ML20204H183
| ML20204H183 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 10/12/1984 |
| From: | Woolever E DUQUESNE LIGHT CO. |
| To: | Murley T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| 2NRC-4-168, 84-10, ZNRC-4-168, NUDOCS 8411120203 | |
| Download: ML20204H183 (5) | |
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Pittsburgh, PA 15205 October 12, 1984 United States Nuclear Regulatory Commission Region 1 631 Park Avenue King of Prussia, PA 19406 ATTENTION:
Dr. Thomas E. Murley Administrator
SUBJECT:
Beaver Valley Powar Station - Unit No. 2 Docket No. 50-412 Ilydrogen Control System Failure due to Spurious Operation of Motor-Operated Valves Reportable Significant Deficiency Report 84-10 Gentlemen:
This final report is in reference to reportable Significant Defi-ciency 84-10 relating to " Hydrogen Control System Spurious Operation of Motor-Operated Valves." Pursuant to the requirements of 10CFR50.55(e), the attached final report subs tant iates that the initially reported condi t ion has been evaluated as not report ab le. No additional information or reports on this item are, therefore, anticipated.
DUQUESNE LICHT COMPANY By f
E.tJ. Woolever Vice President SDH/wjs Attachment a
Mr. R. DeYoung, Director (3) (w/a) cc:
Ms. M. Ley, Project Manager (w/a)
Mr. E. A. Licitra, Project Manager (w/a)
Mr. G. Walton, NRC Resident Inspector (w/a)
INPO Records Center (w/a)
NRC Document Control Desk (w/a) i SUBSCRIBED AND S RN T BEFORE ME THIS
/M DAY OF C
, 1984.
d L.
841112O203 841012 Notary Public PDR ADOCK 05000412 S
PDR ANITA ELAINE REITER, NOTARY PUBUC ROBINSON TOWNSHIP, A'.LEGHENY COUNTY MY COMMISSION EXFIRES OCTOP:R 20.1986 i,
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Units:d St:tco Nuciscr R2gulctcry Commicsion Dr. Thomac E. Murlsy Page 2
. COMMONWEALTH GF PENNSYLVANIA )
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SS:
COUNTY OF. ALLEGHENY
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On'this -//
day of
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, before me, 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 execute and file the foregoing Submittal on behalf of said Compan,/ and (3) the statements set forth in the Submit tal are true and correct to the best of his knowledge, d
Notary Public ANITA ELAINE REITER, NOTARY PUBLIC ROBINSON TOWNSHIP, ALLEGHENY COUNTY MY COMMISSION EXPIRES OCTOBER 20,1986 b
p BEAVER VALLEY POWER STATION - UNIT NO. 2
. DUQUESNE LIGHT COMPANY Reportable Significant Deficiency Report 84-10 Hydrogen Control System Failure due to Spurious Operation of Motor-Operated Valves 1.
SUMMARY
A Failure Modes and E f fe ct s Analysis (FME A) performed on the po s t-DBA hydrogen control system (HCS) indicated that in a post-accident condition with the HCS systems in operation, a spurious opening of the mtor-oper-ated valves lis ad below could cause a failure of the HCS system to per-form its intende'd safety function.
2HCS*MOV110A
'2HCS*MOV110B 2HCS*MOV113A 2HCS*MOV113B These above valves are isolation valves for the inlet and outlet line of the containment atmosphere purge subsystem. See Attachment A.
.2.
IMMEDIATE ACTION TAKEN The design of the post-DBA HCS (including valve control circuitry) was reviewed, and means for correcting the subject deficiency were developed.
Mr. S. D. Hall, Acting Manager, Regulatory Af fairs, BVPS-2, notified Mr.
Lowell Tripp,.NRC Region I of fice, of a reportable significant deficiency on September 24, 1984. Further discussion by telephone between Mr. Tripp, Mr. Hall, ' and Mr.
J.
Hough ton (Duquesne Light Company) took place on
- September 25, 1984.
In this discussion, it was stated that Duque sne Light. Company's 30-day report woul d indicate that this item would be identified as not being repo rt able based on an evaluation conducted by Du(uesne Light Company.
3.
DESCRIPTION OF THE PROBLEM The hydrogen recombiner air inlet line and the contaiment purge blower line are common to both recombiners; the air inlet line is connected to the discharge side of the recombiners, and the purge blower line is con-nect ed to the suc t ion side of the recombiners (see Attachment A).
The inlet air lines and purge lines to each recombiner are equipped with the normally closed, parallel, electrically operated valves identified in (1) above.
^
4.
ANALYSIS OF SAFETY IMPLICATION
. No single spurious active failure could be postulated which would prevent primary containment integrity from being maintained during normal plant conditions.
The four valves (2HCS*MOV110A, -110B, and 2HCS*MOV113A, and
-113B) are normally closed during normal and pos t-accident operation.
The only time that they are intended to be open is for testing purposes s
'during normal plant operation or if both hydrogen recombiners would
g, J. 3 1-
' f ail, in a post-accident condition, af ter the recombiners had been placed
'into operation.. Operation of. these. valves is provided only via remote electrical control stations in the plant..
5.
CORRECTIVE ACTION TO REMEDY DEFICIENCY Valves ; 2HCS*MOV110A, - 2HCS*MOV110B, 2HCS*MOV113A, and 2HCS*MOV113B are closed during normal and post-accident operating mdes.
To ensure. that spurious ' opening of the subject valves does not cause failure of the hydrogen control system to pe rform its intended safety functions in a pos t-accident condition, an administrative. procedure will be implement ed that '.will require that the four (4) breakers in MCC*2E11 an* *2E 12 that
-supply power ~for these valves are to be maintained in the de-energized (open) mde during. normal and pos t-accident edes of ope ration.
It is
-expected that this procedure will be incorporated into the ap propria te I
~
operating manual by December-30, 1984.
6.
DATE CORRECTIVE ACTION WILL BE ACHIEVED This is the final report and it is anticipated that no additional reports will be submitted.
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IIILET
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,% o CONTAIStfEli h 211CS*MOV110A(AO) a ir 1r
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l LEAK COLLECTION SYSTEM CONTAINMENT 211CS*MOV110B 1 '
ATHOSPilERE A C l
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PURCE BLOWER h
H TO C0!1TAINMENT I
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IlYDROGEN CON LENT IlY*RT-IB 211CS
- MOVil3B (BP)
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