ML20065E695
| 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) | |
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; PHILADELPHIA ELECTRICi COMPANY , 1, e~
* '1 NUCLEAR GROUP HEADQUARTERS . ,
3% d l'955 65 CHESTERBROOK BLVD. ! R) ' WAYNE, PA 19087 5691 G m .
-(215) 640-6000; Sept' ember 19,:1990l 9l n
. Docket Nos. 50-352 0
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License Nos. NPF-39' # NPF-85 , . n (.;c < 1 s! hk U.S. Nuclear.Regul' atory Commission 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..
- 1 SpecialiReport.
o m Gentlemen: 4 y ,, NRCGenericLetter(GL).89-19,datedSeptember20.1 1989.1 requested ; 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 .< v flicensees-to provide a: schedule ior.: implementation-of the recommendations and
- 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 . t ' l [ N k ,
. . ;As identified in our MayT4,1990 letter, anL investigation was;perfonned:
;concerning a-Reactor Pressure' Vessel (RPV) rapid'depressurization' transient:-..
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@a3;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. :} !r .. .e m :N , , e . < .. , ~ I fC 9 M.'! gpr t[i . , + y 9010020265 900919 s - PDR ADOCK 05000352"
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Very truly yours, u
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- N G.'A. Hunt , Jr. *
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"1 ' ' Nuclear Engineering and Services: H
Attachment:
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. : cc: T. T.' Martin, Administrator, Region I, USNRC 9.. .
.u DT.-.J. Kenny tUSNRC. Senior Resident' Inspector, LGS- % ,
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-Attachment' y
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Page l'of IL j it
.g3 g Docket Nos. 50-352
'-E H 353 5 4
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-Limerick Generating Station ; Units l'and 2-Generic Letter 89-19
' ' l H
" Request for Action Related to Resolution of l 1 .
Unresolved Safety-Issue A-47 fSafety Implication of. Contml Systems in LWR Nuclear Power Plants'" i Special Report '
~
c Ai referenced to in our response to Generic Letter 89-19, dated May 4.1990,- u a separate investigatioa was performed concerning a Reactor Pressure Vessel :
, ;(RPV), rapid:depresTurizat'on transient which could result in D an overfill! '
l
, 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 l 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 -
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which could be due to Sondensate. injection.: This procedure is applicable 1 1
.whenever RPV overfill. transient would be a concernO during normal operation ' ,
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
- s. ,
- or-by visual Observation of an increase in RFV level indicated by the RPVl level 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 e
.the High. Pressure Coolant' Injection (HPCI) and Reactor Core Isolation Cooling j 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 o . Reducing RPV water inventory with Main Turbine Bypass Valve or Safety; C u . Relief' Valves (SRVs) operation to avoid flooding the Main Steas; Lines.. O M - u
- q o- Draining Main Steam lines via steam line: drains to the condenser. u o SRV operation:with Main Steam lines flooded..
.]
o 'c t 0: Incorporation of a reactor pressure and temperature-diagram for p y Permissible SRV Discharge of: Water (Procedure OT-110 BASES only).- y q A 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' j 2
are sufficient;to ensureithat the' operators can mitigate RPV averfill events.'
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