ML19327A891

Proposed Tech Specs Reducing Number of Suppression Chamber to Drywell Vacuum Breaker Pairs Required to Be Operable as Three

ML19327A891
Person / Time
Site:	Limerick
Issue date:	10/11/1989
From:	PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:
Shared Package
ML19327A890	List: ML19327A889 ML19327A891
References
NUDOCS 8910190037
Download: ML19327A891 (5)

Text

, . .

6 J e ATTACHMENT 2

LIMERICK GENERATING STATION *

Docket Nos. 50-352 I 50-353 License Nos. NPF-39

• NPF-85 i

PROPOSED TI:CHNICAL SPECIFICATIONS CHANGES List of Attached Change Pages ,

i Unit 1 [

3/4 6-44  !

B 3/4 6-4 >

t Unit 2 l 3/4 6-44 '

l B 3/4 6-4 t l

l. ,

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1-l l-l 8910190037 891011 PDR ADOCK0500gp, P

l

. CONTAINMENT SYSTEMS 3/4.6.4 VACUUM RELIEF SUFPRESSION CHAMBER - DRYWELL VACUUM BREAKERS i

l LIMITING CONDITION FOR CPERATION 3.6.4.1 Three pairs of suppression chamber - drywell vacuum breakers shall be i

OPERABLE and all suppression chamber-drywell vacuum breakers shall be closed.

APPLICABILITY: OPERATIONAL CNDITIONS 1, 2, and 3.

ACTION:

I

a. With one or more vacuum breakers in one of the three required pairs of suppression chamber - drywell vacuum breaker pairs inoperable for '

opening but known to be closed, restore at least one inoperable pair of vacuum breakers to OPERABLE status 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 HOT SHUTDOWN within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and in COLD SHUTDOWN within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

b. With one suppression chamber - drywell vacuum breaker open, verify the other vacuum breaker in the pair to be closed within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />; restore the open vacuum breaker to the closed position 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 within the HOT SHUTDOWN following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and in COLD SHUTDOWN

c. With one position indicator of any suppression chamber - drywell yacuum breaber inoperable:

1. Verify the other vacuum breaker in the pair to be closed within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> and at least once per 15 days thereafter, or

2. Verify the vacuum breaker (s) with the inoperable position indicator to be closed by conducting a test which demonstrates that the AP is maintained at greater than or equal to 0.7 psi for one -

hour without makeup within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> and at least once per 15 days thereafter.

Otherwise, be in at least HOT SHUTDOWN within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and in COLD SHUTDOWN within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

LIMERICK - UNIT 1 3/4 6-44

CONTAINMENT SYSTEMS ,

r

- BASCS ,

DEPRESSURIZATION SYSTEMS (Continued)

Because of the large volume and thermal capacity of the suppression pool, the volume and temperature normally changes very slowly and monitoring these -

parameters daily is sufficient to establish any temperature trends. By requiring '

the suppressica pool temperature to be frequently recorded during periods of significant heat addition, the temperature trends will be closely followed so that appropriate action can be taken.

In addition to the limits on temperature of tae suppressian chamber pool water, operating procedures define the action to be taken in the event a safety.

relief valve inadvertently opens or sticks open. As a minimum this action shall include: (1) use of all available means to close the valve, (2) initiate suppression pool water cooling, (3) initiate reactor shutdown, and (4) if other safety-t : lief valves are used to depressurize the reactor, their discharge shall be separated from that of the stuck-open safety / relief valve to assure mixing and

'.  ;

uniformity of energy insertion to the pool. -

M4.6.3 PRIMARY CONTAINMENT ISOLATION VALVES Tne OPERABILITY of the primary containment isolation valves ensuret that the containment atmosphere will be isolated from the outside environment in the event of a release of radioacti'O material to the containment atmosphere or pressurization of the containment and is consistent with the requirements of GDC 54 through 57 of Appendix A of 10 CFR Part 50. Containment isolation within the time limits specified.for those isolation valves designed to close automatically ensures that the release of radioactive material to the environment will be consistent with the assumptions used in the aralyses for a LOCA.

E4.6.4 VACUUM RELIEF Vacuum relief valves are provided to equalize the pressure between the suppression chamber and drywell. This system will maintain the structural integrity of the primary containment under conditions of large differential pressures.

The vacuum breakers between the suppression chamber and the drywell must not be inoperable in the open position since this would allow bypassing of the suppression pool in case of an accident. Two pairs of valves are required to protect containment structural integrity. There are four pairs of valver. (three to provide minimum redundancy) so that operation may continut for up to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> with no more than two pairs of vacuum breakers inoperable in the closed position.

Each vacuum breaker valve's position indication system is of great enough sensitivity to ensure thd the maximum steam bypass leakage coefficient of A

@ = 0.05 ft2 l for the vacuum relief system (assuming one valve fully open) will not be exceeded.

LIMERICK - UNIT 1 B 3/4 6-4

. . . - _ . _ - =- - - -

.. i CONTAINMENT SYSTEMS l,

• 3/4.6.4_ VACUUM RELIEF SUPPRESSION CHAMER - DRYWELL VACUUM PREAKERS i

L LIMITING CONDITION FOR OPERATION i

d 3.6.4.1 Three pairs of suppression chamber - drywell vacuum breakers shall be OPERABLE and all suppreuion chamber-drywell vacuum breakers shall be closed.

APPLICABILITY: OPERATIONAL CONDITIONS 1, 2, and 3.

ACTION:

4

a. With one or more vacuum breakers in or.e of the three required pairs of  ;

suppression chamber - drywell vacuum breaker pairs inoperable for opening but known to be closed, restore at least one inoperable pair '

of vacuum breakers to OPERABLE status 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 HOT SHUTDOWN within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and in COLD SHUTDOWN within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. ,

b. With one suppression chamber - drywell vacuum breaker open, verify the other vacuum breaker in the pair to be closed within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />; restore the open vacuum breaker to the closed position 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 HOT SHUTDOWN within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and in COLD SHUTDOWN within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

c. With one position indicetor of any suppression chamber - drywell vacuum breaker inoperable: ,

1. Verify the other vacuum breaker in the pair to be closed within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> and at least once per 15 days thereafter, or

2. Verify the vacuum breaker (s) with the inoperable position indicator '

to be closed by con 1ucting a test which demonstrates that ti.e AP is maintained at greater than or equal to 0.7 psi for one hour without makeup within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> and at least once per 15 days ,

thereafter.

Otherwise, be in at least HOT SHUTDOWN within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and in COLD SHUTDOWN within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

l LIMERICK - UNIT 2 3/4 6 44 -

n'5 2 515?9

• e

1 .

_ CONTAINMENT SYSTEMS

. . i.

H

• BASES 4

DEPRES$URIZATION SYSTEMS (Cnntinued) i j

Because of the large volume and thermal capacity of the suppression pool, the

volume and temperature normally changes very slowly and monitoring thase '

L parameters daily ie sufficient to establish any temperature trends. By requiri;q

' the suppression pool. temperature to be frequently recorded during periods of significant heat addition, tne temperature trends will be closely followed so that appropriate action can be taken.

In addition to the limits on temperature of the suppression chamber pool water, oper,ating procedures define the action to be taken in the event a safety- .

relier valve inadvertently opens or sticks open. As a minimum'this action shall include: (1)useofallavailablemeanstoclosethevalve,(2) initiate h suppressionpoolwa+.ercooling,(3)initiatereactorshutdown,and(4)ifother i._ safety-relief valves are used to depressurize the reactor, their discharge shall 1 be separated from that of the stuck-open safety / relief valve to assure mixing and j uniformity of energy insertion to the pool.

J j 3/4.6.3 PRIMARY CONTAINMENT ISOLATION VALVES a

~'

~ The OPERABILITY of the primary containment isolation valves ensures that the containment atmosphere will be isoleted from the outside environment in the event j' of a release of radicartive material to the containment atmosphere or 1 pressurization of the containment and is consistent with the requirements of GOC 54 through 57 of Appendix A of 10 CFR Part 50. Containment isolation within the 4

time limits specified for those isolation valves designed to close automatically ensures that the release of radioactive material to the environment will be

, consistent with the assumptions used in the analyses for a LOCA.

q'

+ .

3/4.6.4 VACUUM REllEF Vacuum relief valves are provided to equalize the pressure between the

! suppression chamber and drywell. This system will maintain the strt.ctural 4 L integrity of the primary containment under conditions of large differential pressures.

1 The vacuum breakers between the suppression chamb P and the drywell must not

{

be inoperable in the open position since this would allow bypassing of the suppression pool in case of an accident. Two pairs of valves are required to protect containment structural integrity. Therearefourpairsofvalves(three to pavide minimum redundancy) so that operation may continue for up to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> with no more than two pairs of vacuum breakers inoperable in the closed position.

Each vacuum breaker valve's position indication system is of great enough sensitivity to ensure that the maximum steam bypass leakage coefficient of A * ~

4 = 0.05 ft2 ,

for the vacuum relief system (assuming one valve fully open) will not be exceeded.

LIMERICK - UNIT 2 8 3/4 6-4 m252 -