ML20010A612
| ML20010A612 | |
| Person / Time | |
|---|---|
| Site: | Byron, Braidwood  |
| Issue date: | 07/24/1981 |
| From: | Tramm T COMMONWEALTH EDISON CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, 2344N, NUDOCS 8108110606 | |
| Download: ML20010A612 (2) | |
Text
O/M3/56 I
[~' s Commonwe:lth Edison
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) One First National Plaza. Ch.cago, Illinois
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T 7 Address Reply to: Post Office Box 767
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/ Chicago, Illinois 60690
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i July 24, 1981
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-3 Mr. James G. Keppler, Director mm Directorate of Inspection and 4
posses Enforcement - Region III D
7 U.S. Nuclear Regulatory Commission N
8 799 Roosevelt Road m
Glen Ellyn, IL 60137
Subject:
Byron Station Units 1 and 2 Braidwood Station Units 1 and 2 Motor Operated Valve Failure to Close 50.55(e) Deficiency Report Number 81-03 NRC Docket Nos.50-45t,/455/456/457
Dear Mr. Keppler:
lune 18, 1981',, Commonwealth Edison notified Mr. John I
Ne'
^
sur office that certain motor operated valves at Byron ant sod appear to have a deficiency reportable pursuant to 10 CFR.v.55(e).
This letter fulfills the thirty-day reporting requirement of 50.55(e) regarding that item.
DESCRIPTION OF DEFICIENCY The failure of the Westinghouse Electro-Mechanical Division remotely-operated three inch gate valves to close, was previously reported to NRC.
The list of deficient gate valves has been expanded to include 6, 8, 12 and 14 inch valves and 3 and 4 inch low pressure valves.
ANALYSIS OF SAFETY IMPLICATIONS A list of the valves and the safety significance of their failure to close is attached.
CORRECTIVE ACTION Westinghouse has made recommendations for modifications to the motor operators for these valves.
It is expected that these modifications will be completed by the end of this year.
Please address any questions that you have regarding this matter to this office.
Very truly yours, T. R. Tramm Nuclear Licensing Administrator fh k
l Attachment cc:
Director of Inspection and Enforcement i
8108110606 810724 k
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2344N PDR ADOCK 05000454 g
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....p Attachment Byron /Braidwood System valve #
&nction: Safety Significance of Failure to Close Fully CVCS ll2B&C Charging purrp suction valves from VCT:
The failure of these valves to close could result in a diversion of flow from the charging pumps on ECCS actuation.
- However, thre is a check valve in series with these valves which prevents backflow.
1120&E Charging pump suction valves from the RWST:
These valves are required to open on I
ECCS actuation.
However, they are required to close when switching to long term cooling.
Failure to close could result in diversion of flow from the charging pumps if the charging pumps are required for long term cooling (small break).
However, there is a check valve in series with these valves.
SIS 8804A Charging pump suction from RHRS:
This valve is required to open for long term cooling.
It is normally closed.
88048 SI pump suction from RHRS:
This valve is required to open for long term cooling.
It is normally closed.
8923A&B SI pump suction valves from RWST: These valves are normally open and not required to close.
8806 SI pumps common suction from RWST:
This valve is normally open and is not required for ECCS actuation.
It is required to be closed for long term cooling.
Failure to close could result in diversion of flow from the SI pumps.
- However, there is a check valve in series with this pump.
8807A&B Charging pump - SI pump suction crossties: These valves are normally closed.
8924 Charging pump - SI pump suction crosstie:
This valve is nonnally open and not required to close.
RHR 8701A&B RHR pump suction valves from hotleg: These valves are normally closed and used 8702A&B only during normal shutdown long term cooling.
8716 RHR pump discharge crosstie:
This valve is normally open and is not required to close.
1 0444b/2*
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.