ML25168A267

08-18-82 ACRS Report on Grand Gulf Nuclear Station Unit 1

ML25168A267
Person / Time
Site:	Grand Gulf
Issue date:	08/18/1982
From:	Shewmon P Advisory Committee on Reactor Safeguards
To:	Palladino N NRC/Chairman
References
Download: ML25168A267 (1)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION ADVISORY COMMITTEE ON REACTOR SAFEGUARDS WASHINGTON, D. C. 20555 August 18, 1982 Honorable Nunzio J. Palladino Chairman U.S. Nuclear Regulatory Commission Washington, D.C. 20555

SUBJECT:

ACRS REPORT ON GRAND GULF NUCLEAR STATION UNIT l During its 268th meeting, August 12-14, 1982, the Advisory Committee on Reactor Safeguards completed its review of the application of the Mississippi Power & Light Company (MP&L), Middle South Energy, Inc., and the South Mississippi Electric Power Association for an operating license for the Grand Gulf Nuclear Station Unit l.

The unit is to be operated by MP&L.

The Com-mittee provided an Interim Report, dated October 20, 1981, on the operation of Grand Gulf Unit 1.

In completing its review/the Committee had the benefit of Subcommittee meetings on July 29-30, 1982 and on August 11, 1982, discus-sions with representatives of the Applicant and the NRC Staff, and of the documents listed.

In its Interim Report, the ACRS listed two outstanding issues:

dynamic loads on structures above the Mark III suppression pool due to froth impact hydrogen control Our Interim Report concluded that, with due consideration to the recommenda-tions of that report and subject to the satisfactory completion of construc-tion, staffing, and preoperational testing, it would be acceptable for Grand Gulf Nuclear Station Unit l to be operated at power levels up to 5% of full power.

The NRC Staff has stated that the matter of dynamic loads on structures above the suppression pool is now resolved.

The ACRS is satisfied with the resolu-tion of this matter.

Since October 1981, several additional detailed ques-tions have been raised concerning suppression pool performance and resulting loads. The Committee has reviewed this matter and is satisfied with the manner in which the NRC Staff is handling the questions involved.

Hydrogen control systems for Mark III containments are being developed by the Hydrogen Control Owners Group.

Efforts by the Owners Group are being di -

rected toward the development of a hydrogen ignition system which makes use of distributed ignition sources.

In addition, MP&L has performed plant-8207180076 681

Honorable Nunzio August 18, 1982 speci fie analyses of hydrogen control measures for Grand Gulf.

Although some questions remain concerning the optimum number and location of ig-nitors, the NRC Staff has reached the interim conclusion that MP&L has shown that the hydrogen ignition system will provide reasonable assurance of protection against breach of containment following the generation of a substantial quantity of hydrogen for several significant postulated accident scenarios.

We agree with the Staff.

A final evaluation of the hydrogen control system remains to be completed.

The ACRS expects to review the final NRC Staff position regarding accepta-bility of this approach on a generic basis and requests that the NRC Staff arrange for such a review at the appropriate time.

The NRC Staff has indicated that MP&L has an adequately competent staff to operate the Grand Gulf Station when enhanced by supplemental advisory staff with relevant BWR experience.

During the first year of operation, the ACRS believes MP&L should continue to strengthen its nuclear plant management and its technical support capability.

MP&L has proposed to include in the Grand Gulf Emergency Procedures a pro-vision for venting the containment in the unlikely event of buildup of pressures* above the design basis.

The NRC Staff has not completed its review of this proposal.

The ACRS wishes to be advised_ when the NRC Staff has reached a position on this matter and to have an opportunity to comment generically or specifically.

If due consideration is given to the items mentioned above and to those mentioned in our Interim Report of October 20, 1981, the ACRS believes there is reasonable assurance that the Grand Gulf Nuclear Station Unit 1 can be operated at power levels up to 3833 MWt without undue ris"k to the health and safety of the public.

References:

Sincerely, P. Shewmon Chairman

1. Mississippi Power & Light Company, "Final Safety Analysis Report, Grand Gulf Nuclear Station Units 1 and 2," Volumes 1-22, with Amendments 25-52

2.

Letters from L. F. Dale, Mississippi Power & Light Company to H. R.

Denton, U. S. Nuclear Regulatory Commission:

a.

7/15/82 regarding Regulatory Guide 1.97 compliance license condition 2.C(23)

b.

7/15/82 regarding action plans for resolution of Mr. J. H. Humphrey's concerns 682

Honorable Nunzio August 18, 1982

3.

U.S. Nuclear Regulatory Commission, "Safety Evaluation Report Related to the Operation of Grand Gulf Nuclear Station Units 1 and 21 11 USNRC Report NUREG-0831. dated September 1981 with Supplement No. 1 dated December 1981, Supplement No. 2 dated June 1982, and Supplement No. 3 dated June 1982

4.

Letter from Mr. J. M. Humphrey to A. Schwencer, NRC regarding comments on containment design, dated June 17, 1982 683