ML19341C058
| ML19341C058 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 01/27/1981 |
| From: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | Mattimoe J SACRAMENTO MUNICIPAL UTILITY DISTRICT |
| References | |
| NUDOCS 8102280554 | |
| Download: ML19341C058 (1) | |
Text
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'b UNITED STATES
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. NUCLEAR 95GULATORY CCMMISSION
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/8 7'90 N. CALIFORNIA BOULEVARD k ' ' [v d[
?UITE 200,'.*lALNUT CREEK PLAZA
- ,,,a WALNUT CREEM. CALIFORNIA 94596 January 27, 1981 Cs Docket No. 50-312 x' d.
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FE305E81*fi Sacramento Municioal Utility District P. O. Box 15230 gw#oung /C)
Sacramento, California 95813 c)
Q-Attention: Mr. John J. Mattimoe h/
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Assistant General Manager Gentlemen:
The enclosed IE Bulletin No. 81-01 is forwarded for your action with regard to your nuciear power facilities with operating license or near tenn operating license (NT01.).
To assist the NRC in evaluating tne value/ impact of each bulletin on all licensees, it *..culd be helpful if you would provide an estimate of the manpower expended in the review and preparation of the report (s) required by the bullatin. Please estimate separate'iy the manpower associated with corrective actions required by this bulletin.
Should you have any questions regarding this bulletin or the actions required of you, please contact this office.
Sincerely,
,? w.-
,c u b 34 --
i R. H. Engelken Director
Enclosures:
L 1.
2.
Recently issued IE Bulletins cc w/ enclosures:
.R. J. Rcdriguez, SMUD L. G. Schwieger, SMUD p
si 022 s offY
SSINS No.: 6820 Accession Fo.:
3005050075 lEB 81-01 UNITED STATES NUCLEAR REGULATORY CCPMISSION OFFICE OF INSPECTION A!!D ENFORCEPENT VASHINGTON, D.C.
20555 Janua ry 27, 1981 IE Bulletin No. 81-01: SURVEILLANCE OF MECHAMICAL SNUBBERS Descriotion of Circumstances:
Several instances of failures of mecnanical snubbers sucolied by International Nuclear Safeguarcs Corocration (INC) have been identified'that indicate possible deficiencies in tnese snubbers. A summary of the failures that nave occurred is provided below:
1.
_0n August 9,.1974, the Tennessee Valley ' Authority submitted event report
' BFA0-50-260/741W identifying 11 of la INC.Mocel MSVA-1A snuobers tnat were found inoperaole on Browns Ferry Nuclear Power Station Unit 2 and
-subsecuently identifiec 5 of:14 inoperacie units on Browns Ferry Nuclear Pcwer' Unit-No 3.
All of these units were found to be frozen, and tne cause was attributed to a failure to iubricate the parts during assembly.
The failed snubbers were replaced with new. units oroduced by. the same manufacturer.
2.
-On Acril-12, 1976, the St..Lucie Plant Unit 1 facility of Florida Power whe'ein five and Light' Corporaticn submitted event report No. 50-335-76-9 r
INC Madei' MSVA-1 snubbers were identified as. inoperable because they were
-fcund to le frozen.
The failures were caused by oxidation on the internals and -by imprcper ' assembly. All INC mechanical snubbers were replaced with-
' units produced by another manufacturer.
3.
On April '8,1977, Iowa' Electric Light and 'Pcwer Company submitted 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.
~
4.
On December 5,1979, personnel from the Nuclear Regulatory Commission visited Cepartment of Energy (DOE) facilities at Richland.. Washington, to obtain information on 00E. 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,
.FFTF. examined more than 800 of. these mechanical snubbers by removing them from-their installation and found that 43, or about 5% of those examined,
=were frozen. The plant was still under construction so the snubbers had
- seen no-service and had been subjected to only normal construction enviror.ments for 1: to 2 years.
l SSINS No.:
6820 Accession No.:
8005050075 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 IE Bulletin No. 81-01 January 27, 1981 Page 1 of 7 SURVEILLANCE OF MECHANICAL SNUBBERS Description of Circumstances:
Several instances of failures of mechanical snubbers supplied by International l
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 BFA0-50-260/741W identifying 11 of 14 INC Model MSVA-1A snubbers that were found inoperable on Browns Ferry Nuclear Power Station Unit 2 and subsequently 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 attribned 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 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 were replaced with those produced by another manufacturer.
4.
On December 5, 1979, personnel from the Nuclear Regulatory Commission visited Department of Energy (00E) 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 enteredintosystemunder[:
20DTD C001 nuo No. of pages:
a.l
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