ML20052A389
| ML20052A389 | |
| Person / Time | |
|---|---|
| Site: | Bellefonte  |
| Issue date: | 04/15/1982 |
| From: | Mills L TENNESSEE VALLEY AUTHORITY |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| REF-PT21-82 10CFR-050.55E, 10CFR-50.55E, NUDOCS 8204280291 | |
| Download: ML20052A389 (2) | |
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TENNESSEE VALLEY AUTHORITY CH ATTANOOGA. TENNESSEE 37401 400 Chestnut Street Tbwer II April 15, 1 l2
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2 U.S. Nuclear Regulatory Omunission
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Region II Mr. James P. O'Reilly, Regional Adrainistr['rk;p[
Attn 101 Marietta Street, Suite 3100 Atlanta, Georgia 30303
Dear Mr. O'Reilly:
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WHRPONIE NUCLEAR PLAbrf UNITS 1 AND 2 - B0PEET STUDS IMPROPERLY TORQUED ON DECAY HEAT REMWAL VALVES - BLRD-50-438/82-04, BLRD-50-439/82 SIE GED INrERIM RE90er I
%e subject deficiency was initially reported to NBC-OIE Inspector R. V. Crlenjak on December 22, 1981 in accordance with 10 CFR 50.55(e) as NCR 1686. This was followed by our first interim report dated January 20, t
1982. Enclosed is our second interim report. We expect to subnit our next report by June 28, 1982. We consider 10 CFR Part 21 applicable to this deficiency.
l If you have any questions concerning this matter, please get in touch with
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R. H. Shell at FTS 858-2688.
1 Very truly yours, TDNESSEE VALLEY AITIHORITY l
L. M. Mills, Manager l
Nuclear Regulation and Safety Enclosure cca Mr. Richard C. DeYoung, Director (Enclosure)
Office of Inspection and Enforcement U.S. Nuclear Regulatory Canuaission l
Washington, DC 20555 i
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ENCLOSURE BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 BONNET STUDS IMPROPERLY TORQUED ON DECAY HEAT REMOVAL VALVES NCR 1686 BLRD-50-438/82-04, BLRD-50-439/82-04 1C CFR 50.55(e)
SECOND INTERIM REPORT Description of Deficiency The following Borg-Warner (Van Nuys, California) bolted bonnet gate valves were furnished on contract 77K38-86163-8 and were found by field inspection to have bonnet studs which were torqued to values less than required by the applicable vendor drawing (i.e., 160-200 foot-pounds).
Borg-Observed Warner Torque Mark No.
Item No.
Drawing No.
Serial No.
(Ft Lbs) 3AWO412-ND-35 636 80140 26165*
50-100 26166 20-100 26167 20-100 261685 0-180 3AWO412-ND-45 638 80130 26598 20-180 Interim Progress The portion of the valves which are installed and operational (as indicated by *) have been retorqued to the value presently required by the vendor drawing.
Borg-Warner was contacted and informed of the deficiency. Their response is contained in a letter dated March 22, 1982 (MEB 820330 500). Borg-Warner's investigation concluded that the current torque requirements which were based on a gasket factor from ASME Section VIII, Division J, Table UA-49.1 1971 edition do not in all cases effect a metal to metal contact between body and bonnet flanges. Under such conditions, the gasket could take a set during storage thus reducing the gasket force on the studs / nuts and subsequently contribute to the " low torque" condition.
The torque values have been reassessed based on an increase of the gasket factors by ASME and even higher recommended factors by the gasket manufacturer. Borg-Warner is in the process of updating all documents as required to include the revised torque values. Additionally, they have made recommendations of torque values depending upon stud size.
TVA will retorque the valves listed above to the newly defined values.
Additionally, TVA will require Borg-Warner to furnish a list of all valves supplied to TVA where this situation exists and they will be retorqued as required.
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