ML20024C122
| ML20024C122 | |
| Person / Time | |
|---|---|
| Site: | Byron, Braidwood, 05000000 |
| Issue date: | 07/07/1983 |
| From: | Lentine F COMMONWEALTH EDISON CO. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| 6903N, NUDOCS 8307120281 | |
| Download: ML20024C122 (2) | |
Text
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s Commonwealth Edison
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/ One First N tional Pitzt, Chicago. Illinois
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( O } Address Reply to: Post Office Box 767 (f
Chicago, lilinois 60690 July 7, 1983 Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, DC 20555
Subject:
Byron Station Units 1 and 2 Braidwood Station Units 1 and 2 Containment Leak Rate Testing NRC Docket Nos. 50-454, 50-455, 50-456 and 50-457 Reference (a):
April 19, 1983, letter from F. G.
Lentine to H. R. Denton.
Dear Mr. Denton:
Reference (a) provided information regarding containment leak rate testing at Byron and Braidwood Stations and requested certain exemptions from the requirements of 10 CFR 50, Appendix J.
This is to request an additional exemption from Type C testing requirements for the Containment Sump Isolation Valves, MOVSI8811A and B.
These valves should be excluded from Type C testing for the following reasons:
1)
In order to perform local leak rate testing of each Containment Sump Isolation Valve, the corresponding train of the Residual-Heat Removal (RHR) System would have to be removed from service, and personnel would have to enter the containment sump to attach some kind of pressurization / sealing apparatus to the recirculation pipe opening.
The conditions required for these two actions are mutually exclusive.
During operation, access to the sump is precluded.
During a refueling outage, removal of an RHR train from service is considered an unsafe practice and is restricted by technical specifications.
2)
During the injection phase of the Leakage Design Basis Accident, spilled reactor coolant and injection water would be filling the containment sump; the (closed) sump isolation valves would be water-sealed and not exposed to the containment atmosphere.
Any leakage past the sump isolation valves would be into the closed RHR system.
3)
During the recirculation phase of the Leakage Design Basis Accident, the sump isolation valves would be open and recirculation flow would be returned by the RHR system to the containment.
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J. G. Keppler July 7, 1983 Due to the above. considerations, and in view of the fact that valve integrity is verified in the course of the Type A test, we believe that the exemption 6f. valves MOV8811A and B from Type C testing is justified.
Please address any questions regarding this matter to this office.
One signed original and forty (40) copies of this letter are provided for your use.
Very truly yours, f
F.
G. Lentine Nuclear Licensing Administrator 1m 6903N
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