ML20195K006
| ML20195K006 | |
| Person / Time | |
|---|---|
| Issue date: | 05/19/1999 |
| From: | Shirley Ann Jackson, The Chairman NRC COMMISSION (OCM) |
| To: | Vietticook A NRC OFFICE OF THE SECRETARY (SECY) |
| Shared Package | |
| ML20195J986 | List: |
| References | |
| REF-10CFR9.7 SECY-99-133-C, NUDOCS 9906210183 | |
| Download: ML20195K006 (2) | |
Text
r NOTATION VOTE RESPONSE SHEET TO:
Annette Vietti-Cook, Secretary FROM:
CHAIRMAN JACKSON
SUBJECT:
SECY-99-133 - FINAL REVISION TO 10 CFR 50.65 TO REQUIRE LICENSEES TO PERFORM ASSESSMENTS BEFORE PERFORMING MAINTENANCE w/ comments Approved. X Disapproved Abstain Not Participating COMMENTS:
See attached comment.
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hirley Ann Jackson i
SIGNATURE
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May 19, 1999 DATE Entered on "AS" Yes No
- U'2;ggg7;ggie CORRESPONDENCE PDR l C.I
Chairman Jackson's Comments on SECY-99-133 I commend the staff for completing this rulemaking effort, which represents.the culmination of a multi-year effort to bring a required level of regulatory oversight to the conduct of maintenance during shutdown conditions and to on-line maintenance during power operation. I approve the proposed rule for the reasons cited in the staff's recommendations. As the increased use of on-line maint.enance surfaces vulnerabilities that the design bases for reactor plants did not consider fully, namely multiple safety-related components out-of-service simultaneously, it is altogether appropriate that the NRC take this action.
As the staff engages our stakeholders in the development of regulatory guidance for this rule, l
there should be a clear understanding that structures, systems and compo' ents (SSCs) which n
l directly support high risk-significant (or "high risk") SSCs are themselves to be considered within the scope of assessments. Additionally, I believe that the method ultimately developed for determining high risk SSCs which are "in scope" must provide confidence that the SSCs which are identified as high risk remain current. My concem in this area is that changes to plant design (such as the addition of new equipment or the abandonment-in-place of existing equipment),
operational practices (such as crediting increased amounts of manual operator action), or external conditions (such as environmental impacts which may affect cooling or ventilation systems supporting key equipment) can change the risk significance of various SSCs. For instance, at facilities such as Salem and Turkey Point, seasonal variations in the volume of aquatic grasses in
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the ultimate heat sinks make the screen wash systems associated with the pumps for the heat sinks very important to the overall core cooling capability of the facility on a variable basis. The staff should ensure that such possibilities are taken into account in developing guidance and implementing the rule.
Finally, the staff should ensure that the guidance developed for this rulemaking advances a holistic approach to assess ~mg the risk of maintenance activities. I concur with the ACRS conclusion that the Configuration Risk Management Program (CRMP), described in some technical specifications, was designed primarily to support the risk-informed extension of technical specification allowed outage times for individual components (as opposed to a number ofcomponents or systems). As a result, combinations oflow-safety-significant SSCs that, taken together, might represent a high risk condition are not covered under the scope of the CRMP.
l The guidance developed for the implementation of this rulemaking should advance the' position -
that an assessment should be performed, at least once, which would identify possible combinations oflow risk-significant SSCs that should be treated within the scope of a(4) of the proposed rule. In the alternative, other methods that would consider the impact oflow risk significant SSCs would be acceptable, such as robust risk monitoring methods which can be demonstrated to have addressed this concern.
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