ML19341A425
| ML19341A425 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 01/15/1981 |
| From: | Devincentis J PUBLIC SERVICE CO. OF NEW HAMPSHIRE |
| To: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, SBN-148, NUDOCS 8101230497 | |
| Download: ML19341A425 (1) | |
Text
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comp.nvorm =e SSWOOK STATION Engineering Office:
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1671 Worcester Road Framingham, MA 01701 January 15, 1981 SBN-148 El Ref SBP-80-288 1
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T.F. Q 2.2.2 U.S. Neuelar Regulatory Commission Region I 631 Park Avenue King of Prussia, Pennsylvania 19406 Attention: Office of Inspecti*cn and Enforcement
Reference:
1.
Docket No. 50-443 and 50-444 2.
Telecon of 12/16/80 between J. Mattia NRC and John DeVincentis YAEC
Subject:
10 CFR 50.55 (e) Final Report on Design Deficiency of Pipe Supports
Dear Sir:
The enclosed report is submitted in accordance with the requirements This deficiency was reported to the Region I Inspection of 10 CFR 50.55 (e).
and Enforcement Office, b'j telephone, on 12/16/80.
Very truly yours, s'
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[JohnDeVincentis Project Manager bec's:
BBBeckley JDV: tan ACCerne WAHarvey Enclosure JHHerrin JMof fman rector of Inspection & Enforcement DNMerrill cc:
U.S. NRC, Washington, D.C.
20555 O/
SRMiller WJMiller e.RPPic::uti Project Ropes & Gray
/ lI JWSingleton SBSturgeon GSThomas UE&C and W (SB-LOR 3 t 3V f0] O 1230991b
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a Introduction On Tuesday, December 16, 1980, Mr. J. DeVincentis, Seabrook Project Manager for Yankee Atomic Electric Company, reported by telephone to Mr. J. Mattia, NRC Region I Inspection and Enforcement Inspector for the Seabrook Project, a design deficiency associated with the design of pipe supports.
Background
As a result of finding deficiencies in the support design for other projects, the review of approximately 1700 Seabrook supports designed prior to.
February 1,1980 was initiated. Out of these 1700 supports 85 random supports were invest' gated as a representative sample. While reviewing these 85 supports, it was discovered that some supports did not meet all design requirements.
These supports were designed and checked based on the ASME code requirements, however, there were no other detaile4 formal guidelines issued for designers to follow. In February,1980, Pipe Support Design Guidelines were issued to pipe support design personnel.
This document included the criteria for the cesign of expansion anchors, minimum weld size requirements, as well as a check list for designers and checkers to insure that they consider all the design parameters.
Safety Implications There is no evidence to ate in the review that any of the design deficiencies could have caused a support to lose its structural integrity.
Evaluation of the system safety is not contemplated since all of the supports under review will be checked or modified to completely comply with the requirements of the ASME Code. The review modifications are planned to support the pipe erection schedule.
Source and Nature of Deficiency A sampling of 85 calculations showed 24 with errors. Five (5) of the errors would cause the pipe supports to not meet the requirements of the ASME Code.
Eleven errors were due to a change in the design criteria furnished by the "U"
bolt supplier. The balance were minor human errors. There was no generic type problem with the method of calculations'. The number of human errors in this sample confirm the need for a ' full review of the balance of the calculations.
Corectve Action Following corrective action has been taken to eliminate f uture occurrences of this problem.
1.
A controlled formal design manual has been issued to all design personnel.
2.
A check list is used to make sure that designers confirm that they have considered all the design requirements of the guidelines. The checker also uses and initials the check list confirming that the design adequately meets design guidelines. All identified deficiencies are addressed in the check list.
3 A training session has been conducted for all pipe support design personnel emphasizing the design requirements.
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