ML20055D041

Discusses Design Verification Program Re Main Steam Support Structure.Extension of Completion Date for Project Justified Since Documentation,Not Mod of Main Steam Support Structure Is Reason for Delay

ML20055D041
Person / Time
Site:	Trojan File:Portland General Electric icon.png
Issue date:	06/29/1990
From:	Walt T PORTLAND GENERAL ELECTRIC CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9007030133
Download: ML20055D041 (2)

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M N W MCoriixuw June 29, 1990 Trojan Nuclear Plant Docket 50-344 License NPF-1 U.S. Nuclear Regulatory Commission Attn Document Control Desk Washington DC 20555

Dear Sirs:

Design Verification Program Main Steam Support Sttveture By letter dated January 20, 1989 " Design Verification Programs", Portland General Electric Company (PCE) reported the results of three major programs which were begun in 1987 to provide assurance that the original civil engineering design of the Trojan Plant is adequate and conforms to the accepted engineering practices at that time. Also noted in the letter were outstanding items and completion dates for those items.

Several of those items involve structural evaluations of the Main Steam Support Structure (MSSS).

By letter dated April 14, 1989 " Trojan Nuclear Plant Long-Term Pipe Support Design Verification Program", the status of the outstanding items noted in the letter of January 20, 1989, was provided. The status included a new due date of June 30, 1990, for three of the MSSS evaluation items.

It was explained that the commitment date was being extended to facilitate the use of a new computer codo for analyzing the effects of a High-Energy Line Break (HELB) in the MSSS.

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The HELB analysis has taken longer than initially projected. The results which are needed for the MSSS structural effects analysis have been obtained and will be verified and approved by August 31, 1990. As discussed in our letter of April 14, 1989 and agreed to by the Trojan i

Plant Architect-Engineer, who will be performing the-structural effects analysis, the analysis will take four months to complete. As discussed with the Trojan Project Manager, Mr. Roby Bevan, on June 22, 1990, confirmation of the existing M3SS will thus be accomplished by December 31, 1990.

Based on the evaluations described in our letter of January 20, 1989, the extension of the completion date for this project is justified, since it is a matter of documentation rather than modification of the MSSS.

Sincerely, r bi e c d E -

T. D. Walt Acting Vice President, Nuclear c:

Mr. John B. Martin Regional Administrator, Region V U.S. Nuclear Regulatory Commission Mr. David Stewart-Smith State of Oregon Department of Energy Mr. R. C. Barr NRC Resident inspector Trojan Nuclear Plant