ML19308B983
| ML19308B983 | |
| Person / Time | |
|---|---|
| Site: | Oconee, Crane  |
| Issue date: | 09/23/1970 |
| From: | Hendrie J Advisory Committee on Reactor Safeguards |
| To: | Seaborg G US ATOMIC ENERGY COMMISSION (AEC) |
| Shared Package | |
| ML19308B954 | List: |
| References | |
| TASK-TF, TASK-TMR NUDOCS 8001170723 | |
| Download: ML19308B983 (5) | |
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r' ai.- r ADVISORY COMMITTEE ON REACTOR SAFEGUARDS l
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UNITED STATES ATOMIC ENERGY COMMISSION WASHINGTON. D.C. 20545 September 23, 1970 t.
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Honorable Glenn T. Seaborg Chairman U. S. Atomic Energy Commission Washington, D. C.
20545 REPORT ON OCONEE NUCLEAR STATION UNIT NO.1
Subject:
Dear Dr. Seaborg:
17-19, 1970, the Advisory Committee During its 125th meeting, Sept ember f the on Reactor Safeguards completed its review of the app The Committee met with the Station at power levels up to 2568 MJ(t).
13-15, 1970 and Subcommittee applicant during its 124th meeting, Augustat the site and on Ju y 31, 1970 l
23, 1970, In the course of the review, meetings were held on June t
and September 9, 1970, in Washington, D. C.
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the Committee had the benefit of discussions with representatives an g-consultants of the applicant, Corporation, and the AEC Regulatory Staf f, and of study of the document Vn listed.
The Oconee Station is located in a rural area of Oconce County, South The nearest population center is Anderson, 21 miles south, The minimum exclusion distance for Carolina.
with a population of about 41,000.
Low Popu-the completed three-unit power station will be one mile and the I
The lation Zone radius will be six miles containing about 3,400 peopl i
water supply for the plantThe lake and associated recreational facilities are ex-the applicant.
pected to attract a transient population to the area.
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The application covers Oconee Units 1, 2, and 3, but this report applies only to Unit 1, which will employ the first of the Babcock and Wilcox l
l two-loop, four-pump, pressurized water reactor, nuclear ste 1
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The Committee systems. facilities and services are shared in varicus arrangements.
has reviewed the temporary arrangements necessitated by operation o It is believed that the while Units 2 and 3 are still under construction.
h proposed physical measures and administrative procedures to isolate t e from construction activities are adequate.
operating unit 8001170 M 2 00PV 3
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l0l Honorable Glenn T. Seaborg September 23, 1970 The Committee reported to you on the construction permit application for this power station on July 11, 1967. At that time the proposed operating power was to have been 2452 FM(t); the current proposal for operating at powers as high as 2568 FW(t) is justified by the applicant, primarily on the basis of a flatter power distribution.
Prior to operation at the higher power 1cvel, reactor operation should be reviewed by the Regulatory Staff.
The prestressed concrete containment building is similar to those for the Palisades and Point Beach plants which have been reviewed recently for operation.
The Committee recommends that the applicant accelerate his studies of means of preventing common failure modes from negating scram action and of design features to make tolerable the consequences of failure to scram when required during anticipated transients. As solutions develop and are evaluated by the Regulatory Staff, appropriate action should be proposed and taken by the applicant on a reasonable time scale. The Committee wishes to be kept in-formed.
The applicant has proposed using a power-to-flow ratio signal as a diverse means to cause shutdown of the reactor if emergency core cooling action should be initiated. The Co:nnittee believes it is necessary that either the h
equipment associated with this signal be demonstrated to be able to survive the accident environment for an adequate time or a different, diverse trip signal be employed. This matter shoald be resol.ved to the satisfaction of the Regulatory Staff.
The Committee suggests that developmental techniques, such as neutron noise analysis and use of accelerometers, be considered as an aid in ascertaining displacements, changes in vibration characteristics, and the presence of loose parts in the primary systems. The Committee notes the desirability of the continuing use of some thermocouples in the core.
The Connittee 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 loss-of-coolant accident. The applicant proposes to make use of a purging technique after a suitable time delay sub-sequent to the accident. Relatively high off-site doses possibly could result fo11 ming purging of the containment. The Committee recommends that purging systems be incorporated in the plant but that the primary protection in this regard should utilize a hydrogen control method which keeps the hydrogen concentration within safe limits by means other than purging. The t
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I September 23, 1970 Honorable Glenn T. Seaborg i hydrogen control system and provisions for containment atmosphere mixing and sampling should have redundancy and instrumentation suitable for an engineered safety feature; these should be made available within the first The Committee wishes to be kept informed of two years of power operation.
the resolution of this matter.
stated that the amount of radioactivity in liquid wastes nor-The applicant mally will not be greater than one percent of 10 CFR Part 20 limiting con-centrations af ter dilution with the minimum flow (30 cfs) below the Keowee Larger flows will have proportionately smaller limiting concentrations.
The mean annual discharge from the Keowce dam is expected to be 1,100 cu. ft./
dam.
The of f-gas system has holding tank and filtering capability and gas re-Icase rates are not expected to exceed a few percent of 10 CFR Part 20 limits.
sec.
In order to protect against the postulated consequences of the accidental the appifcant has stated that either, he will dropping of a fuel element, install filters in the fuci pool building exhaust system, or the equivalent This e ter should control and protection will be assured by another method.
be resolved to the satisfaction of tha Regulatory Staf f within the t-year of power operation.
Improved calculational techniques are being applied to the analysis of the k
efficacy of the emergency core cooling system in the unlikely event of a loss-Interim results appear to be acceptable, but further of-coolant accident.
calculations are needed and some phenomena important to the course of the accident require f 2rther study. This matter siould be resolved in a manner 5
The Commit-satisfactory to the Regulatory Staff prior to operation at power.
l tee wishes to be kept informed.
The reactor is calculated to have a positive moderator coefficient of reactiv-ity at power which will become negative as boron is remcved from the coolant The applicant concurrent with build-up of fission products and fuel burnup.
plans to perform tests to verify that divergent azimuthal xenon oscillations The Committee recommends that the Regulatory cannot occur in this reactor.
Staff follow the measurements and analyses related to these tests.
A conservative method of defining pressure vessel fracture toughness should l
that is satisfactory to the Regulatory Staff.
emp oye Other problems relating to large water reactors which have been identified by the Regulatory Staff and the ACRS and cited in previous reports to you should be dealt with appropriately by the Staff and applicant in the Oconee i
Unit 1 power plant as suitable approaches are developed.
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23, 1970 September &T. Seaborg if due believes that,bject to natisfac-on Reactor Safeguards i g there is mentioned above, and su and preoperational test n perated
>untaitt ee Nuclear Plant Unit I can be ohealth and
- n to the items an of construction ithout undue risk to the nurance the Oconee jls up to 2568 W(t) w 5 public.
Sincerely yours,
/s/
Joseph M. IIendrie Chairman Stratton are presented below:
cormuents by Dr. W. R.
stared to accompany thecalculations which which are overly
,high off-site doses which I believe to besituation, should are based on i
used purging operat on of assumptionsis my opinion that the and that the pro-nu:nbe r severe tection for the ude a It s ervative.
much less cynr arise, would bewould provide adequate proin this regard and therei ed by this fore ed purge systemLth and safety of the publ ccontrol equipment requ r i
additional hydrogennot necessary."
i ter is List of References acnt:
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lionorable Glenn T. Seaborg September 23, 1970
References:
1.
Amendment No. 7 to Duke Power Company Application for Oconee Nuclear Station, Units 1, 2, and 3, consisting of Final Safety Analysis Report, Volumes I and II, received June 4, 1969 2.
Amendments Nos. 8 through 21 and Revised Ataendment No. 13 to the License Application.
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