Loops-MODE 4 B 3.4.6 BASES LCO loops and RHR loops. Any one loop in operation provides enough (continued) flow to remove the decay heat from the core with forced circulation.

An additional loop is required to be OPERABLE to provide redundancy for heat removal.

Note 1 permits all RCPs or RHR pumps to be de-energized for

< 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months per 8 hour9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months period. The purpose of the Note is to permit tests that are designed to validate various accident analyses values.

These tests are initially performed during startup testing. However, if changes are made to the RCS that would cause a change to the flow characteristics of the RCS, the input values must be revalidated by conducting the test again. The 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months time period is adequate to perform the necessary testing, and operating experience has shown that boron stratification is not a problem during this short period with no forced flow.

Utilization of Note 1 is permitted provided the following conditions are met along with any other conditions imposed by initial startup test procedures:

a.

No operations are permitted that would dilute the RCS boron concentration, therefore maintaining the margin to criticality.

Boron reduction is prohibited because a uniform concentration distribution throughout the RCS cannot be ensured when in natural circulation; and

b.

Core outlet temperature is maintained at least 1 00F below saturation temperature, so that no vapor bubble may form and possibly cause a natural circulation flow obstruction.

Note 2 requires that the secondary side water temperature of each SG be < 50IF above each of the RCS cold leg temperatures before the start of an RCP any time during MODE 4 operation with any RCS cold leg temperature s the Cold Overpressure Protection System (COPS) arming temperature specified in the PTLR. This restraint is to prevent a low temperature overpressure event due to a thermal transient when an RCP is started. The Note further restricts starting an RCP to a range of temperature differentials between the SGs and the RCS that is consistent with analysis assumptions used to demonstrate that the RHR design pressure is not exceeded when the RHR suction isolation valves are open.

(continued)

Vogtle Units 1 and 2 B 3.4.6-2 Revision No. 1

Pressurizer Safety Valves B 3.4.1 0 B 3.4 REACTOR COOLANT SYSTEM (RCS)

B 3.4.10 Pressurizer Safety Valves BASES BACKGROUND The pressurizer safety valves provide, in conjunction with the Reactor Protection System, overpressure protection for the RCS. The pressurizer safety valves are of the pop type. The valves are spring loaded and self actuated by direct fluid pressure with backpressure compensation. The safety valves are designed to prevent the system pressure from exceeding the system Safety Limit (SL), 2735 psig, which is 110% of the design pressure.

Because the safety valves are self actuating, they are considered independent components. The relief capacity for each valve, 420,000 lb/hr at a pressurizer pressure of 2560 psig, is based on postulated overpressure transient conditions resulting from a complete loss of steam flow to the turbine with the reactor operating at 102 percent of engineered safeguards design power. The relief rate is stated at a pressure of 2560 psig which is equivalent to the former set pressure of 2485 psig plus 3% for set pressure tolerance and valve accumulation. This event results in the maximum surge rate into the pressurizer, which specifies the minimum relief capacity for the safety valves. The decrease in set pressure to 2460 psig and increase in tolerance does not significantly affect the relief capacity of the safety valves.

The discharge flow from the pressurizer safety valves is directed to the pressurizer relief tank. This discharge flow is indicated by an increase in temperature downstream of the pressurizer safety valves or increase in the pressurizer relief tank temperature or level.

Overpressure protection is required in MODES 1, 2, 3, 4, 5, and MODE 6 with the reactor vessel head on; however, in MODE 4 with any RCS cold leg temperature < the COPS arming temperature specified in the PTLR, MODE 5, and MODE 6 with the reactor vessel head on, overpressure protection is provided by operating procedures and by meeting the requirements of LCO 3.4.12, 'Cold Temperature Overpressure Protection System (COPS).'

The upper and lower pressure limits are based on the +/- 2%

tolerance requirement assumed in the safety analyses. The lift setting is for the ambient conditions associated with (continued)

Vogtle Units 1 and 2 B 3.4.1 0-1 Revi skion No. 2

I Pressurizer Safety Valves B 3.4.1 0 BASES BACKGROUND (continued)

MODES 1, 2, 3, and MODE 4 with all RCS cold leg temperatures >

the COPS arming temperature specified in the PTLR. This requires either that the valves be set hot or that a correlation between hot and cold settings be established.

I The pressurizer safety valves are part of the primary success path and mitigate the effects of postulated accidents. OPERABILITY of the safety valves ensures that the RCS pressure will be limited to 110% of design pressure.

The consequences of exceeding the American Society of Mechanical Engineers (ASME) pressure limit (Ref. 1) could include damage to RCS components, increased leakage, or a requirement to perform additional stress analyses prior to resumption of reactor operation.

APPLICABLE SAFETY ANALYSES All accident and safety analyses in the FSAR (Ref. 2) that require safety valve actuation assume operation of three pressurizer safety valves to limit increases in RCS pressure. The overpressure protection analysis (Ref. 3) is also based on operation of three safety valves. Accidents that could result in overpressurization if not properly terminated include:

a.

Uncontrolled rod withdrawal from full power;

b.

Loss of reactor coolant flow;

c.

Loss of external electrical load;

d.

Loss of normal feedwater;

e.

Loss of all AC power to station auxiliaries;

f.

Locked rotor; and

g.

Feedwater line break.

Detailed analyses of the above transients are contained in Reference 2. Safety valve actuation is required in events c, e, and f (above) to limit the pressure increase. Compliance with this LCO is consistent with the design bases and accident analyses assumptions.

(continued)

Vogtle Units 1 and 2 B 3.4.10-2 Revision No. 2

Pressurizer Safety Valves B 3.4.1 0 BASES (continued)

LCO Pressurizer safety valves satisfy Criterion 3 of 10 CFR 50.36 (c)(2)(ii).

The three pressurizer safety valves are set to open at an RCS pressure of 2460 psig, and within the specified tolerance, to avoid exceeding the maximum design pressure SL, and to maintain accident analyses assumptions. The upper and lower pressure tolerance limits are based on the +/- 2% tolerance requirements assumed in the safety analyses.

The limit protected by this Specification is the reactor coolant pressure boundary (RCPB) SL of 110% of design pressure.

APPLICABILITY In MODES 1, 2, 3, and MODE 4 with all RCS cold leg temperatures >

the COPS arming temperature specified in the PTLR, OPERABILITY of three valves is required because the combined capacity is required to keep reactor coolant pressure below 110% of its design value during certain accidents. MODE 3 is conservatively included, although the listed accidents may not require the safety valves for protection.

The LCO is not applicable in MODE 4 with any RCS cold leg temperature s the COPS arming temperature specified in the PTLR, MODE 5, or MODE 6 (with the reactor vessel head on) because the cold overpressure protection system is in service. Overpressure protection is not required in MODE 6 with reactor vessel head removed.

The Note allows entry into MODE 3 and MODE 4 with all RCS cold leg temperatures > the COPS arming temperature specified in the PTLR with the lift settings outside the LCO limits. This permits testing and examination of the safety valves at high pressure and temperature near their normal operating range, but only after the valves have had a preliminary cold setting. The cold setting gives assurance that the valves are OPERABLE near their design condition.

Only one valve at a time will be removed from service for testing. The 54 hour6.25e-4 days 0.015 hours 8.928571e-5 weeks 2.0547e-5 months exception is based on 18 hour2.083333e-4 days 0.005 hours 2.97619e-5 weeks 6.849e-6 months outage time for each of the three valves. The 18 hour2.083333e-4 days 0.005 hours 2.97619e-5 weeks 6.849e-6 months period is derived from operating experience that hot testing can be performed in this timeframe.

(continued)

Vogtle Units 1 and 2 B 3.4.10-3 Revi skion No. 3

Pressurizer Safety Valves B 3.4.1 0 BASES (continued)

ACTIONS A.1 With one pressurizer safety valve inoperable, restoration must take place within 15 minutes. The Completion Time of 15 minutes reflects the importance of maintaining the RCS overpressure protection system. An inoperable safety valve coincident with an RCS overpressure event could challenge the integrity of the pressure boundary.

B.1 and B.2 If the Required Action of A.1 cannot be met within the required Completion Time or if two or more pressurizer safety valves are inoperable, the plant must be brought to a MODE in which the requirement does not apply. To achieve this status, the plant must be brought to at least MODE 3 within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and to MODE 4 with any RCS cold leg temperature s the COPS arming temperature specified in the PTLR within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months . The allowed Completion Times are reasonable, based on operating experience, to reach the required plant conditions from full power conditions in an orderly manner and without challenging plant systems. In MODE 4, with any RCS cold leg temperature s the COPS arming temperature specified in the PTLR, overpressure protection is provided by the cold overpressure protection system. The change from MODE 1, 2, or 3 to MODE 4 with any RCS cold leg temperature s the COPS arming temperature specified in the PTLR, reduces the RCS energy (core power and pressure), lowers the potential for large pressurizer insurges, and thereby removes the need for overpressure protection by three pressurizer safety valves.

SURVEILLANCE SR 3.4.10.1 REQUIREMENTS SRs are specified in the Inservice Testing Program. Pressurizer safety valves are to be tested in accordance with the requirements of Section Xl of the ASME Code (Ref. 4), which provides the activities and Frequencies necessary to satisfy the SRs. No additional requirements are specified. The lift settings shall be 2 2410 psig and

< 2510 psig. The lift setting pressures shall correspond to ambient conditions of the valves at normal operating temperature and pressure.

(continued)

Vogtle Units 1 and 2 B 3.4.10-4 Revision No. 2

COPS B 3.4.12 B 3.4 REACTOR COOLANT SYSTEM (RCS)

B 3.4.12 Cold Overpressure Protection Systems (COPS)

BASES BACKGROUND The COPS controls RCS pressure at low temperatures so the integrity of the reactor coolant pressure boundary (RCPB) is not compromised by violating the pressure and temperature (P/T) limits of 10 CFR 50, Appendix G (Ref. 1). The reactor vessel is the limiting RCPB component for demonstrating such protection. The PTLR provides the maximum allowable actuation logic setpoints for the power operated relief valves (PORVs) and the maximum RCS pressure for the existing RCS cold leg temperature during cooldown, shutdown, and heatup to meet the Reference 1 requirements during the COPS MODES or other specified condition in the COPS Applicability.

I The reactor vessel material is less tough at low temperatures than at normal operating temperature. As the vessel neutron exposure accumulates, the material toughness decreases and becomes less resistant to pressure stress at low temperatures (Ref. 2). RCS pressure, therefore, is maintained low at low temperatures and is increased only as temperature is increased.

The potential for vessel overpressurization is most acute when the RCS is water solid, occurring only while shutdown; a pressure fluctuation can occur more quickly than an operator can react to relieve the condition. Exceeding the RCS P/T limits by a significant amount could cause brittle cracking of the reactor vessel. LCO 3.4.3, MRCS Pressure and Temperature (PIT) Limits,' requires administrative control of RCS pressure and temperature during heatup and cooldown to prevent exceeding the PTLR limits.

This LCO provides RCS overpressure protection by having a minimum coolant input capability and having adequate pressure relief capacity. Limiting coolant input capability requires both safety injection pumps to be incapable of injection into the RCS and the accumulators to be isolated. The pressure relief capacity requires either two redundant RCS relief valves or a depressurized RCS and an RCS vent of sufficient size, One RCS relief valve or the open RCS vent is the overpressure protection device that acts to terminate an increasing pressure event.

(continued)

Vogtle Units 1 and 2 B 3.4.12-1 Revi si on No.

l

COPS B 3.4.12 BASES BACKGROUND PORV Requirements (continued)

When a PORV is opened in an increasing pressure transient, the release of coolant will cause the pressure increase to slow and reverse. As the PORV releases coolant, the RCS pressure decreases until a reset pressure is reached and the valve is signaled to close.

The pressure continues to decrease below the reset pressure as the valve closes.

RHR Suction Relief Valve Requirements During the COPS MODES or other specified condition in the COPS Applicability, the RHR System is operated for decay heat removal and low pressure letdown control. Therefore, the RHR suction isolation valves are open in the piping from the RCS hot legs to the inlets of the RHR pumps. While these valves are open and the RHR suction valves are open, the RHR suction relief valves are exposed to the RCS and are able to relieve pressure transients in the RCS.

The RHR suction isolation valves and the RHR suction valves must be open to make the RHR suction relief valves OPERABLE for RCS overpressure mitigation. The RHR suction relief valves are self-actuated water relief valves with pressure tolerances and accumulation limits established by Section III of the American Society of Mechanical Engineers (ASME) Code (Ref. 3) for Class 2 relief valves.

RCS Vent Requirements Once the RCS is depressurized, a vent exposed to the containment atmosphere will maintain the RCS at containment ambient pressure in an RCS overpressure transient, if the relieving requirements of the transient do not exceed the capabilities of the vent. Thus, the vent path must be capable of relieving the flow resulting from the limiting COPS mass or heat input transient, and maintaining pressure below the P/T limits. The required vent capacity may be provided by one or more vent paths.

(continued)

Vogtle Units 1 and 2 B 3.4.12-3 Revi skion No. l

COPS B 3.4.12 BASES (continued)

APPLICABLE SAFETY ANALYSES Safety analyses (Ref. 4) demonstrate that the reactor vessel is adequately protected against exceeding the Reference 1 P/T limits.

In MODES 1, 2, 3, and MODE 4 with all RCS cold leg temperatures >

the COPS arming temperature specified in the PTLR, the pressurizer safety valves will prevent RCS pressure from exceeding the Reference 1 limits. In MODE 4 with any RCS cold leg temperature s the COPS arming temperature specified in the PTLR and below, overpressure prevention falls to two OPERABLE RCS relief valves or to a depressurized RCS and a sufficient sized RCS vent. Each of these means has a limited overpressure relief capability.

I The actual temperature at which the pressure in the P/T limit curve falls below the pressurizer safety valve setpoint increases as the reactor vessel material toughness decreases due to neutron embrittlement. Each time the PTLR curves are revised, the COPS must be re-evaluated to ensure its functional requirements can still be met using the RCS relief valve method or the depressurized and vented RCS condition.

The PTLR contains the acceptance limits that define the COPS requirements. Any change to the RCS must be evaluated against the Reference 4 analyses to determine the impact of the change on the COPS acceptance limits.

Transients that are capable of overpressurizing the RCS are categorized as either mass or heat input transients, as discussed below.

Mass Input Tvpe Transients

a.

Inadvertent safety injection; or

b.

Charging/letdown flow mismatch.

Heat Input Type Transients

a.

Reactor coolant pump (RCP) startup with temperature asymmetry between the RCS and steam generators.

(continued)

I I

Vogtle Units 1 and 2 B 3.4.12-4 Revision No. 1

I COPS B 3.4.12 BASES APPLICABLE SAFETY ANALYSES (continued)

The following are required during the COPS MODES or other specified condition in the COPS Applicability to ensure that mass and heat input transients do not occur, which either of the COPS overpressure protection means cannot handle:

a.

Rendering both safety injection pumps incapable of injection;

b.

Deactivating the accumulator discharge isolation valves in their closed positions; and

c.

Disallowing the start of an RCP if the secondary temperature is more than 500F above the RCS cold leg temperature in any one loop. With the RHR suction isolation valves open, this value is reduced to 250F at an RCS temperature of 3500F and varies linearly to 500F at an RCS temperature of 200OF for RHR design pressure considerations. LCO 3.4.6, 'RCS Loops-MODE 4,'

and LCO 3.4.7, NRCS Loops-MODE 5, Loops Filled,' contain notes on this limitation that provide this protection.

The Reference 4 analyses demonstrate that either one RCS relief valve or the depressurized RCS and RCS vent can maintain RCS pressure below limits when both centrifugal charging pumps are actuated. Thus, the LCO requires both safety injection pumps to be incapable of injecting into the RCS during the COPS MODES or other specified condition in the COPS Applicability.

Since neither one RCS relief valve nor the RCS vent can handle the pressure transient caused by accumulator injection when RCS temperature is low, the LCO also requires accumulator isolation when accumulator pressure is greater than or equal to the maximum RCS pressure for the existing RCS cold leg temperature allowed in the PTLR. The isolated accumulators must have their discharge valves closed and the valve power supply breakers fixed in their open positions.

PORV Performance The fracture mechanics analyses show that the vessel is protected when the PORVs are set to open at or below the limits shown in the PTLR. The setpoints are derived by analyses that model the performance of the COPS, assuming (continued)

Vogtle Units 1 and 2 B 3.4.12-5 Revision No. 1

COPS B 3.4.12 BASES APPLICABLE PORV Performance (continued)

SAFETY ANALYSES the mass injection transient of two centrifugal charging pumps and the positive displacement pump injecting into the RCS, and the heat injection transient of starting an RCP with the RCS 500F colder than the secondary coolant. These analyses consider pressure overshoot and undershoot beyond the PORV opening and closing, resulting from signal processing and valve stroke times. The PORV setpoints at or below the derived limit ensure the Reference 1 P/T limits will be met.

NOTE----------------------------------------

Although the positive displacement pump (PDP) was replaced with the normal charging pump (NCP), the current mass injection transient analysis assumes two centrifugal charging pumps and the positive displacement pump. Westinghouse performed an evaluation of the effect of replacing the PDP with the NCP and obtained acceptable results without reanalysis of the mass injection transient. Reference Westinghouse letter, GP-1 6838 from J. L. Tain to J. B. Beasley, Jr.,

dated August 13, 1998, COPS PORV Setpoint for New Charging Pump.

The PORV setpoints in the PTLR will be updated when the revised P/T limits conflict with the COPS analysis limits. The P/T limits are periodically modified as the reactor vessel material toughness decreases due to neutron embrittlement caused by neutron irradiation. Revised limits are determined using neutron fluence projections and the results of examinations of the reactor vessel material irradiation surveillance specimens. The Bases for LCO 3.4.3,

'RCS Pressure and Temperature (P/T) Limits,' discuss these examinations.

The PORVs are considered active components. Thus, the failure of one PORV is assumed to represent the worst case, single active failure.

RHR Suction Relief Valve Performance The RHR suction relief valves do not have variable pressure and temperature lift setpoints like the PORVs. Analyses show that one RHR suction relief valve with a setpoint at or between 440 psig and 460 psig (Ref. 9) will pass flow greater than that required for the limiting COPS transient while maintaining RCS pressure less than the P/T limit curve.

(continued)

Vogtle Units 1-and 2 B 3.4.12-6 Revis i on No. 2

COPS B 3.4.12 BASES APPLICABLE RHR Suction Relief Valve Performance (continued)

SAFETY ANALYSES As the RCS P/T limits are decreased to reflect the loss of toughness in the reactor vessel materials due to neutron embrittlement, the RHR suction relief valves must be analyzed to still accommodate the design basis transients for COPS.

The RHR suction relief valves are considered active components.

Thus, the failure of one valve is assumed to represent the worst case single active failure.

RCS Vent Performance With the RCS depressurized, analyses show a vent size of 1.5 square inches (based on an equivalent length of 10 feet of pipe, i.e., a vent capable of relieving 685 gpm waterf low at 722 psig) is capable of mitigating the allowed COPS overpressure transient. The capacity of a vent this size is greater than the flow of the limiting transient for the COPS configuration, with both safety injection pumps incapable of injecting into the RCS, maintaining RCS pressure less than the maximum pressure on the P/T limit curve.

The RCS vent size will be re-evaluated for compliance each time the P/T limit curves are revised based on the results of the vessel material surveillance.

The RCS vent is passive and is not subject to active failure.

The COPS satisfies Criterion 2 of 10 CFR 50.36 (c)(2)(ii).

LCO This LCO requires that the COPS is OPERABLE. The COPS is OPERABLE when the minimum coolant input and pressure relief capabilities are OPERABLE. Violation of this LCO could lead to the loss of low temperature overpressure mitigation and violation of the Reference 1 limits as a result of an operational transient:

To limit the coolant input capability, the LCO requires both safety injection pumps to be incapable of injecting into the RCS and all accumulator discharge isolation valves closed and immobilized when accumulator pressure is greater than or equal to the maximum RCS pressure for the existing RCS cold leg temperature allowed in the PTLR.

(continued)

Vogtle Units 1 and 2 B 3.4.12-7 Revi sion No. 3

I COPS B 3.4.12 BASES LCO (continued)

The elements of the LCO that 1'rovide low temperature overpressure mitigation through pressure relief are:

a.

Two RCS relief valves, as follows:

1.

Two OPERABLE PORVs; or A PORV is OPERABLE for the COPS when its block valve is open, its lift setpoint is set to the limit required by the PTLR and testing proves its ability to open at this setpoint, and motive power is available to the two valves and their control circuits. The PORVs (PV-455A and PV-456A) are powered from 125 V MCCs 1/2AD1M and 1/2BD1M, respectively. The PORVs are to be considered OPERABLE whenever these MCCs are available to supply power.

2.

Two OPERABLE RHR suction relief valves; or An RHR suction relief valve is OPERABLE for the COPS when its RHR suction isolation valve and its RHR suction valve are open, its setpoint is at or between 440 psig and 460 psig, and testing has proven its ability to open at this setpoint.

3.

One OPERABLE PORV and one OPERABLE RHR suction relief valve; or

b.

A depressurized RCS and an RCS vent.

An RCS vent is OPERABLE when open with an area of 2 1.5 square inches (based on an equivalent length of 10 feet of pipe, i.e., capable of relieving 685 gpm at 722 psig).

Each of these methods of overpressure prevention is capable of mitigating the limiting COPS transient.

I APPLICABILITY This LCO is applicable in MODE 4 with any RCS cold leg temperature s the COPS arming temperature specified in the PTLR, in MODE 5, and in MODE 6 when the reactor vessel head is on. The pressurizer safety valves provide overpressure protection that meets the Reference 1 PIT limits in MODES 1, 2,3, and MODE 4 with all RCS cold leg temperatures > the COPS arming temperature specified in the PTLR. When the reactor vessel head is off, overpressurization cannot occur I

LCO 3.4.3 provides the operational PIT limits for all MODES.

LCO 3.4.10, "Pressurizer Safety Valves," requires the (continued)

VogUe Units 1 and 2 B 3.4.12-8 Revision No.

2

I COPS B 3.4.12 BASES APPLICABILITY (continued)

OPERABILITY of the pressurizer safety valves that pro6vide overpressure protection during MODES 1, 2, 3, and MODE 4 with all RCS cold leg temperatures > the COPS arming temperature specified in the PTLR.

Low temperature overpressure prevention is most critical during shutdown when the RCS is water solid, and a mass or heat input transient can cause a very rapid increase in RCS pressure when little or no time allows operator action to mitigate the event.

The Applicability is modified by a Note stating that accumulator isolation is only required when the accumulator pressure is more than or at the maximum RCS pressure for the existing temperature, as allowed by the P/T limit curves. This Note permits the accumulator discharge isolation valve Surveillance to be performed only under these pressure and temperature conditions.

ACTIONS A Note modifies the ACTIONS table. The Note prohibits entry into MODE 6 with the vessel head on from MODE 6 and MODE 5 from MODE 6 with the vessel head on. Entry into MODE 4 from MODE 5 is already prohibited by LCO 3.0.4.

(continued)

I I

Vogile Units 1 and 2 B 3.4.12-9 Revisison No. 2

COPS B 3.4.12 BASES ACTIONS A.1 (continued)

With one or more safety injection pumps capable of injecting into the RCS, RCS overpressurization is possible.

Rendering the safety injection pumps incapable of injecting into the RCS within 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months to restore restricted coolant input capability to the RCS reflects the urgency of removing the RCS from this condition.

B.1, C.1, and C.2 An unisolated accumulator requires isolation within 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months . This is only required when the accumulator pressure is at or more than the maximum RCS pressure for the existing temperature allowed by the P/T limit curves.

If isolation is needed and cannot be accomplished in 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months , Required Action C.1 and Required Action C.2 provide two options, either of which must be performed in the next 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months . By increasing the RCS temperature to > the COPS arming temperature specified in the PTLR, an accumulator pressure of 678 psig cannot exceed the COPS limits if the accumulators are fully injected. Depressurizing the accumulators below the COPS limit from the PTLR also gives this protection.

The Completion Times are based on operating experience that these activities can be accomplished in these time periods and that the likelihood that an event requiring COPS during this time is small.

D.1 In MODE 4 with any RCS cold leg temperature s the COPS arming temperature specified in the PTLR, with one required RCS relief valve inoperable, the RCS relief valve must be restored to OPERABLE status within a Completion Time of 7 days. Two RCS relief valves in any combination of the PORVS and the RHR suction relief valves are required to provide low temperature overpressure mitigation while withstanding a single failure of an active component.

The Completion Time considers the facts that only one of the RCS relief valves is required to mitigate an overpressure transient and that the likelihood of an active failure of the remaining valve path during this time period is very low.

(continued)

Vogtle Units 1 and 2 B 3.4.12-1 0 Revi si on No. 2

COPS B 3.4.12 BASES ACTIONS E.1 (continued)

The consequences of operational events that will overpressurize the RCS are more severe at lower temperature (Ref. 7). Thus, with one of the two RCS relief valves inoperable in MODE 5 or in MODE 6 with the head on, the Completion Time to restore two valves to OPERABLE status is 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .

The Completion Time represents a reasonable time to investigate and repair several types of relief valve failures without exposure to a lengthy period with only one OPERABLE RCS relief valve to protect against overpressure events.

F.1 The RCS must be depressurized and a vent must be established within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months when:

a.

Both required RCS relief valves are inoperable; or

b.

A Required Action and associated Completion Time of Condition A, C, D, or E is not met; or

c.

The COPS is inoperable for any reason other than Condition A, B,C, D,orE.

The vent must be sized > 1.5 square inches (based on an equivalent length of 10 feet of pipe) to ensure that the flow capacity is greater than that required for the worst case mass input transient reasonable during the applicable COPS MODES or other specified condition in the COPS Applicability. This action is needed to protect the RCPBi from a low temperature overpressure event and a possible brittle failure of the reactor vessel.

The Completion Time considers the time required to place the unit in this Condition and the relatively low probability of an overpressure event during this time period due to increased operator awareness of administrative control requirements.

(continued)

Vogile Units 1 and 2 B 3.4.12-1 1 Revision No. 2

rI COPS B 3.4.12 BASES SURVEILLANCE SR 3.4.12.1 and SR 3.4.12.2 REQUIREMENTS To minimize the potential for a low temperature overpressure event by limiting the mass input capability, both safety injection pumps are verified incapable of injecting into the RCS, and the accumulator discharge isolation valves are verified closed and locked out.

The safety injection pumps are rendered incapable of injecting into the RCS through at least two independent means such that a single failure or single action will not result in an injection into the RCS.

The Frequency of 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months (for the safety injection pumps and accumulators) is sufficient, considering other indications and alarms available to the operator in the control room, to verify the required status of the equipment.

SR 3.4.12.3 Each required RHR suction relief valve shall be demonstrated OPERABLE by verifying its RHR suction isolation valves are open and by testing it in accordance with the Inservice Testing Program.

This Surveillance is only required to be performed if the RHR suction relief valve is being used to meet this LCO. For Train A, the RHR suction relief valve is PSV-8708A and the suction isolation valves are HV-8701A and B. For Train B, the RHR suction relief valve is PSV-8708B and the suction isolation valves are HV-8702A and B.

The RHR suction valves are verified to be opened every 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months .

The Frequency is considered adequate in view of other administrative controls such as valve status indications available to the operator in the control room that verify the RHR suction isolation valves remain open.

The ASME Code, Section Xl (Ref. 8), test per Inservice Testing Program verifies OPERABILITY by proving proper relief valve mechanical motion and by measuring and, if required, adjusting the lift setpoint.

SR 3.4.12.4 The RCS vent of 2 1.5 square inches (based on an equivalent length of 10 feet of pipe) is proven OPERABLE by verifying its open condition either:

(continued)

Vogtle Units 1 and 2 B 3.4.12-12 Revision No. 3

COPS B 3.4.12 BASES SURVEILLANCE SR 3.4.12.4 (continued)

REQUIREMENTS

a. Once every 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months for a valve that cannot be locked.

b. Once every 31 days for a valve that is locked, sealed, or secured in position. A removed pressurizer safety valve fits this category.

The passive vent arrangement must only be open to be OPERABLE.

This Surveillance is required to be performed if the vent is being used to satisfy the pressure relief requirements of the LCO 3.4.12 b.

SR 3.4.12.5 The PORV block valve must be verified open every 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months to provide the flow path for each required PORV to perform its function when actuated. The valve must be remotely verified open in the main control room. This Surveillance is performed if the PORV satisfies the LCO.

The block valve is a remotely controlled, motor operated valve. The power to the valve operator is not required to be removed, and the manual operator is not required to be locked in the inactive position.

Thus, the block valve can be closed in the event the PORV develops excessive leakage or does not close (sticks open) after relieving an overpressure situation.

The 72 hour8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months Frequency is considered adequate in view of other administrative controls available to the operator in the control room, such as valve position indication, that verify that the PORV block valve remains open.

SR 3.4.12.6 Performance of a COT is required within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months after decreasing RCS temperature to

the COPS arming temperature specified in the PTLR and every 31 days on each required PORV to verify and, as necessary, adjust its lift setpoint. The COT will verify the setpoint is within the allowed maximum limits in the PTLR. PORV actuation could depressurize the RCS and is not required.

A Note has been added indicating that this SR is required to be performed 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months after decreasing RCS cold leg temperature to s the COPS arming temperature specified in the PTLR. The 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months considers the unlikelihood of a low temperature overpressure event during this time.

(continued)

Vogtle Units 1 and 2 B 3.4.12-13 Revision No. 2

ECCS -

Operating B 3.5.2 BASES (continued)

APPLICABILITY In MODES 1, 2, and 3, the ECCS OPERABILITY requirements for the limiting Design Basis Accident, a large break LOCA, are based on full power operation. Although reduced power would not require the same level of performance, the accident analysis does not provide for reduced cooling requirements in the lower MODES. The centrifugal charging pump performance is based on a small break LOCA, which establishes the pump performance curve and has less dependence on power. The SI pump performance requirements are based on a small break LOCA. MODE 2 and MODE 3 requirements are bounded by the MODE 1 analysis.

This LCO is only applicable in MODE 3 and above. Below MODE 3, the SI signal setpoint is manually bypassed by operator control, and system functional requirements are relaxed as described in LCO 3.5.3, 'ECCS-Shutdown.'

As indicated in the Note, either flow path may be isolated in MODE 3, under controlled conditions, to perform pressure isolation valve testing per SR 3.4.14.1. The flow path is readily restorable from the control room.

In MODES 5 and 6, plant conditions are such that the probability of an event requiring ECCS injection is extremely low. Core cooling requirements in MODE 5 are addressed by LCO 3.4.7, 'RCS Loops -

MODE 5, Loops Filled," and LCO 3.4.8, "RCS Loops-MODE 5, Loops Not Filled.' MODE 6 core cooling requirements are addressed by LCO 3.9.5, 'Residual Heat Removal (RHR) and Coolant Circulation -

High Water Level," and LCO 3.9.6, Residual Heat Removal (RHR) and Coolant Circulation -

Low Water Level.N I

I (continued)

Vogtle Units 1 and 2 B 3.5.2-6 Revision No. 1

v t e Letter Sequence Other
TAC:MC2225, (Approved, Closed) TAC:MC2226, (Approved, Closed) TAC:MC2227, (Approved, Closed) TAC:MC2228, (Approved, Closed) TAC:MC3090, (Approved, Closed) TAC:MC3091, (Approved, Closed)
Initiation Acceptance... Administration Withholding Request Acceptance Questions 13 September 2004 Answers Results Approval Other: ML041170002, ML043280621, ML050690216, ML050840305, ML050910029, ML051110619, NL-04-1981, Response to NRC Questions Regarding Request to Revise Technical Specifications and Pressure and Temperature Limits Report
MONTHYEAR2004-09-13 [Table View]

ML050910029

Text

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