ML17331B066

Proposed Tech Specs 3/4.5.1, Accumulators.

ML17331B066
Person / Time
Site:	Cook
Issue date:	11/12/1993
From:	INDIANA MICHIGAN POWER CO. (FORMERLY INDIANA & MICHIG
To:
Shared Package
ML17331B065	List: ML17331B064 ML17331B066
References
NUDOCS 9311190288
Download: ML17331B066 (25)

Text

ATTACHMENT 2 TO AEP:NRC:1186 EXISTING TECHNICAL SPECIFICATION PAGES MARKED TO REFLECT PROPOSED CHANGES 9311190288 931112

,PDR ADOCK, 05000315 P PDR,

C ~ C~LIqa SYSTEMS ~ECCS LIMITING CONOITIOH i OR . cALT:"N reactor coola'nt system accumulator shall be OPERA8t.E ~f th:

3.5.1 Each

a. The isolation valve o"en, A contained "ora ed ~ater volume of between 921 and 971 cubic feet ~

c A boron concen:ration of between 2400 ppm and 2600 ppm, and

d. . A nitrogen =";.er-"ressure of be ~een :85 and <58 psfg.

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"'a "r f"""er~b ~ue-  :-.e isolatio valve

=".e isola valve or

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~i RVE L lC. REOUIRcue( S 4.5-1 Each accumulator shall be demonstrated OP"="-.ABLE:

At least once "er 12 hours by: +p ~ p << ,I d

in tt',e tanks, and

2. 'I ri "~"".", ".'" each accumulator is "lati "n valve is open.

Pressurizer pressure above 1000 psig.

0. C. COOK - UNIT 1 3/4 S-1 ~

->nm~~~ M~

EMERGENCY CORE COOLING SYSTEMS aM~

SURVEILLANCE RE UIREMENTS Continued pov

b. At least once per 31 days and>within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> after each solution volume increase of greater than or equal to 1% of tank volume y

.verifying the boron concentration of the accumulator solutio

c. At least once per 31 days when the RCS pressure is above 000 psig, by verifying that power to the isolation valve operato is disconnected by removal of the breaker from the circ t.

~h Ver44-:yea~ = 1-east utomat

( k4.4

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1+f~lj J Qv up~

p~ -4)

COOK NUCLEAR PLANT - UNIT 1 3/4 5-2 AMENDMENT NO.g P7,$ $ $ ,

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3 4.5 EMERGENCY CORE COOLING SYSTEMS BASES 3 4.5.1 ACCUMULATORS The OPERABILITY of each RCS accumulator ensures that a sufficient volume of borated water will be immediately forced into the reactor core through each of the cold legs in the event the RCS pressure falls below the pressure of the accumulators. This initial surge of water into the core provides the initial cooling mechanism during large RCS pipe ruptures.

The limits on accumulator volume, boron concentration and pressure ensure that the assumptions used for accumulator injection in the safety analysis are met.

The accumulator power operated isolation valves are considered to be "operating bypasses" in the context of IEEE Std. 279-1971, which requires that bypasses of a protective function be removed automatically whenever permissive conditions are not met. Zn addition, as these accumulator isolation valves fail to meet single failure criteria, removal of power to the valves is required.

he imits operation with an a m a reason >>

cept a isolation valve clos minimizes the time exposur of the plant to LOC event occurring conc ent with failure of an a ional accumulator h may result in unac table peak cladding te atures. If a clo d

'lation valve canno e immediately opened,' e full capability o e cumulator is not ailable and prompt a is required to ce t e ctor in a mod where this capabi is not required.

3 4.5.2 and 3 4.5.3 ECCS SUBSYSTEMS The OPERABILITY of two independent ECCS subsystems ensures that sufficient emergency core cooling capability will be available in the event of a LOCA assuming the loss of one subsystem through any single failure consideration.

Either subsystem operating in conjunction with the accumulators is capable of supplying sufficient core cooling to limit the peak cladding temperatures within acceptable limits for all postulated break sizes ranging from the double ended break of the largest RCS cold leg pipe downward. In addition, each ECCS subsystem provides long term core cooling capability in the recirculat'ion mode during the accident recovery period.

COOK NUCLEAR PLANT - UNIT 1 . B 3/4 5-1 AMENDMENT NO. 53

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3 4. 5 EMERGENCY CORE COOLING SYSTEMS ECCS ACCUMULATORS LIMITING CONDITION FOR OPERATION 3.5.1 Each reactor coolant system accumulator shall he OPERABLE with:

a. The fsolation valve open,

b. h contafned berated vater volume of between 921 and 971 cubfc feet,

c. h boron concentratfon beechen 2400 ppm and 2600 ppm, and

d. h nitrogen cover-pressure of betveen 585 and 658 psig.

APPLICABILITY: MODES 1, 2, and 3.*

ACTION:

o accumulator fnyp~ab e, except as a~rult o a c PC PlIA+ iso tfon valve, re~@re the fnoperable accumulator to OP LE status

>4 thin one hour Kbe fn HOT SHUTDOWN fthfn the next hours.,

s)'. i<

fifth one a umulator inoperable ue to the isola on valve being, closed, ther immediately o n the fsolatio alvemEbe in HOT STAND vithfn one hour an e fn HOT S vt,thin the next

.~~ SURVEILLANCE RE UIREMENTS 4.5.1 Each accumulator shall bc demonstrated OPERABLE:

a. At least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> by:

1. Verifying the contained borated vater volume and nitrogen cover-prcssure in the taaks, and I~

2. 'erifying that each accumulator isolation valve is open.

• Pressurizer Prcssure above 1000 psig.

COOK NUCLEAR PIANT - UNIT 2 3/4 5-1 AMENDMENT NO. ~4. P4

.)

EMERGENCY CORE COOLING SYSTEMS

~ g f-e ~ I.J SURVEILLANCE RE UIREMENTS Continued

b. At least once per 31 days and>within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> after each solution volume increase greater than or equal to 18 of tank volume by verifying the boron concentration of the accumulator solu ion.

c At least once per 31 days when the RCS pressure is ab e 2000 psig by verifying that power to the isolation valve operato is disconnected by removal of the breaker from the circuit.

~ex44ji~g-th eh-aoeumulatar matf.call tion noh CQ o g ~ d'd i 4;y m /~re (,

~a+ r ~ f2) r ~~ f-~

COOK NUCLEAR PLANT - UNIT 2 3/4 5-2 AMENDMENT NO.g g3l'

~ I.

3/4. 5 EMERGENCY. CORE CODLING SYSTEMS 8ASES 3/4. 5.1 ACCUMULATORS The OPERABILITY of each RCS accumulator ensures that a sufffcient volume of borated water will be immediately forced inta the reacto~ core through each of the cold legs fn the event the RCS pressure falls below the pressure of the accumulators. This initial surge of water into the core provides the fnftfaI cooling mechanism during large RCS pipe ruptures.

The limits on accumulator volume, bo~on concentration and pressure ensure that the assumptions used for accumulato~ injection in the safety analysis are met.

The accumulator po~er operated isolation valves are considered to be "operating bypasses" in the context of IEEE Std. 279-1971, ~hich requires that bypasses of a protective functian be removed autamatfcally whenever permfssfve conditions are not met. In addition, as these accumulator isolation valves fail ta meet single faf lure criteria, removal of power to the valves is required.

g p)~ a e 'pera isolat on with valve closed m'izes a

1 ccumulator inoperable the time exposure

'nal for any reason excep e plant ta a LOCA th'o e ent curring cancurre with failure of an ad accumulator which may g t fn unacceptabl peak cladding tempera es. If a closed iso n valve c

a nnot be immedia ilable a d y opened, the full ~ ilfty of one accum mpt action is requ~8 to place the reactor in a mode wh or fs not requ> red.

3/4. 5. 2 and 3/4. 5. 3 ECCS SUBSYSTEMS The OPERABILITY of twa independent ECCS subsystems ensures that sufficient emergency core cooling capability will be available in the event of a LOCA assuming the loss of'ne subsystem through any single failure consideration.

Either subsystem operatfng in conjunction with the accumulators is capable of supplying sufffcfent core cooling to limit the peak cladding temperatures within acceptable limits for all'postulatad break sizes ranging from. the double ended break of the Iargest RCS cold Ieg pipe downward. In addition, each ECCS subsystem provides long term care cooling capability in the recirculation mode during the accident. recovery period.

0. C. COOK - UNIT 2 8 3/4 5-1'mendment Na. 39

With one accumulator inoperable due to boron concentration not within limits, restore boron concentration to within limits within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or be in at least MODE 3 within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and reduce pressurizer pressure to less than or equal to 1,000 psig within the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.

With one accumulator inoperable for reasons other than boron concentration not within limits, restore the accumulator to OPEMLE status within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />, or be in at least MODE 3 within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and reduce pressurizer pressure to less than or equal to 1,000 psig within the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.

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If the boron concentration of one accumulator is not within limits," it must be returned to within the limits within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. In this Condition, ability to maintain subcriticality or minimum boron precipitation time may be reduced. The boron in the accumulators contributes to the assumption that the combined ECCS water in the partially recovered core during the early reflooding phase of a large break LOCA is sufficient to keep that portion of the core subcritical. One accumulator below the minimum boron concentration limit, however, will have no effect on available ECCS water and an insignificant effect on core subcriticality during reflood, Boiling of ECCS water in the core during reflood concentrates boron in the saturated liquid that remains in the core. In addition, current analysis techniques demonstrate that the accumulators do not discharge following a large main steam line break for the majority of plants. Even if they do discharge, their impact is minor and not a design limiting event. Thus, 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> is allowed to return the boron concentration to within limits.

If one accumulator" is inoperable for a reason other than boron concentration, the accumulator must be returned to OPERABLE status within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. In this Condition, the required contents of three accumulators cannot be assumed to reach the core during a LOCA. Due to the severity of the consequences should a LOCA occur in these conditions, the 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> completion time to open the valve, remove power to the valve, or restore the proper water volume or nitrogen cover pressure ensures that prompt action will be taken to return the inoperable accumulator to OPERABLE status. The completion time minimizes the potential for exposure of the plant to a LOCA under these conditions.

If the accumulator cannot be returned to OPERABLE status within the associated 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 MODE 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and pressurizer pressure reduced to s 1000 psig within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 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.

If more than one accumulator is inoperable, the plant is in a condition outside the accident analyses; therefore, LCO 3.0.3 must be entered immediately.

I ' ~

ATTACHMENT 3 TO AEP:NRC:1186 PROPOSED REVISED TECHNICAL SPECIFICATION PAGES

3 4 5 EMERGENCY CORE COOLING SYSTEMS ECCS ACCUMULATORS LIMITING CONDITION FOR OPERATION 3.5.1 Each reactor coolant system accumulator shall be OPERABLE with:

a. The isolation valve open,

b. A contained borated water volume of between 921 and 971 cubic feet,

c. A boron concentration between 2400 ppm and 2600 ppm, and

d. A nitrogen cover-pressure of between 585 and 658 psig.

APPLICABILITY: MODES 1, 2 and 3.*

ACTION'.

With one accumulator inoperable due to boron concentration not within limits, restore boron concentration to within limits within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or be in at least Mode 3 within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and reduce pressurizer pressure to less than or equal to 1000 psig within the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.

b. With one accumulator inoperable for reasons other than boron concentration not within limits, restore the accumulator to OPERABLE status within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />, or be in at least Mode 3 within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and reduce pressurizer pressure to less than or equal to 1000 psig within the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.

SURVEILLANCE RE UIREMENTS 4.5.1 Each accumulator shall be demonstrated OPERABLE:

a. At least once per 12 hours by:

Verifying the contained borated water volume and nitrogen cover-pressure in the tanks, and

2. Verifying that each accumulator isolation valve is open.

• Pressurizer Pressure above 1000 psig.

COOK NUCLEAR PLANT - UNIT 1 3/4 5-1 AMENDMENT NO.

EMERGENCY CORE COOLING SYSTEMS SURVEILLANCE RE UIREMENTS Continued

b. At least once per 31 days and, for the affected accumulator(s),

within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> after each solution volume increase of greater than or equal to 1X of tank volume (that is not the result of addition from the refueling water storage tank) by verifying the boron concentration of the accumulator solution.

C. At least once per 31 days when the RCS pressure is above 2000 psig, by verifying that power to the isolation valve operator is disconnected by removal of the breaker from the circuit.

COOK NUCLEAR PLANT - UNIT 1 3/4 5-2 AMENDMENT NO,

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Jl 3 4 5 EMERGENCY CORE COOLING SYSTEMS BASES 3 4.5 1 ACCUMULATORS The OPERABILITY of each RCS accumulator ensures that a sufficient volume of borated water will be immediately forced into the reactor core through each of the cold legs in the event the RCS pressure falls below the pressure of the accumulators. This initial surge of water into the core provides the initial cooling mechanism during large RCS pipe ruptures.

The limits on accumulator volume, boron .concentration and pressure ensure that the assumptions used for accumulator injection in the safety analysis are met, The accumulator power operated isolation valves are considered to be "operating bypasses" in the context of IEEE Std. 279-1971, which requires that bypasses of a protective function be rem'oved automatically whenever permissive conditions are not met. In addition, as these accumulator isolation valves fail to meet single failure criteria, removal of power to the valves is required.

If the boron concentration of one accumulator is not within limits, it must be returned to within the limits within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. In this Condition, ability to maintain subcriticality or minimum boron precipitation time may be reduced. The boron in the accumulators contributes to the assumption that the combined ECCS water in the partially recovered core during the early reflooding phase of a large break LOCA is sufficient to keep that portion of the core subcritical.

One accumulator below the minimum boron concentration limit, however, will have no effect on available ECCS water and an insignificant effect on core subcriticality during reflood. Boiling of ECCS water in the core during reflood concentrates boron in the saturated liquid that remains in the core. In addition, current analysis techniques demonstrate that the accumulators do not discharge following a large main steam line break for the majority of plants.

Even if they do discharge, their impact is minor and not a design limiting event. Thus, 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> is allowed to return the boron concentration to within limits.

If one accumulator is inoperable for a reason other than boron concentration, the accumulator must be returned to OPERABLE status within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. In this Condition, the required contents of three accumulators cannot be assumed to reach the core during a LOCA. Due to the severity of the consequences should a LOCA occur in these conditions, the 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> completion time to open the valve, remove power to the valve, or restore the proper water volume or nitrogen cover pressure ensures that prompt action will be taken to return the inoperable accumulator to OPERABLE status. The completion time minimizes the potential for exposure of the plant to a LOCA under these conditions.

If the accumulator cannot be returned to OPERABLE status within the associated 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 MODE 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and pressurizer pressure reduced to s 1000 psig within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. The COOK NUCLEAR PLANT - UNIT 1 B 3/4 5-1 AMENDMENT NO.

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EMERGENCY CORE COOLING SYSTEMS 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.

If more than one accumulator is inoperable, the plant is in a condition outside therefore, LCO 3.0.3 must be entered immediately.

the accident analyses;

. 3 4 5 2 and 3 4 5.3 ECCS SUBSYSTEMS The OPERABILITY of two independent ECCS subsystems ensures that sufficient emergency core cooling capability will be available in the event of a LOCA assuming the loss of one subsystem through any single failure consideration.

Either subsystem operating in conjunction with the accumulators is capable of supplying sufficient core cooling to limit the peak cladding temperatures within acceptable limits for all postulated break sizes ranging from the double ended break of the largest RCS cold leg pipe downward. In addition, each ECCS subsystem provides long term core cooling capability in the recirculation mode during the accident recovery period.

COOK NUCLEAR PLANT - UNIT l B 3/4 5-la AMENDMENT NO.

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3 4.5 EMERGENCY CORE COOLING SYSTEMS ECCS CCUMULATORS LIMITING CONDITION FOR OPERATION 3.5.1 Each reactor coolant system accumulator shall be OPERABLE with:

a. The isolation valve open,

b. A contained borated water volume of between 921 and 971 cubic feet,

c. A boron concentration between 2400 ppm and 2600 ppm, and

d. A nitrogen cover-pressure of between 585 and 658 psig.

APPLICABILITY: MODES 1, 2, and 3.*

ACTION:

a. With one accumulator inoperable due to'oron concentration not within limits, restore boron concentration to within limits within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or be in at least Mode 3 within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and reduce pressurizer pressure to less than or equal to 1000 psig within the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.

b. With one accumulator inoperable for reasons other than boron concentration not within limits, restore the accumulator to OPERABLE status within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />, or be in at least Mode 3 within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and reduce pressurizer pressure to less than or equal to 1000 psig within the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.

SURVEILLANCE RE UIREMENTS 4.5.1 Each accumulator shall be demonstrated OPERABLE:

a. At least once per 12 hours by:

Verifying the contained borated water volume and nitrogen cover-pressure in the tanks, and

2. Verifying that each accumulator isolation valve is open.

'Pressurizer Pressure above 1000 psig.

COOK NUCLEAR PLANT - UNIT 2 3/4 5-1 AMENDMENT NO. 04,

EMERGENCY CORE COOLING SYSTEMS SURVEILLANCE RE UIREMENTS Continued

b. At least once per 31 days and, for the affected accumulator(s),

within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> after each solution volume increase greater than or equal to 13 of tank volume (that is not the result of addition from the refueling water storage tank) by verifying the boron concentration of the accumulator solution.

c ~ At least once per 31 days'hen the RCS pressure is above 2000 psig by verifying that power to the isolation valve operator is disconnected by removal of the breaker from the circuit.

COOK NUCLEAR PLANT - UNIT 2 3/4 5-2 AMENDMENT NO.

I j

3 4 5 EMERGENCY CORE COOLING SYSTEMS BASES 3 4 5 1 ACCUMULATORS The OPERABILITY of each RCS accumulator ensures that a sufficient volume of borated water will be immediately forced into the reactor core through each of the cold legs in the event the RCS pressure falls below the pressure of the accumulators. This initial surge of water into the core provides the initial cooling mechanism during large RCS pipe ruptures.

The limits on accumulator volume, boron concentration and pressure ensure that the assumptions used for accumulator injection in the safety analysis are met.

The accumulator power operated isolation valves are considered to be "operating bypasses" in the context of IEEE Std. 279-1971, which requires that bypasses of a protective function be removed automatically whenever permissive conditions are not met. In addition, as these accumulator isolation valves fail to meet single failure criteria, removal of power to the valves is required.

If the boron concentration of one accumulator is not within limits, it must be returned to within the limits within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. In this Condition, ability to maintain subcriticality or minimum boron precipitation time may be reduced. The boron in the accumulators contributes to the assumption that the combined ECCS water in the partially recovered core during the early reflooding phase of a large break LOCA is sufficient to keep that portion of the core subcritical.

One accumulator below the minimum boron concentration limit, however, will have no effect on available ECCS water and an insignificant effect on core subcriticality during reflood. Boiling of ECCS water in the, core during reflood concentrates boron in the saturated liquid that remains in the core. In addition, current analysis techniques demonstrate that the accumulators do not discharge following a large main steam line break for the majority of plants.

Even if they do discharge, their impact is minor and not a design limiting ev'ent. Thus, 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> is allowed to return the boron concentration to within limits.

If one accumulator is inoperable for a reason other than boron concentration, the accumulator must be returned to OPERABLE status within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. In this Condition, the required contents of three accumulators cannot be assumed to reach the core during a LOCA. Due to the severity of the consequences should a LOCA occur in these conditions, the 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> completion time to open the valve, remove power to the valve, or restore the proper 'water volume or nitrogen cover pressure ensures that prompt action will be taken to return the inoperable accumulator to OPERABLE status. The completion time minimizes the potential for exposure of the plant to a LOCA under these conditions.

If the accumulator cannot be returned to OPERABLE status within the associated 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 MODE 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and pressurizer pressure reduced to 5 1000 psig within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. The COOK NUCLEAR PLANT - UNIT 2 B 3/4 5-1 AMENDMENT NO. 30

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EMERGENCY CORE COOLING SYSTEMS ACCUMULATORS (Continued) 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.

If more than one accumulator is inoperable, the plant is in a condition outside the accident analyses; therefore, LCO 3.0.3 must be entered immediately.

3 4 5 2 and 3 4 5 3 ECCS SUBSYSTEMS The OPERABILITY of two independent ECCS subsystems ensures that sufficient emergency core cooling capability will be available in the event of a LOCA assuming the loss of one subsystem through any single failure consideration.

Either subsystem operating in conjunction with the accumulators is capable of supplying sufficient core cooling to limit the. peak cladding temperatures within acceptable limits for all postulated break sizes ranging from the double ended break of the largest RCS cold leg pipe downward. In addition, each ECCS subsystem provides long term core cooling capability in the recirculation mode during the accident recovery period.

COOK NUCLEAR PLANT - UNIT 2 B 3/4 5-la AMENDMENT NO. QO

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