ML20133H770

Safety Evaluation Re Util Response to Generic Ltr 83-28, Item 4.1,concerning Reliability of Reactor Trip Sys.Actions Specified by Item 4.1 Satisfactorily Completed,Based on Licensee Review of Sources of vendor-recommended Mods

ML20133H770
Person / Time
Site:	Trojan File:Portland General Electric icon.png
Issue date:	10/10/1985
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20133H757	List: ML20133H754 ML20133H770
References
GL-83-28, TAC-53106, NUDOCS 8510180107
Download: ML20133H770 (2)

Text

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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION GENERIC IMPLICATIONS OF SALEM ATW5 EVENT GENERIC LtIIER 83-28, ITEM 4.1 PORTLAND GENERAL ELECTRIC COMPANY TROJAN NUCLEAR PLANT DOCKET NO. 50-344 I.

INTP0 DUCTION On February 25, 1983, during startup of the Salem Unit 1 plant, both circuit breakers in the Reactor Trip System failed to open automatically upon receipt of a valid trip signal. As a result of that event, the NRC's Office of Inspection and Enforcement issued IE Bulletin 83-01 which described the event and requested specified prompt corrective and preventive actions by licensees. As the cause and ramifications of the event were more clearly developed, the NRC's Office of Nuclear Reactor Regulation issued on July 8, 1983, Generic Letter 83-28, " Required Actions Based on Generic Implications of Salem ATWS Events." This letter addressed issues related to reactor trip system reliability and general management capability.

" The letter was sent to all licensees of operating reactors, applicants for operating licenses and holders of construction permits.

One of the areas of reactor trip system reliability considered in Generic Letter 83-28 (GL 83-28) is that of vendor-reconrnended modifications. This is identified in GL 83-28 as Item 4.1.

This evaluation considers the acceptability of the response to this item provided by the Portland General Electric Company (the licensee) for the Trojan Nuclear Plant (the facility).

II. EVALUATION Item 4.1 of GL 83-28 states, in part, as follows:

"All vendor-recommended reactor trip modifications shall be reviewed to verify that either:

(1) each modification has, in fact, been implemented; or (2) a written evaluation of the technical reasons for not implementing a modification exists.

... Modifications not previously made shall be incorporated or a written evaluation shall be provided."

By letters dated November 4,1983 and July 19, 1985, the licensee responded to a number of GL 83-28 items, including Item 4.1.

Regarding Item 4.1, the licensee reported the following possible sources of vendor recommendations had been reviewed:

the Westinghouse Technical Bulletin Index dated June 20, 1983; the Westinghouse Data Letter Index dated June 20, 1983 and the licensee-Westinghouse correspondence file for the i

period from 1968 to September 1983.

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2 As a result of this search, the licensee identified four recommended modifications:

three affecting the reactor trip breakers, and one affecting the Solid State Protection System. The licensee's letter of November 4,1983 stated implementation of three of the modifications had been confirmed and implementation of the fourth would be verified prior to restart from the 1984 refueling outage. The licensee's letter of July 19, 1985 confirmed the fourth modification had, in fact, been implemented in both reactor trip breakers, both bypass breakers, and a spare breaker in the warehouse.

III. CONCLUSION Based on the licensee's review of sources of vendor-recommended modifications to the reactor trip system and confirmation that all recommended modifications have been implemented, the staff concludes the licensee has satisfactorily completed the actions specified by Item 4.1 of Generic Letter 83-28. Accordingly, this item is closed.

Date:

October 10, 1985 Principal Contributor:

G. Zwetzig, Region V e

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