ML20010J310
| ML20010J310 | |
| Person / Time | |
|---|---|
| Site: | Trojan File:Portland General Electric icon.png |
| Issue date: | 09/17/1981 |
| From: | Withers B PORTLAND GENERAL ELECTRIC CO. |
| To: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| References | |
| IEB-79-14, NUDOCS 8109300294 | |
| Download: ML20010J310 (2) | |
Text
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PECBVED Docket No. 50-344
!N amme Pbrtlanci General Electric Corgxiny
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September 17, 1981 Trojan Nuclear Plant Docket 50-344 License NPF-1 Mr. R. H. Engelken, Director E
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U. S. Nuclear Regulatory Commission Region V
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1990 N. California Blvd.
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3h Walnut Creek, CA 94596 9 pgg,A.y /
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Dear Mr. Engelken:
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Seismic Analyses for As-Built
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Safety-Related Piping Systems On January 19, 1981 Portland General Electric Company (PGE) provided preliminary results of field walkdowns of all safety-related piping with diameter greater than 2-1/2 inches, which were conducted during the refueling outages in 1979 and 1980 in response to IE Bulletin 79-14.
Additional walkdowns were conducted during the refueling outage in 1981. This letter supplements the January 19 PGE letter and provides updated information on the as-built condition of the safety-related piping systems.
A total of 542 isometric drawings were reviewed by the walkdowns. Piping and hanger design on 189 isometrics were subsequently determined to require reanalysis. The results of the reanalyses completed to date have identified the need for modifications on 83 pipe supports and the addition of three new supports. The support modifications range from the addition of minor stiffening plates to the installation of support bracings.
Seventy-five of the required 83 modifications, as well as j
the three new supports, have been completed to date. The remaining support modifications are scheduled to be completed by January 1, 1982.
Reanalysis of four pipe supports and nine valve components have not yet j
been completed. The pipe supports being reviewed are those on the reactor vessel head seal leak-off line. Portions of the seal leak-off f
line inside the reactor vessel cavity were not inspected until June 1981 l
and the data for loading reanalyses were transmitted to our consultant on l
July 14, 1981. The result of the reanalyses will not be available until the end of this year. The valve components under review include i
I evaluation of valve accelerations on pressurizer relief / safety valves and j
their associated block valves (seven valves) and nozz.2 loadings on l
excess letdown line valves (two valves). The valve manufacturers have r
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Portland General ElectricConpany Mr. R. H. Engelken Septembe r 17, 1981 Page two been contacted to conduct recnalysis of accelerations and loadings.
It is expected that _ie reanalysis will be completed by January 1, 1982.
If tha need for modifications is identified by the reanalysis, this work will be completed and reported to the NRC by resumption of power operation (Mode 1) for Cycle 5 in 1982.
Upon completion of the above described ongoing review and any resulting modifications, the requirements of IE Bulletin 79-14 will be completed.
To date, no system inoperability has been identified through the IE Bulletin 79-14 review and there has been no impact to safety of Trojan operations.
Sincerely, 2
2 Bart D. Withers Vice President Nuclear c:
Mr. Robert A. Clark, Chief Operating Reactors Branch No. 3 Division of Licensing Mr. Lynn Frank, Director State of Oregon Department of Energy