ML20138S098

Requests Review of Encl Re Comments & Recommendations Concerning Indian Point Special Proceeding & Commission Decision Cli 85-06

ML20138S098
Person / Time
Site:	Indian Point
Issue date:	11/06/1985
From:	Palladino N NRC COMMISSION (OCM)
To:	Ward D Advisory Committee on Reactor Safeguards
References
CLI-85-06, CLI-85-6, NUDOCS 8511190521
Download: ML20138S098 (1)

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- UNITED STATES NUCLEAR REGULATORY COMMISSION

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.E WASHWGTON, D. C. 20555 p*

/ November 6,1985 CHAIRMAN -

Mr. David A. Ward Chairman Advisory Committee on Reactor Safeguards U.S. Nuclear Regulatory Commission Washington, D. C. 20555

Dear Mr. Ward:

By letter dated October 12, 1985, (copy enclosed), five members of the Advisory Committee provided comments and recommendations related to the Indian Point Special Proceeding and the Commission Decision (CLI 85-06).

Since "relatively broad considerations" are discussed in the letter, it would be beneficial to the Commission to have the views of the ACRS as a whole. Therefore, we request that you review the enclosed letter with the entire Advisory Committee and provide a report to the Commission.

Sincerely, y . f fdw &"

Nunzio J. Palladino

Enclosure:

As Stated 8511190521 R 851106 0 ADOCK 05000247 PDR L -

ENCLOSURE 1: ,

s October 12, 1985 l

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\

Honorable Nunzio J. Palladino Chairman \ '

U. S. Nuclear Regulatory Comission Washington, D. C. 20555

Dear Dr. Palladino:

I

Subject:

INDIAN POINT SPECIAL PROCEEDING We recognize that the Comission has acted on the Indian Point Special.

Proceeding but believe that it is worthwhile to provide some coments and recomendations for your further reflection. We shall not go into details of the proceeding but deal only with relatively broad consid-I

. erations, as follows:

1. Mr. Rowsnme of the NRC Staff testified that Inoian Pgint, Unit 2

' has a median frequency of core melt of roughly 4 x 10- per reactor l year for the "after fix" staff analysis described in the NRC testimony on Comission Question One, with a similar result for Indian Point, Unit 3. If this value were approximately represen-tative of the U. S. light water power reactors, it would suggest a chance of about one in two of a core melt accident by the year 2000 and a likelihood of essentially unity over the life of the current LWRs.

The uncertainties in the estimate for Indian Point are clearly large, with some factors pointing to possible overestimate and others to underestimate.

l We believe .that, especially for a high power nuclear power plant at one of the most highly populated sites in the U. S., the NRC should continue to strive for a substantial reduction in both the pre-dicted core melt frequency and the uncertainty therein.

Indian Point, Units 2 and 3, are evaluated by the Licensee and the NRC Staff as having a relatively effective containment in the presence of many, if not most, severe core accidents. However, these analyses res.t on incompletely understood phenomena, on generic rather than detailed examinations of containment (and plant) behavier, and on an incomplete set of accident scenarios.

Mr. Rowsome stated that he would be only mildly surprised if the consequences were a factor of 40 higher (or 200 lower) than the NRC Staff estimates.

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Honorable Nunzio J. Palladino 2. "The NRC Staff did not recomend design or operational improvements for the Indian Point units except- for a reliability assurance prog ram. However, they stated that, "it is the ensemble of evi-dence and ' the continued use of the PRA as a risk management tool (the sa fety assurance program) . . . that supported the staff recomenda tions." The majority of the ASLB recomended in favor of a filtered venting ' concept in view of the large uncertainties in

-the risk assessment and the high surrounding population density.

The Comission itself took a position less conservative than either the Staff or the majority of the ASLB.

3. Since the Staf f testimony at the Indian Point hearings, senior members of the NRC Staff have written coments in connection with ~

consideration of the NRC Safety Goals which are possibly at odds with the Indian Point decision. The Safety Goal Task Force, which includes Messrs. Murley, Rowsome, and Ernst, among others, raised the core melt frequency objective to first line status. Mr. Ernst and Mr. Minogue, in memoranda of May 10, 1985 and May 21, bdth support working toward the cora melt safety goal of 10 j985, per reactor year for existing nuclear power plants. Mr. Denton, in his memorandum of June 12, 1985, recomends a still more stringent core melt goal for existing plants.

4. In its report to you of July 17, 1985, the ACRS expressed its belief, "that the Comission frequency of not more than 10-ghould state that per reactor yeara is mean-core-melt an NRC objec-tive for all but a few, small, existing nuclear plants, and that, keeping in mind the considerable uncertainties, prudence and judgment will tend to take priority over benefit-cost analysis in working toward this goal."

5. We strongly support this ACRS position, and that a median estimate core melt frequency of 4 x 10 ge believeper rea'ctor year

_ (with very large uncertainties), for a high power plant at one of the most densely populated sites in the U. S., is too large for the

-long term and represents a situation requiring specific attention.

While we agree that it is acceptable for Indian Point, Units 2 and

. 3, to continue to operate, we recomend that the Comission require that both the Licensee and the NRC Staff develop, on some reason-able schedule, a plan for work intended to reduce both the esti-mated core melt frequency and the uncertainty therein. In addi-tion, we believe that detailed containment performance evaluation should be given particular emphasis at sites like Indian Point. It is our , belief that Comission policy should reflect prudence and

! come down on the side of safety, where the uncertainties remain t

large, giving appropriate consideration to both prevention and

Honorable Nunzio J. Palladino mitigation. We believb that, particularly if innovative approaches are used, significant 'mprovements in safety are achievable for Indian Point, Units 2 and 3, at reasonable costs.

Sincerely,

[Tavid Okrent, University of California Los Angeles, Califorrita 3se C. Ebersole, Tennessee Valley Authority, retired, Knoxville, Tennessee Dade W. Moeller, Harv~ard University Boston, Massachusetts

& s. Al Glenn A. Reed, Wisconsin Electric Power Company, Retired, Two Rivers, Wisconsin L

Charles J.~ vy ie, Duke r Company, Retired, Char te, a rolina cc: Comissioner Roberts Comissioner Asselstine Comissioner Bernthal Comissioner Zech Other Members of the Advisory Comittee on Reactor Safeguards

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