ML19256F522
| ML19256F522 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 05/15/1970 |
| From: | Hendrie J Advisory Committee on Reactor Safeguards |
| To: | Seaborg G US ATOMIC ENERGY COMMISSION (AEC) |
| Shared Package | |
| ML19256F505 | List: |
| References | |
| ACRS-1648, NUDOCS 7912190321 | |
| Download: ML19256F522 (3) | |
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lt.im L9 W ADVISORY COMMITTEE ON RF. ACTOR SAFEGUARDS p
UNITED STATES ATOMIC VAERGY COMMISSION WASHINGTON. D.C.10345 May 15, 1970 Honorable Glenn T. Seaborg Chairman U. S. Atomic Energy Co= mission Washington, D. C.
20545
Subject:
REPORT ON THE MILLSTONE NUCLEAR POWER STATION UNIT 2
Dear Dr. Seaborg:
During its 121st meeting, May 7-9, 1970, the Advisory Comittee on Reactor Safeguards completed its review of the application by The Connecticut Light and Power Company, The Hartford Electric Light Company, The Millstone Point Company, and Western Massachusetts Elec-tric Company for authorization to construct the Millstone Nuclear Power Station Unit 2.
The project was previously considered during
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an ACRS Subcommittee meeting on May 1,1970, and the site was visited by an ACRS Subcomittee on November 20, 1969. During its review, the Comittee had the benefit of discussions with representatives of the applicant, Co=bustion Engineering Corporation, Bechtel Corporation, members of the AEC Regulatory Staff, and their consultants. The Com-mittee also had the benefit of the documents listed below.
The Committee reported to you on the Millstone site on July 19, 1965, in regard to 'he Millstone Nuclear Power Station Unit 1, a 2011 MWt boiling water reactor. Millstone Unit 2, a 2560 MWt pressurized water reactor, will be constructed adjacent to Unit 1.
Facilities shared by the two units include the control room, the stack, the swice.hyard, and fire protection services. During the construction of Unit 2, a security system will be instituted to control access to Unit 1.
The proposed pressurized water reactor is similar in design to the pre-viously reviewed Hutchinson Island, Calvert Cliffs, and Maine Yankee reactors (ACRS reports dated March 12,1970, March 13,1969, and July 19, 1968). The power level of Millstone Unit 2, at 2560 MWt, represents an increase of five percent over the 2440 MWt power level of these reactors.
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Honorable Glenn T. Seaborg May 15, 1970 The containment system consists of a steel-lined, prestressed concrete cylindrical structure and a steel-framed enclosure building. The en-closure building provides the capability for collecting the leakage of gases from the concrete structure and for discharging these gases through filters to the existing 375-foot stack. The several emergency core cooling systems are similar to previously reviewed designs.
Further study is required with regard to potential releases of radio-activity in the unlikely event of gross damage to an irradiated fuel assembly in the spent fuel pool. This matter should be resolved in a manner satisfactory to the AEC Regulatory Staff.
The Committee reiterates its interest it active participation by appli-cants in overall quality assurance programs in order to assure the con-struction of s.tfer plants.
The Committee has commented in previous reports on the development of systems to control the buildup of hydrogen in the containment which might follow in the unlikely event of a major accident. The applicant proposes to make use of a technique of purging through the enclosure building filters af ter a suitable time delay subsequent to the accident.
However, the Coccittee recocuends that the primary protection in this
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regard should utilize a hydrogen control method which keeps the hydrogen concentration within safe limits by means other than purging. The capa-bility for purging should also be provided. The hydrogen control system and provisions for containment atmosphere mixing and sa=pling should have redundancy and instrumentation suitable for an engineered safety feature. The Coccittee wishes to be kept infor=ed of the resolution of this matter.
The applicant should accelerate completion of his studies of means of preventing common failare modes from negating scram action and of de-sign features to make tolerable the conscquences of failure to scram when required during anticipated transi.ents.
The applicant has stated that turbine-generated missile damage shall not preclude the safe shutdown of the plant. Some questions remain with regard to possible effects of turbine-generated missile damage to Millstone Unit 1.
This matter, as well as the adequacy of measures to control turbine overspeed, should be resolved in a manner satisfac-tory to the Regulatory Staff.
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u, ord Honorable Glenn T. Seaborg May 15,1970
,e, Other problems related to large water reactors have been identified by the Regulatory Staff and the ACRS and cited in previous ACRS reports.
The Cor=nittee feels that resolution of these items should apply equally to Millstone Unit 2.
The Committee believes that the above items can be resolved during con-struction and that, if due consideration is given to these items, this second nuclear unit proposed for the Millstone site can be constructed with reasonable assurance that it can be operated without undue risk to the health and safety of the public.
Sincerely yours,
/s/
Joseph M. Hendrie Chairman
References:
1.
Letter from Day, Berry and Howard, dated February 26, 1969; License Application: Volumes 1 and 2 of Preliminary Safety Analysis Report 2.
Amendments 1 through 8 to the Preliminary Safety Analysis Report C3b l6cA W U
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