ML19330A822

Advises That All Actions Committed to in Util Re Resumption of Power Operations Now Completed.Summary of Results for Wall Mods Re Heavyweight Doubleweight Wythe, Std Weight Double Wythe & Single Wythe Walls Encl

ML19330A822
Person / Time
Site:	Trojan File:Portland General Electric icon.png
Issue date:	07/25/1980
From:	Broehl D PORTLAND GENERAL ELECTRIC CO.
To:	Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
References
TAC-12369, NUDOCS 8007290554
Download: ML19330A822 (2)

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"_ ~ a Portland General ElectricCompany i

Donald J. Broeni Assistant Vce Presicent July 25, 1980 Trojan Nuclear Plant Docket 50-344 License NPF-1

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Mr. R. H. Engelken, Director U. S. Nuclear Regulatory Commission Region V Suite 202, Walnut Creek Plaza 1990 N. California Blvd.

Walnut Creek, CA 94596

Dear Sir:

4 As stated in my letter of July 12, 1980, all actions required prior to resumption of power operations in accordance with my June 28, 1980 letter have been completed. Further, inasmuch as the Trojan Nuclear Plant resumed power operations on July 19, 1980, this letter constitutes the " report describing the results of our evaluations" to "be furnished to the NRC within 10 days after the resumption of power operation" committed to in my June 28 letter.

The following summarizes the results for heavyweight double wythe walls having safety significance exceeding the June 28, 1980 criteria and/or which were modified prevfously based upon LER 79-15, Supplement 4 criteria:

9 walls modified with throughbolts 2 walls modified with structural steel (1 cantilever)

_1 wall removed from the STARDYNE model with equipment removed 12 heavyweight double wythe walls The following summarizes the results for standard weight d;able wythe walls having safety significance exceeding June 28, 1980 ctiteria:

4 walls modified with 4tructural steel (no cantilevrrs) 7 walls accepted for interim based on nonlinear displacement

___ critoria or removed from STARDYNE

(<30 /

11 standard weight double wythe walls j;

j C) u: sw sa:rnon s:reet eeam.o ezn snu

Podia:d General Ele::tricCciwiy Mr. R. H. Engelken July 25, 1980 Page 2 The following summarizes the results for single wythe walls having safety significance exceeding the June 28, 1980 criteria:

5 walls modified with structural steel (4 cantilevers) 10 walls accepted for interim based on nonlinear displacement

__, criteria and/or removed from STARDYNE model 15 single wythe walls Two double wythe masonry walls with structural frequencir.a less than 20 cps provide support for safety-related equipment as defined in the June 28 letter. These walls (one normal weight and one heavy weight) support instrumentation (local indicators, transmitters and switches) which, although they form part of the system pressure boundary, do not have any control functions; thus, there is no adverse impact on the safety-related systems.

Those walls which have not yet been modified will be reevaluated with the interstory displacements from the finite element analysis. Those which exceed the 10 and 20 psi interwythe shear or bending criteria will be modified by October 31, 1980. Preliminary indications from the finite element analyses performed to date indicate that the predictions are well within the June 28, 1980 criteria.

Sincerely, e

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~1 c:\\1Mr. R. A. Clark, Chief Operating Reactors Branch No. 3 Division of Licensing U. S. Nuclear Regulatory Cocsission Mr. Lynn Frank, Director State of Oregon Department of Energy