ML16223A231

Implementation Guidance for the Maintenance Rule

ML16223A231
Person / Time
Issue date:	04/26/1993
From:	Shewmon P Advisory Committee on Reactor Safeguards
To:	Taylor J NRC/EDO
References
D930426
Download: ML16223A231 (2)

Text

D930426 Revised: June 24, 1993 Mr. James M. Taylor Executive Director for Operations U.S. Nuclear Regulatory Commission Washington, D.C. 20555

SUBJECT:

IMPLEMENTATION GUIDANCE FOR THE MAINTENANCE RULE During the 396th meeting of the Advisory Committee on Reactor Safeguards, April 15-17, 1993, we discussed with the NRC staff the status of its proposed implementation guidance for the Maintenance Rule, 10 CFR 50.65. We also heard from representatives of NUMARC on this matter and had the benefit of the documents referenced.

The staff's present plan is that this implementation guidance will be in the form of the Regulatory Guide entitled "Monitoring the Effectiveness of Maintenance at Nuclear Power Plants" that endorses the NUMARC 93-01 document as an acceptable means of complying with the provisions of the Maintenance Rule. Both of these documents have been issued for public comment and the comments received have been analyzed by the staff. In addition, NUMARC conducted a validation and verification effort to test the guidance in the NUMARC 93-01 document by having a number of licensees apply it to their plants. The staff participated in this effort. We commend both the staff and NUMARC for their efforts in producing what appears to be a well-considered approach to implementation of the performance-based Maintenance Rule.

The process is now at a point where the staff and NUMARC are finalizing their respective documents with the expectation that they will be issued in final form by June 30, 1993. Contrary to what is stated in the draft of the regulatory guide, we do expect to review these documents when they are completed.

At this time, we have the following comments to offer:

On many occasions, we have provided comments on the trigger-value approach proposed by the staff to resolve Generic Issue B-56, "Diesel Generator Reliability." The proposed regulatory guide for implementing the Maintenance Rule explicitly endorses the trigger value procedure for "monitoring emergency diesel generator (EDG) performance against EDG target reliability levels." It is categorically impossible to demonstrate the reliability of EDGs using this method. We remain strongly opposed to its use for this purpose and continue to recommend that the staff's implementation guidance for the Station Blackout Rule, 10 CFR 50.63, be revised to deal with this issue.

When this is done, the regulatory guide should be appropriately revised.

We agree with the staff's approach in resolving our concerns regarding maintenance in power plant switchyards. We recommend, however, that appropriate plant management exercise control of

all such switchyard activities to prevent the kind of unantici-pated events that have occurred in the past.

Sincerely, Paul Shewmon Chairman

References:

1. Draft Regulatory Guide DG-1020, "Monitoring the Effectiveness of Maintenance at Nuclear Power Plants," November 1992

2. Draft of Final Regulatory Guide (formerly DG-1020), Regulatory Analysis and Backfit Analysis for 10 CFR 50.65, "Monitoring the Effectiveness of Maintenance at Nuclear Power Plants" (hand dated April 13, 1993)

3. Draft NUMARC 93-01, Revision 3, "Industry Guideline for Monitoring the Effectiveness of Maintenance at Nuclear Power Plants," March 24, 1993 Revised Page