ML20084N006
| ML20084N006 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 05/23/1983 |
| From: | Woolever E DUQUESNE LIGHT CO. |
| To: | Allan J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, 2NRC-3-034, 2NRC-3-34, 83-01, 83-1, NUDOCS 8306020428 | |
| Download: ML20084N006 (4) | |
Text
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liWR 2NRC-3-034 (412)787 - 5141 Tele 3
Nuclear Construction Division Robinson Plaza, Building 2, Suite 210 Pittsburgh, PA 15205 United States Nuclear Regulatory Commission Region I 631 Park Avenue King of Prussia, PA 19406 ATTENTION:
Mr. J. Allan Act ing Administrator
SUBJECT:
Beaver Valley Power Station - Unit No. 2 Docket No. 50/412 Pot ent ial De f ic i e ncy of Wes t inghou se Cate Valve Pos i t io n Indication Sign i f ic a nt Deficiency No. 83-01 Gentlemen:
Pursuant to the requirement s of 10 C FR50.5 5 ( e ), the Final Report on Pot ent ial Deficiency in Wes t inghouse Gate Valve Po s i t io n Ind ica t io n is a t t ached fo r your rev i ew.
It there are any que s t io ns ccnce rni ng this report, please contact the Beaver Valley Unit 2 Project Office.
DUQUESNE LIGHT COMPANY U
'f By
.f E. Y. Woolever Vice President I
RWF/wjs l
At tachment l
cc:
Mr. R. DeYoung, Director Of fice of Ins pect ion and Enforcement (3) (w/ attachment)
NRC Document Control Desk (w/ attachment)
Mr. G. Walton, NRC Res ident Inspector (w/ attachment)
Ms. L. Lazo, Project Manager (w/ attachment)
SUBSCRIBED AND SWORN TO BEFORE ME THIS l
M6 DAY OF Wluy 1983.
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,a n Not ary Public N"' FLAINE REITER, NOTARY PUDuc ROE.WSON 'OY!NSHIP, ALLEGHENY CGUN 6 r MY COMMISS:0N EXPinES OCTOBER 20,195$
8306020420 830523 7
PDR ADOCK 05000412 ggt S
United States Euclear Regulatory Commission Mr. J. Allan page 2 COMMONWEALTH OF PENNSYLVANIA )
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SS:
COUNTY OF ALLEGHENY
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On this
,Q 3 d day of M
///3
, be fo re me,
a Notary Public in and for said (/ Commonweal t h and County, pe rso nal ly appeared E. J.
Woole ve r, who be ing duly sworn, deposed and said that (1) he is Vice President of Duquesne Light, (2) he is duly authorized to exe-cute and file the fo regoing Submit tal on behal f of said Company, and (3) the statements set fo rt h in the Submittal are true and correct to the bes t of his knowledge.
Not ary Public ANITA ELAINE REITER, NOTARY PUBLIC ROBINSON TOWNSHIP, ALLEGHENY COUNTY MY COMMISSION EXPlRES OCTOBER 20,1986
BEAVER VALLEY POWER STATION - UNIT NO. 2 DUQUESNE LIGHT COMPANY Final Report on Potential Deficiency of Westinghouse Gate Valve Position Indication 1.
SUMMARY
Wes t inghouse has ident if ied a pot ent ial significant de fici ency in Wes t inghou se supplied EMD gate valve position indicat ion ins trument a-t ion wh ich could result in an ind ic a t io n that the valve is "c los ed" prior to the valve disc fully isolating flow.
Should the valve stall or bind following the premature indication, the operator would have an inaccurate indication of true valve position.
2.
IMMEDIATE ACTION TAKEN On January 12, 1983, Duquesne Light Company not ified B. Crocker of the Region I of fice by telephone.
Duquesne Light Company also ins truct ed Westinghouse to cont inue with their inves t iga t ion of the pot ent ial deficiency.
3.
DESCRIPTION OF DEFICIENCY A geared limit switch rotor is set to pr ov ide an electrical bypass of the OPEN to rque switch at the beginning of the opening stroke.
On a c los ing stroke, this swi tch ch anges state be fo re the flow pa th is c omple tel y blocked.
As a result, it is likely that mo ni to r and/or i
ind ica to r lights al so ope rated by that rot or will indicate valve closure slightly before the flow path is completely shut off.
If the valve were to stop between this setpoint and the full shut of f pos i-t io n, a flow path through the valve could exist even though a CLOSE indication had been achieved.
The various generic gate valve applica t ions have been rev iewed to det ermine those that may result in un ac cep t ab le c ons eque n ces.
These are:
j a.
Hot leg safety injection (high and low pressure) b.
Alternate cold leg (high pressure) injection (3-loop plants only) c.
Cold leg injection (low head) l l
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1
e All valves which have been identified as potentially requiring mdifi-c at ion and which incorrect position indication by itself could cause an un ac cep t ab le s itua t ion that vio la t es the es t ab lished licens ing basis for Beaver Valley Power Station Unit 2 are:
8816 8886 8889 8814 8888A 8888B 4.
ANALYSIS OF SAFETY IMPLICATIONS Inac curate pos it ion indication of safe ty-rela t ed iso la t ion valves could result in imprope r sy s tem iso la t ion or sys tem ope rat io n ani possible inaccurate operator res ponse, degrading the af fected sys tem's ability to perform its safety function.
5.
CORRECTIVE ACTION TO REMEDY DEFICIENCY Westinghouse has comple t ed a plant specific review for Beaver Valley Power S t atio n Unit 2.
It confirms that the six (6) valves listed above are the only safety rela t ed valves which could require corree-t ions due to this pot ent ial s ignificant de ficiency.
Duquesne Light Company will modify the Wes t inghou se-s upplied pos it io n indica tion wiring on each of the six safety related valves to use a torque switch input in place of the cur re nt limit swi tch.
This change will ensure that true valve position will be provided to the operator for these six EMD gate valves. This change is expected to be completed by June, 1984.
6.
ADDITIONAL REPORTS This is the final report.
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