05000369/LER-1981-077, Forwards LER 81-077/01T-0.Detailed Event Analysis Encl

Forwards LER 81-077/01T-0.Detailed Event Analysis Encl

ML20009F631
Person / Time
Site:	McGuire
Issue date:	06/03/1981
From:	Ouellette R DUKE POWER CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML20009F632	List: 05000369/LER-1981-077, Forwards LER 81-077/01T-0.Detailed Event Analysis Encl 05000369/LER-1981-077-01, /01T-0:on 810521,ASME Code Rejectable Indications Found in Vendor Seal Plate to Door Frame Welds During Nondestructive Exam of Personnel Lock Shim Plate Welds. Caused by Use of Seal Rather than Structural Welds
References
NUDOCS 8107310368
Download: ML20009F631 (3)

LER-1981-077, Forwards LER 81-077/01T-0.Detailed Event Analysis Encl

Event date:
Report date:
3691981077R00 - NRC Website

text

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WILLI AM O. PA R M L A, J R.

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June 3, 1981 273-4o82

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Mr. James P. O'Reilly, Director

- g U. S. Nuclear Regulatory Commission Q'

Region II g'

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- j Atlanta, Georgia 30303 T

Re: McGuire Nuclear Station Unit i EE****

Docket No. 50-369

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Dear Mr. O'Reilly:

Please find attached Reportable Occurrence Report R0-369/81-77. This report concerns rejectable indications found in the vendor seal plate to door frame welds on the personnel locks.

This incident was considered to be of no significance with respect to the health and safety of the public.

Very truly yours,

/'

7 William O. Parker, Jr.

RWO:pw Attachment cc:

Director Mr. Bill Lavallee Office of Management and Program Analysis Nuclear Safety Analysis Center U. S. Nuclear Regulatory Corcmission

?. O. Box 10412 Washington, D. C.

Palo Alto, CA 94303 Ms. M. J. Graham Resident Inspector - NRC McGuire Nuclear Station 4 Q) 8107310368 810603 DR ADOCK 05000

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i McGUIRE NUCLEAR STATION INCIDENT REPORT Report Number:

81-77 Report Date:

. Tune 3, 1981 Occurrence Date: May 21, 1981 Facility: McGuire Nuclear Station Unit 1, Cornelius, N. C.

Introduction

An ASME Coda deviation was discovered during retrofitting and minor alteration work on the McGuire Nuclear Station Unit 1 personnel locks.

The personnel locks, therefore, not being in full Code compliance did not meet the specified requirements of the McGuire FSAR, Section 3.8.2.1 (2).

The deviation was first discovered en May 5, 1981.

Subsequent verification, evaluation and additional examination was conducted from May 5, 1981 to May 19, 1981.

The deviation was reported on Thursday, May 21, 1981 to Mr. Art Johnson of the NRC, Region II, by Mr. D. B. Lampke.

Background !nformation:

The four (4) personnel locks (two per unit) for the McCuire Nuclear Station were designed by the W. J. Woolley Company of River Forest, Illinois.

This company also supervised the fabrication of the locks by their subcontractor, Progressive Fabricators, Inc., of St. Louis, Missouri.

The general arrangement of the personnel locks is the same for all four locks.

The locks are Class B Vessels constructed and stamped in accordance with the 1968 ASME Ccde, including addenda through the summer of 1970.

Each personnel lock has fcur (4) inflatable seals per lock, two (2) for each door.

For the past several months, Duke Power Company, together with W. J.

Woolley Company and several inflatable seal manufacturers, have been working to solve a separate problem involving a number of seal failures. A part of the retrofitting related to the seal problem involved welding shim plates to the stainless steel seal plates en the door frames in order to minimize the seal closure gap.

Description of Deficiency: During nondestructive examination of the shim plate welds, Code rejectable indications were found in the vendot seal plate to door frame welds.

The vendor was contacted concerning the nature and examination requirements for these welds.

The welds were identified to be non-structural seal welds. A review of the Code of record by the Owner indicates that the welds in question require liquid penetrant (PT) or magnetic particle (MT) in-spection for full code compliance.

W. J. Woolley Company records indicated that the welds were inspected and accepted by the fabricator. However, when reinspected by the Owner, the welds did not pass the acceptance criteria.

Report Number:

81-77 Page 2 Safety Implications:

The welds to the seal plate are not structural welds, and are classified as seal welds only. As such the welds have no technical minimum size requirement and are only required to perform a sealing function.

Bypass leakage from containment can only occur if each weld has a thru-thickness defect.

Redundancy is accomplished by having two welds per seal, two seals per door and two doors per lock.

The welds in question have passed numerous leak rate tests.

In addition, they will be leak tested a minimum of once each 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> during plant operation.

If leakage is detected in excess of that permitted by the plant Technical Specifications, standard procedures are in effect to locate and repair the source of the leakage.

Thus, standard plant operating procedures would have precluded excessive bypass leakage that could have caused a safety hazard.

Corrective Action

All seal plate welds for the " nit 1 McGuire personnel locks were PT inspected by the owner.

The inspection, including acceptance criteria, was done in accordance with the Owner's approved procedures and the ASME Code.

All rejectable indications were removed by grinding and/or welding and re-tested. All weld repairs were done in accordance wi+5 ASME Code requirements and were reviewed by the Authorized Code Inspector.

Following inspection and repair work, each air lock was pressure tested and leak rate tested to the requirements of the Station Technical Specifications.

The corresponding welds for the McGuire Unit 2 personnel locks will be in-spected, tested and repaired, as required.

This work will be completed by December 31, 1982.