ML20003C765
| ML20003C765 | |
| Person / Time | |
|---|---|
| Issue date: | 01/28/1981 |
| From: | Minogue R NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES) |
| To: | Dircks W NRC OFFICE OF THE EXECUTIVE DIRECTOR FOR OPERATIONS (EDO) |
| Shared Package | |
| ML20003C742 | List: |
| References | |
| REF-10CFR9.7, RULE-PRM-50-29, TASK-OS, TASK-SG-029-3, TASK-SG-29-3 NUDOCS 8103180224 | |
| Download: ML20003C765 (2) | |
Text
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UNITED STATES E
h NUCLEAR REGULATORY COMMISSION
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- p WASHINGTON, D. C. 20555 S. Y bm- %, v /a JAN 2 81931
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MEMORANDUM FOR: William J. Dircks Executive Director for Operations FROM:
Robert B. Minogue, Director Office of Nuclear Regulatory Research
SUBJECT:
PROPOSED ATWS RULE When the proposed ATWS rule was submitted to the Comission some months ago, the Office of Research concurred with expressed reservations about the ability to support tha proposed rule' based on the documented record presented to the Commission. Specifically, the staff's recommendations had evolved over a period of several years, and the documentation in its final assembled form did not fully and coherently reflect the rationale underlying these recomendations.
Efforts made to improve and provide more coherence to this documentation in the staff paper were not fully successful.
Since that time, feedback from the Commission and further
. staff work have led to a redrafted rule which is in your hands for submittal to the Comission.
In conjunction with the Comission review, RES was asked to provide an independent staff evaluation of certain ATWS calculations which had been presented to the Comission and that evaluation, forwarded by my memorandum of December 19, 1980, included a different perspective that questioned the validity of the approach to the ATWS rule. Since this challenge represents an apparent differing view in the staff, we have tried to resolve our differeness on the ATWS rule.
The complexity and difficult history of this issue and the proposed rule make simple reconciliation of views virtually impossible at this stage.
We in RES share the NRR view that the risk of ATWS events justifies some action by the NRC; however, we would accept a different approach and less extensive short-term NRC action. We also reccanize that a fundamental change in approach and a fresh start are not a realistic alternative l
after so many years of intensive staff work.
There are so many calls placed on the. resources of NRR and the rest of the staff that it is not l
reasonable to devote more substantial resources now to ATWS.
The following is an alternative which the Commission.sy wish to consider:
We feel that the principal priority is.to deal.with the potential for ATWS occurrence in boiling water reactors with Mark I and Mark II contain-l ments, all of which are either licensed to operate or under construction l
permit. This could be dealt with substantially by a limited interim rule which would require such reactors to add a diverse logic system to l
provide automatic operation of an adequate Standby Liquid Control System j
with the additional benefit of diverse actuation of reactor trip and 810318egy,]i
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William J. Dircks JAN 2 613G1 recirculation pump trip from that logic system.
The Commission could act to require this interim part alone in the short term ano let the balance of this complex consideration of ATWS fixes and related performance criteria be subsumed by the current rulemaking activities now underway with respect to safety goals, standard engineered safeiy features, and degraded core cooling. Unfortunately, the presently proposed ATWS rule is not structured in a way that this interim action would be clearly extractable.
I therefore suggest that the Commission publish the entire proposed rule as it stands, recognizing the limited interim rule option discussed above.
Industry comments already in hand have identified other interim options. The Commission should be in a better position to choose after receiving public comment on the merits of the full rule.
/d4d6.
Robert B. Minogue, Director Office of Nuclear Regulatory Research 4
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