ML19308B963
| ML19308B963 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 07/17/1969 |
| From: | Hanauer S Advisory Committee on Reactor Safeguards |
| To: | Seaborg G US ATOMIC ENERGY COMMISSION (AEC) |
| Shared Package | |
| ML19308B954 | List: |
| References | |
| TASK-TF, TASK-TMR NUDOCS 8001170694 | |
| Download: ML19308B963 (3) | |
Text
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ADVISORY COMMITTEE ON REACTOR SAFEGUARDS
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UNITED STATES ATOMIC ENERGY COMMISSION WASHINGTON. D C.
July 17, 1969 Honorable Glenn T. Seaborg Chairman U. S. Atomic Energy Commission Washington, D. C. 20545
Subject:
REPORT ON THREE MILE ISIMD NUCLEAR STATION UNIT 2
Dear Dr. Seaborg:
At its 111th meeting, July 10-12, 1969, the Advisory Comittee on Reactor Safeguards reviewed the proposal of the Metropolitan Edison Company and the Jersey Central Power and Light Company to construct Unit 2 at the Three Mile Island Nuclear Station. A Subconnaittee also met to review this project on June 26, 1969. During its review, the Committee had the benefit of discus-sions with representatives and consultants of both applicants, the Babcock and Wilcox Company, Burns and Roe, Inc., General Public Utilities Corp.,
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and the AEC Regulatory Staff. The Committee also had available the docu-ments listed below.
The plant will be located adjacent to Unit 1 on Three Mile Island near the east shore of the Susquehanna River, about 10 miles southeast of Harrisburg, Pe nnsylvania. The nucicar steam supply system, engineered safety features, reactor building, and aircraf t hardening protection are similar to those of Unit 1, noted in our January 17, 1968, and April 12, 1968, reports. Unit 2 will be ope rated at a power level of 2452 MWt.
Review of Unit 2 has taken into account the similarities of the Three Mile Island units, new features, updating of the research and development programs, and further evaluations of the site. The review also included matters prev'.-
ously identified that warrant careful consideration for all large, water-cooled power reactors; the Committee believes that resolution of these matters should apply equally to this reactor.
The estimate of probable maximtra flood discharge in the Susquehanna. River the site is being revised upwards by the U. S. Army Corps of Engineers atand will be larger than had been considered in the design of Unit 1.
The applicant has stated that both units will be protected by measures which would assure a safe, orderly shutdown of the reactors in the event of the maximum flood, C
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Honorable Glenn T. Seaborg July 17, 1969 Y
The applicant has conducted a test program in support of his proposal to grout The Committee the stranded tendons for the containment prestressing system.
believes that adequate grouting can be attained through proper and careful execution of the procedures developed in this program. The applicant has 115% of design pressure to proposed a program of periodic proof testing at monitor the integrity of the containment, which has been designed conserva-tively to obviate any adverse effects of repeated proof testing at this high The Committee believes that such a program, involving measurement of deformations and thorough inspection for cracking of the concrete during pressure.
each proof test, will provide reasonable assurance of the continued integrity of the containment.
Further review is necessary of the research and development being completed for the alkaline sodium thiosulfate spray additive to deterrine whether the spray systems as proposed need augmentation to achieve requnred performance Provisions will be incorporated ir the design of in postulated accidents.
the containment system to permit equipment additions if nece:sary to ensure limiting the radiological consequences of a loss-of-coolant accident to doses significantly below the 10 CFR 100 guideline values.
The applicant has been considering a purge system to cope with potential
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hydrogen buildup from various sources in the unlikely event of a loss-of-coolant accident. Additional studies are needed to establish the accepta-These studies bility of this system and to consider alternative approaches.
should include allouance for icvels of zircaloy-water reaction which could occur if the effectiveness of the emergency core cooling system were signifi-cantly less than predicted. The Committee believes that this matter can be resolved during construction of the reactor.
The Committee reiterates its belief that the instrumentation design should be reviewed for common f ailure modes, taking into account the possibility of systematic, non-random, concurrent failures of redundant devices, not con-sidered in the single-failure criterion. The applicant should show that the proposed interconnection of control and safety instrumentation will not adversely affect plant safety in a significant manner, considering the The Committee believes that possibility of systematic component failure.
this matter can be resolved during construction of the reactor.
The Committee believes that, for transients having a high probability of occurrence, and for which action of a protective system or other engineered safety feature is vital to the public health and safety, an exceedingly high probability of successful action is needed. Common failure modes must be The Committee considered in ascertaining an acceptabic level of protection.
recommands that a study be made of the possibic consequences of hypothesized failures of protective systems during anticipated transients, and of steps to be taken if needed. The Committee believes that this matter can be resolved during construction of the reactor.
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July _17,1969 Y Honorable Glenn T. Seaborg means of in-service licant study possible ctor for the presence of loose parts in the reaystem, and The Committee recommends that the app other portions of the primary s monitoring for vibration or d practical and approptiate.
pressure vessel as well as inimp'ement such means as are t retain its integrity throug ouThe applicant h t the bsequent cooling period.dioactivity, cor-
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post-accident cooling system mus (including of coolant temperature, pH, racontainment course of an accident and the su T/,
r other parts of the Degeneration of com-should review the effects chanisms lly abrasive slurries.
rosive materials from the core o impellers, and seals by any of these meid to potent J
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stored chemicals), and potentia Particular attention should be pai ilar metals in thes ponents such as filters, pump reviewed.
adequacy of the design, should be arising from the use of diss m inspection details concerning the i
quality assurance, and in-serv ced between the The Committee recommends that l
ump flywhecis be resolveIn this connection, l
i the material characterist cs, requirements of the main coolant-p of quality hasize the need and importance well as con-Staff.
applicant and the Regulatory nd monitoring programs, as the Committee continues to emp assurance, in-service inspection aservative safety i
ideration construction, and that, if due consosed for t l
d site The Advisory Committee on Reactor d with-tioned can be resolved during f /C is given to the foregoing, Unit 2 propassurance that it can be oper i
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constructed with reasonabicd safety of the public.
out undue risk to the health an can be Sincerely yours, I
/s/ Stephen H. Hanauer Stephen H. Hanauer 1
r Chairman i
Unit 2, Preliminary Safety Analysis Three Mile Island Nucicar Station -6, Oyster Creek Nuclear S
References:
Report, Volumes 1-4 (Amendment No.
1.
Unit 2, Docket No. 50-320).
i Licenses.
Amendments 7-10 to Application for d July 3,1969.
2.
Metropolitan Edison Company letter date 3.
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