ML19312D171

Revised Pages 167a & 184 for Tech Spec Changes Re drywell- Suppression Chamber Differential Pressure

ML19312D171
Person / Time
Site:	Cooper
Issue date:	03/17/1980
From:	NEBRASKA PUBLIC POWER DISTRICT
To:
Shared Package
ML19312D170	List: ML19312D169 ML19312D171
References
NUDOCS 8003210382
Download: ML19312D171 (2)

Text

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..a .

LLMITING CONDITIONS FOR OPERATION SURVEILLANCE REQUIREMENT j 3.7 . (cont'd) 4.7 (cont'd)

E.. Drywell-Suppression Clianber E. Drywell-Suppression Chamber Differential Pressure Differential Pressure

1. Differential pressure between the 1. The pressure differential drywell and suppression chamber between the drywell and shall be maintained at equal to suppression chamber shall

'l or greater than 1.1 psid except be recorded at least once as specified in a, b, and c below, each shift.

.a.: This differential shall be established within 26. hours af ter placing the mode switch in run.

b. This differential may be de-l creased to less than 1.1 psid 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> prior to placing mode switch in refuel or shut-d own.

c. This-differential may be

! decreased to less than 1.1 psid for a maximum of four (4) hours during required operability testing of the HPCI system pump, the RCIC system pump, and the drywell-

i. pressure suppression chamber vacuum breakers.

2. If the differential pressure of specification 3.7.E.1 cannot be maintained, and the differential pressure cannot be restored within

. the subsequent six (6) hour period, an orderly shutdown shall be initi-ated and the reactor shall be in -

Hot Standby in-six (6) hours and in .

a Cold Shutdown condition within the following 18 hours2.083333e-4 days <br />0.005 hours <br />2.97619e-5 weeks <br />6.849e-6 months <br />.

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-167a- 80 032107 M

.o,-6 g,,.'+-

e J3.7.D'&'4,7,D;(contsd)

- 'The pr'imary containment .is penetrated by several small diameter instrument

? lines connected to the reactor coolant system. Each instrument line contains-ua 0.25 inch restricting orifice inside the pcisary containment and an excess

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flow' check valve'outside'the primary' containment. A program for periodic testing'and. examination of the excess flow check valves is performed as follows:

1. LVessel at pressure sufficient to actuate valves. This.could be at time of= vessel hydro following a refueling outage.

l2. ' Isolate sensing line from its instrument at the instrument manifold.

3.- Provide means for observing and ' collecting the instrument drain or

. vent valve flow..

4.. Open vent or drain valve.

a.. Observe flow cessation and any leakage rate.

Jb . - Reset valve af ter test completion.

5. The head seal leak' detection line cannot be tested in this manner. This valve will not be exposed to primary system pressure except under unlikely conditions of seal f ailure where it could be partially pressurized to reactor pressure. Any leakage path is restricted at the source and there-f ore this valve need not be tested. This valve is in a sensing line that is not safety related.

6. Valves will be accepted if a marked decrease in flow rate is cha'rved and

- the leagage_ rate is acceptable.

3.7.E Bases In conjunction with the Mark -I Containmoit Short Term Progr:m, a

- plant unique analysis was performed as described in, the licensee's letter of October 4,1976, which demonstrated a factor of s afety of

' at!1 east two for the weakest element in the suppression chazber support system and attached piping. The maintenance of dry well-suppression chamber differential pressure of 1.1'psid and a suppression l chamber water level corresponding to a downcomer submergens e range of three' to four. fect will assure =the' integrity of the supprension chamber l

-when subjected to' post-LOCA suppression pool hydrodynamic forces.

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