ML20039F473
| ML20039F473 | |
| Person / Time | |
|---|---|
| Site: | Bellefonte  |
| Issue date: | 01/05/1982 |
| From: | Mills L TENNESSEE VALLEY AUTHORITY |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| REF-PT21-81 10CFR-050.55E, 10CFR-50.55E, NUDOCS 8201130026 | |
| Download: ML20039F473 (2) | |
Text
TENNESSEE VALLEY AUTHORITY y<34,,
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January 5, 1982 JM/ 7 All " N BLRD-50-438/81-68 BLRD-50-439/81-67 Mr. James P. O'Reilly, Director Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Region II - Suite 3100 101 Marietta Street Atlanta, Georgia 30303
Dear Mr. O'Reilly:
BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 - OVERTORQUING OF BOLTS ON FLOW CONTROL VALVE - BLRD-50-438/81-68, BLRD-50-439/81 FINAL REPORT The subject deficiency was initially reported to NRC-0IE Inspector R. V. Crlenjak on October 22, 1981 in accordance with 10 CFR 50.55(e) as NCR 1620. This was followed by our first interim report dated November 20, 1981. Enclosed is our final report. We consider '10 CFR Part 21 applicable to this deficiency.
If you have any questions concerning this matter, please get in touch with R. H. Shell at FTS 858-2688.
Very truly yours, TENNESSEE VALLEY AUTHORITY fy
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h L' M.' Mills, Manager Nuclear Regulation and Safety o
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Enclosure cc:
Mr. Richard C. DeYoung, Director (Enclosure) kg Office of Inspection and Enforcement yJ Washington, DC 20555 A, JjI8'
,9 U.S. Nuclear Regulatory Commission
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ENCLOSURE BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 OVERTORQUING OF BOLTS ON ELOW CONTROL VALVE BLRD-50-438/81-68, BLRD-50-439/81-67 10 CFR 50 55(e)
FINAL REPORT Description of Deficiency
' During torquing operation in the field on the motor operator adapter to the residual heat removal isolation valve (mark No. 3AWO412-ND-3 12-inch ASME j
-III Class 2 motor-operated gate valve), a bolt failed..0ther bolts on-examination showed elongation. All bolts had been torqued to 518 ft-lbs.
The vendor drawing (Borg-Warner drawing 80590) requires 500-550 ft-lbs.
These bolts were provided by Borg-Warnee of Van Nuys, California.
Safety Implications When TVA installed the motor operator adaptor to the residual heat removal isolation valve (per. Borg-War.ner drawing), the 3/4" attaching.
bolts became overstressed. Had this condition gone uncorrected, these bolts might have broken, thereby rendering the motor operator ineffectual. This condition could violate the intedrity of the.
containment isolation, thus adversely affecting the safety of the
-operations of the plant.
Corrective Action Borg-Warner was contacted. Their review of the problem showed that the
. torque value listed on drawing 80590 for the motor operator adapter to yoke e
connection bolts was in error.
Borg-Warner revised the drawing to show the correct torque value (120-140 ft-lbs). TVA has replaced the bolts using the newly defined torque I
values and verified that tapped threads in the adapter are not damaged.
Additionally, Borg-Warner has reviewed all drawings / contracts supplied to TVA and determined that this situation does not exist el.?ewhere.
W l
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