ML20010C894
| ML20010C894 | |
| Person / Time | |
|---|---|
| Site: | Big Rock Point File:Consumers Energy icon.png |
| Issue date: | 08/19/1981 |
| From: | Hoffman D CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | Crutchfield D Office of Nuclear Reactor Regulation |
| References | |
| TASK-07-03, TASK-7-3, TASK-RR LSO5-81-08-036, LSO5-81-8-36, NUDOCS 8108210181 | |
| Download: ML20010C894 (3) | |
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A. August 19, 1981 Docket No. 50-155
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'Bj "' *M* g sa w,; w u 20193 Mr. David P. Hoffman A
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Consumers Power Company
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1945 W. Parnall Road q
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Dear fir. Hoffman:
RE:
SEP TOPIC VII-3, SYSTEMS REQUIRED FOR SAFE SHUTDOWN, SAFETY EVALUATI0tl REPORT (BIG ROCK POIllT)
The enclosed staff safety evaluation is based on a contractor's document that has been made available to you previously. This document supports the findings of the staff safety evaluation of Topic VII-3 and recomends mod-ifications to several plant systems.
The need to actually implement these changes will be determined during the integrated safety assessment. This safety evaluation may be revised in the future if your facility design is changed or if HRC criteria relating to this topic are modified before the integrated assessment is completed.
Sincerely, Dennis it. Crutchfield, Chief Operating Reactors Branch No. 5 Division of Licensing
Enclosure:
As stated
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NRC FORM 318 (10 80) NRCM oua OFFICIAL RECORO COPY esam e-m
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f SYSTEMATIC EVALUATION PROGRAM TOPIC _VII-3 BIG ROCK POINT TOPIC VII-3, SYSTEMS REQURIED FOR SAFE SHUTDOWN I.
INTRODUCTION The systems aspects of the review of Systems Required for Safe Shutdown was conducted as part of Topic V-10.B (RHR Reliability).
This safety evaluation is limited to the electrical instrumentation and control sys-tems identified as being required for safe shutdown.
Plant systems that are needed to achieve and maintain a safe shutdown condition of the plant, including the capability for prompt hot shutdown of the reactor from out-side the control room were reviewed.
Included also, was a review of the design capability and method of bringing the plant from a high pressure condition to low pressure cooling assuming the use of only safety grade equipment. The objectives of the' review were to assure:
(1) The design adequacy of the safe shutdown system to (a) initiate automatically the operation of appropriate systems, including the reactivity control systems, such that specified acceptable fuel design limits are not exceeded as a result of anticipated operat-tional occurrences or postulated accidents and (b) initiate the operation of systems and components required to bring the plant to a safe shutdcan.
(2) That the required systems and equipment, including necessary in-strumentation and controls te maintain the unit in a safe condition during hot shutdown, are located at appropriate' places outside the control room and have a potential capability for subsequent cold shutdown of the reactor through the suitable procedures.
(3) That only safety grade equipment is required to bring the reactor coolant system from a high pressure condition to a low pressure cooling condition.
II.
REVIEW CRITERIA The review criteria are presented in Section 2 of the EG&G Report
" Electrical, Instrumentation, and Control Features of Systems Required for Safe Shutdown Big Rock Point Nuclear Station".
III.
RELATED SAFETY TOPICS AND INTERFACES Review areas outside thescope of this topic and safety topics are dependent on the present topic information for completion are identified in Section 3 of the EG&G Report.
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REVIEW GUIDELINES The review guidelines are presented in Section 4 of the EG&G Report.
V.
EVALUATION As noted in the EG&G Report, the systems requried to take Big Rock Point from hot shutdown to cold shutdown, assuming only offsite power is avail-able or only onsite power is available and a single fatiure, are capable j
of initiatton to bring the plant to safe shutdown and are in compliance with current licensing criteria and the safety objectives of SEP Topic VII-3, except that the instrumentation available to control room operators to reach and maintain the reactor in cold shutfown conditions does not naet current licensing criteria since a single failure can cause a loss of vital indication such as reactor temperature, pressure and level, as well as process instrumentation for safe shutdown systems.
VI. CONC!.USIONS Big Rock Point satisfies all of the requirements for Safe Shutdnwn except i
for a lack of redundancy in vital indication for primary and secondary processes. Therefore, the staff proposes that the Big Rock Point design be modified to provide redundant and independent instruments for those process variables that are required to protect the public health and safety.
Examples of such instruments and systems are given in Section 7 of our contractor's report.
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