April 19, 1999
Dr. William D. Travers
Executive Director for Operations
U.S. Nuclear Regulatory Commission
Washington, D.C. 20555-0001
Dear Dr. Travers:
SUBJECT: REEVALUATION OF GENERIC SAFETY ISSUE PROCESS
During the 461st meeting of the Advisory Committee on Reactor Safeguards, April 7-10, 1999, we completed our review of the reevaluation of the generic safety issue (GSI) process. During our review, we had the benefit of discussions with representatives of the NRC staff and the documents referenced.
Conclusions and Recommendations
- The preliminary draft Management Directive (MD) 6.4, "Generic Issue Process," and the associated Handbook appear to provide an effective way to implement the revised GSI process.
- We recommend that the staff conduct a pilot study to evaluate the effectiveness of using the MD for implementing the revised GSI process prior to developing a final version of MD 6.4 and the associated Handbook.
- The staff proposes to use a risk-informed technical screening of new generic issues. The staff, however, needs to further develop the screening methodology for estimating the risk significance of generic issues. This methodology should include examination of results of the individual plant examination (IPE) and individual plant examination of external events (IPEEE) processes and should include an uncertainty analysis.
- We remain concerned about the technical resolution of the remaining GSIs. We plan to review the proposed resolution of these GSIs. The staff should provide a schedule for forwarding the resolution packages of these GSIs to us to facilitate our planning of the workload.
We have had a long-standing interest in the GSI process. During 1998, we reviewed the mechanism for addressing GSIs and the proposed priority rankings of several GSIs, and identified a number of concerns in our letters of March 16 and October 16, 1998.
As a result of our concerns, the Office of Nuclear Regulatory Research (RES) reevaluated the GSI process to determine what changes were warranted to improve its effectiveness. Based on the reevaluation, RES has developed a revised GSI process to assess issues that are of generic interest but that may or may not be safety significant.
On the basis of the reevaluation, RES has proposed changes to the GSI process that provide for an expanded scope, programmatic purpose, a disciplined process, and the application of management tools to execute the revised process. RES proposes to implement the revised GSI process through the MD and an associated Handbook. We agree with this approach.
The use of risk insights in a screening process is a good practice. The staff described a proposed method for technical screening of generic issues, which would use risk insights related to changes in core damage frequency (CDF) or large, early release frequency (LERF). We have concerns about the applicability of the proposed screening method for generic issues. The problem with the proposed risk-informed screening process is the determination of changes in CDF and LERF due to particular generic issues for the set of affected plants. We believe it is impractical and not cost beneficial to exercise each plant-specific PRA for these determinations. A method for selecting a representative PRA for such determinations has not been defined.
Dana A. Powers
Memorandum dated February 8, 1999, from John W. Craig, Office of Nuclear Regulatory Research, NRC, to John T. Larkins, Executive Director, ACRS, Subject: Transmittal of Presentation Material for March 11, 1999 Presentation to ACRS.
U. S. Nuclear Regulatory Commission, Rough Draft, Management Directive 6.4, "Generic Issue Process," dated February 22, 1999, Revision 3 (Predecisional).
- Letter dated March 16, 1998, from R. L. Seale, Chairman, ACRS, to L. Joseph Callan, Executive Director for Operations, NRC, Subject: SECY-98-001, Mechanism for Addressing Generic Safety Issues.
- Letter dated May 28, 1998, from L. Joseph Callan, Executive Director for Operations, NRC, to Robert L. Seale, Chairman, ACRS, Subject: SECY-98-001, Mechanism for Addressing Generic Safety Issues.
- Letter dated October 16, 1998, from R. L. Seale, Chairman, ACRS, to L. Joseph Callan, Executive Director for Operations, NRC, Subject: Proposed Priority Rankings of Generic Safety Issues: Tenth Group.
Letter dated November 27, 1998, from William D. Travers, Executive Director for Operations, NRC, to Robert L. Seale, Chairman, ACRS, Subject: Proposed Priority Rankings of Generic Safety Issues: Tenth Group.