ML20072F959
| ML20072F959 | |
| Person / Time | |
|---|---|
| Site: | Bellefonte  |
| Issue date: | 06/20/1983 |
| From: | Mills L TENNESSEE VALLEY AUTHORITY |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| REF-PT21-83 10CFR-050.55E, NUDOCS 8306280222 | |
| Download: ML20072F959 (2) | |
Text
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.,r TENNESSEE VALLEY AUTHORITY CHATTANOOGA, TENNESSEE 374ot y
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June 20, 1983 rg*
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BLRD-50-439/81-20 W
9a U.S. Nuclear Regulatory Comission
~ Region II P
Attn: Mr. James P. O'Reilly, Regional Administrator 101 Marietta Street, NW, Suite 2900 i-Atlanta, Georgia 30303
Dear Mr. O'Reilly:
BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 - DECAY HEAT REMOVAL VALVE DEFICIENCY - BLRD-50-439/81 REVISED FINAL REPORT The subject deficiency was initially reported to NRC-0IE Inspector R.-W. Wright on February 12, 1982 in accordance with 10 CFR 50.55(e) as NCR 1315. This was followed by.our final report dated March 13, 1981.
. A comitment was made in TVA's second pupplemental response to violation 50-438, 50-439/82-23-04, dated December 17, 1982 to revise the final report on NCR 1315. Enclosed is our revised 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 L.
. Mills, Nanager Nuclear Licensing Enclosure cc:
Mr. Richard C. DeYoung, Director (Enclosure)
Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, D.C.
20555 Records Center (Enclosure)
Institute of Nuclear Power Operations
-1100 circle 75 Parkway, Suite 1500
' Atlanta, Georgia 30339
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ENCLOSURE BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 DECAY HEAT REMOVAL VALVE DEFICIENCY NCR 1315 BLRD-50-439/81-20 10 CFR 50.55(e)
REVISED FINAL REPORT Description of Deficiency The control valve for the decay heat cooler cutlet, supplied by ACF Industries, Inc., WKM Valve Division, Houston, Texas to B&W for use in the Decay Heat Removal System, was determined to be deficient. The deficiency resulted from the lower stem, valve plug, and lock pin being mismachined.
This mismachining results in the failure of the lock pin to stay in place during normal operation of this valve. As stated in their letter to TVA dated March 9,1983, B&W has attributed the cause of this nonconformance to some form of human error, either failure to follow procedures or improper execution of procedures.
Safety Implications The failure of this valve could result in the failure of the Decay Heat Removal System, which would allow the reactor core to be inadequately cooled, thus affecting the safe operations of the plant.
Corrective Actions The lower stem valve plug and lock pin has been replaced in the 2DH-HV3B Valve.
The three other WKM valves supplied by B&W to TVA were disassembled and inspected and found to be correctly machined.
Since this NCR occurrence, WKM has sold the control valve design to a company that is not qualified as a nuclear industry supplier. Therefore,
action to prevent recurrence is no longer feasible nor warranted.
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