ML20094S575

Rev 9 to OT-100 Bases, Reactor Low Level - Bases

ML20094S575
Person / Time
Site:	Limerick
Issue date:	04/01/1992
From:	Hopkins L PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:
References
PROC-920401, NUDOCS 9204150174
Download: ML20094S575 (6)

Text

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e oT-200 n^scs Rev-

• I I 3924020820 Page 1 of 4

a. CAH/smk i

PHILADELPHIA ELECTRIC COMPANY LIHERICK GENLRATING STATION gg OT-100 REACTOR LOW LEVEL - BASES -l 5

1.0 ENTRY CONDITIONS 1.1 Unexpected / unexplained drop in RPV water level.

This procedure specifies actions to be.taken in response-to an ur. expected or unexplained decrease in reactor level.

Some typical events covered by this procedure are the trip of a RFP or condensate pump, and failure of the feedwater control system in the minimum flow direction. Entry into this procedure is inappropriate under shutdown conditions when reactor level is being manually controlled. Manual operation of the feedwater system while in a shutdown ..

condition will require the operator to routinely compensate for unexpected decreases in water level, and the majority of the steps in the procedure are applicable only to high power operation.

O 2.0 J,MMEDIATE OPERATOR ACTIONS 2.1 Reduce Reactor power per Reactor Maneuvering Shutdown Instructions until normal level is restored.

Reactor low level results from an imbalance.between The fastest way reactor feedwater input and reactor steam output.

to reduce steam output following a sudden decrease in feedwater flow, and thereby terminate the' reactor level decrease, is to reduce recire, flou.

2.2 IP a RTP controller malfunction exists, THEN take manual control of RPPs.

If a RFP controller has failed, transferring from the auto to manual control mode may restore sufficient feedwater flow. Transferring control from a RPP's controller to its motor speed changer may also prevent a low level scram if feed flow can be increased in time.

O 9204150174 920401 PDR ADOCK 05000352 L P PDR l.

I OT-100 BASES, Rev. 9 l Page 2 of 4

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1 1 JF 4 stam' condition occurs, tD m~

.4 enter T-101 AMD exit this procedure.  ;

This step reminds-the operator that the 01 procedure should be exited and the RPV Control procedure must be entered on a Reactor Low Water Level scram.

3.0 FOLLOW-UP ACTIONS i 3.1- IP level drop was caused by RPP OR Condensate Pump trip, THEN determine cause of trip AND restart pump. ,

The operator should determine the cause of any pump trip which caused the level decrease. The pumps should be

-returned-to service as soon as possible to allow full power operation. ,

3.2 IP level drop was caused by RPP controller malfunction, THEN return RFP to its normal control mode after malfunction is cleared.

Since automatic'RPP control requires the least operator l

attention, efforts should be made to return to the automatic control mode as soon as possible.

3.3 IP level drop was caused by failure of feed flow / steam flow signal, '

AND-level is stabilized at 35 in.,

YHEN consider swapping.to single element control AND restor'ng PW control to automatic until repaire-can be ,

Ma3e. ,

Since automatic RPP control requires the least operator attention, and single element. control does not use feed -

flow / steam flow inputs, on a failure of either of these signals efforts should be made to return to the automatic >

single element mode as soon as possible.

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' O'I - 10 0 B AS ES , Rev. 9 j l Pago J of 4 I C AH / s n.k 3.4 IP level drop is riot evident on-redundant instrumento, THEN consider possible instrument sensing line failure AND verify actual level utilizing inst runents with Independent sensing lines.

In the event that redundant inst rument s ic not respond correspondingly, it is essential to util.ze independent instruments to determine actual level and thus respond accordingly. An indicated level reduction can occut frca leakage / failure of an instruments variab;e leg, while an indicated level increase can occur trcm 4 eakageffailure cf an instruments reference leg. (Reference Rescd ut ien of Generic Issue 101) 3.5 IP the selected FW 1evel transmitter has failed, TlEN transfer to the alternate level transmitter.

If the selected level transmitter is t alli t.g , it la appropriate to transfer to the alternate . r a nsnti t t e r to stop the level transient and restore reaet.r leve; t ,

norr.al. (Re*erence: Resolution of Generic Isste 101) 3.6 IP recirc runback occurred, TEEN reset the runback per S43.0.B.

Certain plant conditions, specified under OT-100, Verification of Automatic Actions, will cause t t.e reeltc.

pumps to runback to achieve 62% rated ccre flou cr 28i rated speed. When these plant conditicno have be e r.

cleared, the runback logic must be reset i t, order +

.aasr the speed of the recire. M-G :.ets.

3.7 IP third condensate pump is not available, THEN maintain RFP suction pressure above 3u0 psig by limiting Reactor power.

When fewer than three condensate pumps are operating, feed flow must be restricted to prevent tripp;ng the RPPs on low suction pressure. The actual low suction pressure trip point setting of the RTPs is 241 psig. 100 psig has been conservatively chosen as a limit to acccant for possible calibration shift.

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l OT-100 BAE9S, Rev. 9 l

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4.0 VERIFICATION OP AUTOMATIC _ ACTIONS Actions Cond1tions j 4.1 ~ Recirc. reduced to a One RTP ulth less than  !

speed corresponding to 20% flow r 62% rated core flow. AND low reac?or level  !

IT/.5") .

i 02 One condensate pump tripped ,

with total Feedwater flow i l- greater than 85%

4.2 Recire. runback to 28% of Total reedwater flow icas indicated speed than 20%

Ol low Reactor level (12.5')I of Pump discharge valve less than 90% open.

4.3 REACTOR HI-LO LEVEL alarm 30" 4.4 hram 12.5" t.oup'II isolation 1

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DATE 04/03/92 09150 NRMS RECEIPT ACKNOWLEDGEMENT SEQUENCE # 3924020S20 9

LGS PROCE,DURES - APPROVED ORIGINALS D1$ TAC 00E- OT-U1 TOs NRC UTFSITE PROCEDNQ OT-100 BASES REVISION 009 DATE 04/01/91

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PLEASE RLTURN THIS FORM PRuuPTLY TO LCS ADMIN. SERVICES (LGS-340 )

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DATE 04/03/92 09

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ATTACHED IS-A COPY oft i PROCEDNO OT-100 BASES .,

REVISION 009 OATE 04/01/92 UNCONTROLLE03 LIBRARY, INDO, NUNEZ, R.

l 100 BASES, 101, 101 BASES, 103, 103 BASES, 104 ,

OINFO-OT-100,104 BASES, 112, 112 BASES, 116, 116 BASES 6

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