DCL-84-367, Responds to IE Bulletin 84-03 Re Potential for & Consequences of Refueling Cavity Water Seal Failure.Plant Seal Assembly Limits Large Leak Via metal-to-metal Contact. Gross Failures of Cavity Water Seal Unlikely
| ML20100H878 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 11/30/1984 |
| From: | Brand D PACIFIC GAS & ELECTRIC CO. |
| To: | Martin J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| References | |
| CON-#185-532 DCL-84-367, IEB-84-03, IEB-84-3, OL, NUDOCS 8412100132 | |
| Download: ML20100H878 (2) | |
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MC PACIFIC GAS AND EI ECTRIC
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November 30, 1984 PGandE Letter No.: DCL-84-367 Mr. John B. Martin, Regional Administrator U. S. Nuclear Regulatory Comoission, Region V 1450 Maria Lane, Suite 210 Walnut Creek, CA 94596-5368 Re: Docket No. 50-275, OL-DPR-80 Docket No. 50-323 Diablo Canyon Units 1 and 2 IE Bulletin No. 84-03, Refueling Cavity Water Seal 4
Dear Mr. Martin:
PGandE has reviewed IE Bulletin No. 84-03 which directs licensees to evaluate the potential for, and consequences of, a refueling cavity water seal failure and to provide a summary report.
Diablo Canyon has maintained the original NSSS Supplier's seal ring assembly design..This design is significantly different from the Haddam Neck seal ring assembly. The Diablo Canyon assembly consists of a metal-to-metal surface with double seals on the inside reactor flange and double seals on the outside of the seal ring. This type of seal assembly would physically limit a large
. leak due to the metal-to-metal contact. A leak test of the seal assembly is performed as required at each refueling. Should a small leak develop due to the unlikely failure of the double seal, the makeup capacity from two 3000 gpm RHR pumps could easily maintain water level.
Since a gross failure of the reactor refueling cavity water seal is not considered applicable to Diablo Canyon, no further actions to mitigate the 8412100132 841130PDRADOCK05000g G
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'Mr. J." B.- Martin PGandE Lctter No. DCL-84-367-November 30, 1984 Page 2 consequences of such a' failure are considered appropriate.
. Kindly acknowledge receipt of this material-on the enclosed copy of this:
letter and return it in the enclosed addressed envelope.
Respectfully submitted, Pa e Gas an Electric Co pany By 6 bwk D.MrWF Vice President 4
Engineering Robert Ohlbach Subscribed and sworn to before me
- Philip A. Crane, Jr.
this 30th day of November 1984 Richard F. Locke Attorneys for Pacific Ga d Electric Compan l1 AD Bhhflfp A~.~fr~ane,'J a
V Nantef J. Lefna' ster,.NDtery Public in SEAL
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