ML20217D273
| ML20217D273 | |
| Person / Time | |
|---|---|
| Issue date: | 02/10/1998 |
| From: | Mcgaffigan E NRC COMMISSION (OCM) |
| To: | Hoyle J NRC OFFICE OF THE SECRETARY (SECY) |
| Shared Package | |
| ML20217D082 | List: |
| References | |
| SECY-97-287-C, NUDOCS 9803270364 | |
| Download: ML20217D273 (3) | |
Text
NOT ATIO N VOTE RESPONSE SHEET TO:
John 'C. Hoyle, Secretary i
FROM:
COMMISSIONER MCGAFFIGAN
SUBJECT:
SECY-97-287 - FINAL REGULATORY GUIDANCE ON RISK-INFORMED REGULATION: POLICY ISSUES Approved'4 """+ Disapproved + "'f' Abstain Not Participating Request Discussion COMMENTS:
See attached comments.
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SIGNATURE
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-}!IOb'Y Release Vote / >s /
DATE Withhold Vote /
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Entered on "AS" Yes Y No in " Ens 7J88" CORRESPONDENCE PDR
Commissioner McGaffican's Comments on SECY-97 287 I want to commend the staff on the clarity and substance of the discussions concerning the four policy matters identified in SECY-97-287, although I have some reservations concerning how the staff has implemented'the policy recommendations of this paper in the final Regulatory Guide and Standard Review Plan now before the Commission (SECY-98-015).
While those reservations will be subjects of my future vote on SECY-98-015. I feel it is important to make some comments on them now where they relate to my vote on SECY-97-287.
I have strong reservations about the importation of " current licensing basis (CLB)" from 10 CFR Part 54 into the assessment of plants currently licensed under 10 CFR Part 50.
The use of CLB (see Background of SECY-97-287 and the more extensive discussion in SECY-98-015) is a potential policy issue in its own right.
The use of CLB was opposed by several commenters and, though the staff modified its discussion of the use of the term in SECY-98-015. it is not clear to me that it would not be better to avoid the use of the term entirely in the current Part 50 context.
I mention this point because I want to make it clear that my vote on the current SECY should not be viewed as an endorsement of the use of CLB as proposed by the staff in SECY-98-015.
1 I support the staff's recommendation to replace the " risk-neutral" policy for plants with CDFs above 10
- per reactor year and/or LERFs above 10~5 per reactor year with one that permits "very small" calculated increases in those measures.
I endorse the use of a definition for "very small" as a change in CDF of less than 10-6 per reactor year and a change in LERF of less than 10
per reactor year.
I would note that this might also be used as one measure cf the term " minimal" in the context of revision of Section 50.59 (the subject of SECY-97-205) and of "so small" in NEI-96-07.
As the staff points out, these values are " considered to be representative of the limit of resolution for PRA models."
One issue not raised by staff in SECY-97-287 is the cut-off proposed in SECY-98-015 under which applications which result in increases above 105 per year in C0F. or above 10 6 per year in LERF "would not normally be considered.'
This hard cut-off, whether the license's CDF is currently 10-4 or 10'S or 10~6 per year, needs more consideration in my view.
I am not sure why a licensee with a CDF of 1.5 X 10'5 per year, for example, should not be allowed to apply for a 1.5 X 10 per year increase which would still leave the licensee more 5
than a factor of 3 below the baseline CDF guideline.
2 I approve the staff recommendation on the treatment of uncertainties in
^
comparison of PRA results with theiacceptance guidelines.
I want to join with Chairman Jackson in asking the staff to provide for the review of the Commission and stakeholders the actual methodology used in implementation of the decision-making process of the pilot programs.
I. agree with Commissioner Diaz in disapproving the expenditure of more of the
. Commission's scarce resources on conducting additional research in the area of shutdown operations. The methodology outlined by the staff for interim use, that is, continuation of the use of' current operating CDF/LERF guidelines, is acceptable.
The acceptance guidelines for temporary plant changes merit additional staff review and assessment. This issue will also arise in the context of the proposed change to the Maintenance Rule under which configuration control during maintenance would become a requirement.
But not all. temporary plant changes will come under the Maintenance Rule even after the proposed revision is finalized.
So we will need a consistent approach'on these acceptance guidelines in future revisions to Regulatory Guide 1.174 and Regulatory Guide 1.160/NUMARC 93-01.
Having briefly reviewed SECY-98-015 in the context of voting on this paper I am concerned that there may be more policy issues in the final draft such as use.of the term " current licensing basis" or the hard cut-off for increases in CDF or LERF, that could benefit from focused stakeholder comment. Therefore, I would recommend that SECY.-98-015 be released immediately not with the purpose of reopening the four issues dealt with in this paper, but to identify any other major issues between stakeholders and staff needing Commission resolution _ before Regulatory Guide 1.174 and' Standard Review Plan Ciiapter 19 are published.
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NUCLEAR REGULATORY COMMISSION WASHINGTON. O C. 205S5-0001 g
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o March 19, 1998
'Of f tCE Of THE SECRETARY L MEMORANDUM TO:
L. Joseph Callan xec tive Director for Operations bt___
FROM:
/o C.
I, Secretary
SUBJECT:
STAFF REQUIREMENTS - SECY-97-287 - FINAL REGULATORY GUIDANCE ON RISK-INFORMED REGULATION: POLICY ISSUES The Commission has approved the staff's recommendation to allow very small increases in core damage frequency (CDF) and large early release frequency (LERF) independent of the baseline calculated CDF/LERF, provided that licensees track and the NRC staff monitor the cumulative effect of changes. The Commission also approved the definition of "very small" as changes less than.10* per reactor year for CDF and less than.104 per reactor year for LERF.
The staff should recognize that risk insights continue to be one input to the integrated decision
. making process and the proposed values s ould be considered a guideline and not a hard cut-h off.
The Commission has approved the staff's recommendation for the treatment of uncertainties in (PRA results. As the pilot programs are completed, the salient features of the decision making process should be documented to the Commission to ensure a consistent, scrutable and common understanding as to how risk-informed decisions should be promulgated. in particular, the paper should clarify the treatment of uncertainties and the role of increased NRC management attention in the decision making process in the pilot programs.
The staff should assess for future Commission consideration industry programs for standardizing and certifying nuclear facility PRAs.
(EDO)
(SECY Suspense:
10/30/98) 1
' As part of the FY 1999 budget, the Commission approved "... development of improved human and organizational reliability analysis and data, and to perform additional risk studies associated with reactor low power and shutdown operatiori." However, the Commission has not approved the staff's recommendation that consideration of possible additional shutdown risk acceptance guidelines be undertaken as part of the research effort. The staff should inform the.
Commission of the results of these risk studies for future Commission consideration. The
[f/[b Commission has approved the recommendation to maintain the CDF and LERF guidelines for gg) c both power and shutdown operations. The staff should appropriately crodit compensatory
, measures taken to mitigate increases in CDF and LERF during shutdown or outage conditio LThe Commission has approved the staff's' recommendation to conduct an assessment of risk-informed acceptance guidelines for temporary changes to plant configuration.s.; The s
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- e Commission noted that this effort will take place in the future. At present, except for the special case of Technical Specification changes, only time-averaged guidelines will be used, in assessing these acceptance guidelines for temporary plant configurations, staff should weigh the merits of temporary changes that may lead to improved safety, and should ensure that appropriate compensatory measures are taken into account that could mitigate the conditional n
CDF and LERF. This issue will also arise in the context of the proposed changa to the Maintenance Rule under which configuration control during maintenance wouid become a requirement, but not all temporary changes will come under the Maintenance Rule even after
'the proposed revision is finalized. The staff should ensure a consistent approach is used for future revisions to Regulatory Guide 1.174 and Regulatory Guide 1.160/NUMARC 93-01.
In addition, a rick 4nformed approach should not focus exclusively on when risk increases should be allowed. If risk insights reveal significant vulnerabilities, r!sk reduction may be the appropriate goal for both licensees and the Commission.
cc:
Chairman Jackson Commissioner Dieus Commissioner Diaz Commissioner McGaffigan OGC ClO CFO OCA OlG Office Directors, Regions, ACRS, ACNW, ASLBP (via E-Mail)
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