ML20062D168
| ML20062D168 | |
| Person / Time | |
|---|---|
| Site: | Bellefonte  |
| Issue date: | 07/29/1982 |
| 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, NUDOCS 8208050474 | |
| Download: ML20062D168 (2) | |
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TENNESSEE VALLEY AUTHORITY CHATTANOOGA. TENNESSEE 374ol 400 Chestnut Street Tower II July 29, N8d!" 2
^ 8 : 3I BLRD-50-438/81-63 BLRD-50-439/81-61 U.S. Nuclear Regulatory Commission Region II Attn:
Mr. James P. O'Reilly, Regional Administrator 101 Marietta Street, Suite 3100 Atlanta, Georgia 30303
Dear Mr. O'Reilly:
BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 - PIPE HANGER SUPPORTS ADDED TO AUXILIARY FEEDWATER PIPE TRENCH - BLRD-50-438/81-63, BLRD-50-439/81 FINAL REPORT The subject deficiency was initially reported to NRC-0IE Inspector R. V. Crlenjak on September 24, 1981 in accordance with 10 CFR 50.55(e) as NCR BLN CDB 8101. This was followed by our interim reports dated October 21, 1981 and March 31, 1982. Enclosed is our final report.
If you have a9y questions concerning this matter, please get in touch with R. H. Shell at FTS 858-2688.
Very truly yours, TENNESSEE VALLEY AUTHORITY DSL -
L. M. Mills, Manager Nuclear Licensing Enclosure cc:
Mr. Richard C. DeYoung, Director (Enclosure)
Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, DC 20555 8208050474 820729 DR ADOCK 95000 '
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An Equal Opportunity Emp! oyer
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.. g p ENCLOSURE BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 PIPE HANGER SUPPORTS ADDED TO AUXILIARY FEEDWATER PIPE TRENCH NCR BLN CDB 8101 BLRD-50-438/81-63, BLRD-50-439/81-61 10 CFR'50.55(e)
FINAL REPORT Description of Deficiency The auxiliary feedwater (AFW) pipe trench design and construction drawings (8YWO316-X1 series) have been completed since September 1977. The AFW pipe trench is a reinforced concrete structure housing quality level pipes (Seismic Category I) including the auxiliary steam line, and Nonseismic Category I pipes. Under the original design, two embedded strip plates (continuous) were placed on each vertical interior concrete wall to support pipe hanger loads. A large number of additional pipe hanger supports have been installed whose loacs and locations were not identified nor-designed for in the original calculations. TVA's investigation revealed that the pipe hanger design drawings and the added anchors had not been reviewed by all responsible design groups.
Safety Implications If this deficiency had remained uncorrected, the additional unreviewed loads might have been added such that a structural shear failure of the cantilevered support walls or overhang from the added pipe support loads was a possibility. The failure of any portion of the trench system could have disabled the safety-related lines. TVA's investigation shows the structural sections of the trench to be adequate, therefore, there is no condition adverse to the safety of operations of the plant.
Corrective Action The entire AFW trench and tunnel sections have been investigated for the added pipe support plate loads. The critical pipe support loads were combined with the other operating design loads and the structural adequacy of the system has been verified. Consequently, the reinforced concrete tunnel and trench structures have been determined to be adequate and will be used as is.
The responsible TVA organization was instructed to route all pertinent information for review to all groups involved in accordance with the TVA Division of Engineering Design procedure. TVA is investigating generic deficiencies related to inadequate design review in response to QA audit M81-13 deficiency 5.
This audit deficiency has been reported as a 10 CFR 50.55(e) item and generic corrective actions.will be reported in the response to this item.
Based on TVA's review of pertinent drawings / documents, the deficiency does not extend to other structures at this or other nuclear plants.
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