ML20203K415
| ML20203K415 | |
| Person / Time | |
|---|---|
| Site: | Bellefonte  |
| Issue date: | 08/06/1986 |
| From: | Gridley R TENNESSEE VALLEY AUTHORITY |
| To: | Grace J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| NUDOCS 8608200292 | |
| Download: ML20203K415 (2) | |
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TENNESSEE VALLEY AUTHORITY CHATTAt4COOA. TCr4r4CGGCC 374G1 SN 157B Lookout Place BLRD-50-438/84-21 AUG 0 61986 BLRD-50-439/84-20 U.S. Nuclear Regulatory Commission Region II Attn:
Dr. J. Nelson Grace, Regional Administrator 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 dear Dr. Grace:
BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 - INCORRECT INSULATION WEIGHTS FOR INTAKE PUMPING STATION PIPING - BLRD-50-438/84 -21, BLRD-50-439/84 FINAL REPORT The subject deficiency was initially reported to NRC-OIE Inspector Ross Butcher on February 21, 1984 in accordance with 10 CFR 50.55(e) as NCR BLN BLP 8405.
Enclosed is our final report.
If you have any questions, please get in touch with D. L. Terrill at FTS 858-2682.
Very truly yours, TENNESSEE VAL EY AUTHORITY R. L. Gridley, irector Nuclear Safety and Licensing Enclosure Mr. James Taylor, 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 8608200292 860806 PDR ADOCK 05000438 s
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I An Equal Opportunity Employer -
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ENCLOSURE BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 INCORRECT INSULATION WEIGHTS FOR INTAKE PUMPING STATION PIPING BLRD-50-438/84-21 AND BLRD-50-439/84-20 10 CFR 50.55(e)
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Description of Deficiency During a review of ' he applicable insulation and modes analysis data for the essential raw coolfog water (ERCW) piping in the intake pumping station it was determined that certain insulation weights were in error.
Further investigntion revealed that documented design calculations for determining the actual insulation weights fer some pipe sizas did not exist.
It was determined that
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these conditions occurred due to a change in insulation type which was not picked up in the design. The insulation and mode analysis data sheet drawings were not changed and the piping analysis was not revised. TVA has determined that the root cause of this error was that the design work was performed in a special projects group outside the Bellefonte Engineering Project (BLEP) and the individual performing the work was either not aware of his full responsibilities regarding this change or simply made an engineering oversight. This item was discovered after the work was transferred back into BLEP.
The remainder of the ERCW system was reviewed and found correct.
No generic implications exist since this condition is considered cn isolated occurrence.
Safety Implications 1
Incorrect design input data could possibly have resulted in a nonconservative analysis and an inadequate piping design and installation. This could potentially have resulted in a failure of the ERCW system during a design basis earthquake. This potentially could have adversely affected the safe operation of the plant.
Corrective Action TVA has completed the calculations for insulation weights and documented the weights. The insulation and mode analysis drawings have been revised to reflect the new weights.
The piping reanalysis, support redesign and rework is scheduled to be completed by six months before fuel load of the applicable unit.
Since the time of this occurrance, a number of changes / steps have been taken which will lessen the probability of recurrance of a similar condition:
(1) Work of this type is now being performed either in BLEP or by individuals under direct supervision of BLEP; and (2) A number of training initiatives and procedural changes (especially in design control) have occurred from 1982 onward in the Division of Nuclear' Engineering (e.g., February 1982 action plan to instruct individuals in procedures affecting their work and June 1985 issuance and training to Office of Engineering Procedures, OEP - 11. " Change Control" (Now NEP-6.1), etc.).
These steps are considered adequate actions required to prevent recurrance.
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