ML19350B659
| ML19350B659 | |
| Person / Time | |
|---|---|
| Site: | Sterling |
| Issue date: | 03/04/1981 |
| From: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Arthur J ROCHESTER GAS & ELECTRIC CORP. |
| References | |
| NUDOCS 8103230206 | |
| Download: ML19350B659 (1) | |
Text
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[(f jg UNITED STATES NUCLEAR REGULATORY COMMISSION S 3.r, g
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D Docket No. 50-485 Rochester Gas and Electric Corporation U
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ATTN: Mr. J. E. Arthur 6
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g Gentlemen:
IE Sulletin No. 81-01, " Surveillance of Mechanical Snubbers," transmitted to you on January 27, 1981, has been revised to change the identification of the pcwer reactor facil' ties with construction permits to which the Bulletin is applicable.
This change does not affect your requirements with respect to the original Bulletin. As a result, the enclosed revised pages 5 and 6, are forwarded to you for information.
If you desire additional information regarding this matter, please contact this office.
Sincerely, CZ r
H. Grier Director
Enclosures:
Revised pages 5 and 6 of IE Bulletin 81-01 and List of Recently Issued IE Bulletins CONTACT:
D. L. Caphton (215-337-5266) cc w/encis:
C. R. Anderson, Manager, QA Lex K. Larson, Esquire N. A. Petrick, Executive Director, SNUPPS Gerald Charnoff, Esquire 810 828 0 ACAo A
SSENS No.:
6820 Accession No.:
8005050075 IEB 81-01 UNITED STATES
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<b S "' F NUCLEAR REGULATORY COMMISSION Eg
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OFFICE OF INSPECTION AND ENFORCEMENT
"" es WASHINGTON, D.C.
20555 January 27, 1981 IE Bulletin No. 81-01:
SURVEILLANCE OF MECHANICAL SNUBBERS Description of Circumstances:
Several instances of failures of mechanical snubbers supp' lied by International Nuclear Safeguards Corporation (INC) have been identified that indicate possible deficiencies in these snubbers. A summary of the failures that have occurred is provided below:
1.
On August 9, 1974, the Tennessee Valley Authority submitted event report BFAO-50-260/741W identifying 11 of 14 INC Model MSVA-1A snubbers that were found inoperable on Browns Ferry Nuclear Power Station Unit 2 and subsequently identiftad 5 of 14 inoperable units on Browns Ferry Nuclear Power Unit No 3.
All of these units were found to be frozen, and the cause was attributed to a failure to lubricate the parts during assembly.
The failed snubbers were replaced with new units produced by the same manufacturer.
2.
On April. 12, 1976, the St. Lucie Plant Unit 1 facility of Florida Power and Light Corporation submitted event report No. SC-335-76-9 wherein five INC Model MSVA-1 snubbers were identified as inoperable because they were found to be. frozen. The failures were caused by oxidation on the internals and by improper assembly. All INC mechanical snubbers were replaced with units produced by.another manufacturer.
3.
On April 8,1977,- Iowa Electric Light and Power Company. :ubmitted event report No. 77-23 for the.Duane Arnold Energy Center facility that identi-fied~13 INC Model IMSVA-1 Type AS snubbers to be frozen; the cause of failure was' attributed to.large amounts of interior oxidation. The units were replaced with those produced by another manufacturer.
0n December 5,1979, personnel from the. Nuclear Regulatory Commission
.4..
visited Department of Energy (DOE) facilities at Richland, Washington, to obtain information on DOE experience with INC snubbers at the Fast Flux Test Facility.(FFTF). The' DOE-owned FFTF was equipped with more than 4,000 mechanical pipe restraints (snubbers) supplied by INC.
In 1978, lFFTF examined more than 800 of these mechanical snubbers.by removing them, frot their. installation and found that 43, or about 5% of those examined,
.wsre frozen. The plant was still.under construction so the snubbers had seen no service and had been subjected to only normal construction environments for 1 'to 2 years.
Attachment:
.Recently issued.'IE-bulletins-6