ML20248E686
| ML20248E686 | |
| Person / Time | |
|---|---|
| Site: | Trojan File:Portland General Electric icon.png |
| Issue date: | 04/04/1989 |
| From: | Cockfield D PORTLAND GENERAL ELECTRIC CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 8904120334 | |
| Download: ML20248E686 (3) | |
Text
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e ammme Portland General ElectricCorprzy David W. Cockfield Vice President, Nuclear April 4, 1989-Trojan Nuclear Plant Docket 50-344 License NPF-1 U.S. Nuclear Regulatory Commission ATTN:
Document Control Desk Washington DC 20555
Dear Sirs:
Inservice Inspection Relief Requests In accordance with the provisions of Title 10, Chapter I of the Code of Federal Regulations, Part 50, Section S5a, Paragraph g [10 CFR 50.55a(g)],
the attached request for relief from inservice inspection (ISI) require-ments.of Section XI (1983 Edition with Summer 1983 Addenda) of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code is submitted for your review and approval.
Relief is requested from the code requirement to perform a v.'umetric or surface examination, as applicable, of the pressurizer vessel skirt weld. The proposed alternative examination will be performed during the 1989 refueling outage.
Sincerely, W
1 l
l Attachment c:
Mr. John B. Martin 9g Regional Administrator, Region V j
000.
U.S. Nuclear Regulatory Commission l
l 1
SID Mr. William T. Dixon 0
State of Oregon
'M Department of Energy (9 0 i
O hk Mr. R. C. Barr y
NRC Resident Inspector l
.Q Trojan Nuclear Plant
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121 SW Satrnon Street Podiand Oregon 97204
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Trojen Cucl$ar Pltnt' Docum nt Control Dask i
. Docket 50-344 April 4, 1989-
'm License NPF-1 Attachment Page 1 of 2 INSERVICE INSPECTION RELIEF REQUEST Component
Description:
I Pressurizer Vessel Skirt Weld Code Class:
ASME XI Class 1 - Vessel ASME XI Examination Requirements:
Subsection IWB, Table IWB-2500-1, Examina'4an Category B-H, Item Number.B8.20, reouires that a volumetric or surface examination be-performed, as applicable, for the required examination surface of
' Figures IWB-2500-13, 14, or 15 each inspection interval.
Basis for Relief:
Neither method can be performed to satisfy code requirements over all required areas. The skirt weld inner face (area C-D of attached figure) is not readily accessible because it is concealed by a pattern of electric heater cable penetrations and insulation.
Furthermore, the radiation levels there are estimated at 4 to 5 R/hr.
These high radiation levels and physical restrictions make examination by ultrasonic or surface examination impractical for the pressurizer vessel skirt weld inner surface.
The postulated failure of an attachment weld of this configuration is more probable in the area identified as A-B on the attached figure, and is unlikely to affect the integrity of the pressure retaining boundary of the j
vessel.
l i
1 Alternative Examination:
A combination of methods will be utilized to achieve weld examination.
A surface examination supplemented by a best effort ultrasonic examination will be performed on the outer face (area A-B) of the pressurizer integrally welded skirt attachment each inspection interval.
i LGD/mr/2463W.0389 1
Trojan Nuc1 car Plant Documsnt Control Dask Dockst 50-344 April 4, 1989 i
LitGnss NPF-1 Attachment Page 2 of 2 W w c w.= A c e h -rammw coeve***
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Side View of Pressurizer Skirt FlGURES
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