ML13357A051

Synopsis of Revisions Included in Watts Bar Unit 2 Developmental Revision H of Technical Specifications and Technical Specification Bases. Part 2 of 2

ML13357A051
Person / Time
Site:	Watts Bar
Issue date:	12/12/2013
From:	Tennessee Valley Authority
To:	Office of Nuclear Reactor Regulation
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ML13357A047	List: ML13357A048 ML13357A050 ML13357A051 ML13357A053 ML13357A054
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Download: ML13357A051 (76)

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RCS Specific Activity B 3.4.16 BASES (continued)

APPLICABLE The LCO limits on the specific activity of the reactor coolant ensures that SAFETY the resulting 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> doses at the site boundary and Main Control Room ANALYSES accident doses will not exceed the appropriate 10 CFR 100 dose guideline limits and 10 CFR 50, Appendix A, GDC 19 dose guideline limits following a SGTR or MSLB accident. The SGTR and MSLB safety analysis (Ref. 2) assumes the specific activity of the reactor coolant at the LCO limit and an existing reactor coolant steam generator (SG) tube leakage rate of 150 gallons per day (GPD). The safety analysis assumes the specific activity of the secondary coolant at its limit of 0.1 1 iCi/gm DOSE EQUIVALENT 1-131 from LCO 3.7.14, "Secondary Specific Activity."

The analysis for the SGTR and MSLB accidents establish the acceptance limits for RCS specific activity. Reference to these analyses is used to assess changes to the unit that could affect RCS specific activity, as they relate to the acceptance limits.

The analyses are for two cases of reactor coolant specific activity. One case assumes specific activity at 0.265 PCi/gm DOSE EQUIVALENT 1-131 with an iodine spike immediately after the accident that increases the iodine activity in the reactor coolant by a factor of 500 times the iodine production rate necessary to maintain a steady state iodine concentration of 0.265 jiCi/gm DOSE EQUIVALENT 1-131. The second case assumes the initial reactor coolant iodine activity at 2-1-14 pICi/gm DOSE I EQUIVALENT 1-131 due to a pre-accident iodine spike caused by an RCS transient. In both cases, the noble gas activity in the reactor coolant equals the LCO limit of 100/E tpCi/gm for gross specific activity.

The analysis also assumes a loss of offsite power at the same time as the SGTR and MSLB event. The SGTR causes a reduction in reactor coolant inventory. The reduction initiates a reactor trip from a low pressurizer pressure signal or an RCS overtemperature AT signal. The MSLB results in a reactor trip due to low steam pressure.

The coincident loss of offsite power causes the steam dump valves to close to protect the condenser. The rise in pressure in the ruptured SG discharges radioactively contaminated steam to the atmosphere through the SG power operated relief valves and the main steam safety valves.

The unaffected SGs remove core decay heat by venting steam to the atmosphere until the cooldown ends.

(continued)

Watts Bar - Unit 2 B 3.4-84 (developmental) BHI

RCS Specific Activity B 3.4.16 BASES APPLICABLE The safety analysis shows the radiological consequences of an SGTR SAFETY and MSLB accident are within the appropriate 10 CFR 100 and ANALYSES 10 CFR 50, Appendix A, GDC 19 dose guideline limits. Operation with (continued) iodine specific activity levels greater than the LCO limit is permissible, if the activity levels do not exceed 241-14 ýtCi/gm DOSE EQUIVALENT 1-131, in the applicable specification, for more than 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />. The safety analysis has concurrent and pre-accident iodine spiking levels up to 24-14 piCi/gm DOSE EQUIVALENT 1-131. I The limits on RCS specific activity are also used for establishing standardization in radiation shielding and plant personnel radiation protection practices.

RCS specific activity satisfies Criterion 2 of the NRC Policy Statement.

LCO The specific iodine activity is limited to 0.265 tiCi/gm DOSE EQUIVALENT 1-131, and the gross specific activity in the reactor coolant is limited to the number of piCi/gm equal to 100 divided by E (average disintegration energy of the sum of the average beta and gamma energies of the coolant nuclides). The limit on DOSE EQUIVALENT 1-131 ensures the 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> thyroid dose to an individual at the site boundary and accident dose to personnel in the Main Control Room during the Design Basis Accident (DBA) will be within the allowed thyroid dose. The limit on gross specific activity ensures the 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> whole body dose to an individual at the site boundary and accident dose to personnel in the Main Control Room during the DBA will be within the allowed whole body dose.

The SGTR and MSLB accident analysis (Ref. 2) shows that the 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> site boundary dose levels and Main Control Room accident dose are within acceptable limits. Violation of the LCO may result in reactor coolant radioactivity levels that could, in the event of a SGTR or MSLB, lead to site boundary doses that exceed the 10 CFR 100 dose guideline limits, or Main Control Room accident dose that exceed the 10 CFR 50, Appendix A, GDC 19 dose limits.

(continued)

Watts Bar - Unit 2 B 3.4-85 (developmental) A

RCS Specific Activity B 3.4.16 BASES (continued)

APPLICABILITY In MODES 1 and 2, and in MODE 3 with RCS average temperature

_>500 0 F, operation within the LCO limits for DOSE EQUIVALENT 1-131 and gross specific activity are necessary to contain the potential consequences of an accident to within the acceptable Main Control Room and site boundary dose values.

For operation in MODE 3 with RCS average temperature < 500 0 F, and in MODES 4 and 5, the release of radioactivity in the event of a SGTR is unlikely since the saturation pressure of the reactor coolant is below the lift pressure settings of the main steam safety valves.

ACTIONS A.1 and A.2 With the DOSE EQUIVALENT 1-131 greater than the LCO limit, samples at intervals of 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> must be taken to demonstrate that the limit of 24-14 gCi/gm is not exceeded. The Completion Time of 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> is I required to obtain and analyze a sample. Sampling is done to continue to provide a trend.

The DOSE EQUIVALENT 1-131 must be restored to within limits within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />. The Completion Time of 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> is required, if the limit violation resulted from normal iodine spiking.

A Note permits the use of the provisions of LCO 3.0.4.c. This allowance permits entry into the applicable MODE(S) while relying on the ACTIONS.

This allowance is acceptable due to the significant conservatism incorporated into the specific activity limit, the low probability of an event which is limiting due to exceeding this limit, and the ability to restore transient specific activity excursions while the plant remains at, or proceeds to power operation.

(continued)

Watts Bar - Unit 2 B 3.4-86 (developmental) AH I

RCS Specific Activity B 3.4.16 BASES ACTIONS B.1 and B.2 (continued)

With the gross specific activity in excess of the allowed limit, an analysis must be performed within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> to determine DOSE EQUIVALENT 1-131. The Completion Time of 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> is required to obtain and analyze a sample.

The change within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> to MODE 3 and RCS average temperature

< 500OF lowers the saturation pressure of the reactor coolant below the setpoints of the main steam safety valves and prevents venting the SG to the environment in an SGTR event. The allowed Completion Time of 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> is reasonable, based on operating experience, to reach MODE 3 below 500OF from full power conditions in an orderly manner and without challenging plant systems.

C.1 If a Required Action and the associated Completion Time of Condition A is not met or if the DOSE EQUIVALENT 1-131 is greater than 24-14 pCi/gm, the reactor must be brought to MODE 3 with RCS average temperature < 500OF within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. The Completion Time of 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> is reasonable, based on operating experience, to reach MODE 3 below 500OF from full power conditions in an orderly manner and without challenging plant systems.

SURVEILLANCE SR 3.4.16.1 REQUIREMENTS SR 3.4.16.1 requires performing a gamma isotopic analysis as a measure of the gross specific activity of the reactor coolant at least once every 7 days. While basically a quantitative measure of radionuclides with half lives longer than 15 minutes, excluding iodines, this measurement is the sum of the degassed gamma activities and the gaseous gamma activities in the sample taken. This Surveillance provides an indication of any increase in gross specific activity.

Trending the results of this Surveillance allows proper remedial action to be taken before reaching the LCO limit under normal operating conditions. The Surveillance is applicable in MODES 1 and 2, and in MODE 3 with Tavg at least 500 0 F. The 7-day Frequency considers the unlikelihood of a gross fuel failure during the time.

(continued)

Watts Bar - Unit 2 B 3.4-87 (developmental) AHI

Containment B 3.6.1 BASES APPLICABLE Satisfactory leakage rate test results are a requirement for the SAFETY establishment of containment OPERABILITY.

ANALYSES (continued) The containment satisfies Criterion 3 of the NRC Policy Statement.

LCO Containment OPERABILITY is maintained by limiting leakage to < 1.0 La, except prior to the first start up after performing a required Containment Leakage Rate Testing Program leakage test. At this time, applicable leakage limits must be met.

Compliance with this LCO will ensure a containment configuration, including equipment hatches, that is structurally sound and that will limit leakage to those leakage rates assumed in the safety analysis.

Individual leakage rates specified for the containment air lock (LCO 3.6.2), purge valves with resilient seals, and Shield Building containment bypass leakage (LCO 3.6.3) are not specifically part of the acceptance criteria of 10 CFR 50, Appendix J, Option B. Therefore, leakage rates exceeding these individual limits only result in the containment being inoperable when the leakage results in exceeding the acceptance criteria of Appendix J, Option B.

APPLICABILITY In MODES 1, 2, 3, and 4, a DBA could cause a release of radioactive material into containment. In MODES 5 and 6, the probability and consequences of these events are reduced due to the pressure and temperature limitations of these MODES. Therefore, containment is not required to be OPERABLE in MODES 5 and 6 to prevent leakage of radioactive material from containment. The requiremonts for cont4a!nmnt during MODE= 6 are addroso;-d- 'A LCO- 3.9.41, Contann ontrationu (continued)

Watts Bar - Unit 2 B 3.6-3 (developmental) AH

Containment Air Locks B 3.6.2 BASES (continued)

APPLICABLE The DBAs that result in a significant release of radioactive material within SAFETY containment are a loss of coolant accident and a rod ejection accident ANALYSES (Ref. 2). In the analysis of each of these accidents, it is assumed that containment is OPERABLE such that release of fission products to the environment is controlled by the rate of containment leakage. The containment was designed with an allowable leakage rate (La) of 0.25%

of containment air weight per day (Ref. 2), at the calculated peak containment pressure of 15.0 psig. This allowable leakage rate forms the basis for the acceptance criteria imposed on the SRs associated with the air locks.

The containment air locks satisfy Criterion 3 of the NRC Policy Statement.

LCO Each containment air lock forms part of the containment pressure boundary. As part of containment pressure boundary, the air lock safety function is related to control of the containment leakage rate resulting from a DBA. Thus, each air lock's structural integrity and leak tightness are essential to the successful mitigation of such an event.

Each air lock is required to be OPERABLE. For the air lock to be considered OPERABLE, the air lock interlock mechanism must be OPERABLE, the air lock must be in compliance with the Type B air lock leakage test, and both air lock doors must be OPERABLE. The interlock allows only one air lock door of an air lock to be opened at one time. This provision ensures that a gross breach of containment does not exist when containment is required to be OPERABLE. Closure of a single door in each air lock is sufficient to provide a leak tight barrier following postulated events. Nevertheless, both doors are kept closed when the air lock is not being used for normal entry into and exit from containment.

APPLICABILITY In MODES 1, 2, 3, and 4, a DBA could cause a release of radioactive material to containment. In MODES 5 and 6, the probability and consequences of these events are reduced due to the pressure and temperature limitations of these MODES. Therefore, the containment air locks are not required in MODES 5 and 6 to prevent leakage of radioactive material from containment. The roquiromnts for the

,n-,inmon'*t air locks .iunq MGOFDE 6 aro addr in LC* 3.0.1,

,sed "Containment PenetrRtW0ns."

(continued)

Watts Bar - Unit 2 B 3.6-7 (developmental) AH

Containment Isolation Valves B 3.6.3 BASES (continued)

APPLICABILITY In MODES 1, 2, 3, and 4, a DBA could cause a release of radioactive material to containment. In MODES 5 and 6, the probability and consequences of these events are reduced due to the pressure and temperature limitations of these MODES. Therefore, the containment isolation valves are not required to be OPERABLE in MODES 5 and 6.-

The requireme~nts for contaiAnment isolation valVe6 during MODE 6 are addrocod in LCOQ 3.9.4, "C*oAinmoRnRRt Ponotration,"

ACTIONS The ACTIONS are modified by a Note allowing penetration flow paths, to be unisolated intermittently under administrative controls. These administrative controls consist of stationing a dedicated operator (licensed or unlicensed) at the valve controls, who is in continuous communication with the control room. In this way, the penetration can be rapidly isolated when a need for containment isolation is indicated. For valve controls located in the control room, an operator (other than the Shift Operations Supervisor (SOS), ASOS, or the Operator at the Controls) may monitor containment isolation signal status rather than be stationed at the valve controls. Other secondary responsibilities which do not prevent adequate monitoring of containment isolation signal status may be performed by the operator provided his/her primary responsibility is rapid isolation of the penetration when needed for containment isolation. Use of the Unit Control Room Operator (CRO) to perform this function should be limited to those situations where no other operator is available.

A second Note has been added to provide clarification that, for this LCO, separate Condition entry is allowed for each penetration flow path. This is acceptable, since the Required Actions for each Condition provide appropriate compensatory actions for each inoperable containment isolation valve. Complying with the Required Actions may allow for continued operation, and subsequent inoperable containment isolation valves are governed by subsequent Condition entry and application of associated Required Actions.

The ACTIONS are further modified by third Note, which ensures appropriate remedial actions are taken, if necessary, if the affected systems are rendered inoperable by an inoperable containment isolation valve.

In the event the isolation valve leakage results in exceeding the overall containment leakage rate, Note 4 directs entry into the applicable Conditions and Required Actions of LCO 3.6.1.

(continued)

Watts Bar - Unit 2 B 3.6-16 (developmental) AH

HMS B 3.6.8 BASES BACKGROUND When the HMS is initiated, the ignitor elements are energized and heat (continued) up to a surface temperature Ž_1700'F. At this temperature, they ignite the hydrogen gas that is present in the airspace in the vicinity of the ignitor.

The HMS depends on the dispersed location of the ignitors so that local pockets of hydrogen at increased concentrations would burn before reaching a hydrogen concentration significantly higher than the lower flammability limit. Hydrogen ignition in the vicinity of the ignitors is assumed to occur when the local hydrogen concentration reaches a minimum 5.0 volume percent (v/o).

APPLICABLE The HMS causes hydrogen in containment to burn in a controlled manner SAFETY as it accumulates following a degraded core accident (Ref. 3). Burning ANALYSES occurs at the lower flammability concentration, where the resulting temperatures and pressures are relatively benign. Without the system, hydrogen could build up to higher concentrations that could result in a violent reaction if ignited by a random ignition source after such a buildup.

The hydrogen ignitors are not included for mitigation of a Design Basis Accident (DBA) because an amount of hydrogen equivalent to that generated from the reaction of 75% of the fuel cladding with water is far in excess of the hydrogen calculated for the limiting DBA loss of coolant accident (LOCA). The hydrgon . onc..-entr.ation ro..ulting from a DBA cAn beA M.Atainta-nd 18-66 thRAn the- flamFmab9ility "imit ucin*g the hydroge rocombinorc. The hydrogen ignitors.,hewe.'e-', have been shown by probabilistic risk analysis to be a significant contributor to limiting the severity of accident sequences that are commonly found to dominate risk for plants with ice condenser containments. As such, the hydrogen ignitors are considered to be risk significant in accordance with the NRC Policy Statement.

(continued)

Watts Bar - Unit 2 B 3.6-43 (developmental) AH

Divider Barrier Integrity B 3.6.13 BASES SURVEILLANCE SR 3.6.13.3 REQUIREMENTS (continued) Verification, by visual inspection, after each opening of a personnel access door or equipment hatch that it has been closed makes the operator aware of the importance of closing it and thereby provides additional assurance that divider barrier integrity is maintained while in applicable MODES.

SR 3.6.13.4 Not used.The di-ider barrior o6al can be field 6pliced for ropa!r purposes utilizing a cold bond procedure rather than the original field Gplice-technique of vulcanization. However, the cod bond adhesive, which works in conjunc~tion with a bolt array to splice the field joint, cOulId not be heat aged te 40 years plaRt life pFr6rto ac,-ptability testing. ProlRn*gd expesure te the elevaotehd tempeFatutres required foFheat aging the sA'e materia-l w.as destructive to the adhesive. The seal mnaterial war, heat aged to 40 years equivalent ago, and the entire joint assembly war, irFradi~ated- to- 10 year nrmFRal operation plus accident integrated doese-,

Conducting periodic peel tests On the test specimensR provides assuranca that the ad-hesive has net degraded in the containmen-.t environmAFent. The

.v jjoint ,followed dby y1 8month sfthe pepeo llength hissgreate rtha n14' "an d366month sifthe Pepee llengthi sless tha nor requal lt o12" ir sbased dupo nthe eorigina lvendor's srecommendatio nwhichi s6base dupo nbaselin eexAa minaRtio1 nofthe estre ngth ofthe eadhesive. Therefore ,the eF requ enc ywa: - scon c ud e dtnobenAsco t abI ofrom a; r eAliahdbili ty tndnn int SR 3.6.13.5 Visual inspection of the seal around the perimeter provides assurance that the seal is properly secured in place. The Frequency of 18 months was developed considering such factors as the inaccessibility of the seals and absence of traffic in their vicinity, the strength of the bolts and mechanisms used to secure the seal, and the plant conditions needed to perform the SR. Operating experience has shown that these components usually pass the Surveillance when performed at the 18 month Frequency. Therefore, the Frequency was concluded to be acceptable from a reliability standpoint.

REFERENCES 1. Wafts Bar FSAR, Section 6.2, "Containment Systems."

Watts Bar - Unit 2 B 3.6-83 (developmental) AH

CCS B 3.7.7 B 3.7 PLANT SYSTEMS B 3.7.7 Component Cooling System (CCS)

BASES BACKGROUND The CCS provides a heat sink for the removal of process and operating heat from safety related components during a Design Basis Accident (DBA) or transient. During normal operation, the CCS also provides this function for various non-essential components, as well as the spent fuel storage pool. The CCS serves as a barrier to the release of radioactive byproducts between potentially radioactive systems and the Essential Raw Cooling Water (ERCW) System, and thus to the environment.

The CCS is arranged as two independent, full-capacity cooling trains, Train A and Train B. Train A in Unit 2 is served by CCS Hx B and CCS pump 2A-A. Pump 2B-B, which is actually Train B equipment, is also normally aligned to the Train A header in Unit 2. However, pump 2B-B can be realigned to Train B on loss of Train A.

Train B is served by CCS Hx C. Normally, only CCS pump C-S is aligned to the Train B header since few non-essential, normally-operating loads are assigned to Train B. However, pump 2B-B can be realigned to the Train B header on a loss of the C-S pump.

Each safety related train is powered from a separate bus. An open surge tank in the system provides pump trip protective functions to ensure that sufficient net positive suction head is available. The pump in each train is automatically started on receipt of a safety injection signal, and all non-essential components will be manually isolated.

CCS Pump 1B-B may be substituted for CCS Pump C-S supplying the Unit 2 CCS Train B header provided the OPERABILITY requirements are met.

Additional information on the design and operation of the system, along with a list of the components served, is presented in the FSAR, Section 9.2.2 (Ref. 1). The principal safety related function of the CCS is the removal of decay heat from the reactor via the Residual Heat Removal (RHR) System. This may be during a normal or post accident cooldown and shutdown.

(continued)

Watts Bar - Unit 2 B 3.7-36 (developmental) GHI

CCS B 3.7.7 BASES LCO c. If CCS Pump 11B-B is substituted for CCS Pump C-S supplying (continued) the Unit 2 CCS Train B header, CCS Pump IB-B is only considered OPERABLE when aligned to the CCS Train B header and operating.

The isolation of CCS from other components or systems not required for safety may render those components or systems inoperable but does not affect the OPERABILITY of the CCS.

CCS Pump 1B-B only receives a safety injection (SI) signal from Unit 1. If CCS Pump I B-B is in a standby mode and is aligned as a substitute for CCS Pump C-S, then Unit 2 CCS train B will not be operable. Conversely, if CCS Pump 1B-B is operating and aligned as a substitute for CCS Pump C-S supplying the CCS Train B header, then Unit 2 CCS Train B is OPERABLE. The presence of an SI signal in Unit 2 will have no effect on CCS Pump 1B-B and the pump will continue to operate. In the event of a loss of offsite power, with or without an SI signal present, CCS Pump I B-B will be automatically sequenced onto its respective diesel and continue to perform its required safety function.

APPLICABILITY In MODES 1, 2, 3, and 4, the CCS is a normally operating system, which must be prepared to perform its post accident safety functions, primarily RCS heat removal, which is achieved by cooling the RHR heat exchanger.

In MODE 5 or 6, the OPERABILITY requirements of the CCS are determined by the systems it supports.

(continued)

Watts Bar - Unit 2 B 3.7-38 (developmental) AH I

CCS B 3.7.7 BASES SURVEILLANCE S R 3.7.7.4 REQUIREMENTS (continued) This SR verifies proper automatic operation of the CCS pumps on an actual or simulated actuation signal. The CCS is a normally operating system that cannot be fully actuated as part of routine testing during normal operation. The 18 month Frequency is based on the need to perform this Surveillance under the conditions that apply during a unit outage and the potential for an unplanned transient if the Surveillance were performed with the reactor at power. Operating experience has shown that these components usually pass the Surveillance when performed at the 18 month Frequency. Therefore, the Frequency is acceptable from a reliability standpoint.

This SR does not apply to CCS Pump 1B-B when substituted for CCS Pump C-S to establish operability of Unit 2 CCS Train B. CCS Pump 1B-B does not receive an SI actuation signal from Unit 2. If it is operating and aligned as a substitute for CCS Pump C-S supplying the CCS Train B header, the presence of an SI signal in Unit 2 will have no effect on CCS Pump 1B-B and the pump will continue to perform its required safety function. In the event of a loss of offsite power, with or without an SI signal present, CCS Pump 1B-B will be automatically sequenced onto its respective diesel and continue to perform its required safety function.

SR 3.7.7.5 This SR assures the operability of Unit 2 CCS Train B when CCS Pump I B-B is substituted for CCS Pump C-S. Since CCS Pump I B-B does not receive an Sl actuation signal from Unit 2, by verifying the pump is aligned and operating, assurance is provided that Unit 2 CCS Train B will be operable in the event of a Unit 2 SI actuation.

REFERENCES 1. Watts Bar FSAR, Section 9.2.2, "Component Cooling System."

2. Watts Bar Component Cooling System Description, N3-70-4002.

Watts Bar - Unit 2 B 3.741 (developmental) AH I

ABGTS B 3.7.12 B 3.7 PLANT SYSTEMS B 3.7.12 Auxiliary Building Gas Treatment System (ABGTS)

BASES BACKGROUND The ABGTS filters airborne radioactive particulates from the area of the fuel p*ol following a fuel handling a*ccden;t aRd from the area of active Unit 2 ECCS components and Unit 2 penetration rooms following a loss of coolant accident (LOCA).

The ABGTS consists of two independent and redundant trains. Each train consists of a heater, a prefilter, moisture separator, a high efficiency particulate air (HEPA) filter, two activated charcoal adsorber sections for removal of gaseous activity (principally iodines), and a fan. Ductwork, valves or dampers, and instrumentation also form part of the system.

A second bank of HEPA filters follows the adsorber section to collect carbon fines and provide backup in case the main HEPA filter bank fails.

The downstream HEPA filter is not credited in the analysis. The system initiates filtered ventilation of the Auxiliary Building Secondary Containment Enclosure (ABSCE) exhaust air following receipt of a Phase A containment isolation signal or a high radiatienR Gigal from, the spent fuel pool area.

The ABGTS is a standby system, not used during normal plant operations. During emergency operations, the ABSCE dampers are realigned and ABGTS fans are started to begin filtration. Air is exhausted from the Unit 2 ECCS pump rooms, Unit 2 penetration rooms, and fuel handling area through the filter trains. The prefilters or moisture separators remove any large particles in the air, and any entrained water droplets present, to prevent excessive loading of the HEPA filters and charcoal adsorbers.

The plant design basis requirFeS that when movinRg irradiated fuel in the Auxiliar; Building and/or Containment With the Containment open to the Aui~~ Buildingq A:39GE SpG a signal fQAthe Gpem fW8uu90 radi-ation moritorm 0 RE 90 102 and 103 Will initiate a C-otainment Ventilatior n Isolation (VI) in addition to their rnormnl funcrtin. In addition, a 6ignal froEm the cnAtaiFnment purge radc-iafionmnior I RE 90 130 and 131 or othr VI signal " 11initiate that po.tion of the ABI normal*l nitiated by the spent fuel poo0 radiation monitors.. Additionally, a Contah."inmentIolation Phase A (SI -igRal) from the operatiRg unit, high temper~ature inthe Auxiliary Building air intakes, or manual AB!

(continued)

Watts Bar - Unit 2 B 3.7-63 (developmental) GH

ABGTS B 3.7.12 BASES BACKGROUND .:viw cas a ivi B J w anaui inl tne* ne~uina*

tl *J w

• uni* inl meu cas vwnre incv At Jl (continued) .J~ fl11 7Ifl~ TV U~~fl T~rTYfl~ TtJ ~~tJT I flJ fl T~ I ~LIflflILfl 3 ~IAIThAII ~ - V in nerie nit will initiitn

• CVI in the ether ,-nit ineorder to maintain thoee vv inrumentato mAut remnain operable when moeving i~rradiated fuel in the Auxiliar" Building ifthe containment air locGks, penetrations, equipment hatch, etc. arc open to the Auxiliary Buildin~g BSCE9 spacaes. Inaddlitio, the ABGTS mu-st remain operable if these cOntainment penotratipoc arc eoon to the Auxiliary Building durina- -- " J ........ 0 ......

vnt n # -nf ;-,,4;-+ . f..r 1 ;n ; 14;A +n~ ;, +~n V'rar"Orl 01 01- - 0 r1a a t7wrl cz rimorl .

The ABGTS is discussed in the FSAR, Sections 6.5.1, 9.4.2, 15.0, and 6.2.3 (Refs. 1, 2, 3, and 4, respectively).

APPLICABLE The ABGTS design basis is established by the consequences of the SAFETY limiting Design Basis Accident (DBA), which is a LOCA. fue[Iamdllf§ 4

ANALYSES .,n,.,, nn TI', aanl'16*6c -S thA .,Ihn-h

'A'n~rnn Nintan =GanQ#CiVR IV*I I II I The analysis of the LOCA assumes that radioactive materials leaked from the Emergency Core Cooling System (ECCS) are filtered and adsorbed by the ABGTS. The DBA analysis of the fuel handling accident assumes that only one train of the ABGTS is functional due to a single failure that disables the other train. The accident analysis accounts for the reduction in airborne radioactive material provided by the one remaining train of this filtration system. The amount of fission products available for release from the ABSCE is determined for a fue! handfIng accident and for a LOCA. The assumption.. ... s*ad 4 .analySiSforF a4 fu-el handli-ng accident felloW the guidance proVided in Regulatory Guide 1.25 (Ref. 5) and NUREG/CR 5009 (Ref. 10). The assumptions and analysis for a LOCA follow the guidance provided in Regulatory Guide 1.4 (Ref. 65).

The ABGTS satisfies Criterion 3 of the NRC Policy Statement.

tiDI Building withl containmen~t air locks Or penetrations open to theo Auxiliary Building ABSCE spaceS, Or when moving fuel in the Auxiliary Building w:ith the con~tainment equipm~ent hatch open, the proVisions to9ntit a C-VI from. the rpent fulpelrdation monRitors and to initiate ain A.-I ki.u., Me Pertien 9+ an :Aoi normally Munatee Sy fme 6ponmi+U9!peefi r-adiation moenitors6) from a CVI, including a CVI initiated by the containment purge monitors, in the event of a fue! handling accident (FH1A) must be in place and functeionig. Additionally, a Containment Isolation Phase A (SI Sign~a!) from the oer~eat*R1 unit, higlh (continued)

Watts Bar - Unit 2 B 3.7-64 (developmental) GH

ABGTS B 3.7.12 BASES APPLICABLE lin temnperature the- Aux;Ilinay Building air intake,, Or manual ABI Will causo SAFETY a CVI 6igna! in tho refueling unit. The centainmonRt equipment hatch ANALYSES cannoet be open When moGVing irradiated fuel inside containmen~t in (continued) accordance with TOch*i*al Specifcatieon3.9.4.

The ABGT-S i6 required to be opeFable during movement of irradiated fuel in the Auxiliay Buwilding during any m*dA and during moveent ofR iRradiated fuel in th* ReRa;ctor Builing whenthe RAciltor Building is establirhed as pant of the ABSCE boundary (seo T-S 3.3.8, 3.7.12, &

3.0.4). Whenming"irra*dated fuel inside containment, at least one train of the onmtaimetpug system mnust be operating Or the containmenAt mAust beisolated. Whleýn* moeving l irradiated fuel in the Auxiliary Building duý,ng timne wheRn the contain*ent is olpento the Auxiliary Buildirg ABSGE6pa~6containment PU~ a eoperated, btoperatieRon h systemR 06 not required. However, whether. the containmenRt purge systemA is6 operated o-r-not in this; confguration, all containmenRt Ventilatiniolato valves and associated isrmnaonmust remnain operable. Ti requirement is cesr to ensure a CVI can be accomAplished "FRo the spent fuel peel ra-d-;ia~tion moni-R..to-rs- in.the event of a F-H.A in the Auxiliary Building. Additionally, a Containment Isolation Phase A (SI signal) fram the operating unit, high temnperature in the Auxiliar-y B3uilding air intakes, Or mnanual ABI 4.0ll cause a CVI cigna! in the refueling unit. In the case where the containment of both units is open to the Auxiliary BuldingF~

spaces, a CVI in one unit will initiate a CVI in the ether unit in order to maintain these spaces open to the ABSCE.

LCO Two independent and redundant trains of the ABGTS are required to be OPERABLE to ensure that at least one train is available, assuming a single failure that disables the other train, coincident with a loss of offsite power. Total system failure could result in the atmospheric release from the ABSCE exceeding the 10 CFR 100 (Ref. 7-6) limits in the event of a fuel handling accident or LOCA.

The ABGTS is considered OPERABLE when the individual components necessary to control exposure in the fiel haii'ii-bAuxiliary Building are OPERABLE in both trains. An ABGTS train is considered OPERABLE when its associated:

a. Fan is OPERABLE;

b. HEPA filter and charcoal adsorber are not excessively restricting flow, and are capable of performing their filtration function; and (continued)

Watts Bar - Unit 2 B 3.7-65 (developmental) GH

ABGTS B 3.7.12 BASES LCO c. Heater, moisture separator, ductwork, valves, and dampers are (continued) OPERABLE, and air circulation can be maintained.

APPLICABILITY In MODE 1, 2, 3, or 4, the ABGTS is required to be OPERABLE to provide fission product removal associated with ECCS leaks due to a LOCA and leakage from containment and annulus.

In MODE 5 or 6, the ABGTS is not required to be OPERABLE since the ECCS is not required to be OPERABLE. During mo'-ement of irradiatod fudel in the fue! handling area, the ABGTS8 is roquirod to be QPE=RARLP to alleviate the cOnceqIUoncoc of a fuel handling accident. See additienal d*iGc3uccF~oQ in tho Backoron-d ;;nd Aen'*Rable Safot': AnaIV6ic Goctionc ACTIONS A._1 With one ABGTS train inoperable, action must be taken to restore OPERABLE status within 7 days. During this period, the remaining OPERABLE train is adequate to perform the ABGTS function. The 7-day Completion Time is based on the risk from an event occurring requiring the inoperable ABGTS train, and the remaining ABGTS train providing the required protection.

B.1 and B.2 IR MODE 1, 2, 3, or 1, wWhen Required Action A.1 cannot be completed within the associated Completion Time, or when both ABGTS trains are inoperable, the plant must be placed in a MODE in which the LCO does not apply. To achieve this status, the plant must be placed in MODE 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, and in MODE 5 within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. The 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.

(continued)

Watts Bar - Unit 2 B 3.7-66 (developmental) AH

ABGTS B 3.7.12 BASES AGTQNS (Ge~tRued)

%AA, 0 a" atla ;rv A A *.tPri A . 4 UmMi" + k 0 wcrmp ICP+ w A  ;+k; r_1

+k W ruga

r%7 14 GGFAPI8ti9R T4AB, GIWOR9 FRevement of iFFadiated fuel ;;rsAmhI;A OR the fUel haRdIiR9 aFea, the OPPRARI F= AI3GT_9 tFaiR must be staFt immediately ear fuel rneyeMeAt 6UspeRded. This aGtiGA eA661F86 that the FeFna6A4A@ tr-ROR is GO PERABLE, that Re URElete6ted faWUFe6 PFeYeAtiR@

ation %kill eAr_,UF, aRd that aRy acAiye fail mw*ll he re dily if the system is not plaGed iR epeFatien, thir, aGtiG 6PeF16i9R 9f fUel FnGY8Fn6At, WhiGh pFeGludes a fue-I an-roid-ent. T4;' FeGlude the FneyemeRt ef fuel assemblies te a 6afe P96iti9R.

9.4 VVh8R tWO tFaiRG of the ABGT-S aFe 'RepeFable du Rk4_

• Ffad*ated fuel assemblies in the fuel handliRg aFea-, ýansfieen immust be takeR te E)Iaee the URit iR a GgRditiw; iR WhiGh the I=GG de96 not apply. A.0ion A

• l m I I I I Em arsembfies *Rthe fuel na Thrs does A9t PF9Glude t FR9Y9FneAt 9f A-19-1 t9 a Giale SURVEILLANCE SR 3.7.12.1.

REQUIREMENTS Standby systems should be checked periodically to ensure that they function properly. As the environmental and normal operating conditions on this system are not severe, testing each train once every month provides an adequate check on this system.

Monthly heater operation dries out any moisture accumulated in the charcoal from humidity in the ambient air. The system must be operated for ý!10 continuous hours with the heaters energized. The 31 -day Frequency is based on the known reliability of the equipment and the two train redundancy available.

(continued)

Wafts Bar - Unit 2 B 3.7-67 (developmental) AH

ABGTS B 3.7.12 BASES SURVEILLANCE SR 3.7.12.2 REQUIREMENTS (continued) This SR verifies that the required ABGTS testing is performed in accordance with the Ventilation Filter Testing Program (VFTP). The ABGTS filter tests are in accordance with Regulatory Guide 1.52 (Ref. 8).

The VFTP includes testing HEPA filter performance, charcoal adsorber efficiency, minimum system flow rate, and the physical properties of the activated charcoal (general use and following specific operations).

Specific test frequencies and additional information are discussed in detail in the VFTP.

SR 3.7.12.3 This SR verifies that each ABGTS train starts and operates on an actual or simulated actuation signal. The 18-month Frequency is consistent with Reference 87.

SR 3.7.12.4 This SR verifies the integrity of the ABSCE. The ability of the ABSCE to maintain negative pressure with respect to potentially uncontaminated adjacent areas is periodically tested to verify proper function of the ABGTS. During the post accident mode of operation, the ABGTS is designed to maintain a slight negative pressure in the ABSCE, to prevent unfiltered LEAKAGE. The ABGTS is designed to maintain a negative pressure between -0.25 inches water gauge and -0.5 inches water gauge (value does not account for instrument error) with respect to atmospheric pressure at a nominal flow rate > 9300 cfm and < 9900 cfm. The Frequency of 18 months is consistent with the guidance provided in NUREG-0800, Section 6.5.1 (Ref. 98).

An 18-month Frequency (on a STAGGERED TEST BASIS) is consistent with Reference 87.

REFERENCES 1. Watts Bar FSAR, Section 6.5.1, "Engineered Safety Feature (ESF)

Filter Systems."

2. Watts Bar FSAR, Section 9.4.2, "Fuel Handling Area Ventilation System."

3. Watts Bar FSAR, Section 15.0, "Accident Analysis."

(continued)

Watts Bar - Unit 2 B 3.7-68 (developmental) SH

ABGTS B 3.7.12 BASES REFERENCES 4. Watts Bar FSAR, Section 6.2.3, "Secondary Containment (continued) Functional Design."

5-, Rogulatory Guido 1.25, Mach 197-2, "A ,.umptien Uso-,d for Fiyalwatkng tho Potentilal Radielogical Consoquoncoc of a Fuol NAMOilnn --M WRR,uIAZoA 40a;ter 14AtRAc.

65. Regulatory Guide 1.4, "Assumptions Used for Evaluating the Potential Radiological Consequences of a Loss of Coolant Accident for Pressurized Water Reactors."

-76. Title 10, Code of Federal Regulations, Part 100.11, "Determination of Exclusion Area, Low Population Zone, and Population Center Distance."

87. Regulatory Guide 1.52 (Rev. 2), "Design, Testing and Maintenance Criteria for Post Accident Engineered-Safety-Feature Atmospheric Cleanup System Air Filtration and Adsorption Units of Light-Water Cooled Nuclear Power Plants."

98. NUREG-0800, Section 6.5.1, "Standard Review Plan," Rev. 2, "ESF Atmosphere Cleanup System," July 1981.

F dm I i BP 4 NUL-IGt.G Water,-c'-e MoAn ottri, U.oS? NLearneg lIuAnup I Fuel in Liaht W~ator PoW8r Reactors." UJ. S. Nuclear ReaulatoR' 60mmiSc9ion. 1-orur':mm.

Watts Bar - Unit 2 B 3.7-69 (developmental) BH

Fuel Storage Pool Water Level B 3.7.13 B 3.7 PLANT SYSTEMS B 3.7.13 Fuel Storage Pool Water Level BASES BACKGROUND The minimum water level in the fuel storage pool meets the assumptions of iodine decontamination factors following a fuel handling accident. The specified water level shields and minimizes the general area dose when the storage racks are filled to their maximum capacity. The water also provides shielding during the movement of spent fuel.

A general description of the fuel storage pool design is given in the FSAR, Section 9.1.2 (Ref. 1). A description of the Spent Fuel Pool Cooling and Cleanup System is given in the FSAR, Section 9.1.3 (Ref. 2). The assumptions of the fuel handling accident are given in the FSAR, Section 4 4 515.5.6 (Ref. 3).

APPLICABLE The minimum water level in the fuel storage pool meets the assumptions SAFETY of the fuel handling accident described in Regulatory Guide 1.26 ANALYSES (Ref.4)1.183 (Ref. 4.) The Total Effective Dose Equivalent (TEDE) for control room occupants, individuals at the exclusion area boundary, and individuals within the low population zone will remain within 10 CFR 50.67 (Ref. 5) and Regulatory Position C.4.4 of Regulatory Guide 1.183 for a fuel handling accident. The reoult*ant 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> thyroid dseo per pernsR at the ourv*ohn area bo*unday is a small fractin Of the 10 CFR 100 (Ref. 5) limits.

According to Reference 43, there is 23 ft of water between the top of the damaged fuel bundle and the fuel pool surface during a fuel handling accident. With 23 ft of water, the assumptions of Reference 4 can be used directly. In practice, this LCO preserves this assumption for the bulk of the fuel in the storage racks. In the case of a single bundle dropped and lying horizontally on top of the spent fuel racks; however, there may be < 23 ft of water above the top of the fuel bundle and the surface, indicated by the width of the bundle. To offset this small non-conservatism, the analysis assumes that all fuel rods fail, although analysis shows that only the first few rows fail from a hypothetical maximum drop.

The fuel storage pool water level satisfies Criterion 2 of the NRC Policy Statement.

(continued)

Watts Bar - Unit 2 B 3.7-68 (developmental) AH

Fuel Storage Pool Water Level B 3.7.13 BASES (continued)

REFERENCES 1. Watts Bar FSAR, Section 9.1.2, "Spent Fuel Storage."

2. Watts Bar FSAR, Section 9.1.3, "Spent Fuel Pool Cooling and Cleanup System."

3. Watts Bar FSAR, Section 5.4 , "Fuel Handling Accident."

4. Regulatory Guide 1.25, March 1072, "Assumptions Used for Eg'alwat6ng the Potentfial Radiological Gonsogueonces of a Fuel Handli*g AccideRt iR the Fuel Handling and Storage Facility for BOiling and Pressurized Wat- r Roactors."Regulatory Guide 1.183, "Alternate Source Terms for Evaluation Design Basis Accidents at Nuclear Power Reactors", July 2000.

5. Title 10, Code of Federa! Regulations, Part 100.11, "Determninatio of Exclu6ion Area, Low Population Zone, and Popu-lation C-enter QDta~e-!Title 10, Code of Federal Regulations, 10 CFR 50.67, "Accident Source Term."

Watts Bar - Unit 2 B 3.7-70 (developmental) AH

Spent Fuel Assembly Storage B 3.7.15 B 3.7 PLANT SYSTEMS B 3.7.15 Spent Fuel Assembly Storage BASES BACKGROUND The spent fuel pool contains flux trap rack modules with 1386 storage positions and that are designed to accommodate new fuel with a maximum enrichment of 4.95 + 0.05 weight percent U-235 and fuel of various initial enrichments when stored in accordance with paragraph 4.3.1.1 in Section 4.3, Fuel Storage.as high a6 3.8 Weight percen~t UJ235 withut restrictions. Storago of fuel assemblies w.,ith enric;hFment beo 3..

3.8 and 5.0 weight percent requires "ithorfuel burnup in accordance With paragraph 4.3.1.1 or placement in .torage locations which have face adjacent storage coils coentaining either water o~r fuel Rrassoblioc with accum~ulated bUFrup of at least 20.0 MWDI~gU in accordance with Spocification 4.3.1.1.

The water in the spent fuel storage pool normally contains soluble boron, which results in large subcriticality margins under actual operating conditions. However, the NRC guidelines, based upon the accident condition in which all soluble poison is assumed to have been lost, specify that the limiting keff of 0.95 be evaluated in the absence of soluble boron. Hence, the design is based on the use of unborated water, which maintains the storage racks in a subcritical condition during normal operation with the racks fully loaded. The double contingency principle discussed in ANSI N-16.1-1975, and the April 1978 NRC letter (Reference 1) allows credit for soluble boron under other abnormal or accident conditions, since only a single accident need be considered at one time. For example, an abnormal scenario could be associated with the improper loading of a relatively high enrichment, low exposure fuel assembly. This could potentially increase the criticality of the storage racks. To mitigate these postulated criticality-related events, boron is dissolved in the pool water. Safe operation of the spent fuel storage design with no movement of assemblies may therefore be achieved by controlling the location of each assembly in accordance with the accompanying LCO. Prior to movement of an assembly in the pool, it is necessary to perform SR 3.9.9.1.

(continued)

Watts Bar - Unit 2 B 3.7-76 (developmental) AH I

DC Sources - Operating B 3.8.4 BASES BACKGROUND 125 V Vital DC Electrical Power Subsystem (continued)

Additionally, battery boards 1,11, III, and IV have manual access to the fifth vital battery system. The fifth 125V DC Vital Battery System is intended to serve as a replacement for any one of the four 125V DC vital batteries during their testing, maintenance, and outages with no loss of system reliability under any mode of operation.

Each of the vital DC electrical power subsystems provides the control power for its associated Class 1E AC power load group, 6.9 kV switchgear, and 480 V load centers. The vital DC electrical power subsystems also provide DC electrical power to the inverters, which in turn power the AC vital buses. Additionally, they power the emergency DC lighting system.

The vital DC power distribution system is described in more detail in Bases for LCO 3.8.9, "Distribution System - Operating," and LCO 3.8.10, "Distribution Systems - Shutdown."

Each vital battery has adequate storage capacity to carry the required load continuously for at least 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> in the event of a loss of all AC power (station blackout) without an accident or for 30 minutes with an accident considering a single failure. Load shedding of non-required loads will be performed to achieve the required coping duration for station blackout conditions.

Each 125 VDC vital battery is separately housed in a ventilated room apart from its charger and distribution centers, except for Vital Battery V.

Each subsystem is located in an area separated physically and electrically from the other subsystem to ensure that a single failure in one subsystem does not cause a failure in a redundant subsystem. There is no sharing between redundant Class 1E subsystems, such as batteries, battery chargers, or distribution panels.

The batteries for the vital DC electrical power subsystems are sized to produce required capacity at 80% of nameplate rating, corresponding to warranted capacity at end of life cycles, de-rated for minimum ambient temperature and the 100% design demand. The voltage limit is 2.13 V per coll, Which cOrreSPOnds to a total minimum voltage output of 128 V per batt,';' (132 V for Vital Battery, V). The criteria for sizing large lead storage batteries are defined in IEEE-485 (Ref. 5).

(continued)

Watts Bar - Unit 2 B 3.8-49 (developmental) AH

DC Sources - Operating B 3.8.4 BASES BACKGROUND 125 V Vital DC Electrical Power Subsystem (continued)

The battery cells are of flooded lead acid construction with a nominal specific gravity of 1.215. This specific gravity corresponds to an open cell voltage of 2.07 Volts per cell (Vpc). For a 58 cell battery (DG battery), the total minimum output voltage is 120 V; for a 60 cell battery (vital battery) the total minimum output voltage is 124 V; and for a 62 cell battery ( 5 th vital battery), the total minimum output voltage is 128 V. The open circuit voltage is the voltage maintained when there is no charging or discharging. Once fully charged, the battery cell will maintain approximately 97% of its capacity for 30 days without further charging per manufacturer's instructions. Optimal long term performance, however, is obtained by maintaining a float voltage from 2.20 to 2.25 Vpc. This provides adequate over-potential, which limits the formation of lead sulfate and self discharge.

Each Vital DC electrical power subsystem has ample power output capacity for the steady state operation of connected loads required during normal operation, while at the same time maintaining its battery bank fully charged. Each battery charger also has sufficient capacity to restore the battery bank from the design minimum charge to its fully charged state within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> (with accident loads being supplied) following a 30 minute AC power outage and in approximately 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> (while supplying normal steady state loads following a 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> AC power outage), (Ref. 6).

The battery charger is normally in the float-charge mode. Float-charge is the condition in which the charger is supplying the connected loads and the battery cells are receiving adequate current to optimally charge the battery. This assures the internal losses of a battery are overcome and the battery is maintained in a fully charged state.

When desired, the charger can be placed in the equalize mode. The equalize mode is at a higher voltage than the float mode and charging current is correspondingly higher. The battery charger is operated in the equalize mode after a battery discharge or for routine maintenance. Following a battery discharge, the battery recharge characteristic accepts current at the current limit of the battery charger (if the discharge was significant, e.g., following a battery service test) until the battery terminal voltage approaches the charger voltage setpoint. Charging current then reduces exponentially during the remainder of the recharge cycle. Lead calcium batteries have recharge efficiencies of greater than 91%, so once at least 110% of the ampere-hours discharged have been returned, the battery capacity would be restored to the same condition as it was prior to the discharge. This can be monitored by (continued)

Watts Bar - Unit 2 B 3.8-50 (developmental) BH

DC Sources - Operating B 3.8.4 BASES direct observation of the exponentially decaying charging current or by evaluating the amp-hours discharged from the battery and amp-hours returned to the battery.

(continued)

Watts Bar - Unit 2 B 3.8-51 (developmental) BH

DC Sources - Operating B 3.8.4 BASES (continued)

LCO Four 125V vital DC electrical power subsystems, each vital subsystem channel consisting of a battery bank, associated battery charger and the corresponding control equipment and interconnecting cabling supplying power to the associated DC bus within the channel; and four DG DC electrical power subsystems each consisting of a battery, a battery charger, and the corresponding control equipment and interconnecting cabling are required to be OPERABLE to ensure the availability of the required power to shut down the reactor and maintain it in a safe condition after an anticipated operational occurrence (AOO) or a postulated DBA. Loss of any DC electrical power subsystem does not prevent the minimum safety function from being performed (Ref. 4).

An OPERABLE vital DC electrical power subsystem requires all required batteries and respective chargers to be operating and connected to the associated DC buses.

The LCO is modified by threea Notes. T-he-Note 1 indicates that Vital Battery V may be substituted for any of the required vital batteries.

However, the fifth battery cannot be declared OPERABLE until it is connected electrically in place of another battery and it has satisfied applicable Surveillance Requirements. Note 2 indicate that spare vital chargers 6-S, 7-S, 8-S, or 9-S may be substituted for required vital chargers. Note 3 indicate that spare DG chargers IAI, 1B1, 2A1, or 2B1 may be substituted for required DG chargers. However, the spare charger(s) cannot be declared OPERABLE until it is connected electrically in place of another charger, and it has satisfied applicable Surveillance Requirements.

APPLICABILITY The four vital DC electrical power sources and four DG DC electrical power sources are required to be OPERABLE in MODES 1, 2, 3, and 4 to ensure safe plant operation and to ensure that:

a. Acceptable fuel design limits and reactor coolant pressure boundary limits are not exceeded as a result of AOs or abnormal transients; and

b. Adequate core cooling is provided, and containment integrity and other vital functions are maintained in the event of a postulated DBA.

The DC electrical power requirements for MODES 5 and 6 are addressed in the Bases for LCO 3.8.5, "DC Sources - Shutdown."

(continued)

Watts Bar - Unit 2 B 3.8-53 (developmental) AH

DC Sources - Operating B 3.8.4 BASES

• S AGTI ON A4

/=% -- -- J:L;-- -- A I-OR41Atu /A rO8epreS ent e vita! Gninnel WKHr a 1966 ef ability LU comBpletely respond to an evont, and a potontial loss of ability to rmi enRegized duFrig nrmF~a! operation. Rt.i, therefore, imnperatiye that the operator's attention focus_ on .tabiliinthe plant, minimi~zingq the potential for comIplete loss of PG poworA- to the ff~ecGted train. Tho 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> limint is cncirstont With the All0owed time for. Rannprbe distributo system If one Of the roquirod vital DCG e-lectric4al poWor subs)ystwms is inoperable (e.g., inoperable batter,', inoperable battory charger(s), or inoperable battery charger and associated inoereable battery), the remaining-vital DG electrical power subsystemA has the capacity to support a safe ishutdow-nA an;d to mnitigate an accGident condition. S~ince Asubsequent worst case single failure of the PERmA.BLE SUbsystem; would, however, resut i a ituation Where the ability of the 425V DG electricGal power subsystem; te support its required ESF function is not assured, continued power eperatien sheuld not eXceed 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />s6. The 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> COMPIAetiGn TimeA isbased en Regulator', Guide 1.93 (Ref. 8) and reflects a roasenable timne to assess plant status as a functioin- of the inopcrable vital DC electrical poere subsystemn and, if the vital DG electrical poWer subsystem is not restorFed to OPERABLE status, to prepare to effect an orderly and safe (GGRtined) if the inoper-able vita! DG electrical power sub6ystmOR cannot be restored te OPERABLE status within the required Com~pletion Tim~e, the plant Must be brought to a MODE in whic-h the LCGO does net apply. To9 achieve this status, the plant mnust be brought to at le-ast MODE 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and to MODE 5 within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. The allowed Completion Times are-reasonable, based on operating eXPerience, to reach the required plant con-ditios fromR full power conditions i an orderly manner ;And Withou t challenging plant systems. The Comple~tionR T~i.m._etobring the plant to MODE 5 is consistent With the timeA required in Regulatory Guide 1.93 (Ref.4.

Condition C representG one DG with a losseof ability to completely-respond to an event. SincGe a subsequent single failure onR the eppesite train Gould result in a situation; wh~ere the required ESP function is net asSUred, con~tinued power o~peration should net e*ceed 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />. The

-2hortime0 lim.it is consR.istent With the allowed tim:e forF an nprbl ia DG Beletrical power subsystem.

(continued)

Watts Bar - Unit 2 B 3.8-54 (developmental) AH

DC Sources - Operating B 3.8.4 BASES 94 If tho DG DG ol*ocFtGrl p*We* subystof*cGnnot be restored to OPERA., 1LE status in the ascctatd Completion, Time, the a6sociatod DG May be incapable of pe~ferming it6 inended- funcAtion and must be immediat.ly declared R+operable. This d^+laration al- o require. 9,ntY into applicable ConRditions and Requirod Ac-tions Jfr -Anineporable DG, LCOQ 3.8.1, "AG SourFGos Operating."

ACTIONS A.1. A.2, A.3. E.1. E.2. and E.3 Conditions A and E represent one channel with one battery charger inoperable (e.g., the voltage limit of SR 3.8.4.1 or SR 3.8.4.2 is not maintained). The ACTIONS provide a tiered response that focuses on returning the battery to the fully charged state and restoring a fully qualified charger to OPERABLE status in a reasonable time period. Required Actions A.1 and E.1 require that the battery terminal voltage be restored to greater than or equal to the minimum established float voltage within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />. This time provides for returning the inoperable charger to OPERABLE status or providing an alternate means of restoring battery terminal voltage to greater than or equal to the minimum established float voltage. Restoring the battery terminal voltage to greater than or equal to the minimum established float voltage provides good assurance that, within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />, the battery will be restored to its recharged condition from any discharge that might have occurred due to the charger inoperability.

A discharged battery having terminal voltage of at least the minimum established float voltage indicates that the battery is on the exponential charging current portion (the second part) of its recharge cycle. The time to return a battery to its fully charged state under this condition is simply a function of the amount of the previous discharge and the recharge characteristic of the battery.

Thus, there is good assurance of fully recharging the battery within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />, avoiding a premature shutdown with its own attendant risk.

(continued)

(eentied)

Watts Bar - Unit 2 B 3.8-55 (developmental) AH

DC Sources - Operating B 3.8.4 BASES ACTIONS A.1, A.2, A.3, E.1, E.2, and E.3 (continued)

If battery terminal float voltage cannot be restored to greater than or equal to the minimum established float voltage within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />, and the charger is not operating in the current-limiting mode, a faulty charger is indicated. A faulty charger that is incapable of maintaining established battery terminal float voltage does not provide assurance that it can revert to and operate properly in the current limit mode that is necessary during the recovery period following a battery discharge event that the DC system is designed for.

If the charger is operating in the current limit mode after 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />, that is an indication that the battery is partially discharged and its capacity margins will be reduced. The time to return the battery to its fully charged condition in this case is a function of the battery charger capacity, the amount of loads on the associated DC system, the amount of the previous discharge, and the recharge characteristic of the battery. The charge time can be extensive, and there is not adequate assurance that it can be recharged within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.

Required Actions A.2 and E.2 require that the battery float current be verified less than or equal to 2 amps for the vital battery and less than or equal to 1 amp for the DG battery. This indicates that, if the battery had been discharged as the result of the inoperable battery charger, it is now fully capable of supplying the maximum expected load requirement. The 2 amp value for the vital battery and the I amp value for the DG battery are based on returning the battery to 98% charge and assume a 2% design margin for the battery. If at the expiration of the initial 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> period the battery float current is not less than or equal to 2 amps for the vital battery or I amp for the DG battery, then this indicates there may be additional battery problems and the battery must be declared inoperable.

Required Actions A.3 and E.3 limit the restoration time for the inoperable battery charger to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. This action is applicable if an alternate means of restoring battery terminal voltage to greater than or equal to the minimum established float voltage has been used (e.g., balance of plant non-Class IE battery charger). The 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> Completion Time reflects a reasonable time to effect restoration of the qualified battery charger to OPERABLE status.

(continued)

(Gentikwed)

Watts Bar - Unit 2 B 3.8-56 (developmental) AH

DC Sources - Operating B 3.8.4 BASES ACTIONS B.1 and F.1 (continued)

Conditions B and F represent one channel (subsystem) with one battery inoperable. With one battery inoperable, the DC bus is being supplied by the OPERABLE battery charger. Any event that results in a loss of the AC bus supporting the battery charger will also result in loss of DC to that subsystem. Recovery of the AC bus, especially if it is due to a loss of offsite power, will be hampered by the fact that many of the components necessary for the recovery (e.g., diesel generator control and field flash circuits, AC load shed and diesel generator output circuit breakers, etc.) will likely rely upon the battery. In addition, any DC load transients that are beyond the capability of the battery charger and normally require the assistance of the battery will not be able to be brought online.

The 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> limit allows sufficient time to effect restoration of an inoperable battery given that the majority of the conditions that lead to battery inoperability (e.g., loss of battery charger, battery cell voltage less than 2.07 V, etc.) are identified in Specifications 3.8.4, 3.8.5, and 3.8.6 together with additional specific Completion Times.

C.1 and G.1 Conditions C and G represent a loss of one DC electrical power subsystem to completely respond to an event, and a potential loss of ability to remain energized during normal operation. It is, therefore, imperative that the operator's attention focus on stabilizing the unit, minimizing the potential for complete loss of DC power to the affected subsystem. The 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> limit is consistent with the allowed time for an inoperable DC distribution subsystem.

(continued)

Watts Bar - Unit 2 B 3.8-57 (developmental) AH

DC Sources - Operating B 3.8.4 BASES ACTIONS D.A and D.2 (continued)

If one of the required DC electrical power subsystems is inoperable for reasons other than Conditions A or B for the vital batteries or Conditions E or F for the DG DC electrical power subsystem, the remaining DC electrical power subsystem has the capacity to support a safe shutdown and to mitigate an accident condition.

Since a subsequent worst case single failure could, however, result in the loss of the minimum necessary DC electrical subsystems to mitigate a worst case accident, continued power operation should not exceed 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />. The 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> Completion Time is based on Regulatory Guide 1.93 (Ref. 8) and reflects a reasonable time to assess unit status as a function of the inoperable DC electrical power subsystem and, if the DC electrical power subsystem is not restored to OPERABLE status, to prepare to effect an orderly and safe unit shutdown. If the inoperable Vital DC electrical power subsystem cannot be restored to OPERABLE status within the required Completion Time, the plant must be brought to a MODE in which the LCO does not apply. To achieve this status, the plant must be brought to at least MODE 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and to MODE 5 within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. 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. The Completion Time to bring the plant to MODE 5 is consistent with the time required in Regulatory Guide 1.93 (Ref.8).

H.1 If the DG DC electrical power subsystem cannot be restored to OPERABLE status in the associated Completion Time, the associated DG may be incapable of performing its intended function and must be immediately declared inoperable. This declaration also requires entry into applicable Conditions and Required Actions for an inoperable DG, LCO 3.8.1, "AC Sources-Operating."

(continued)

(GGetiAed)

Watts Bar - Unit 2 B 3.8-58 (developmental) AH

DC Sources - Operating B 3.8.4 BASES SURVEILLANCE SR 3.8.4.1 and SR 3.8.4.2 REQUIREMENTS Verifying battery terminal voltage while on float charge for the batteries helps to ensure the effectiveness of the battery chargers, which support char9g4g ,ystem and"*, the ability of the batteries to perform their intended function. Float charge is the condition in which the charger is supplying the continuous charge required to overcome the internal losses of a battery (or battery cell) and maintain the battery (or a battery cell) in a fully charged state while supplying the continuous steady state loads of the associated DC subsystem. On float charge, battery cells will receive adequate current to optimally charge the battery. The voltage requirements are based on the nominal design voltage of the battery and are consistent with the minimum float voltage established by the battery manufacturer. For example, the minimum nominal terminal voltage for the 5th Vital Battery is 136 V (62 cells times 2.20 Vpc); the minimum nominal terminal voltage for the vital batteries is 132 V (60 cells times 2.20 Vpc); and the minimum nominal terminal voltage for the DG batteries is 128 V (58 cells times 2.20 Vpc). These voltage levels maintain the battery plates in a condition that supports maintaining the grid life.

The voltage requirements listed above are based on the critical design voltage of the battery and are consistent with the initial voltages assumed in the battery sizing calculations. The 7 day Frequency is consistent with manufacturer recommendations and IEEE-450 (Ref. 9).

SURVEILL.\NCE SR 3.8.4.3 (nti~ued) Verifying that for the vital batteries that the alternate feeder breakers to each required battery charger is open ensures that independence between the power trains is maintained. The 7 day Frequency is based on engineering judgment, is consistent with procedural controls governing breaker operation, and ensures correct breaker position.

SR 3.8.4.4 This SR demonstrates that the DG 125V DC distribution panel and associated charger are functioning properly, with all required circuit breakers closed and buses energized from normal power. The 7 day Frequency takes into account the redundant DG capability and other indications available in the control room that will alert the operator to system malfunctions.

(continued)

(G94Awed)

Watts Bar - Unit 2 B 3.8-59 (developmental) AH

DC Sources - Operating B 3.8.4 BASES S-R 3-8.4.5- and SR 3.8.".

Visual inspection to detect corrosion of tho batter' coil6 and connoctions, Or m~asuromen9t of thoe resitncQ of oach inter cell, *nter rack, inter tfir and-terinlonection, provides an indication Of physical damage or abnormnal doterioration that could potontialy degrade bafttor, The- limits-es99tablisbh-d- forF thiS SR must be no more than 20% above the rosistance as me~aur*ed duFrig installation, Or not above the coiling value esF-t-ablishe-d by the manufacturwer.

The SurelaoFrequency for those inspections, Which can detect conditions th-at c-an cauepwer losses due to resistance heatini 92 days. T-his Frequency is considered accoptable based- en oer)ating experience related to detecting corrosion tFreds.

99-,444-7 Visual finspection of the b-ater,' cells, cell plates, and batter,' rack provides an indication Of physical damage or abnormnal deterioration that could potentially degrade bailr, perfermanco.

The 12 month FrFequency for this SR is consistent with IEEE 450 (Ref. 9),

which recomm~en~ds detailed visual inspection Of Gell condition and rack inRtegritY on a YearlY basis.

(continued)

(GeRtined)

Watts Bar - Unit 2 B 3.8-60 (developmental) AH

DC Sources - Operating B 3.8.4 BASES SU RVEILLANGE SR 3.8.4.8. SR 3.8.4.9 and SR 3.8.4.10 REQUIREMENTS e*IenIIIeM) Visual inspection and resistance mneaurements of inter c9ll, intor rack, inter tier, and-torminal connction provid-e nP ind-ication of physic~al damage Or abnOrMa! deterioration that could indicate degraded batter; conditwion. The anti corrosion mnaterial is used to help enSUre good-oloctrical cennoct-iens- and- to reduweq term~inal deterioIrato. The visual insooction for orrQoQio i; Anot inodo o ouiro rmova~l of Rn nrpection under each terminal connection... The Fremo.Val Of Vi.ib corrosior iSa pre.entiye mnaintenanc.e SR. The presence oOf Yis*

corrosion does not necessarily repFreset a failurwe of this SR provi'ded ViIGIEDu GurrF;u wmvU 9G Rng Poriom3nc a 01 9T bK 6.0 or I-OF purposes Of trending, inter cell (vital and DG batteries) and inter tier (Vital and DG batteries) connections are measured from batter; post to batter; post. Inter rack (Vital batteries), inter tier (IDG Batteries), and terminal connections (Vital and DG batteries) are measured fromA teFrminal lug to bae~y post, The cnnec~tion resisrta~nce limits for SR 3.8.1.9 and SR 3.8.4.10 shalIl be no Moe% than 20%0 above the resistance as mneasured duringintlao, or not above the ceiling value established by the mnanufacturer-.

The Sur.'eillanco F-Fequencies of 12 moneths isconsistent With IEEME 450 (Ref. 9), which recommFends cell to cell and term~inal connection-resistance mneasurement on a yearly basis.

SR 3.8.4.1 This SR requires that each vital batter' charger be capable of Freharging its assocated batter' fromn a capacity Or serVice discharge test while supplying normnal leads, or alternatively, operating at cuwrrent limi*t forP A mnmmof 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> at a nominal 125 VDC. These requirements are based on the design Gapasity of the chargers (Ref. 1) and their perform~ance characteristic of current limfit operation for a substantial portion of the recharge period. Batter,' charger output current is limited to 110% to 125% onf the -200amAp rated output. R9Gharging the batter,' o testing forF a minimu;-m of 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> is suffiient to verify,the output capabikity of the charger can be sustained, that current limit adjustments are properly set and that PFotect'ye devices Will not inhibit porfGFrmanco at current limfit settings. According to Regulator; Guide 1.32 (Ref. 6), the batter,' charger supply is requirFed to be-: b--ased-on the !argest combined demands of the various steady state leads and the Gharging capacity to restore the batter,' fromn the design minimumF charge state to the fully charged state, irrespective of the status of the plant during thos~e demand occurrences. Verifying the Gapability of the charger to operate in sustained currFent limit cnionesrsthat these rqients,can be satisfied.

(continued)

Watts Bar - Unit 2 B 3.8-61 (developmental) AH

DC Sources - Operating B 3.8.4 BASES SURVEII I t\r" SR 3.8.4.11 (continu-d)

REQU IREMENTS The ~iir"niIhnrn l-rnntinn~v ~ ~ccontiblo olven mc olant conditions requir.ed to perform the test ;;Ad the other admini6.tative c ontr.... xisting to ensure adequate charger performnance during th96e 18 moneth interVals.

in addition, this Frequency is intended to be consistent with expected fue!

Thisq SR is-modified by a Note. The reason forF the Note isthat perfoFrming the Survoillanco mnay PeotUrb the electric al distribution system and-challenge safe systems. his Sis AnogRally perFoed during MODES 5 and 6 since it would require the DC e'ectriGca power subsytem to be inoperable durin~g performnance of the test. HoweVer, this Surveillance mnay be performned in MOIDES 1, 2, 3, Or 4 provided the Vital laý++a.X. ig r,,,ihr.+iti a,'Iq OR*tWJl 1 *fii ith waa..ara I GOr tdata., 1i -r'iraw+

ta .. mat,

,. ha tbanfar ian ak attneta +d +nr +i ft +1, ic, D r- vamlan -tnnnnr

ýIrw" M C3 MCI 0 0 . ncl

,evet6may inGlude:;

=I

1) UnexPected Gopeational events which causethe equi!pment peor Mednc.-O ntctuon th Bo I aew'elrloman,-, icrW,-ni b adeeuat dcmntat;ionm Of thA required Derfqrmnance

...... .. * ...... r --.

us aVAiWAble and I-, a

• JL...

S.....

tin tht peforanceof

~f!4 reuirs II ~ AMDI M,

his I

[** ..... II ....

provided the mainRtenanco was required, OF pBefFRmod i ojnto withmainenane rqurd to maintain OPERABILITY Or reliability.

(continued)

Watts Bar - Unit 2 B 3.8-62 (developmental) SHI

DC Sources - Operating B 3.8.4 BASES SURPVEl1l IANICG-E SR-. 8.44-2 REQU......I.I...R-EME-N..iTS (GGoRiW~.e4 -t-HI6 am....................U..........................................to recharging its associated batter; fromn a capacity or sor.;icoe disccharge test while supplying normnal loads. T-his roquirmen9t is based on the design capacity of the chargers (Ref. 13) and their perform~ance characteristic Of currenFA-t liMit oporation for a substantial portion Of the recharg PeRiOd.

Batter; charger output curren-t is limited- to a maximum- of 140%9 of the 20 amAp rated output. Recharging the batter; Verifies the output capability of the chargeFrcan be sustained, that current limit adjustmenRts r properly ret and that proetec-tive devoices will not inhibit perfoFrmance at current limnit sefttngs. According to Regulator; Guide 1.32 (Ref. 6), the bailer,' charger supply is required to be based on th lags combined demnands of the vOariou,-s steady state Iead6 and the charging capacity to restore the batter' fromA the design miniMmum harge state to the ful~y charged state, irrespeoct-Ve oaf the s-tatus, of the plant during these demnand occurrences. Verif,'ig the capability Of the charger to operate in a 6setained cuwrre-nt limit conndmitin esrsthat these eqrmnts can beq satisfied.

The Surveillance FrFequency is aGceptable, giVen the plant conditions required to perfoFrm the test and the eteramiisrtie otrols existingq to ensure adequate charger performnance during these 18 mon~th intervals.

Inaddition, this Frequencyi inen edt be consistent with expected fuel GeG&8 e8Rths-.

PFo the DG DC eloctrica! subsystem, this Survoillanco mnay be performned in MODES 1,2, 3, Or 4 inconjunction With L-GCO .. .)ic the DG DC electFical power subs6ystem Iuppl-o.lads only for the inoperable; diesel generator and would no9t otherxise challenge safet systems6 supplied fromn vital electrical distribution systems. A dditionally, credit mnay be taken for unplanned events that satisf' this SR. Examples of unplanned events mayARGiude*

1) Unexpected operational eventS which cause the equipmnentt performA the funcionIG specified by this Survoillanco, for whichý adequate documentaitionof the required performnance Iavailable; aRd 2-) PestA ncrrec-tive mnaintenance testing that requires perform~ance of-this Surveillance in order to restore the component toaO-PE-R-A.B-LF-,

provided the mnaintenanc wsrqied, Or performed inconjunction With mnaintenance required to mantIn OPRABILITY Or reliabwlity.

(continued)

Watts Bar - Unit 2 B 3.8-63 (developmental) SHI

DC Sources - Operating B 3.8.4 BASES SURVEiLLANCE R-384.-3 REQUIREMENTS (Ge*t 4inue) A batter; .... i. e to.t,

• . a pe.ial t*st Of batter,+ capability, as found, to satisfy the deign r r ts (batte.,' duty cYc!. ) of the PG electrical pe*,r systeM. T-hodc g Fate and test *l**th should corr*espod to INorst cAs- design dut cc l.e requirements based on References 10 The Surveillance FrFequoncy of 18 months is consistent with the-rec..Rmendations of RegulatFo' Guide 1.32 (Ref. 6) and Regulatorp Guide 1.1 29 (Ref. 11), which state that the ba#,e; seVice- test should be performlced durFng refueling operatioRn orat som*eother outage,ith intervals betweeR tests, not to eXceed 18 mROnths.

This S-R is-modified by b~s No-tesr. Note 1 allows- the perfoq~ance of a modified performRance disc-harge test in lieu of a service test once per 60 mnonths. The moAd-ifi~ed perform~ance discharge test is a simulated duty cycle consisting Of just tWo rates: the o-ne minute rate published for the batter' o the Iargest cu.. ent load Of the duty cycI fo-llowed by the test rate employed for the perform~ance test, both Of which envelope the duty cycl9eof the sepoir.'e test. Since the ampere hours remRoved by a rate-d onemnutedischarge represents a very small peotien of the batter' capacity, the test rate can; be changed to that forF the perform~ance test without compromnising the result of the performnance discharge test. The batter; termin;al voltage for the moqdified perform~ance discharge test shou-ld remain above the minim.. batter' terminal voltage specified in the batterF se-rvire ts*÷f;t fFr the dratien Rof time equal to that of the se*#eie A modified d6hqetest

,-, ro!fldi., uschargeis a test of the batter;""

"*,h,

• cat~

apacity aidits and...; ability tto.,

,*ai,,_.. ,

provide a high rate, 6o94duration lead (usually the highest rate of the duty GyGle.) This Will oft-e co'nfirmF the ba#tFy's ability to Meet theFritial period of the load duty cycle, in addition to detefRm~inig its percontago of rated capacity. Initial conditions forF the moedified performnance discharge test should be identi*al t* these specified for a serv'ie test.

The reason for Note 2 is that perfeFrming the Surveillance may peF4Urb the

Aital elecntric-al distr-ibution system and challenge safety systems.

However, this SuPIeill~ancc may be perfermoed in MODES 1,2, 3, or 4 provided that Vital Battery V is substituted in accordance with LCO Note 1. For the DG DC e!ectrical subsystem, this suIlPlaSInce may be perFormed in MODES 1 2, 3, ew 4 i conjunction Y with 3.8

, .B since the supplied loads are only forF the inaperable diesel generator and

.would net ether~'ise challenge safety system leads which are supplied (continued)

Watts Bar - Unit 2 B 3.8-64 (developmental) FHI

DC Sources - Operating B 3.8.4 BASES SURVEILLIA\N IGE SR 3.8.4.13 (contin~ued)

REQU IREMVENTS from~ vital electrical distribution systemAS. Addi4tionally, croFdit mnay be takon for unplanned eventS that satisfy this SR. Eixamplos of unplanned eyents Fey iRGId9&

1) Unexpected oporatfional ovonts whic~h cause the equipment to-perfoFrm the,func-tion specified by thi6 SurVoilIaRG9, for Which-adequate documentation of the required performsance is available; and

2) Post cor-rocntive m~aintn~anco te-sting that requires pcrf49rmanco Of this Sur.'oillanco in order to restore the comAponent to OPERABLE,-

provided the mnaintenance was required, or pe~rfor-med in conjuncGtion with mnaintenan~e required to maintain GPERDABILIT ojýr F liabi~y SR.-2.R4.14 Abatter; performnance discharge test is a test of constant curr~ent capasity of a batter,', normnally done in the as found-cniin after having' boon in I

% I .7 l accoptance test. Thno test is Rtenoea to aee81Frmie oereall battor; 14 rraaA A . ,a +a n -n w9rd a tyr-I taw 0 aga dri Anl.tood!3W.

A batter' moedifiod performance disch~arge test is doscribod in the Bases for SR 3.8.41.3 Either the batter; perform;anc discharge test Or the modified performance discharge test isacceptable for 6atisfyi~ng SR 3.8.4.14; however, only the moedified perform~ance discharge test may be used to satisfy~ SR 3.8.4.14 while 6atisf,'ing the requirementso SR 3.8.4.13 at the same time.

The accepta~nce c~riteria for this Surweillance are consistent With IFEEE 50 ID f aX aA 1MCAr ID fX r, Yk c- a.anc f.a .'4'n+ka++I-battr, be replaced if its capacity is below 80% of the msanufacturer rating. A capac~ity of 80% shows that the battory rate of deterioration is inc-mar.

inn a a ranl 4-n + amttaInzr

+hm0, a,,rr~ +~nntt yvarl orw 5 a P w "apda V M%7 w "d rokati m Uri 5.

(continued)

Watts Bar - Unit 2 B 3.8-65 (developmental) FHI

DC Sources - Operating B 3.8.4 BASES SURVEILLANCE SR 3.8.4.14 (continued)

REQUIREMENTS The Su~ilneFrequencY forF this test is nrmFFally 60 mnonths. if the batter,' shows degradation, or ifthe ba~qoy has, re~ached REM ofit expoctod life and capacity is 4100% o-f the m~anu-facturerFs rating, the SurVeillance Frequency is reduced to 12 months. However, ifthe baftery shoWs no degradation but has roachod 85%0 of its expected life, the 8ur~oillance FrFequency is,only reduceAd- to :24 months, for baqtteries that retain capacit" :ý100% Of the .manuRIfacAturer's rating. Degradationi

• ndicated, accordinig to IEEE= 150 (Ref. 0), When the batter! capacity drops by moreA than I10% relative to itGapacity OR theB preVious pe~feFmaF;Ge tes6t Or When it is ->10%below-4. thte manu1facturer rating.

These Frequece arecnsistent with the recomernedations in IEEE 450 (Ref. )

This SR is modified by aRNote. The r-eason for the Note is that pe~fGFming the Surveillanae mnay pe~turb the vital electWArica distribution system and challenge safety systems. However, this Suryoillanco may be pe~feFmod in MOIDES I,2, 3, Or 4 provided that Vital Batteny V is-isubshtit-uted in accordance with. the- LCO Note. For the- -QDG- D electrical subsystem, this sur~veillance mnay be pe~fGFmed in MODES I, 2, 3, or 4 in conjunction With LCOG 3.8.4 .B since the supplied leads are only for the inoperable dioese generator and would not etheorwise c~hallen~ge safety system lea;ds which are supplied fro~m v.it-al electrica! distribution systems. Additionally, credit mnay be taken for unplanned events that satisfy' this SR. IExamples of unplanned 6evets m~ay include:

1) Un~eXpected operational evoenRts %whichcause the equipment to9-LrnJ+!-

uuIQFui=+H ui.url MuGiu4i:3 HU tIiii 01.J.1ý--

.. . . . . . . I b...

.

W'...

. .

adequate documen9t-at-ion of the required ponertomancoe is-available; and

2) Post corrective msaintenance testinqI that requires qo40frmaRce of this I I I provided the maintenance wasr*,equired, Vo*Vd Or poV in, coFnjuntion wit;hm~aintenance required to maintain OPER.AB-ILITY or reliability.

(continued)

Watts Bar - Unit 2 B 3.8-66 (developmental) BH

DC Sources - Operating B 3.8.4 BASES (continued)

SURVEILLANCE SR 3.8.4.5 and SR 3.8.4.6 REQUIREMENTS (continued) These SRs verify the design capacity of the vital and DG battery chargers. According to Regulatory Guide 1.32 (Ref. 6), the battery charger supply is recommended to be based on the largest combined demands of the various steady state loads and the charging capacity to restore the battery from the design minimum charge state to the recharged state, irrespective of the status of the unit during these demand occurrences. Verifying the capability of the charger to operate in a sustained current limit condition ensures that these requirements can be satisfied.

The SRs provide two options. One option requires that each vital battery charger be capable of supplying 200 amps (20 amps for the DG battery charger) at the minimum established float voltage for 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. Recharging the battery or testing for a minimum of 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> is sufficient to verify the output capability of the charger can be sustained, that current limit adjustments are properly set and that protective devices will not inhibit performance at current limit settings.

The other option requires that each battery charger be capable of recharging the battery after a service test coincident with supplying the largest coincident demands of the various continuous steady state loads (irrespective of the status of the plant during which these demands occur). This level of loading may not normally be available following the battery service test and will need to be supplemented with additional loads. The duration for this test may be longer than the charger sizing criteria since the battery recharge is affected by float voltage, temperature, and the exponential decay in charging current. The battery is recharged when the measured charging current is < 2 amps for the vital batteries and < I amp for the DG batteries.

The Surveillance Frequency is acceptable, given the plant conditions required to perform the test and the other administrative controls existing to ensure adequate charger performance during these 18 month intervals. In addition, this Frequency is intended to be consistent with expected fuel cycle lengths.

(continued)

Watts Bar - Unit 2 B 3.8-67 (developmental) SH

DC Sources - Operating B 3.8.4 BASES (continued)

SURVEILLANCE SR 3.8.4.7 REQUIREMENTS A battery service test is a special test of battery capability, as (continued) found, to satisfy the design requirements (battery duty cycle) of the DC electrical power system. The discharge rate and test length should correspond to worst case design duty cycle requirements based on References 10 and 12.

The Surveillance Frequency of 18 months is consistent with the recommendations of Regulatory Guide 1.32 (Ref.6) and Regulatory Guide 1.129 (Ref.11), which state that the battery service test should be performed during refueling operations or at some other outage, with intervals between tests, not to exceed 18 months.

This SR is modified by two Notes. Note I allows the performance of a modified performance discharge test in lieu of a service test.

The modified performance discharge test is a simulated duty cycle consisting of just two rates; the one minute rate published for the battery or the largest current load of the duty cycle, followed by the test rate employed for the performance test, both of which envelope the duty cycle of the service test. Since the ampere-hours removed by a rated one minute discharge represents a very small portion of the battery capacity, the test rate can be changed to that for the performance test without compromising the results of the performance discharge test. The battery terminal voltage for the modified performance discharge test should remain above the minimum battery terminal voltage specified in the battery service test for the duration of time equal to that of the service test.

Note 2 allow the plant to take credit for unplanned events that satisfy this SR. Examples of unplanned events may include:

1) Unexpected operational events which cause the equipment to perform the function specified by this Surveillance, for which adequate documentation of the required performance is available; and

2) Post corrective maintenance testing that requires performance of this Surveillance in order to restore the component to OPERABLE, provided the maintenance was required, or performed in conjunction with maintenance required to maintain OPERABILITY or reliability.

(continued)

Watts Bar - Unit 2 B 3.8-68 (developmental) BH

DC Sources - Operating B 3.8.4 BASES (continued)

REFERENCES 1. Title 10, Code of Federal Regulations, Part 50, Appendix A, General Design Criterion 17, "Electric Power System."

2. Regulatory Guide 1.6, "Independence Between Redundant Standby (Onsite) Power Sources and Between Their Distribution Systems,"

U.S. Nuclear Regulatory Commission, March 10, 1971.

3. IEEE-308-1971, "IEEE Standard Criteria for Class IE Power Systems for Nuclear Power Generating Stations," Institute of Electrical and Electronic Engineers.

4. Watts Bar FSAR, Section 8.3.2, "DC Power System."

5. IEEE-485-1983, "Recommended Practices for Sizing Large Lead Storage Batteries for Generating Stations and Substations,"

Institute of Electrical and Electronic Engineers.

6. Regulatory Guide 1.32, "Criteria for Safety-Related Electric Power Systems for Nuclear Power Plants," February 1977, U.S. Nuclear Regulatory Commission.

7. Watts Bar FSAR, Section 15, "Accident Analysis" and Section 6 "Engineered Safety Features."

8. Regulatory Guide 1.93, "Availability of Electric Power Sources,"

U.S. Nuclear Regulatory Commission, December 1974.

9. IEEE 450 41980i!199, "IEEE RecomFendod Practice for Maintenance Testing and Roplacomont of Large Load Storage-BatteFrie for Generating Stations and Subsystemrs," Institute of Electricnal ,andE!ectronic Engineers.IEEE-450-2002, "IEEE Recommended Practice for Maintenance, Testing and Replacement of Vented Lead - Acid Batteries for Stationary Applications," Institute of Electrical and Electronics Engineers, Inc.

10. :WA Calc'u-ltihn WB.N EEB MS T-1 ! 0003, "125 VDC Vital Batter' and Char*ge Evaluatien."TVA Calculation EDQ00023620070003, "125V DC Vital Battery System Analysis"

11. Regulatory Guide 1.129, "Maintenance Testing and Replacement of Large Lead Storage Batteries for Generating Stations and Subsystems," U.S. Nuclear Regulatory Commission, February 1978.

12. TVA Calculation WBN EEB-EDQ00023620070003, "125V DC Vital Battery System Analysis."

13. Watts Bar FSAR, Section 8.3.1, "AC Power System."

Watts Bar - Unit 2 B 3.8-69 (developmental) SH

DC Sources - Shutdown B 3.8.5 BASES (continued)

LCO The 125V Vital DC electrical power subsystems, each vital subsystem channel consisting of a battery bank, associated battery charger, and the corresponding control equipment and interconnecting cabling within the channel; and the DG DC electrical power subsystems, each consisting of a battery, a battery charger, and the corresponding control equipment and interconnecting cabling, are required to be OPERABLE to support required trains of the distribution systems required OPERABLE by LCO 3.8.10, "Distribution Systems - Shutdown" and the required DGs required OPERABLE by LCO 3.8.2, "AC Sources - Shutdown." As a minimum, one vital DC electrical power train (i.e., Channels I and Ill, or II and IV) and two DG DC electrical power subsystems (i.e., 1A-A and 2A-A or 1B-B and 2B-B) shall be OPERABLE. This ensures the availability of sufficient DC electrical power sources to operate the plant in a safe manner and to mitigate the consequences of postulated events during shutdown (e.g., fuel handling accidents).

The LCO is modified by athree Notes. The-Note I indicates that Vital Battery V may be substituted for any of the required vital batteries.

However, the fifth battery cannot be declared OPERABLE until it is connected electrically in place of another battery and it has satisfied applicable Surveillance Requirements. Note 2 indicates that spare vital chargers 6-S, 7-S, 8-S, or 9-S may be substituted for required vital chargers. Note 3 indicates that spare DG chargers 1A1, 1B1, 2A1, or 2B1 may be substituted for required DG chargers. However, the spare charger(s) cannot be declared OPERABLE until it is(are) connected electrically in place of another charger, and it has satisfied applicable Surveillance Requirements.

APPLICABILITY The DC electrical power sources required to be OPERABLE in MODES 5 and 6, and during movement of irradiated fuel assemblies, provide assurance that:

a. Required features needed to mitigate a fuel handling accident are available;

b. Required features necessary to mitigate the effects of events that can lead to core damage during shutdown are available; and

c. Instrumentation and control capability is available for monitoring and maintaining the plant in a cold shutdown condition or refueling condition.

The DC electrical power requirements for MODES 1, 2, 3, and 4 are covered in LCO 3.8.4.

(continued)

Watts Bar - Unit 2 B 3.8-63 (developmental) AH

DC Sources - Shutdown B 3.8.5 BASES (continued)

ACTIONS A.1, A.2.1, A.2.2, A.2.3, and A.2.4 If two trains are required by LCO 3.8.10, the remaining train with DC power available may be capable of supporting sufficient systems to allow continuation of CORE ALTERATIONS and fuel movement. By allowing the option to declare required features inoperable with the associated vital DC power source(s) inoperable, appropriate restrictions will be implemented in accordance with the affected required features LCO ACTIONS. In many instances, this option may involve undesired administrative efforts. Therefore, the allowance for sufficiently conservative actions is made (i.e., to suspend CORE ALTERATIONS, movement of irradiated fuel assemblies, and operations involving positive reactivity additions). The Required Action to suspend positive reactivity additions does not preclude actions to maintain or increase reactor vessel inventory, provided the required SDM is maintained.

Suspension of these activities shall not preclude completion of actions to establish a safe conservative condition. These actions minimize probability of the occurrence of postulated events. It is further required to immediately initiate action to restore the required vital DC electrical power subsystems and to continue this action until restoration is accomplished in order to provide the necessary DC electrical power to the plant safety systems.

The Completion Time of immediately is consistent with the required times for actions requiring prompt attention. The restoration of the required vital DC electrical power subsystems should be completed as quickly as possible in order to minimize the time during which the plant safety systems may be without sufficient power.

B.1 If the-one or more DG DC electrical power subsystem cannot be restored to OPERABLE status in the associated Completion Time, the associated DG may be incapable of performing its intended function and must be immediately declared inoperable. This declaration also requires entry into applicable Conditions and Required Actions for an inoperable DG, LCO 3.8.2, "AC Sources - Shutdown."

(continued)

Watts Bar - Unit 2 B 3.8-64 (developmental) AH

DC Sources - Shutdown B 3.8.5 BASES (continued)

SURVEILLANCE SR 3.8.5.1 REQUIREMENTS SR 3.8.5.1 requires performance of all Surveillances required by SR 3.8.4.1 through SR 3.8.4.4-47. Therefore, see the corresponding Bases for LCO 3.8.4 for a discussion of each SR.

This SR is modified by a Note. The reason for the Note is to preclude requiring the OPERABLE DC sources from being discharged below their capability to provide the required power supply or otherwise rendered inoperable during the performance of SRs. It is the intent that these SRs must still be capable of being met, but actual performance is not required.

REFERENCES 1. Watts Bar FSAR, Section 15, "Accident Analysis" and Section 6, "Engineered Safety Features."

2. Watts Bar FSAR, Section 8.0, "Electric Power."

Watts Bar - Unit 2 B 3.8-65 (developmental) AH

Battery GeU-Parameters B 3.8.6 B 3.8 ELECTRICAL POWER SYSTEMS B 3.8.6 Battery Ge94-Parameters BASES BACKGROUND This LCO delineates the limits on battery float current, electrolyte temperature, electrolyte level, and cell float voltage, and spocific g*avity for the 125V vital DC electrical power subsystem and the diesel generator (DG) batteries. A discussion of these batteries and their OPERABILITY requirements is provided in the Bases for LCO 3.8.4, "DC Sources -

Operating," and LCO 3.8.5, "DC Sources - Shutdown." Additional controls for various battery parameters are also provided in Specification 5.7.2.21, "Battery Monitoring and Maintenance Program."

The battery cells are of flooded lead acid construction with a nominal specific gravity of 1.215. This specific gravity corresponds to an open cell voltage of 2.07 Volts per cell (Vpc). For a 58 cell battery (DG battery), the total minimum output voltage is 120 V; for a 60 cell battery (vital battery),

the total minimum output voltage is 124 V; and for a 62 cell battery, (51h vital battery), the total minimum output voltage is 128 V. The open circuit voltage is the voltage maintained when there is no charging or discharging. Once fully charged, the battery cell will maintain approximately 97% of its capacity for 30 days without further charging per manufacturer's instructions. Optimal long term performance, however, is obtained by maintaining a float voltage from 2.20 to 2.25 Vpc. This provides adequate over-potential, which limits the formation of lead sulfate and self discharge as discussed in FSAR, Chapter 8 (Ref. 4).

(continued)

Watts Bar - Unit 2 B 3.8-66 (developmental) AH

Battery GeU-Parameters B 3.8.6 BASES (continued)

APPLICABLE The initial conditions of Design Basis Accident (DBA) and transient SAFETY analyses in the FSAR, Section 6 (Ref. 1) and Section 15 (Ref. 1), assume ANALYSES Engineered Safety Feature systems are OPERABLE. The vital DC electrical power system provides normal and emergency DC electrical power for the emergency auxiliaries, and control and switching during all MODES of operation. The DG battery systems provide DC power for the DGs.

The OPERABILITY of the DC subsystems is consistent with the initial assumptions of the accident analyses and is based upon meeting the design basis of the plant. This includes maintaining at least one train of DC sources OPERABLE during accident conditions, in the event of:

a. An assumed loss of all offsite AC power or all onsite AC power; and

b. A worst case single failure.

Battery aee-parameters satisfy the Criterion 3 of the NRC Policy Statement.

LCO Battery aee-parameters must remain within acceptable limits to ensure availability of the required DC power to shut down the reactor and maintain it in a safe condition after an anticipated operational occurrence or a postulated DBA. Ele-GtelýteBattery parameter limits are conservatively established, allowing continued DC electrical system function even with Category A and- B limits not met. Additional controls for various battery parameters are also provided in Specification 5.7.2.21, "Battery Monitoring and Maintenance Program."

APPLICABILITY The battery aG9-parameters are required solely for the support of the associated vital DC and DG DC electrical power subsystems. Therefore, battery eleGtre9hy4e -sparameter limits are only required when the DC power source is required to be OPERABLE. Refer to the Applicability discussion in Bases for LCO 3.8.4 and LCO 3.8.5.

(continued)

Watts Bar - Unit 2 B 3.8-67 (developmental) AH

Battery G*,e-Parameters B 3.8.6 BASES (continued)

AGTIQNl t A /*AL .......... .. II_ * .... ....... L =! .... L ___'_LL_'= I!___*'A_ i! --

MvTtn oneRA or1 more c I inAs on 9 Foroe oRaIIoRies not1w RItniimiRS k"-,

....,, -.....,.. .....A.mlimitsr notO.. mnet,no.J............-.

Category Category .JB limits; --....- not ,v met, or Category

~...........

... ... A and B liMit6 not mnet) but within the Category C limfitG Gpocified in Table 3.8.6 1 in thA nnnA gaF;%1*Ag LGQ the ba#ecu *r,d9CIFaded but theFe 4r*6till a4ffected WAtt, sntrqie ob osdrdioeal sol1ely as a result of Category A or B limi~t6 not mnet, and operation -6 permnited for a liiedfpe~iGEI The pilot Goelectrolyt4e leyel and float Yoltage are required to be verified to mooet the Category C limit Within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> (Required Action A.1). T-his check Will proVide a quick iniainof the statusrcf the remainder Of the batter' cells. One hour providesA tilme to inspect the electrolyte level and to confiFrm the float voltage of the pilot c8lls. Onie hour is considered a reaRsonabl e amonunt of timne to ee-drfom. the renquired- v~eqrfic~ationF.

%/  ;.r. +; +k + +11 t- + f, 1; ;+ + 0  ; A A +;

provides assurance that during the time needed to restore the parame~ters to the Categor,' A and B limits, the battery is,still capable of pe~f9Fming Its intended fUR4tio. A period- of 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> isF;allowed to comnplete the9 ta verification because specifi gravity mneasurements must be obtained for each cOnn~ected cell. Takin~g *intoconsideration both the time required to p9efGrm the Fequired Verification and the assurance that the batter' Gel!

parameters agre not rseverelY degraded, this tim~e is,coAnsid~ereAd_

re.;r9asonabl. The verfication is repeated at 7 day intorvals until the parameters are restored to Category ,A ,and B limits. This periodi verificOationA is consistent .wfith the noArmFal FrequencGy Of pilot cell-Continued oporation is only permitted for 31 days be fore battery ~ell parame~ters mus1t be4 res6toreAd to_within Category A.and B limnits. With the consi6deration that, while battery capact isdgrdd, sufficient capacity eXists tOp normF~ the intended function ndto lo time to fuly restore the batter' cell parameters, to normnal limits,1 thiS time is acceptable prier to docAinkun the b~atter j. iRnonrabhLo. ... -

(continued)

Watts Bar- Unit 2 B 3.8-68 (developmental) AH

Battery Gell-Parameters B 3.8.6 BASES

,ACTIONS 84 (GORtiRued)

With one or more8 batteries With 9Re Or MoA-re- bhaA#er,' Goil parame;ter outside the Catgor, C Imi,,ts for any cRRon*n*d ci11, uff;co*nt capacity to supply thoeaiu 1erpoctd load Fegu*roment 0s not assurod and the correspondin Co ;ia DG DG e!octrical poWor subsystemn must be doclaroed inoeporable. Additionally, othor potontially oXreFme conditions, SUch as not Gom.pleting the Re.uirod Act8QiRn of Condition A within tho reguirod Completion Timo oravrae&8etrl1o4 teMprature of reprGesetative co1ls falling below 602F for the vital batt1eries or 500 F for DGbateieare als1asefrimeitl declaFrin the associlated vital DG Or DG DG oloctrical power subsystem inoperable.

ACTIONS A.I. A.2. CA,.C.2, and C.3 If one required vital battery or one required DG battery has one or more cell voltage < 2.07 V, the battery is considered degraded.

Within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />, verification of the required battery charger OPERABILITY is made by monitoring the battery terminal voltage (SR 3.8.4.1 or SR 3.8.4.2) and of the overall battery state of charge by monitoring the battery float charge current (SR 3.8.6.1 or SR 3.8.6.2).

This assures that there is still sufficient battery capacity to perform the intended function. Therefore, the affected battery is not required to be considered inoperable solely as a result of one or more cells in one battery < 2.07 V and continued operation is permitted for a limited period up to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

Since the Required Actions only specify "perform," a failure of SR 3.8.4.1, SR 3.8.6.1, SR 3.8.4.2, or SR 3.8.6.2 acceptance criteria does not result in this Required Action not met. However, if one of the SRs is failed, the appropriate Condition(s), depending on the cause of the failures, is entered. If SR 3.8.6.1 or SR 3.8.6.2 is failed, then there is not assurance that there is still sufficient battery capacity to perform the intended function and the battery must be declared inoperable immediately.

B.1. B.2, D.1. and D.2 One required vital battery with float current > 2 amps or one required DG battery with float current > 1 amp indicates that a partial discharge of the battery capacity has occurred. This may be due to a temporary loss of a battery charger or possibly due to one or more battery cells in a low voltage condition reflecting some loss of capacity. Within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />, verification of the required battery charger OPERABILITY is made by monitoring the battery terminal voltage.

(continued)

Watts Bar - Unit 2 B 3.8-69 (developmental) AH

Battery GeU-Parameters B 3.8.6 BASES ACTIONS B.1. B.2, D.1. and D.2 (continued)

If the terminal voltage is found to be less than the minimum established float voltage, there are two possibilities, the battery charger is inoperable or is operating in the current limit mode.

Conditions A and C address charger inoperability. If the charger is operating in the current limit mode after 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />, that is an indication that the battery has been substantially discharged and likely cannot perform its required design functions. The time to return the battery to its fully charged condition in this case is a function of the battery charger capacity, the amount of loads on the associated DC system, the amount of the previous discharge, and the recharge characteristic of the battery. The charge time can be extensive, and there is not adequate assurance that it can be recharged within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> (Required Actions B.2 and C.2). The battery must therefore be declared inoperable.

If the float voltage is found to be satisfactory, but there are one or more battery cells with float voltage less than 2.07 V, the associated "OR" statement in Condition H is applicable and the battery must be declared inoperable immediately. If float voltage is satisfactory and there are no cells less than 2.07 V, there is good assurance that, within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />, the battery will be restored to its recharged condition (Required Actions B.2 and C.2) from any discharge that might have occurred due to a temporary loss of the battery charger.

A discharged battery with float voltage (the charger setpoint) across its terminals indicates that the battery is on the exponential charging current portion (the second part) of its recharge cycle. The time to return a battery to its recharged state under this condition is simply a function of the amount of the previous discharge and the recharge characteristic of the battery. Thus, there is good assurance of fully recharging the battery within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />, avoiding a premature shutdown with its own attendant risk.

If the condition is due to one or more cells in a low voltage condition but still greater than 2.07 V and float voltage is found to be satisfactory, this is not indication of a substantially discharged battery and 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> is a reasonable time prior to declaring the battery inoperable.

Since Required Actions B.1 and C.1 only specify "perform," a failure of SR 3.8.4.1 or SR 3.8.4.2 acceptance criteria does not result in the Required Action not met.

However, if SR 3.8.4.1 or SR 3.8.4.2 is failed, the appropriate Condition(s), depending on the cause of the failure, is entered.

(continued)

Watts Bar - Unit 2 B 3.8-70 (developmental) AH

Battery ,eII-Parameters B 3.8.6 BASES ACTIONS E.1. E.2. and E.3 (continued) With one required vital or DG battery with one or more cells electrolyte level above the top of the plates, but below the minimum established design limits, the battery still retains sufficient capacity to perform the intended function. Therefore, the affected battery is not required to be considered inoperable solely as a result of electrolyte level not met. Within 31 days, the minimum established design limits for electrolyte level must be re-established.

With electrolyte level below the top of the plates, there is a potential for dryout and plate degradation. Required Actions E.1 and E.2 address this potential as well as provisions in Specification 5.7.2.21.b, "Battery Monitoring and Maintenance Program." They are modified by a Note that indicates they are only applicable if electrolyte level is below the top of the plates. Within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />, level is required to be restored to above the top of the plates. The Required Action E.2 requirement to verify that there is no leakage by visual inspection and the Specification 5.7.2.21.b item to initiate action to equalize and test in accordance with manufacturer's recommendation are taken from IEEE Standard 450. They are performed following the restoration of the electrolyte level to above the top of the plates. Based on the results of the manufacturer's recommended testing the battery may have to be declared inoperable and the affected cell(s) replaced.

F.1 With one required vital or DG battery with pilot cell temperature less than the minimum established design limits, 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> is allowed to restore the temperature to within limits. A low electrolyte temperature limits the current and power available. Since the battery is sized with margin, while battery capacity is degraded, sufficient capacity exists to perform the intended function and the affected battery is not required to be considered inoperable solely as a result of the pilot cell temperature not met.

(continued)

Watts Bar - Unit 2 B 3.8-71 (developmental) AH

Battery Gel4-Parameters B 3.8.6 BASES ACTIONS G.1 (continued) With more than one required vital or more than one required DG batteries with battery parameters not within limits as specified in Conditions A through F there is not sufficient assurance that battery capacity has not been affected to the degree that the batteries can still perform their required function, given that redundant batteries are involved. With redundant batteries involved, this potential could result in a total loss of function on multiple systems that rely upon the batteries. The longer Completion Times specified for battery parameters on non-redundant batteries not within limits are therefore not appropriate, and the parameters must be restored to within limits on at least one subsystem within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />.

H.1 With one or more batteries with any battery parameter outside the allowances of the Required Actions for Condition A, B, C, D, E, F or G, sufficient capacity to supply the maximum expected load requirement is not assured and the corresponding battery must be declared inoperable. Additionally, discovering one or more batteries with one or more battery cells float voltage less than 2.07 V and float current greater than 2 amps for the vital batteries or 1 amp for the DG batteries indicates that the battery capacity may not be sufficient to perform the intended functions. Under these conditions, the battery must be declared inoperable immediately.

(continued)

Watts Bar - Unit 2 B 3.8-72 (developmental) AH

Battery ,eU-Parameters B 3.8.6 BASES SURVEOLLA.NGE SR 3.8.64 REQUIREMENTS This 2SR verifirs that Catogo- ; A batt'o c*l Gel' .a..tr .. o cosstn with IEEE1450 (Rof. 2), Whi:h rocommondS r*gula*r ba#e,'.inspetrions (at least ono per moenth) including voltage, 6pecific grayity, and 8'ectrolyte temporature Of pilot cells.

SR -3..*.2 Tho 'uarterlyinSPection9f specific gravity and voltage s cofnsistont with IEEE 450 (Ref. 2). In addition, within 21 hour2.430556e-4 days <br />0.00583 hours <br />3.472222e-5 weeks <br />7.9905e-6 months <br />" of a batter,' dischaFrg

-c110 V (113.5-V for Vital Batter; V or 106.5 V for DG battories) or a batter,' overcharge >-150 V. (155 V for Vital Battor,' V or 1145 V.for DG batteries), the batter; must be de-monstr-ated- to Meet Category B9 li.mi*ts. Tran;;sientS, such as mo~tor starting transients, which m:ayL momenGtarily cause batter,'voltage to drop to *110V (113.5 Vfor Vital Batter; V or 1068.5 V for DG battorios), do not constitute a batter;-

discharge provided the batter' term~inal voltage and float current retuIrn to pro transient values. This inspection isa!so consistent with.1EEE 450 (Ref. 2), which recoAGm.men8ds special inspections following a seVere discharge Or overcharge, to ensurwe that no significant degradation of the batter; occurs as a consequence Of SUch discharge Or overcharge.

This Survoillance verificationA that the average temperature of rapresentatiVo cells is Ž!600 F for the vital batteries, and Ž! 50"F for the DG batteries, 06 consistent with a recommFendation of IEEE=F 450 (Ref. 2),

that s-taRtesR that the temnperatureF of electrolytes in representative cells should be deteFrmined on a quarterly basis.

(continued)

Watts Bar - Unit 2 B 3.8-73 (developmental) AH

Battery ,e4-Parameters B 3.8.6 BASES RI IRIEII I AIICE SR 3.8.6 (GOntnuord)

REQUIREME.NTS Lowor thAn .....nrMa tem.peratures act to ihibit orhro.duco ba#eF,* ' capacity.

T-his SR ensureAs- that tho operating tomApGratures romain within an accoptablo operating range. This limnit is based an mnanUfacturor roconMMenAdations.

Table 3.8.6 I This table dolinoatos the limits on oloctrolyte level, float voltage,-anid Tpecific graVity f thret or drifferent tego'ri The... m*oaning of ac categer,' is discussed belowA.g Cateogeo' A delfinReF thoe OIal paFrAme*te limit for each desigrated pi"*t coA-l inoacRAh batter,. The cells seloctod as pilot Goils -ArethoseA whoco6 tomnPoratUro, voltage, and electrolye spccific gravity approxim~ate the State Of charge of the entire batter,'.

The Categor,' A limits specified for oloctro','t level are based en msanufactrer recommF:enda;-tions[ and- are con~sistent with the guidance i IEEE 450 (Ref. 2), with the extra .1nc,4 lwac above the high water level iRndiation for operatiqng argin to accoun--t for temperatures and charge effects. In -aCdditionRto this. allowanco, footnote (a) to Table 3.8.6 1 perm~its the electrolyte level to- be- -abovethe specified maximum levelI during equal'iig charge, provided it is not OvoF:oW*Rg. Those limits enAsure that the plates suffer no physical damage, and that adequate electFro transfercapabilipF ir, maintained in the event Of transient-conditions. IEEFE 450 (Ref. 2) recommends that electrolye level readings shudbe mnade only after the bhatter, has boon at float charge for at least T7 he togd2 Th .. Gat1e. Lp~ .. JG limi

. ........ fe 90a .... 2.1 r_{ V: *\..1 eell This*'*

16iupaOR IRAM 0;Rsf- rocmmnouGnS OT Intm 'iow kr. d), WRucRi States that prolonged operation of cells 4 2.13 V can reduce the life expectancy of colls.

The Categer,' A limit specified for specific gravity for each pilot cell is

> 1.200 (0.015 below the manufacturer fully charged nominal specific qraVity or a batter,' charging current that had- Stabilized at a low value).

This value ischaracteristic ofta charge-d cell1 with adequate capacity.

ArrGdinFg to IEEE 450 (Ref. 2), the specific gravity readings are based on a tem-eratur' of 77°F (250C).

V- . _ _ \__ w j_

(continued)

Watts Bar - Unit 2 B 3.8-74 (developmental) AH

Battery ,eU-Parameters B 3.8.6 BASES SURVEILL'ANCE SR 3.9.@.3 (con~tin~ud)

REQUIREMENTS; Tk^ cýn~~ nrr. n~

P^t* ,npr ^^ rrnntnM far gnt #a -I nrn.A i c t, "20C 4 a'70t- k "770C '3r.Ofl I +

(0.001) is added to the reading; 1 point iS S..tat*d f.r each ,oF be.ow 77 0 P. The specific gIrai ofIItho oetýrolyte in a cell increasos with a loss of water due toeleGtroly-i*S or e-aporation.

Category B defines the normaI ParFameteFr limlit fr9 each connected Geil.

The term, "connoc3ted cel!" excludes any batte, G*r il that may bejumApred Out.

The Category B3 limits specified for electrolyt!ee lo and float Yeltage are the same as those specified for Categor~' A and have boon discusse13d above. The Category B3 limit specified for specific gravity for each4 connected %1ilis Ž!1.195 (0.020 below the man;ufacturer fuly charged, nem~inal specific gravity) With the aYeragc of all connected calls >1.205 (0.010 below the mqanufacturer fuly charged, Gnoinal 6pecific gravity).

These values AreA ba6Red on manufac~t~urer's recommendations. The minmu speific gravity value required for each cell1 ensures that the effectIs -ofa;; highly charged or neWly inIstaled coil wilIIIlnot Mask overall degradation of the batery.ý Category C defines the limits for each conc*ted cell. These values, although reduced, provide assurance that sufficent capacity exists to performA the intended function and mnaintain a mnargin of safet. When any battery parameter is outside the Category C limits, the assurance of sufficient capacity described above no lon~ger exists, and the battery mnust be declared inoperable.

The Gateaor; C limits specified for eloctrol~e leyel (above the topI of the LL =l IL = -I--i= -- + * ....

plates ana not OVO......g. ensure Mal !Re plafs 6U-,F or no pRysical damage and mnaintain adequate electFro transfer capability.Th Category C li.mits fo-r float#voltage is ba~se~d onA IEEE 450 (Ref. 2), which states that a cell voltage of 2.07 V or below, under float conditions and not caused by elevated temperatue of the Gl', irdicates internal cell problems and May roquire cell replacemnent.

The Cwategory C limFits of average specific gravity Ž115ibaeonR manufacturer recommendations (0.020 below the manufactJurerF recommended fully ch~arged, nominal specific gravity). In addition to that limnit, it isrequired that the specific gravity forF each cnen~ecnted- cell mu st be no)less than 0.020 below the average of all connected cells. This limit ens'-res that the effect of a highly charged or neW cell does not mask oveaell 4dAradatior of the batefr*..1"

............

(continued)

Watts Bar - Unit 2 B 3.8-75 (developmental) AH

Battery Ge4-Parameters B 3.8.6 BASES S1UIRVED\I I AlQ l F- SR 3.80.6.3 (continUod)

REQUIREMENTS MAeotnote X

• I no to- 4ipolo ui-A1 are aoeiicaoio To 6a19ooorv A 1na

..... ...... FE .......... ... j -- -* -

.I,*

7 -

uRR spociti gravity. ootnote (b)to Tal30 .9.6 1 requi'r4Rs- the ahQove mentioned corection for olocrolyto9 level and temperature, withth exception that !eyel correc-tionA i6 not required when batter; charginig cu-'rArnt is; 2 amps OR float charge for vital b~attrioc and 1.0 amps for -

DG batteies. This currenFtA provides, in general. an indication of oereall Bersause of specifics gravity gradients that are produced during th recharging process, delays Of several days May occur While waitfing for the specific gravity to stabilize. A stabilized charger current is a acceptable alternative to specific graVity mneasuremen~t for doteFRmining the sta-te Of charge. This phenomenon is discusse i~n IEEEF 450(Rf2)

Cnnnnf I n^ T-,hi- '1 9 fi I ,Ipp.th^ finp* ^1,r tq g-rrnt t g) , ea 'c an alte"rate to SpeiAfGc Ora*ity f-r Up to 31 days followinr a ba'te,',

recharge. Within 31 days, each connected cell's specific gravity mAust be me-ý;-asurd- to- cn-firmn the sotate of chage. Following a minorG batter; recharge (such as equalizing charge that does not fellw a deep-discharge), specific graVity gradients are no~t Significant, and conf4Frming me~asuremen8ts May be8 made in less than 31 days.-

SURVEILLANCE SR 3.8.6.1 and SR 3.8.6.2 REQUIREMENTS Verifying battery float current while on float charge is used to determine the state of charge of the battery. Float charge is the condition in which the charger is supplying the continuous charge required to overcome the internal losses of a battery and maintain the battery in a charged state. The equipment used to monitor float current must have the necessary accuracy and resolution to measure electrical currents in the expected range. The float current requirements are based on the float current indicative of a charged battery. The 7 day Frequency is consistent with IEEE-450 (Ref. 2).

This SR is modified by a Note that states the float current requirement is not required to be met when battery terminal voltage is less than the minimum established float voltage of SR 3.8.4.1 or SR 3.8.4.2. When this float voltage is not maintained, the Required Actions of LCO 3.8.4 ACTION A or E are being taken, which provide the necessary and appropriate verifications of the battery condition.

Furthermore, the float current limit of 2 amps for the vital battery and 1 amp for the DG battery is established based on the nominal float voltage value and is not directly applicable when this voltage is not maintained.

Watts Bar - Unit 2 B 3.8-76 (developmental) AH

Battery Ge1-Parameters B 3.8.6 BASES SURVEILLANCE SR 3.8.6.3 and SR 3.8.6.6 REQUIREMENTS Optimal long term battery performance is obtained by maintaining (continued) float voltage greater than or equal to the minimum established design limits provided by the battery manufacturer which is 2.20 Vpc. This corresponds to a terminal voltage of 128 V for the DG batteries, 132 V for vital batteries I through IV and 136 V for vital battery V. The specified float voltage provides adequate over-potential, which limits the formation of lead sulfate and self discharge, which could eventually render the battery inoperable.

Float voltages in this range or less, but greater than 2.07 Vpc, are addressed in Specification 5.7.2.21. SRs 3.8.6.3 and 3.8.6.6 require verification that the cell float voltages are equal to or greater than the short term absolute minimum voltage of 2.07 V.

The Frequency for cell voltage verification every 31 days for pilot cell and 92 days for each connected cell is consistent with IEEE-450 (Ref. 2).

SR 3.8.6.4 The limit specified for electrolyte level ensures that the plates suffer no physical damage and maintain adequate electron transfer capability. The minimum design electrolyte level is the minimum level indication mark on the battery cell jar. The Frequency is consistent with IEEE-450 (Ref. 2).

SR 3.8.6.5 This Surveillance verifies that the pilot cell temperature is greater than or equal to the minimum established design limit (i.e., 60 *F for vital batteries and 50 °F for DG batteries). Pilot cell electrolyte temperature is maintained above this temperature to assure the battery can provide the required current and voltage to meet the design requirements. Temperature lower than assumed in battery sizing calculations will not ensure battery capacity is sufficient to perform its design function. The Frequency is consistent with IEEE-450 (Ref. 2).design requirements.

Watts Bar - Unit 2 B 3.8-77 (developmental) AH

Battery eI4-Parameters B 3.8.6 BASES SURVEILLANCE SR 3.8.6.7 REQUIREMENTS A battery performance discharge test is a test of battery capacity (continued) using constant current. The test is intended to determine overall battery degradation due to age and usage.

Either the battery performance discharge test or the modified performance discharge test is acceptable for satisfying SR 3.8.6.7; however, only the modified performance discharge test may be used to satisfy the battery service test requirements of SR 3.8.4.7.

A modified performance test is a test of the battery capacity and its ability to provide a high rate, short duration load (usually the highest rate of the duty cycle). This will often confirm the battery's ability to meet the load duty cycle, in addition to determining its percentage of rated capacity. Initial conditions for the modified performance discharge test should be identical to those specified for a service test.

It may consist of just two rates; for instance the one minute rate for the battery or the largest current load of the duty cycle, followed by the test rate employed for the performance test, both of which envelope the duty cycle of the service test. Since the ampere-hours removed by a one minute discharge represents a very small portion of the battery capacity, the test rate can be changed to that for the performance test without compromising the results of the performance discharge test. The battery terminal voltage for the modified performance discharge test must remain above the minimum battery terminal voltage specified in the battery service test for the duration of time equal to that of the service test.

The acceptance criteria for this Surveillance are consistent with IEEE-450 (Ref. 2) and IEEE-485 (Ref. 3). These references recommend that the battery be replaced if its capacity is below 80%

of the manufacturer's rating. A capacity of 80% shows that the battery rate of deterioration is increasing, even if there is ample capacity to meet the load requirements. Furthermore, the battery is sized to meet the assumed duty cycle loads when the battery design capacity reaches this 80% limit.

Watts Bar - Unit 2 B 3.8-78 (developmental) AH

Battery GeU-Parameters B 3.8.6 BASES SURVEILLANCE SR 3.8.6.7 (continued)

REQUIREMENTS The Surveillance Frequency for this test is normally 60 months. If the battery shows degradation, or if the battery has reached 85% of its expected life and capacity is < 100% of the manufacturer's rating, the Surveillance Frequency is reduced to 12 months. However, if the battery shows no degradation but has reached 85% of its expected life, the Surveillance Frequency is only reduced to 24 months for batteries that retain capacity > 100% of the manufacturer's ratings. Degradation is indicated, according to IEEE-450 (Ref. 2), when the battery capacity drops by more than 10%

relative to its capacity on the previous performance test or when it is

> 10% below the manufacturer's rating. These Frequencies are consistent with the recommendations in IEEE-450 (Ref. 2).

This SR is modified by a Note. The reason for the Note is to allow the plant to take credit for unplanned events that satisfy this SR.

Examples of unplanned events may include:

1. Unexpected operational events which cause the equipment to perform the function specified by this Surveillance for which adequate documentation of the required performance is available; and

2. Post corrective maintenance testing that requires performance of this Surveillance in order to restore the component to OPERABLE, provided the maintenance was required, or performed in conjunction with maintenance required to maintain OPERABILITY or reliability.

REFERENCES 1. Watts Bar FSAR, Section 15, "Accident Analysis," and Section 6, "Engineered Safety Features."

I* * *A AXXX LA *A J LLI*

2. IEEE 450t 1I39U.14995, 'ThL+/- ReocommA-Ondod P-raotico for B3attorio forF GonReating Statioew- and- Subc-htationsn-."IEEE Std 450-2002, "IEEE Recommended Practice for Maintenance, Testing and Replacement of Vented Lead - Acid Batteries for Stationary Applications," Institute of Electrical and Electronics Engineers, Inc.

3. IEEE Std 485-1983, "IEEE Recommended Practice for Sizing Large Lead Storage Batteries for Generating Stations and Substations," The Institute of Electrical and Electronics Engineers, Inc.

4. Watts Bar FSAR, Section 8, "Electric Power."

Watts Bar - Unit 2 B 3.8-79 (developmental) AH

Battery GeU-Parameters B 3.8.6 BASES Watts Bar - Unit 2 B 3.8-80 (developmental) AH

Contn"ment Penetratio-nSTHIS SECTION NOT USED B 3.9.4 B 3.9 REFUELING OPERATIONS B 3.9.4 Centainment PenetrAtionsTHIS SECTION NOT USED During moGVRemen-t Of irra-d-iat-d- fuel1 aseble ithin con-t;4ainment, a release of fisrsion product radioactivity within containment will be9 restricted from; escaping to the enViFronment WhenA the LCQ requiremnents are met.

In MODES 1, 2, 3, and 4, thiG i6 accOMplichod by maintaining containment OPERABLE as described inLCGO 3.6.1, "Containment." In MODE 6, the potential for con-tainmenA-t pressuriZation as a result Of an accident is not likely; therefore, requirements to isolate the containment from the utsde atmosGphe-re can be9 loss Stringent. The LCGO requirements are referre~d to as, "contaRin.ment closure" ra;ther than; "containment OPERABILITY." Containment closure mneans that al!

potontiaI escape paths are closed Or capable of bein~g closed. Since there is no potential for co~tiAFnment pressurization, the Appendix j leakage criteria and tests are not required.

The- containm~ent 6orYes to contain fission product radioactivity that May be released froM the reactorF core follown an acident, such that offsite radiation exposures are mnaintained well wthinR theA irequirFeMenRts of 10 CFR 100. Additionally, the containment provides radiation shieldingq from- the fission products that m~ay be pr9eset in the-containm.entA atmosphere following accident conditieons.

The containm~ent equipment hatch, which is part of the containment pressure bounder,, provides-6 -A means for mo;ving lag eqimnt a;nd comnponents into and ou t of containment. During movLe.ment Of irradiated fuel assemblies within containment, the equipment hatch m~ust be hold in place by at least four bolts. Good enginern pracItice dictates thaRt the bel1ts required by this LCO be approximately equally spaced.

The containment air locks, which are also part Of the containment-pressure bGun~dar,, provide a means for personnel access duFring MODES 1,2, 3, and 4 unit oper-ation in accordancGe with LCOQ 3.6.2, "Containment Air Locks." Each air lock has a dIoor at both ends. The doors are nermally finterlocked to prevent simultaneu openig when containmen9t OPErRAR"I!T isrequired. During Periods,of unit shutdon;s

.When conRtainment closure iSnot required, the door in~terleck mnechanism may be disabled, allowing both doors Of an air lock to remnain open for extended periods when frequent centainment ont ,' isnesa. During (eo~ed)

Watts Bar - Unit 2 B 3.9-11 (developmental) AH

Containment Penetratiens

-8

43.4 BACKGROUND

mo-voment of irradiated fuol assemblies Within containment, containment (G~eRt4~ed) closuro i6 required; therefor9e, the door interF!*k mRocha*i*m may remair dieabed, u n wl~,dprr~M h aaeO 9f

'-irm Gh erirdn.ir 't frtnt-imn nntitn ht~

releaeof fission prFoduc4t radioa4cvity Within Rontainme*nt will e re Ftficted to within regulatory imnits.

The Rea*tor BuildinRg urge Ventilation SyStemt operate. to.u.pply outsideaiMito the onanmn for venRtilation and cooling or heating, to equalize internal and external pressures, and to reduce the co-ncnmtr-ation Of noble gaseS Within containmenRt prior to and during personnel access.

The supply and exhaust l"nes each contain Won isolation valves. Becwau se of their largqe 6, the 24 inch containm.on.t,.rl. O compatment pur.e valves are physically Frestricted to!!; 50 degrees open. The Ro-ace Building Purge and VentW*itn System val*es can be opened in MODES 5 and 6, but are closed automatically by the EnRgineered Safety Feat-ues.AcntuatioRn System (ESFAS). In MODE 65, Iar*ge air exhanges are necessar-y o9onduict refueling opeations. The normal 24 inch purge system is used for this purpose. The ventilation system mnust be either wsolatod OFrcapable of being automatically iselated upon detection of high radiation levels wi0thin containmient.

T-he o-ther coantainment penetrations that provide direct access froAm containment atmospher-e to outside atmosphere m~ust be isolate~d on At least one sidle. slto-a eahee ya PR.L uoai isolation; valve, or by a maulioainvalve, blind flange, Or equivalent.

Eiale isoltiornor musts be approved and may ilude use of a method material that can provide a temprary, atmospheric pressure, ventilation brirfo-r the ether containmenRt penetrations during fuel moGv8emets (Ref. 1). ClOsure by ether valves Or blind flanges may be used if they are similar in capability to those provided for containment irsolation. T-heseA m;ay be conStructed of standardI materials and may be justified on the basis of eithe-r nor-mal an;alycis methods or reasonable engineern judgment (Ref. 4).

APPLICGABL e IDuring movement of irradiated fuel as-se-mblierbmswihn cnanet the SAFETYmost severe radielegical consequences result fromR a fuel handling ANIALYSý accident. The fuelA- handling acc~ident is a postulated event that involves damage to irradiated fuel (Ref. 2). Fuel handling accidents, Inayzed i Re-feqrence-R -2,include drogpping a single irradated fuel assembly-and-handling tool Or a heavy ebject onto other irradiated- fuel assrem~blies.

Watts Bar Unit 2 B

6onta'AInmon Pdonotra!ions 84.44 BASES

.APPLI'C-A'BLE The requ-eirements of LCOQ 3.9.7, "Refueling Cavity Water Level," in RA F;EmTYL conjunction With a minimumu~ decay time of 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> prior to irradiated ful--moVe-men-t- with c-ontainmenRt closuF9recapability en;SureS that the rlAse f flss*on product ra;dnioactivity, subeGu~ent to Afue h ndling acciden~t, results in doese that are well within the guideline Yalue specified in 10 CER 100. Standard RevieW Plan, Section 16.7.4, Rev. 1 (Ref. 3), defines "well within" 10 CFR 100 to bhe- :25% or loss-of the 10- C-FR 100 val-uesr. Thie acceptanco limitS for offitot radiation exposuree will be 25%0 of 10Q CErR 100 values or the NRC staff approved iesg baums IRn~. seecifd ra frac;tion o~f 10 CPR 100Q limit)

Containent peetrat*Gons sat*f' Criterion 3 of the NRC Policy Statemelt.

Thist LG

.... HFlkst~the rsnseRWnAtncnf ef a fiuel handlin, arrident in

.. A.l .,..

f- r.

radioactivity released WithiR contanment. The LCQO requieres any-penetration pro9viding direct accGss fromn the GgntainM9nt atmos~phere te the outside atmoGsphere to be closed eXcept for the OPERA\BLE Reactor Building Purge and Ventilation System penetrations, and the containme.t personnel a*Fle.k.. ForF the-A OPEZR.BLE R*eacto Building Purge and Ven-ti--rla-t System penetration, this LC ensures that these penetrations -are-isowl-able by the Containment Ventilation !solati~ln SystemA.

+Re WIIKJE !I=-+r ogiumn r LflIS LGO enswer thati the autemat purge and exhaust v-alve-closuire tie6pecifed in the F=S.AR can be anchieved- and, therefore9, meeqAt the-asmtosused ~nthe safety-analysis to e-nsu--re t-ha-;t rlae th-rough the valves are terminated, SUch that radielogical doses are within the acceptance limit.

The Gontainment personnel air'oock doors may be open during movemnent of irrFadiated fuel iRthe Ggntainment providted- tha-t onRe deer is capable of being closed- in the event of Afuel hanRdl~ing acciden~t an~d provided that ABT is OPERA~VBLE ORaccoruanco With TS~ 3.7.12. Should a 'e handling accident occGur inside contaiment, one personnel airlock doer will be closed foallowing an eyacuation of contaiment. The LCO is medified by a NoAte- all-owing penetration flew paths with direct -access fromA the Geontainment atmorsphere to the outside atmosphere tob unisolate-d iunderB admnitraivGcotrls Admninistrative controls ensure that 1)appropriate personnel are aware of the open status of the-penetration flow path durin movmet of irrad-iated- fuelA- ýassemblies WONR GGRtaiR ent: 21 SmeGified ORdiy4duals aFe de6k]Rated aRd readliv (GGRtieWd)

WAaft Bar Unit 2 A

69MenaIRnmOn Pd8netrzuionR B 3.94 BASES8 L-Go3) ponotration flow paths, penetrating the Auxiliary Building Socondar,'

(G94Rtued) Containment Enclos6uro (ABSCE=) boundar-y, are limited to less than the BAS*E*- bmroch

" allOWaRnc; ard 4) the ABGTS is OPERA.Er in aCCordance wi;th TS- 3-7.12. Operability of A1BGTS- is required to ,alleviate the consequences of an FHA insi~de containment resUlting in leakage Of airborne Fadieoancive matei~wal past the open airlock Or penetration flow pathsG prior to their closu re-.

.APPLI[C-AB-ILITY The containm~ent penetration requiremnents are applicable during mov'ement of irradiatod fu-1e assemblies wthin containment because this is whern there i,- a potential for the lim*iti*g fuel haRdling accide-nt. In MODES 1, 2, 3, and 4, containmenRt penetration requiremnents are-addressed by LCO 3.6.1. In MODES 5 and 6, when movement of-irradatedfuelassemlieswithn cotainment is net bein~g conducted, the potential for a fuel handling accident dos* nRt exist. Therefore, under these condition no equremets are placed On; containm~ent penetration 6tatu6.

If the- con-ta-inment equipmen~t h~atch, air locks, or an" cntainm~ent penetration that provides direct access from the containment atmosphere to the outside atmosph~ere 16 net in the required status, including the Con-t~ainmen-t VenRtilation Isolatian System net capable of automai ataion hen the purge and exhaust valves are open, the unit mRust be placed in a GenditiGR where the isolation fucinis nt needed. This is accomplished by immediately suspending movement of iF~adiatod fuel assem~blies wIAthiN conA-t-ainment. Performance of these acin hall not preclude com~pletion of mevement of a comAponent to a safe PGsit*Gn.

SURVEILL\ANCE R-3.44 REQUIREMENTS This Sur~eillanca demonsRtrates that each of the containment penetrations required to be in it closed position is in that position. The Survoillance on the open purge and exhaust valves will demonstrate that the valves, are not bloc-ked frm.-m closing. Also the Survoillanco will demon~strate that each valve operatorF ha* moFtiVe PoweF, which will ensure that each valve is capable of being closed by an O-PERA.LR utemWAce n ventRilationisoatosinl Wl;tts Bar UJnit 2 B 3.9 44 (dy 0Gmntl A

Containment Penetrations B 3.9.4 BASES SUR VI:E I AL'lrC QF SR 3.9.1.1 (continued)

REQU REMENTS a.,a,7 Ai re A.

Cl.. -nnnra, ^fa a 00 rMv WIrcp cx-ro or H EMU LI! -- *11-! .... A--! ....

irra a aite e T...

t

.. A. M. I.. . w itn In Illco n II TAinm .. .. i .n. .

I* J selepLed $t ht; commenlirtef with the normal 911Fulrn I P or f!m9 II tot1 I a comnplete fuel handling operations. A sur~lllanco before theo start of refueling operations will provide two or three sUrYoilIRARc Verifications during the applicable period forF this; LCO. As sucoh, this Surveillance ensures that a postulated fuel handling accident that releases fission product radioactivity within the containm~ent Will not reSUlt ina release of significant fis6ion product radio~Acivity to the enViFromen~t in exos 9f thosbe reconmmenR8ded by Standard ReViewM PlanM Section 15.7.4 (Ref. 3).

This Surveillanc~e demonstates that each containmenAt purge and exhaust valve actuates to its isolation position on mnanual initiation Or On an actual or simulated high radiation signal. The 18 mRonth FrequencY m~aintains consistency With ether similar ESFAS itrmnaonand valve testing requirem~ents. LCGO 3.3.6, "Containm~ent Ventilation Isolation; Instrumentation," requires a CHANNEL CHECGK ever' 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and a COT- ever,' 92 days to ensrWe the channel O)PERABILITV durling refueling operations. EvYer' 18 mon9ths, a CHANNELI CALIBRATION is pe~fGFmed.

The soystem actuation reGponse time isdmntaed ever 18 months, dur~ing refueling, On a STAGGERED TEST BASIS. SR 3.65.3.4 de~monstratews that the i~solation time of each valve is in; accordRance With the Inser~ice Testing Prora requrents. These Survellancos peofermed during MODE 6 w.~ill nsr that the valves are capable of clesing a#fte a postulated fuel handl'ing accidenRt to limtarelas of fissio.'n oroduct radioactivity from the GGntainment.

4,; "UsF;e o-f S~iliconGe Sealant to Maintain Con(9taRinmen9t lntegrity ITS.

May 20, 98&-

Watts Ba;r FSAR, Section 15.4.5, "Fuel H4andling Accident.

NUREG 0800, Standard Review Plan, Section; 15.7.4. "Radolpeica Lonsnuenes f Ruel HanclinoU Acci-dents: Keyv. I.I Juiv I MI.

I~*W 4-. Generic Loller 88 17. "Loss of Decay Heat Removal."

WAtt~s Bar Unit 2 a

Refueling Cavity Water Level B 3.9.7 B 3.9 REFUELING OPERATIONS B 3.9.7 Refueling Cavity Water Level BASES BACKGROUND The movement of irradiated fuel assemblies within containment requires a minimum water level of 23 ft above the top of the reactor vessel flange.

During refueling, this maintains sufficient water level in the containment, refueling canal, fuel transfer canal, refueling cavity, and spent fuel pool.

Sufficient water is necessary to retain iodine fission product activity in the water in the event of a fuel handling accident (Refs. 1 and 25). Sufficient iodine activity would be retained to limit offsite doses from the accident to

- 25%0 of 10 CFR 100 limits, as proVided by the guidance of Rtfeie-- the limits defined in 10 CFR 50.67 (Ref. 4) and Regulatory Position C.4.4 of Regulatory Guide 1.183 (Ref. 5).

APPLICABLE During movement of irradiated fuel assemblies, the water level in the SAFETY refueling canal and the refueling cavity is an initial condition design ANALYSES parameter in the analysis of a fuel handling accident in containment,-ae-postulated by Regulato.y Guide 1.25 (Ref. 1). A minimum water level of 23 ft (Regulatory Position G-,---2 of Ref-4Appendix B to Regulatory Guide 1.183) allows an overall iodinea decontamination factor of 40-200 (Regulatory Position G.1.9. of Ref. 1) to be used in the accident analysis fGF iedine. This relates to the assumption that 99% of the total iodine released from the pellet to cladding gap of all the dropped fuel assembly rods is retained by the refueling cavity water. The fuel pellet to cladding gap is assumed to contain 8% of the 1-131, 10% of the Kr-85, and 5% of the other noble gases and iodines from the total fission product inventory in accordance with Regulatory Position of Regulatory Guide 1.183total fuel red iodine ine'ntory (Ref. 1) exGcpt for 1134 Which is assumed to be 12% (Ref. 6).

The fuel handling accident analysis inside containment is described in Reference 21. With a minimum water level of 23 ft and a minimum decay time of 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> prior to fuel handling, the analysis and test programs demonstrate that the iodine release due to a postulated fuel handling accident is adequately captured by the water and offsite doses are maintained within allowable limits (Refs. 4 and 5).

Refueling cavity water level satisfies Criterion 2 of the NRC Policy Statement.

(continued)

Watts Bar - Unit 2 B 3.9-20 (developmental) AH

Refueling Cavity Water Level B 3.9.7 BASES (continued)

LCO A minimum refueling cavity water level of 23 ft above the reactor vessel flange is required to ensure that the radiological consequences of a postulated fuel handling accident inside containment are within acceptable limits, as provided by the guidance of Reference 32.

APPLICABILITY LCO 3.9.7 is applicable when moving irradiated fuel assemblies within containment. The LCO minimizes the possibility of a fuel handling accident in containment that is beyond the assumptions of the safety analysis. If irradiated fuel assemblies are not present in containment, there can be no significant radioactivity release as a result of a postulated fuel handling accident. Requirements for fuel handling accidents in the spent fuel pool are covered by LCO 3.7.13, "Fuel Storage Pool Water Level."

ACTIONS A.1 With a water level of < 23 ft above the top of the reactor vessel flange, all operations involving movement of irradiated fuel assemblies within the containment shall be suspended immediately to ensure that a fuel handling accident cannot occur. The suspension of fuel movement shall not preclude completion of movement of a component to a safe position.

A.2 In addition to immediately suspending movement of irradiated fuel, actions to restore refueling cavity water level must be initiated immediately.

SURVEILLANCE SR 3.9.7.1 REQUIREMENTS Verification of a minimum water level of 23 ft above the top of the reactor vessel flange ensures that the design basis for the analysis of the postulated fuel handling accident during refueling operations is met.

Water at the required level above the top of the reactor vessel flange limits the consequences of damaged fuel rods that are postulated to result from a fuel handling accident inside containment (Ref. 21).

The Frequency of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> is based on engineering judgment and is considered adequate in view of the large volume of water and the normal procedural controls of valve positions, which make significant unplanned level changes unlikely.

(continued)

Watts Bar - Unit 2 B 3.9-21 (developmental) AH

Refueling Cavity Water Level B 3.9.7 BASES (continued) i I I

• I REFERENCES Regulator: Guide 1.25, "Aceump~tIOnS Used tor Eyalwatlneivme t**_*___L_*_I li*i_ J!=l_=:*_l /'%

WAeTenTIa -~Al iicia -GRceciU6REcv 8+ a IrUe I 01RzIno-RIAnt. :.ociuoit in the; Fuoal andhng and Soag Faclty for Boiling and Proessurizoed- Water ReactoFrs," U.S. Nucloar Rogulator,'

Commission, March 23, 197-2-.

21. Watts Bar FSAR, Section 15.4.5, "Fuel Handling Accident."

32. NUREG-0800, "Standard Review Plan," Section 15.7.4, "Radiological Consequences of Fuel-Handling Accidents,"

U.S. Nuclear Regulatory Commission.

43. Title 10, Code of Federal Regulations, Part 20.1201 (a), (a)(1),

and (2)(2), "Occupational Dose Limits for Adults."

- o " "tj ft , . .1 tp , . .1 " ", ., am t;Vt7C2"tV-,-a-.,

JAI~ ni~. I~aeio~oaicai uoncoouencoc OT a i-uoi ~ano~ina Accident, December 197!.Title 10, Code of Federal Regulations, 10 CFR 50.67, Accident Source Term."

5g. NURE&GCR 5000, "Assessiment of the UIS-3 Of EXtend8d BuFRnUP Fuel in Light Water PoWer Reactors," U. S. Nuclear Regulatory Commission, Februarjy 1g8.Regulatory Guide 1.183, "Alternate Source Terms for Evaluation Design Basis Accidents at Nuclear Power Reactors," July 2000.

Watts Bar - Unit 2 B 3.9-22 (developmental) AH

ReacztorF Buildine Purgne A~ir Cle-anu 44UtsTHIS SECTION NOT USED B 3.9.8 B 3.9 REFUELING OPERATIONS B 3.9.8 Reactor Building Purge A.i Cleanup UnWt THIS SECTION NOT USED BASES The4 Reactor Building Purge Air Cleanup Units are aenierdsafet feature of the Reactor Building Purg8 Venltilation System hih s noR Safety feature VentilatioR SY-t-m. The ai-r cleaRup unit contain prefiltw"s, HEPA filters, 2 inch thick charcoal ador{brS, hous'ings and ductwork. Anytime fuel handling oper-ations are being carried an inside the primnary containm~ent, either the containment Ventilation Will be-isolated Or the Reactor Building Purgo air cleanup units Will be OPERA.BLE (Ref. 1).

The Reactor Bufilding Purge Ventilation SystemR provide6 mechanical Yentilation of the prim~ary con~tainm~ent, the instrum~ent room located within the containment, and the ann-dulu. The4 systemn i6 designed to Supply fresh air forF breathing and contamination controel to allow pFersonne acGc6s for mainateRane and refue~ing operation6s--Th.e aust air is filtered by the Reactor Building Purge Air Ceanup Unitsm to limit the release of radio~activity to the enviF4ronment.

The conRtainmqent upper and lower G9ompa~tments aro purged with fresh air by the Reactor Building Purge Ventilation System before oc.upancy. The annu.u. can be purged with fresh air during reactor sh.utdowR or at times

hen the annUIUS vacuumn cOntro systemA of the EmRergency Gas-Treatmfent System is shut down. The instrumont roo is purgd with fr61;h air d.ruring operation of the, Reaor,,,, Building Purge Ventilation System Or *i separatey purged by the InRstFrument Roo Purge Subsystem.. All purge ventilation f*unction are non Safety relatetd The Reazicwr ounuInoR Pdurue Ventiiaugn OYStoM 1s SiZefg 1o DrOVIGO I *

• i II

• i adequate ventilation Tor personnei to ponrmFF Wor~ nsiao the pr Imr contaiRnment and the annulus during al! normal eperatiens. In the even9-t Of a fuel handling acci*d8et, the Reacrto BuildiRn Purge VenIl;atio SysteM *i isolated. The Reactor Building Purge Air Cleanup Units are always-available as passive i,;nline*oR-mp t* to peOFrm their function immwnediately after a fuel handling acciden.t to process activity contain*e exhaust air before it reaches the outsid-e enAvironenMGt.

kGwniped)

Watts Bar - Unit 2 B 3.9-27 (developmental) AH

I I--:L*

Wt1eactor WWF96in AureGler~iaRUp) un4 133.9.9 RASES BACKGROUND The PrFinmar containment oxhaust is monitorted by a radiation deteGtor (G9RtiRued) Which provides automat* c contai- n pruge ,*ntilation S*yt9m nment olatin upon detocting the sotpoinRt randio;activty Rnthe exhaust air streamR. The cnonntainment purge VSnt;ilation n vialvyes

, Will bhO automIGAticOally clGoed up'n the actuation of a Containm*eRt Vent lon (\II\ when**er

.ignal (GVI) the prinmr*, ontainnment is being purged during RFnoral operfiWn or upon manual actutiotn from tho Main CnCtrol Room (Ref. 2). Requirements for CntOnmenRet Vent lme÷ationInstrumentation are oevered byICnO 3.3.6.

APPLICABL P The Reactor Building Purge Vertilation System,; air* Goaup units ensrure SAFETY+ that the rl of FRadio*activity to the eAnviFronment is limited by ineanihig Up G\ntainment exhaust during a fuel handling acmident befor Fhe contaiRnment purge exhaust valvesb arse isolated. Reactor Building Purge Voni÷aio lSystemr filter effichi Gne Of the inputs for the analysis of on,-6 the envro;Gnmental consequences6 of a fuel handling accident.

Containment isolation can only result in smnaller releases of radioactivity to theon oAiGt (Ref.i1o men The Gontainmnt VeRnt Isolation System Ansures that the containment vent ,and purge peRetrationR will b automatically isolated upon detection of high radiation levels within the contaiF;nment (Ref. 2). Containment Vent Isol-ation Iruettini address~ed by LCO 3.3.6.

The Reactor Building Purge Air Cleanup Un~its satisfy'Criterion 3 Of the NRC Policy Statement.

In addition, during moGv9emet of irradiated fuel in the Auxiliar-y Buildig WheR contaiRnment iSopen to the Auxiliary Building spacses, a hig-h radiation signal fro-m the-spent fuel peol acciden~t radiation monitors , a ConAtainm.enAt Isolation Phase A (SI sign~al) frogm the oporating unit, high temRperature in; the Auxiliary Building air intakes, or manul ABI wil initia;te a CVI. In the case where the cOntaiRnmenAt. of.botFuitS isopen to the Auxiliary Building spaces, a CVI in one unit Will initiate a CVI in the other uiinord-er to.m.aintain those spaces open to the ABSCEF.

The safety func~tion of the Reactor Bui4lding Purge Air Cleanu1p Unit is related to the initia! contre! o-f oF.t raito xoures resulting #fro a fuel handling accident insido GGGntainmnt Duig a fuel hand~ling accient nsie ntainment, the Reactor Building Purge Air Cleanup Unit provides a filtered path forF clean~ing up any air leaYing the containment un-til the cneptainment ventilationilioatd Watt*s Br Unit 2 (dvlopmetl)

-- a-toFr IiI-d*RQ UFIrq AOF A (;'GaRUP l IJ 133.9.8 LGQ The plant design basirq*u i,-; s that WhBnA moing irradiated fuel in the (Ge4Rued) Auxi'iar' Building o~!FG1tiMFtWiht9G~aR~~

pen the Awmvia,- Building A S rpa* e.* , asign*n,' I m the-pen fu.l ,F:,en*n monito* 0 RE 90 102 and 103 Will initiate a CVI in addition to their norFm-Al funcRAtion. In aRddi@tion, a 6ignal frmthe coentiainmFent purge radiation monitors* 2 RE( 9(0 130,* and 1 3 rOFthr CIVI -ignal Will iRitiate that pllin of the AB-RI normallyinitiated by the spent fuel pool radiati o monitors. A~dditionally, a CnametIotinPhase A (SI signal) from the operatinRg unit, high temnperature in the Aumiliari Building airinaks or manual ABI1 will cause a CVI signal inR the refueling unit. T-hereforFe, the containment -ventoiationinstrumentatlon mustt remain operable when moing, irr-adiated fuel in the Auxilia*y uildiRng if the c-ntainFmen t Ir*,l-ks penetrations, equipmfent hatch, etc. are open to the Auxiliary Building ABSCE= spaces. In addition, the ABGTS must remain operable if these conRtain.mnt penetrations are open to the Auxiliary Building durng,@

movement of iFradiated fuel in side conAtainmenAt. In the case where the contaiRnment of both units is open; to the Auxiliary Buildingq spaces, a CVI in one- 'unit Will initiatte a C-VI in the_ o-therF unit in order to minai thoseq spaceG open to the ABSCE.

APPLICABILIT An initial assumption in the analysis of a fuel handling accident isd contain*men"i that the occus whileat taccidethd handletd_. Therefore, LCO 3.9.8 is applicable only at thiS ti~m~e. see ad-dition~al discussionr_,(9 inthe Applicable Safety Analysis and L=,CO sections.

AGT-IONS _.Ia~ .

if one Roaster Building Purge Air Cleanup Unit is ineperable, that air ceanup unit m.us;t bhe islated. This places the system in the required

• on4fguration, thus allowing refueling to r-antinue afer- erifying accident the eminn air cleanup unit Is aligned and OPERABLE.

The imeit ompletion T-ime is consistAnt With the required times, fonr actions to be pe~fermed without delay and in a con~troalled mannr.

WAI-+s Bar UnIt 2 B 3.929 (dove lopme ntal) GI

M A1 AI I i tL Reactor tiuMidin l-'urg Air Cleanup Wnt 1349.8 ACTIONS 984 (GGetRued)

WiAth tWon Re-actor Building Purge Air Cloanup Units inoperable, MoQVomo;nt o9f iraitdfuel assemblies_ wIAthin conQtainm~ent mAust b9 suspended.

This prec'udes the possibility of a fuel han~d!ing accident incOntaiRnment

..ith both ReActor Bu ilding Purge AiF Cloanup Unitsinprbe Performa~nce of ths cion shall noGt preclud9 moInG omoentl to a safe peste;*r The immediate Completion Time is consistent With the required times forF actAions, to bhe performned without delay and in a controlled m4annr S'JRVEILLANICE RR34 REQU IREMENTS The_ Ventilllato*n- Filter Tes-ting ProgrFam (VF\TDP) enco'mpass*e the ReaGto*

Building Purge Air Cleanup Unit filter tests in accordance with Regulatory' Guide 1.52 (Ref. 3). The VFTP includes testing the performance of the HEPA filter, charco-al -adeorbsrerefficiency, miiu . f.lew rate, and the physical prope~tios of the actiyated charcoal. Specific test rFreqecs and aditinal nfor at~nae discussed in detail in t-heA VFRTP.

REFERE- CE 4,~ W~ats Bar FSAR, Section 15.5.6, "Einvironmental Consoquencos Of a Postulated FuelA_ Hand-ling Accident."

2- Watts Bar FSAR, Section 0.4.6, "Reactor Building Purge Ventilat~ing system.

3, Regulatory Guide 1.52 (Rev. 02), "IDesign, T-esting and-Maintenan. Criteria for Pest AGccdent Engineered Safety Feature Atmesphere l.ean.p System A;r rFltration and Adsorptieon Units of Light Water Cooled Nuclear Power Plants."

IAIAtts Bar Unit 2 R 29-30 A

Decay Time 3.9.10 B 3.9 REFUELING OPERATIONS B 3.9.10 Decay Time BASES BACKGROUND Section 15.5.6 of the Watts Bar FSAR (Ref. 1) defines the assumptions of the fuel handling accident radiological analysis, including a minimum decay time for irradiated fuel assemblies prior to movement. This assumption ensures that the inventory of radioactive isotopes is at a level that supports the safety analysis assumptions.

To ensure that irradiated fuel assemblies have decayed for the appropriate period of time, a limitation is established to require the reactor core to be subcritical for a time period at least equivalent to the minimum decay time assumption in the fuel handling analysis prior to allowing irradiated fuel to be moved.

Given that no irradiated fuel assembly will be moved outside of the containment until the minimum decay time requirement is met, this requirement also ensures that any irradiated fuel assemblies that are moved outside of the containment meet the decay time assumption in the radiological analysis of the fuel handling accident.

APPLICABLE The radiological analysis of the fuel handling accident (Ref. 1)

SAFETY assumes a minimum decay time prior to movement of irradiated fuel ANALYSES assemblies. The requirements of LCO 3.3.7, "Control Room Emergency Ventilation System (CREVS) Actuation Instrumentation,"

LCO 3.7.10, "Control Room Emergency Ventilation System (CREVS)," LCO 3.7.11, "Control Room Emergency Air Temperature Control System (CREATCS)," and LCO 3.9.7, "Refueling Cavity Water Level," in conjunction with a minimum decay time of 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> prior to irradiated fuel movement ensures that the release of fission product radioactivity, subsequent to a fuel handling accident, results in doses that are within the requirements of 10 CFR 50.67 (Ref. 2) and Regulatory Position C.4.4 of Regulatory Guide 1.183 (Ref. 3).

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

(continued)

Watts Bar - Unit 2 B 3.9-26 Technical Requirements (developmental) H

Decay Time 3.9.10 BASES (continued)

LCO A minimum decay time of 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> is required prior to moving irradiated fuel assemblies within containment. This preserves an assumption in the fuel handling accident analysis (Ref. 1), and ensures that the radiological consequences of a postulated fuel handling accident inside containment are within acceptable limits.

APPLICABILITY This LCO applies during movement of irradiated fuel assemblies within the containment, since the potential for a release of fission products exists.

ACTIONS A.1 When the initial conditions for prevention of an accident cannot be met, steps should be taken to preclude the accident from occurring.

When the reactor is subcritical for < 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br />, movement of irradiated fuel assemblies within containment must be suspended.

This action precludes the possibility of a fuel handling accident in containment. This action does not preclude moving a fuel assembly to a safe position.

The immediate Completion Time is consistent with the required times for actions to be performed without delay and in a controlled manner.

SURVEILLANCE TSR 3.9.10.1 REQUIREMENTS This SR verifies that the reactor has been subcritical for at least 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> prior to moving irradiated fuel assemblies by confirming the date and time of subcriticality. This ensures that any irradiated fuel assemblies have decayed for at least 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> prior to movement. The Frequency of "Prior to movement of irradiated fuel in the containment" is appropriate, because it ensures that the decay time requirement has been met just prior to moving the irradiated fuel.

(continued)

Watts Bar - Unit 2 B 3.9-27 Technical Requirements (developmental) H

Decay Time B 3.9.10 BASES (continued)

REFERENCES 1. Watts Bar FSAR, Section 15.5.6, "Environmental Consequences of a Postulated Fuel Handling Accident."

2. Title 10, Code of Federal Regulations, 10 CFR 50.67, "Accident Source Term."

Watts Bar - Unit 2 B 3.9-28 Technical Requirements (developmental) H

ATTACHMENT 3 WBN Unit 2 TS and TSB Developmental Revision H (Optical Media Storage)