ML20040G536
| ML20040G536 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 02/05/1982 |
| From: | Woolever E DUQUESNE LIGHT CO. |
| To: | Haynes R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, NUDOCS 8202160233 | |
| Download: ML20040G536 (3) | |
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/Q (412) 456-6000 435 Sixth Avenue Pittsburgh. Pennsylvania isais 2DLC United States Nuclear Regulatory Commission 4468 Region I 631 Park Avenue King of Prussia, PA 19406 ATTENTION:
Mr. R. Haynes, Administrator
SUBJECT:
BEAVER VALLEY POWER STATION - UNIT NO. 2 Docket No. 50-412 Pipe Support Beam Attachment Significant Deficiency 81 Final Report Centlemen:
This letter is the final report concerning Significant Deficiency 81-03.
In our December 4,1981, letter to you on this subject, we indicated that an interim report would be submitted by February 5,1982. The evaluation o f t he beam attachments has gone more quickly than expected and the final report addressing the entire scope of the significant deficiency and its reso-lution is herewith submitted. This deficiency is, therefore, considered to be closed and no fu rt he r reports are planned for submittal.
If you have any questions on this matter, please contact our staf f.
DUQUESNE LIGHT COMPANY B
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" y 1. J. Woolever Vice President Attachment
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Mr. R. DeYoung Director of Inspection and Enforcement
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Ms. Jane Grant
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c, FINAL REPORT-ON WELDED TYPE BEAM ATTACHMENTS AT' BEAVER VALLEY POWER STATION'- UNIT NO. 2-1.0
SUMMARY
Power' Piping Company (PPCO), BVPS-2 pipe support vendor, has aupplied HS-
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142 welded type beam attachments for rigid sway. strut sizes 25, 40,~50,
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60, and 80 which when loaded. at application angles other than-vertical, have reduced load ratings which were not originally indicated.
All of the' pipe supports using the HS-142 beam attachments were evaluated.
Of the 811 supports, most were eliminated' as objects of concern because they were not of the affected size categories - or they were loaded vertically. Of the remaining 23, one overicaded strut was ' redesigned for other reasons and. the others were 'found to be loaded within acceptable limits.
2.0 IMMEDIATE ACTION TAKEN After PPC0 indicated 'that a problem could exist, the NRC was notified and an investigation was undertaken to identify the involved pipe supports and evaluate their loading.
3.0 DEFICIENCY PPCO's original design calculations for the HS-142 beam attachment consider. the ' direction of loading in a vertical orientation only.
However, the beam attachments were used at various angles of application as permitted by the PPCO catalog data.
PPC0 has determined that the allowable beam attachment load rating ~at various angles is less than the l
full-rated loads indicated by the catalog and the original calculations.
Specifically, PPCO has determined that' the weld.between' the. baseplate L;
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and pin plates of the beam attachment is the cause of the '. deficiency.
This weld may fail when the beam attachment angle of application is other than vertical and the applied' axial load on the strut assembly exceeds t he derated load for the particular angle of application.
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4.0 ANALYSIS OF SAFETY IMPLICATIONS i _
Had this design deficiency not been discovered, some pipe hangers could have been inadvertently overloaded resulting in pipe' failure.
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' all af fected supports were found to be loaded to values less than the i
reduced load ratings.
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o_ n 5.0 CORRECTIVE ACTION TAKEN TO REMEDY THE DEFICIENCY PPCO performed an analysis to determine the reduced load ratings of HS-142 beam attachments.
This - analysis was reviewed and determined to be acceptable. The HS-142 beam attachments were reviewed to determine which supports should be evaluated in the light of the : reduced load ratings.
This evaluation determined that in all cases the actual loads are less than the reduced load ratings. Additionally, PPCO no longer sells the HS-14 2.
This model.has been replaced by the HS-146.
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