ML20072E197
| ML20072E197 | |
| Person / Time | |
|---|---|
| Site: | Bellefonte  |
| Issue date: | 03/15/1983 |
| From: | Mills L TENNESSEE VALLEY AUTHORITY |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, NCR-1478, NUDOCS 8303210605 | |
| Download: ML20072E197 (3) | |
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o TENNESSEE VALLEY AUTHORITY
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- Wei U CO,I;,a March 15, 1983 33 un ts mg. 5g BLRD-50-438/81-4?
BLRD-50-439/81-50 1
'U.S. Nuclear Regulatory Commission Region II Attn: _ Mr. James P. O'Reilly,' Regional Administrator 101 Marietta Street, Suite 2900 Atlanta,' Georgia 30303
Dear Mr. O'Reilly:
BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 - TOLERANCE FOR TUBULAR STEEL CABLE TRAY HANGERS - BLRD-50-438/81-47, BLRD-50-439/81 FINAL REPORT The subject deficiency was initially reported to NRC-0IE Inspector R. V. Crlenjak on' July 16, 1981 in accordance with 10 CFR 50 55(e) as NCR 1478. This was followed by our interim reports dated August 14 and November 9, 1981 and January 21, April 14, May 24, July 26, and November 5, 1982. Enclosed is our final report.
TVA does not now consider the subject nonconforming condition adverse to the safe operation of the plant. Therefore, TVA will amend its records to delete the subject nonconformance as a 10. CFR 50.55(e) item.
If you have any questions concerning this matter, please get in touch with R. H. Shell at FTS 858-2686.
Very truly yours, TENNESSEE VALLEY AUTHORITY
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L. M.' Mills, Ma ager Nuclear Licensing Enclosure 00:
Mr. Richard C. DeYoung, Director (Enclosure)
Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, D.C.
20555 vr ilC1h 5 830315 830321gK05000 g.2 7 DR AD An Equal Opportunity Employer
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p ENCLOSURE BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 TOLERANCE FOR TUBULAR STEEL CABLE TRAY HANGERS BLRD-50-438/81-47, BLRD-50-439/81-50 10 CPR 50.55(e)'
NCR 1478 FINAL REPORT Description of Deficiency Due to a' misunderstanding between the Bellefonte design project and Bellefonte field forces, the field forces fabricated and installed cable tray hangers outside the tolerances allowed by the seismic analysis.-
As a result of TVA's investigations to determine the cause of this deficiency, additional related deficiencies were discovered.
Consequently, since the disposition of the deficiencies cited in NCR 1478 has already been approved by TVA, nonsignificant NCR 2056 was initiated to document the additional deficiencies.
The root cause of these nonconformances was the failure of the Bellefonte Design Project to point out in correspondence the tolerances listed on the drawings and the failure of the Bellefonte Construction Project to install the supports in accordance with the drawings.
Safety Implications The disposition of NCR 1478 involved the resolution of two concerns. The first concern involved the evaluation of a list of supports which were outside the limits of the tolerances in effect at that time. The second concern involved the establishment of new installation and location tolerances for cable tray supports. First, the list of supports submitted by the field was reviewed and the results of this study revealed that three supports required modification. All other supports were acceptable as installed. Secondly, TVA has established that for cable tray supports an installation (i.e. lengthening or shortening) tolerance of i 1 inch and a location tolerance of i 2 inches is acceptable.
To confirm installation in accordance with issued drawings, a random sampling of remaining cable tray supports in the auxiliary, control, and diesel generator building was inspected. This inspection revealed that two supports out of 197 were installed with an installation tolerance greater than 1 1 inch. This sampling and the deficiencies are recorde! in NCR 2056. A failure rate of 2 in a sample of 197 provides a better than 95-percent confidence level that less than 5 percent of all the cable tray supports installed to date are outside the established tolerances.
In addition, the two supports that deviated from the tolerances were analyzed and dispositioned use as-is.
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In accordance with the Bellefonte inspection acceptance criteria, all supports located outside the 1 2 inch location tolerance have been approved and documented by TVA's Division of Construction electrical engineering supervision during construction.
These were investigated and. dispositioned by TVA's Division of Engineering Design in NCR 1478.
Consequently, TVA has determined that there is no condition adverse to the safety of operations of the plant. Therefore, we no longer consider 10 CPR 50.55(e) to apply to this condition.
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