ML19350D937

Responds to IE Bulletin 81-01, Surveillance of Mechanical Snubbers. All Piping Sys W/Inoperable Mechanical Snubbers Supplied by Intl Nuclear Safeguards Corp Are Acceptable for Continued Operation.Inoperable Snubbers Were Replaced

ML19350D937
Person / Time
Site:	Millstone
Issue date:	05/18/1981
From:	Counsil W NORTHEAST NUCLEAR ENERGY CO.
To:	Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
A01531, A1531, IEB-81-01, IEB-81-1, TAC-08952, TAC-8952, NUDOCS 8105270235
Download: ML19350D937 (2)

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May 18, 1981 Docket No. 50-336 A01531 cq \ l Q, i E Q Mr. Boyce H. Grier, Director I j Region I W hq ,,b ggS I 0 i Office of Inspection and Enforcement c U. S. Nuclear Regulatory Commission p, 631 Park Avenue \ )< . # . s

                                                                                             -{q3 King of Prussia, PA 19406                                                        ,

Gentlemen: Millstone Nuclear Power Station, Unit No. 2 I&E Bulletin No. 81-01, Mechanical Snubbers In response to the Staff's verbal requests of May 15, 1981, Northeast Nuclear Energy Company (NNECO) hereby provides the follow 2.nq information prior to power operation of Millstone Unit No. 2. mTECO has performed stress analyses and,' where appropriate, fatigue evaluations for all the systems on which inoperable mechanical snubbers manufactured by International Nuclear Safeguz.rds Corporation (INC) were installed. The as-found snubber conditions, as determined by a manual stroke test, were utilized as input to these analyses and evaluations. Based on the results of these analyses and evaluations, NNECO has determined that all piping systems on which inoperable INC mechanical snubbers were found are acceptable for continued operation. All INC mechanical snubbers determined to be inoperable were replaced with snubbers of a different design. All snubbers which were determined to be inoperable were found locked in various positions through the range of stroke. NNECO has attributed the cause of failure to be oxidation of the snubber internals based on destructive examination of several snubbers. Additional detailed informa Mon will be provided in accordance with Item

             '4 of I&E Bullei.in No. 81-01. Power operation of Millstone Unit No. 2 is currently scheduled to cocmence at 1500 hours on May 18, 1981.

Very truly yours, NORTHEAST NUCLEAR ENERGY CCMPANY \ f yj a-,/ 'V W. D.' Coun'sil Senior Vice President 1 8105270 N3 4 a

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STATE OF CONNECTICUT)

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Then personally appeared before ne W. G. Counsil, who being duly sworn, did state that he is Senior Vice President of Northeast Nuclear Energy Company, a Licensee herein, that he is authori::ed to execute and file the foregoing information in the name and on behalf of the Licensees herein and that the statements contained in said information are true and correct to the best of his ltnowled 6e and. belief. Notary Public h hakA._ 7 My Commission Expires MarcN 3I,1986 S 5

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