ML20063E817
| ML20063E817 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 08/19/1982 |
| From: | Schroeder C COMMONWEALTH EDISON CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, 4813-N, NUDOCS 8208310040 | |
| Download: ML20063E817 (2) | |
Text
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D/N8 Comm:nwrith Edison One First National Plaza. Chicago. Illinois Address Reply to: Post Othce Box 767 Chicago, l!!inois 60690 Augus t 19, 1982 Mr. Jame s G.
Kepple r, Regio ~'l Adminis trato r Directorate o f Inspection i ad Enfo rcemen t - Region III U.S.
Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, IL 60137
Subject:
LaSalle County Station, Units 1 and 2 Drywell/Wetwell Vaccuum Breakers Final Report - 10 CFR 50.55(e) #82-05 NRC Docke t Nos. 50-373 and 50-374 References (a):
Letter L.O.
De l Geo rg e t o H. R. Den to n dated July 26, 1982, same subject.
(b):
License NPF-ll, Condition 2. C. (3 2).
Dear Mr. Keppler:
Commonwealth Edison notified your o f fice on July 23, 1982 of a possible deficiency resulting from predicted valve s tress greater than ASME code allowable stress.
That notification was made in accordance with 10CFR50.55(e).
This letter fulfills the 30-day requirement by that regulation.
Decription o f Deficiency This deficiency was identified when, evaluating the pressure ef fects o f pool swell, it was determined that the installed thirty inch vacuum breaker valves may not meet ASME allowable stresses.
Valve disk velocities were recently predicted using the maximum pool swell induced c P between the drywell and wetwell.
A bounding analysis indicated there may be small local exceedences of allowable stress values, however, the valves would fulfill their intended safety function.
The results of our assessment, presented to the staff July 23, 1982 were documented in the Reference (a).
Corrective Action Notwithstanding our belief in the present adequacy of these valves, Commonwealth Edison will conduct a confirmatory test on a full size LaSalle valve at the velocities predicted from the bounding load (5.5 psid drywell to wetwell pressure).
The test will be completed and an evaluation presenteo to the NRC by November 1, 1982, as required by Reference (b).
AUG 2 4 E021 8200310040 820819 PDR ADOCK 050003 3
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At Augus t 19, 1982 J. G. Keppler If there are any further questions in this matter, please contact this office.
Very truly yours, 9[/i[BL C.
W.
Schroeder Nuclear Licensing Administrator 1m cc:
Director o f Inspection and En forcement Washington, D.C.
20555 NRC Resident Inspector - LaSalle 4813N l
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