ML20065E695

Forwards Special Rept in Response to 890920 Generic Ltr 89-19 Re Resolution of USI A-47

ML20065E695
Person / Time
Site:	Limerick
Issue date:	09/19/1990
From:	Hunger G PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
REF-GTECI-A-47, REF-GTECI-SY, TASK-A-47, TASK-OR GL-89-19, NUDOCS 9010020265
Download: ML20065E695 (3)

Text

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PHILADELPHIA ELECTRICi COMPANY

, 1, y ya '1 e~ NUCLEAR GROUP HEADQUARTERS. d l'955 65 CHESTERBROOK BLVD. 3% R) ' WAYNE, PA 19087 5691 G m -(215) 640-6000; Sept' ember 19,:1990l 9l n . Docket Nos. 50-352 0 -{ 50-353 j .( License Nos. NPF-39' NPF-85 n 1 (.;c s ! hk U.S. Nuclear.Regul' tory Commission a Attn: Document Control Desk Washington, DC-20555 y J [

SUBJECT:

Limerick Generating' Station, Units 1 and-2 l NRC Generic. Letter 89-19. " Request for Action Related to U Resolution of Unresolved Safety Issue A-47.' Safety Implications d of Control Systems in LWR Nuclear Power Plants'," Submittal of.. SpecialiReport. 1 o m Gentlemen: 4 NRCGenericLetter(GL).89-19,datedSeptember20.1 1989.1 requested y p! > licensees to provide a statement as to whether licensees will? implement the. .[ J, recommendations providedjin Enclosure 2 of the:GL. :;The.GL also required flicensees-to provide a: schedule ior.: implementation-of the recommendations and v

f (the basisifor.the! schedule

or to provide' appropriate-justification if-the-1

-recommendations were not going-to be;implementedi~.0ur response to GL 89-19 for ?i. ' Limerick Generating Stationi(LGS), Units'1 and.'2, was provided by our letters i M' >Ldated. March-20,'1990, and May:4, 1990.-- a v l [ t N k . As identified in our MayT4,1990 letter, anL investigation was;perfonned: N @a

concerning a-Reactor Pressure' Vessel (RPV) rapid'depressurization' transient

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i 3;c 'which could. result in an s erfill condition. As a result of this investigation.- i,f', j procedural: enhancements have been made to ensure that. plant'oprators can more:

effectively. mitigate!a-RPV overfill event, specifically as a reselt of-a; rapid

'9 .RPVLdepressurization. :Our;May.4, 1990 letter stated that the deta'Is of this d E;, ,4 ; investigation and procedural enhancements would;be' included in a'Special Report: Rh ~ submitted to:the NRC. JAccordingly,;the' Attachment-to this letter provides this p, g Special.: Report.

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o. +:- R. t 1 we > Very truly yours, u ^ .e ' ~, .--{' i l . = q ,h,l [ 4.$. N l G.'A. Hunt , Jr.

• i Manager i

Licensing. "1 Nuclear Engineering and Services: H

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T. T.' Martin, Administrator, Region I, USNRC .u 9... DT.-.J. Kenny tUSNRC. Senior Resident' Inspector, LGS-H ,-. ;11 .t. p t . vl k l' i .i rc -3

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w w . -. ~. -~ -Attachment' y . :.. e, Page l'of IL j it .g3 g Docket Nos. 50-352 H '-E 353 5 4 t; -Limerick Generating Station ; Units l'and 2-l ^ Generic Letter 89-19 H " Request for Action Related to Resolution of l Unresolved Safety-Issue A-47 fSafety Implication 1. of. Contml Systems in LWR Nuclear Power Plants'" i Special Report Ai referenced to in our response to Generic Letter 89-19, dated May 4.1990,- ~ c u a separate investigatioa was performed concerning a Reactor Pressure Vessel

(RPV), rapid

depresTurizat'on transient which could result in an overfill!

l D , condition. 'Asta re m it'of.?.his investigation, procedural enhancements have been .made,to ensure that opc*ators can more effectively mitigate an RPV' overfill H ,;1 event, specifically.as a result'of a rapid RPV depressurization. Operational Transient-(OT). procedure OT-110, " Reactor Hioh Level," has been revised and implemented to address the subject issue. Procedure OT-110 is 1 L,4 entered whenever there is.an untxpected or unexplained rise in RPV water. level - H ~ which could be due to Sondensate. injection.: This procedure is applicable 1 . henever RPV overfill. transient would be a concernO during normal operation ' w 1 , g plant: transients, startups and shutdowns. The Main Control Room (MCR) operators; are alerted to this condition by 4*munciation of the. " Reactor HI-LO Level" alarm

or-by visual Observation of an increase in RFV level indicated by the RPVl level s.4

instrumentation.7 The.inusediate' operator action is to reduce feedwater flow "

j until normal level is restored. Follow-up actions : include closing:of the Main : 1 Steam.. Isolation Valves (MSIVs) and the primary containment isolation valves for y .the High. Pressure Coolant' Injection (HPCI) and Reactor Core Isolation Cooling j e g (RCIC); systems'beforetheRPVwaterlevelreaches'thelevelofthe=steamlines. u Procedure OT-110 follow-up actions were revised to provide' additional guidance in the following areas. h o 1 Terminating l condensate. injection.- ~ u o'

Terminating Control Rod Drive (CRD) injection.

,A C . Reducing RPV water inventory with Main Turbine Bypass Valve or Safety; o M . Relief' Valves (SRVs) operation to avoid flooding the Main Steas; Lines.. O u u

q o-Draining Main Steam lines via steam line: drains to the condenser.

u o SRV operation:with Main Steam lines flooded.. .] t 0: Incorporation of a reactor pressure and temperature-diagram for p 'c Permissible SRV Discharge of: Water (Procedure OT-110 BASES only).- o y q yA Licensed operatoritraining on the revisions to Procedure 01-110 are'being '4 conducted via on-shift notifications and will be incorporated:into the Licensed' Operator:Requalification (LOR) Program. ' w" + -Based lon.these actions, existing operating. procedures aM operator training' are sufficient;to ensureithat the' operators can mitigate RPV averfill events.' ~ j 2 ,t L j y oi h( I n 4 u-w--. /w -4 r}}