ML20083Q399
| ML20083Q399 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 02/11/1983 |
| From: | Woolever E DUQUESNE LIGHT CO. |
| To: | Haynes R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, 2NRC-3-009, 2NRC-3-9, 83-01, 83-1, NUDOCS 8302250385 | |
| Download: ML20083Q399 (4) | |
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'AtS 2NRC-3-009 hN N1 Telecon M14 787-2629 Nuclear Cons'ruction Dimion February 11, 1983 Robinson Plaza, Building 2 Suite 710 Pittsburgh, PA 15205 United States Nuclear Regulatory Commission Region I 631 Park Avenue King of Prussia, PA 19406 ATTENTION:
Mr. R. C. Haynes Administrator
SUBJECT:
Beaver Valley Power Station - Unit No. 2 Docket No. 50-41'e Potential Deficiency of Westinghouse Gate Valve Position Indication Significant Deficiency No. 83-01 Gentlemen:
This interim report is in reference to the potential problem in the Westinghouse EMD gate valve position indication instrumentation reported to the Nuclear Regulatory Commission by S. D. Hall, of Duquesne Light Company, on January 12, 1983.
Westinghouse is currently reviewing the Beaver Valley Power Station Unit 2 specific application of the affected gate valves and instrumenta-tion; and, upon completion of this review, will recommend design changes,
where necessary, to remedy the potential deficiency.
Pursuant to the an interim report is submitted, and it is requirements of 10CFR50.55 (e),
expected that a subsequent report on this subject will be issued to the Region I Office by April 29, 1983.
DUQUESNE LIGHT COMPANY s
By E. JV Woolever Vice President RWF/wjs At tachetent cc:
Mr. R. DeYoung, Director Of fice of Inspection and Enforcement (3) (w/a)
NRC Document Control Desk (w/a) ector (w/a)
Mr. G. Walton, NRC Resident Insp/a)
Ms. L. Lazo, Project Manager (w SUBSCRIBED AND 0 'I TO BEFORE ME THIS f/ff DAY OF
, 1983.
Ifnde W W ANITA ELAINE REITER, NOTARY PUBUC ROBINSON TOWNSH!P, ALLECHENY COUNTY
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MY COMMISSION EXPlRES OCTOBER 20,1986 O-8302250385 830211 p
PDR ADOCK 05000412 S
Unitcd StctGs Nuclear R gulctcry Commissicn Mr. R._C. Haynes page 2 COMMONWEALTH OF PENNSYLVANIA )
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COUNTY OF ALLEGHENY
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On this
//6d day of
//[3, before me, f
a Notary Public in and 'for said Commonwealth and County, personally appeared E. J.
Woolever, who being 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 foregoing Submittal on-behalf of said Company, and (3) the statements set forth in the Submittal are true and correct to the best of his knowledge, ad Notary Public ANITA ELAINE GOTfD, NOTARY F'UBLIC
- ROBINSON TCWir.- r >, ALLECHENY COUNTY MY COMMISSION EXf' IRES OCTOBER 20,193G
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BEAVER VALLEY POWER STATION - UNIT NO.-2 4 --
DUQUESNE LIGHT COMPANY-Interim Report on Potential Deficiency of Westinghouse i
Gate Valve Position Indication
' 1.
SUMMARY
. Westingh'ouse has' identified a potential significant.. deficiency ~ in Westinghouse.'supglied EMD gate valve position indication. instrumenta.
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' tion which ' could result in an ' indication that the - valve is " closed" '
prior.to the-valve disc fully isolating flow.
Should the valve' stall L
or bind following the premature indication, the operator would have an inaccurate indication of true valve position.
~2 IMMEDIATE ACTION TAKEN On January 12,1982, Duquesne Light Company notified B. Crocker of the Region I office. by telephone.
Duquesne Light Company also instructed Westinghouse to continue with their investigation of the potential-
~
deficiency.
3.
DESCRIPTION OF DEFICIENCY A geared limit switch rotor is set to provide an electrical bypass of
- the OPEN torque switch at the beginning of the opening stroke. _On a-closing stroke,. this switch changes state before the flow path is' completely blocked.
As a result, it is -likely that monitor and/or indicator lights 'also operated-by that rotor 'will indicate valve closure slightly before the flow path is completely shut off.
If the i
. valve were to stop between this setpoint and the full shut off posi-tion, a flow p'ath through the-valve could exist even though a CLOSE indication had.been' achieved.
Depending on-the plant-specific valve application and consequences of inaccu~ rate closure indication, the wiring of certain valves may need to be altered to meet. operational safety requirements.
This finding was l.
based on Westinghouse generic wiring specification. This issue may not on Duquesne Light Company's specific wiring be applicable deperding requirements or if the subject valves were rewired as part of other l
modifications to increase shut off pressure rating.
~
The - various generic gate valve applications have been reviewed to determine those that may result in unacceptable consequences.
These 4
are:
l' a.
Hot leg safety injection (high and low pressure) l b.
Alternate cold leg (high pressure) injection (3-loop plants only) l-r
- c.. Cold leg injection (low head) o y
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All valves' which have been, identified as potentially requiring modifi-cation and which' incorrect position indication by.itself could cause an unacceptable - situation that violates the. established licensing basis for Beaver: Valley Power._ Station Unit 2 are:
8816 8885 8889 8814 8888A 88888 4.
ANALYSIS OF SAFETY IMPLICATIONS Inaccurate position indication of safety-related -isolation valves could result - in improper system isolation or system' operation and - possible inaccurate operator response, degrading the affected system's ability to perform its safety function.
5.
CORRECTIVE ACTION TO REMEDY DEFICIENCY Westinghouse is currently conducting a plant specific review for Beaver Valley Power Station Unit 2, and, upon completion of this evaluation, will recommend design changes, where necessary, to remedy the problem.
__ 6. ADDITIONAL REPORTS Westinghouse is scheduled to provide results of their design review and recommend a schedule for implementation of any corrective action, if needed, to remedy the potential def_iciency.
Duquesne Light Company plans to issue another report, interim or final, when additional details concerning the corrective ac' ion are available. It is expected that this report will be submitted so Region I by April 29, 1983.
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