ML19256F531
| ML19256F531 | |
| Person / Time | |
|---|---|
| Site: | Zion File:ZionSolutions icon.png |
| Issue date: | 06/17/1977 |
| From: | Bender M Advisory Committee on Reactor Safeguards |
| To: | Rowden M NRC COMMISSION (OCM) |
| Shared Package | |
| ML19256F505 | List: |
| References | |
| ACRS-1648, NUDOCS 7912190346 | |
| Download: ML19256F531 (4) | |
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UNITED STATES
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NUCLEAR REGULATORY COMMISSION W
,e W<- l ADVISOP.Y COMMITTEE ON REACTOR SAFEGUARDS t,
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wasuincron, o. c. 2osss JUNE 17, 1977 Honorable Marcus A. Rnden Chairman U.S. Nuclear Ibgulatory Comission Washington, D.C.
20555 SUELTECT: REPORT ON THE ZICri STATIO1, UNITS 1 AND 2 Dee Mr. Bov-len:
During its 206th maeting, June 9-10, 1977, the Advisory Cor:ttee on
. Reactor Safeguards continued its review oi: the operation of the Zion Stacion, Units 1 & 2.
The Cocnittee had previously discuss?3 operation of tne Zion Station in its reports of August D,1972, May 17,1973, December 9, 1974, and June 9, 1976. A Subcocittee meeting was held in Kenosha, Wisconsin, on May 17, 1977, following a tour of the station by Comittee members. During its review, the Comittee had the benefit f'
of discussions with rep' esentatives of the Co=onwealth Edison Comoany (Licensee), Westinghou.. Clectric Corporation, and the Nuclear Regula-tory Corrission Staff. We Comittee also had the benefit of tne docu-mencs listed.
In 'ts June 9,1976 report, the Cor:nittee identified ten unresolved mat-ters that should be dealt with in a timely fashion if the Zion reactors are to continue to be operated at full power over the lifetime of the plant. Re ten matters identified are as follows:
(1) A revieu of the entire Station for systems interaccion that might lead to significant degradation of safety.
(2) A review of the Station with regard to differences from current criteria, and judgments concerning pssible back-fitting requirements.
(3) ne implementation of instrumentatien to provide early information concerning the course of a full range of pstulated serious accidents, and precedures for inter-f preting and relating this information to cmergency plans.
(4)
Installation of a loose-parts monitoring system as soon
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as practicable.
Evaluation and prompt implementation of improvements in (5) fire protection capability, as necessary.
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.1 Honorable Marcus A.. Rcr. den June 17, 1977 (6) Tinely irclenmtation of nodifications required in connec-tion with the resolution of A'IW5.
(7) Continued studit:s directed to enhanecmant of the capabilf *.y and.eliability of the Emergency Core Cooling Systems.
f.8)
Derenstration of the reliability of the diesel generators to operate with load for extended periods o2 time.
(9) Assessment of the safety significance of the large nunter of reportable events experienced at the station, and prompt inplementation of significant improvecents in ccerational quality assurance.
(10). Pror.pt implementation of improvements in industrial security as appropriate.
The current status of these items was the principal matter of this
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latest review of the Zion Station.
The Comittee believes that little progress has been rade toward res-olution of item 1.
Discussion with the Licensee and tne NRC Staff suggests that this has been the result, at least in part, of a lack of understanding by the Licensee and the NRC Staff of just what is neant by "systens interaction." In thi: respect the Comittee calls attention to its letter of November 8, 1974, to L. Manning ?Iuntzing, Director of Regulation. The Contnittee recommends that, within nine nenths, the Licensee submit to tha NRC Staff, as a minin:um, the results of a study of systems interaction relating to the possibility that failurt. of safety and non-safety systems will interfere with the plant operators
ability to acconplish shutdown heat renoval, together with a plan and schedule for studies of other system interactions of potential safety significance to the Zion Station.
With respect to item 2, for which litile has been done, the Comittee reconmends that, during the next twelve months, the Licensee review the Zion Station for possibly significant differences from current criteria, and that the NRC Staff evaluate this review and report to the ACRS its conclusion concerning possible backfitting require.snts.
'Ihe Conmfttee vishes to review the status of items 1 and 2 within the next eighteen nenths.
Items 3, 5, 6, 7, and 10 are considered by both the ACRS and the NRC Staff to be unresolved mat ters generic to all operat ing light water 4
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Honorable Marcus A. Rowden June 17, 1977 reactors. During the past twelve months, some progress has been made toward the resolution of these generic items and in the planning for the application of appropriate solutions to the ho.. Units. Se Com-mittee recomends that the NRC Staff and Licensee urgently seek reans to expedit.e solutions to outstanding generic items and the implementa-tion of solutions, when feasible, to the Zion Station.
Tne Licensee has made a c..ritment to install loosa-parts monitoring systems on the tw Zior. Station reactors during the 1978 refueling out-ages. S e NRC Staff considers item 4 resolved. Se Cormittee concurs.
In response to item 8, one of the diesel generators was run continuously for seven days at a controlled power output equivalent to the ECCS load.
Whereas the unit ran satisfactorily during this period, the cignificance of the tut results in confirming the capdoility of the emergency power system to prform its intended functions was obscured when, on the seventh day, an operator error led to a large sarge in the load and the destruction of the generator by fire. Se generator failure was the result of an unanticipated interaction between the main electrical pwer generating system, the emergency pwer system, and the loads they I
were sharing. Bis unexpected result increases the urgency for a review of the entire station f.7r interactions between electrical generation, distribution, consumption, and control systems that might lead to signi-fic:nt degradation of safety. We Cormittee recon =ende that this phase of the review (item 1) be given particular attention. De Coumittee wishes to be kept informed.
h e Licensee has, in resp nse to concerns expressed by the NRC Staff, rewritten his operating procedures, expanded employee training programs, and organi::ed as p::t of the Qual'.ty Assurancs program, two independent aud : groups: one group to verify procedural compliance and to audit work in progress, and the other group to identify and resolve problems promptly. D e NRC Staff has also issued amendments to the Zion license which revise the entire administrative control section of the Technical Specifications. Se Conmittee cencludes that these actions of the NRC Staff and Licensee are responsive to item 9 and encourages the Licensee to continue to seek further improvement it: these areas.
He Advisory Comittee on Reactor Safeguards believes that, if due regard is given to the items mentioned above, there is reasonable assurance that the Zion Station Units 1 and 2 can continue to oprate at full p wer, 3250 MWg*, without undue risk to the health and safety of the public.
Sincerely, 7>1.
1624 R gtQ M. Bender Q1 airman A-232
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Honorable Marcus A. Rowden June 17, 1977 References 1.
Report to the ACPS by the Office of Nuclear Reactor Regulation, U. S. Nuclear Regulatory Comnission in the 11atter of Con::enwea'th Edison Conpany Zion Station, Units 1 and 2, dated April 22, 1977.
2.
Supple::ent to the Report by the Office of Nuclear Rear. tor Regulation, NRC, to the ACRS concerning Zion Station, Units 1 and 2, dated Jur.e 8, 1977.
3.
Letter from Co:::~anwealth Edi?on Co. to the Office of Nuclear Reactor Regulation, NRC concerning installation of a loose parts monitoring system, dated January 1, 1977.
4.
Letter from Com:nonwealth Edison Co. to the Office of Nuclear Reactor Regulation, NRC, concerning information on gaseous releases from Zion Station, dated April 1,1977.
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5.
Letter from Cor: onwealth Edison Co. to the Office of Nuclear Reactor Regulation, NRC, concerning a su:=.ary of the diesel generator test, dated April 6, 1977.
6.
Letter from Corr.onwealth Edison Co. to the Office of Nuclear Reactor Regulation, NRC, concerning a report on fire protection, dated April 29, 1977.
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