ML19341A401
| ML19341A401 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 01/19/1981 |
| From: | Delgeorge L COMMONWEALTH EDISON CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| 10CFR-050.55E, 9787A, NUDOCS 8101230433 | |
| Download: ML19341A401 (2) | |
Text
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@ One First National Ptaza. Chicago. Uhno Commonwealth Edison Address Reply to: Post Office Box 767 Chicago. Illiriois 60690 January 19, 1981 Mr. James G. Keppler, Director Directorate of 7.aspection and Enforcement - F Jgion III U.S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, IL 60137 Subje ct:
LaSalle County Station, Units 1 & 2 Anchor / Darling Valve - Yoke Material Final Report - 10 CFR 50.55(e)
NRC Docket Nos. 50-373/374
Dear Mr. Keppler:
Commonwealth Edison notified your of fice on December 18, 1980 of a possible deficiency involving valve yoke material which did not meet the A216 WC8 material specified for 138 Anchor / Darling valves.
That notification was mace in accordance with 10CFR50.55 (e).
This letter fulfills the 30 day reporting requirement of that regulation.
This deficiency was identified when cracks were noticed in the yokes of a number of valves at the Susquehanna Steam Electric Station.
i An analysis and evalua'lon of the most severely cracked valve yoke was performec by the valve manufacturer.
They concluded that the cracking i
l was not due to casting defects, but rather was oue to the yoke material not having the proper mechanical properties.
Purchased as ASTM A-216, i
Grade WCB material, the actual valve yoke material had tensile and yield strengths below the minimum values listed in the ASTM material spe cifi ca tion.
The cracked yokes were all cast by Malcolm Foundry Company, Inc., of Newark, New Jersey.
The foundry is no longer in business.
Anchor / Darling notified Commonwealth Edison of the problem and informed es that 138 of the valves they supplied us were involved.
A program of verifying the tensile strengths of the yokes cast by Malcolm was then set up, but, prior to implementation, subsequent testing at Susquehanna revealed thsc hardness testing was inconclusive and all yokes would have to be changed out.
Of the 138 valves involved, 76 are required for Unit 1 startup, and of these 67 are safety related.
We have met with Anchor / Darling, and have worked out a schedule by which all 138 new yokes will be shipped to LaSalle between February 27 and April 24, 1981.
The defective yokes will be replaced and destroyed, thus preventing their use in the future.
The replacement and any retesting necessary is not expected to have any Bo/7 S
810128og3
i Mr. James G. Keppler, Director January 19, 1981 Page 2
'981.
In as impact on our scheduled Unit 1 fuel load of June 15, this is much as no further evaluation is judged to be requirs:,
considered to be a final report.
Please submit any questions on this matter to this of fice.
Very tru.y yo rs,
. ' De or Nuclear Licensing Administrator NRC Resident Inspector - LSCS cc:
Director of Inspection and
/
Enforcement (Washington, DC)'
9787A
.