ML19343B876
| ML19343B876 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 01/27/1981 |
| From: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Woolever E DUQUESNE LIGHT CO. |
| References | |
| NUDOCS 8102180086 | |
| Download: ML19343B876 (1) | |
Text
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UNITED STATES 8
NUCLEAR REGULATORY COMMISSION o
3 j
REGION I 0
4 631 PARK AVENUE 4
KING OP PRUSSIA, PENNSYLVANIA 19406 4, * * * *,o' j
i JAN 2 71981
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Docket No. 50-412 Duquesne Light Company ATTN:
Mr. E. J. Woolever S
73 Vice President a
435 Sixth Avenue j~
c.;
Pittsburgh, Pennsylvania 15219 a
Gentlemen:
The enclosed IE Bulletin No. 81-01, " Surveillance of Mechanical Snubbers," is forwarded to you for information.
No written response is required.
If you desire additional information regarding this matter, please contact this office.
Sincerely, i
Boy e H. Grier Director l
l
Enclosures:
1.
List of Recently Issued Bulletins CONTACT:
D. L. Caphton (215-337-5266) l cc w/encls:
R. J. Washabaugh, Quality Assurance Manager l
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8102180 0BCa.
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SSINS No.:
6820 i
Accession No.
l 8005050075
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UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 l
January 27, 1981 Page 1 of 7 l
SURVEILLANCE OF MECHANICAL SNUBBERS i
i Description of Circumstances:
Several instances of failures of mechanical snubbers supplied by International i
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:
l 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 i
were found inoperable on Browns Ferry Nuclear Power Station Unit 2 and I
subsequently identified 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.
l The failed snubbers were replaced with new units produced by the same manufacturer.
i l
2.
On April 12, 1976, the St. Lucie Plant Unit 1 facility of Florida Power i
and Light Company submitted event report No. 50-335-76-9 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 submitted event report No. 77-23 for the Duane Arnold Energy Center facility that identi-fied 13 INC Model 1MSVA-1 Type AS snubbers to be frozen; the cause of failure was attributed to large amounts of interior oxidation.
The units l
were replaced with those produced by another manufacturer.
l 4.
On December 5, 1979, personnel from the Nuclear Regulatory Commission visited Department of Energy (DOE) facilities at Richland, Washington, to obtain information on DOE experience Test Facility (FFTF).
The DOE-owned 4,000 mechanical pipe restraints (sn DUPLICATE DOCUMENT FFTF examined more than 800 of these Entire document previously entered into system under:,
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No. of pages:
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