ML20127A559

Forwards 930105 Memo on Interim Plugging Criteria for Plant

ML20127A559
Person / Time
Site:	Trojan File:Portland General Electric icon.png
Issue date:	01/07/1993
From:	Kokajko L Office of Nuclear Reactor Regulation
To:	Cross J PORTLAND GENERAL ELECTRIC CO.
Shared Package
ML20127A563	List: ML20127A559 ML20127A570
References
NUDOCS 9301110329
Download: ML20127A559 (3)

Text

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January 7,1993 Docket No. 50-344 Mr. David Stewart-Smith Oregon Department of Energy Salem, Oregon 97310

Dear Mr. Stewart-Smith:

SUBJEC1: INTERIM PLUGGING CRITERIA FOR TROJAN NUCLEAR PLANT Enclosed is a document for your review. This document-is e memorandum from E. S. Beckjord to T. E. Murley, " Interim Plugging Criteria for Trojan Nuclear Plant." This document presents the position of the Office of Nuclear-Regulatory Research on the interim plugging criteria for- Trojan.

This document has been placed on the Docket File for Trojan Nuclear Plant and as such, has been placed in the NRC and Local Public Document Rooms.

Sincerely, Oiiginal siEnd D Lawrence E. Kokajko, Senior Project Manager Project Directorate V Division of Reactor Projects III/IV/V Office of Nuclear Reactor Regulation

Enclosures:

As stated QISTRIBUTION:

! Docket File NRC & Local PDRs PDV Reading File JRoe MVirgilio TQuay DFoster -LKokajko OGC, 15B18 ACRS(10), P-315 PDV Plant File KPerkins, RV SHoffman, 14820 RAssa 0FFICE LA/PDV , Ni/Mk D/PDV NAME DFoster(MAsb .

kokajko:mc TQuay DATE //6/97 1 /l4/92 ,1 / 7 /92 0FFICIAL RECORD COPY DOCUMENT NAME:TJIPC.LTR l

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%*****/ January 7,1993 Docket No. 50-344 Mr. David Stewa Oregon Departme rgy Salem, Oregon .

Dear Mr. Stewart

SUBJECT:

INTERIM PLUGGING CRITERIA FOR TROJAN NUCLEAR PLANT Enclosed is a document for your review. This document is a memorandum from E. S. Beckjord to T. E. Murley, " Interim Plugging Criteria for Trojan Naclear Plant." This document presents the position of the Office of Nuclear Regulatory Research on the interim plugging criteria for Trojan.

This document has been placed on the Docket File for Trojan Nuclea. Plant and as such, has been placed in the NRC and Local Public Document Rooms.

Sincerely,

]

Lawrence E. Kokajko, Senior Project Manager Project Directorate V Division of Reactor Projects III/IV/V Office of Nuclear Reactor Regulation

Enclosures:

As stated

ENCLOSURE

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JAN 0 51993 MEMORANDUM FOR:

Thomas E. Murley, Direc5r Office of Nuclear Reactor Regulation FROM: Eric S. Beckjord Director Office of Nuclear Regulatory Research

SUBJECT:

INTERIM PLUGGING CRITERIA FOR TROJAN NUCLEAR PLANT The purpose of this letter is to state the position of this Office on the matter of the interim plugging criteria (IPC) for the Trojan nuclear plant.

In Enc)osure (1), the Division of Engineering (DE), RES, provided a discussion of the key technical aspects of the rationale used to support steam generator tube interim plugging criteria (IPC) and ranched the conclusion that operation of Trojan for the remainder of cycle 14 (approximately 4 months) is justified.

I concur in this position.

Calculations of leak rate across the steam generator tubes for a main steam line break (MSLB), and of the core damage frequency for MSLB support this conclusion. These calculations are based on the available information on steam generator tube inspection prior to December 1992. We do not have the results of PGE eddy current tests of a number of tubes taken recently.

The best estimate of the leak rate expected following a MSLB at the end of cycle 14. for a differential pressure of 2600 psi across the tubes is 145 gallons per minute (gpm). The best estimate of core damage frequency for the sequence initiated by MSLB or a stuck open safety valve is 1.4 E-6 per year. I will provide dtscriptions of these calculations as soon as we have completed the uncertainty analysis for them.

I note also that Trojan procedures for MSLB call for stopping high head safety injection pumps at pressure differences substantially below 2600 psi. We will complete an analysis of this in several days. The point of this analysis is that the steam generator tube differential pressure would be less than the value assumed, and accordingly the steam generator tube leakage would be less than 145 gpm.

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Thomas E. Murley 2 JAN 0 51993 In Enclosure (2), J. Hopenfeld Division of Safety Issue Resciution (DSIR),

RES, provided several coments on a draft of Enclosure (1). Enclosore (3) provides DE responses to those coments that apply to final DE memorandum.

Eric 5. Beckjord,{ Jirector Office of Nuclear

• Regulatory Research

Enclosures:

(1) Memorandum, L.C. Shao to E.S. BeckJord, INTERIM PLUGGING CRITERIA FOR TROJAN NUCLEAR PLANT, December 9, 1992.

(2) Note to G. Burdick from J. Hopenfeld, COMMENTS ON DRAFT RES POSITION ON STEAM GENERATOR TUBE INTEGRITY, December 9,1992.

(J) Division of Engineering Responses to Coments of J. Hopenfeld cc: J. Taylor J. Snie:ek J. Roe W. Minners F. Miraglia W. Russell J. Richardson J. Strosnider L. Kokajko J. Fouchard

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