ML19308B959
| ML19308B959 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 07/17/1967 |
| From: | Hanauer S US ATOMIC ENERGY COMMISSION (AEC) |
| To: | Seaborg G US ATOMIC ENERGY COMMISSION (AEC) |
| References | |
| TASK-TF, TASK-TMR NUDOCS 8001170664 | |
| Download: ML19308B959 (3) | |
Text
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UNITED STATES ATOMIC ENERGY COMMISSION WASHINGTON, D.C.
July 17, 1969 Honorable Glenn T. Seaborg Chairman U. S. Atomic Energy Comnission Washington, D. C. 20545
Subject:
REPORT ON TILREE MILE ISIAND NUCLEAR STATION UNIT 2
Dear Dr. Seaborg:
At its 111th meeting, July 10-12, 1969, the Advisory Cocnittee 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 Subcommittee also met to review this project on June 26, 1969. During its review, the Cotraittee 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.,
and the AEC Regulatory Staff. The Cominittee also had availabic the docu-nonts listed below.
The plant will be located adjacent to Unit 1 on Three Mile Island near the cast shore of the Susquehanna River, about 10 miles southeast of Harrisburg, Pe nnsy lv ania. The nuc1 car steam supply system, engineered safety features, reactor building, and aircraft 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 previ-ously identified that warrant careful consideration for all large, water-cooled power reactors; the Conmittee believes that resolution of these matters should apply equally to this reactor.
The estimate of probabic maximum flood discharge in the Susquehanna River at the site is being revised upwards by the U. S. Army Corps of Engineers and will be larger than had been considered in the design of Unit 1.
The applicant has stated that both units will be protected by measuras which would assure a safe, orderly shutdown of the reactors in the event of the maximum flood, C
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lionorable Glenn T. Seaborg Y July 17, 1969
.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 bc attained through proper and careful execution of the procedures developed in this program. The applicant has proposed a program of periodic proof testing at 115% of design pressure to 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 Connittee 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 coupleted for the alkaline sodium thiosulfate spray additive to determine whether the spray systems as proposed need augmentation to achieve required performance Provisions will be incorporated in the design of in postulated accidents.
the containment system to permit equipment additions if necessary 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 hydrogen buildup from various sources in the enlikely 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 allowance 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 failure modes, taking into account the possibility of systematic, non-random, concurrent failures of redundant devices, not con-The a sidered in the single-failure criterion.
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 Common failure modes must be probability of successful action is needed.
The Committee considered in ascertaining an acceptable level of protection.
recommends that a study be made of the possible consequences of hypothesized failures of protect!ve 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 P
Y Honorable Glenn T. Seaborg means of in-service applicant study possible reactor for the presence of loose parts in the The Committee recommends that the tem, and ther portions of the primary sys monitoring for vibration or d practical and appropriate.
pressure vessel as well as in oimplement such means as ar t retain its integrity througThe applicant hout the t cooling period.
The post-accident cooling system musof an accident and the sub or-lant temperature, pH, radioactivity, ct (including should review the ef fects of cooor other parts of the containmenDegenerati course mechanisms lly abrasive slurries.llers, and seals by any of these rosive materials from the core stored chemicals), and potentia Particular attention should be paii ilar metals in t ponents such as filters, pump impe should be reviewed.
h design, arising from the use of diss m ils concerning the adequacy of t einspection quality assurance, and in-servicels be resolved bet The Committec_ recommends that deta l
the material characteristics,of the main coolant-pump flyw eeIn this connection h
lity hasize the need and importance of qua Staff.
requirements well as con-applicant and the Regulatorythe Committee continues t rams, as assurance,.
design.
servative safety margins in Safeguards believes that the items me -if due co n
The Advisory Committee on Reactorresolved during construction, ansed fo d that, i
d with-is given to the foregoing, Unit 2 propossurance that it can be opera C.,
tiened can be A
l can be constructed with reasonab e ad safety of the public.
out undue risk to the health anSincerely yours,
/s/ Stephen H. Hanauer Stephen H. Hanauer Chairman Unit 2, Preliminary Safety Analysis Three Mile Island Nuclear Station -6, Oyster Creek Nuclear St
References:
Report, Volumes 1-4 (Amendment No.
1.
Unit 2, Docket No. 50-320).
Licenses.
Amendments-7-10 to Application for dated July 3,1969.
2.
Metropolitan Edison Company letter 3.
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