ML20217D255
| ML20217D255 | |
| Person / Time | |
|---|---|
| Issue date: | 01/29/1998 |
| From: | Dicus G NRC COMMISSION (OCM) |
| To: | Hoyle J NRC OFFICE OF THE SECRETARY (SECY) |
| Shared Package | |
| ML20217D082 | List: |
| References | |
| SECY-97-287-C, NUDOCS 9803270360 | |
| Download: ML20217D255 (2) | |
Text
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N OT ATIO N VOTE RESPONSE SHEET TO: John C. Hoyle Secretary of the Commission FROM: COMMISSIONER DICUS
SUBJECT:
SECY-97-287 - FINAL REGULTORY GUIDANCE ON RISK-INFORMED REGULATION: POLICY ISSUES Approved X w/ comments Disapproved Abstain Not Participating Request Discussion COMMENTS:
See attached.
M0L, oH Nw SIGNATdRd Release Vote /_X_/
9, DATE /
Withhold Vote / /
Entered on "AS" Yes / No 182 98M 8 7e !
CORRESPONDENCE PDR 1
Commissioner Dieus Comments to SECY-97-287 l approve increases in risk that are appropriately assessed and evaluated, provided that the risk is small and a balance is achieved with compensatory measures in relation to the risk increase. Additionally, I approve the stars treatment of uncertainties in
. comparison of PRA results with the acceptance guidelines. However, the staff should
' assess for future Commission consideration programs to standardize and certify nuclear facility PRAs. To the degree that this activity applies to Materials licensees and programs, the staff should assess this and report back to the Commission on possible implications.
With respect to the stars consideration of "very small" changes, the use of a defined calculated ACDF/LERF of 1% of the baseline values may not be appropriate. Ranges
'of ACDF/LERF should be considered rather than an absolute value so as not to create a defacto risk-based criterion. Recognizing that risk insights continue to be one input
'into a decision making process, staff should identify a range of values for changes which may typically' require NRC approval, and a range which would not require NRC approval (i.e., permitted under 10 CFR 50.59). In this regard staff should also ensure that those individuals charged with the responsibility of reviewing the adequacy of licensee 10 CFR 50.59 evaluations have appropriate objective criteria, guidance and training with which to conduct such reviews.
I approve the stafs approach in assessing the acceptance guidelines for shutdown conditions. Resource commitments to ensure the proper study and development of additional guidance relating to shutdown conditions should be outlined for Commission
' information in a Commission memorandum. The interim guidance suggested for the modification of DG-1061 is appropriate, provided that the staff appropriately credits compensatory measures taken to mitigate the CDF and LERF during a shutdown (or outage) condition.
I approve the stafs approach in assessing acceptance guidelines for temporary plant
. configurations. However, the staff should be cautioned that in considering the relative high conditional CDF and LERF and the duration of the temporary plant changes, the
! . staff should weigh the merits of temporary plant changes that may lead to improved safety, and should ensure that appropriate compensatory measures are taken into laccount that could mitigate the conditional CDF and LERF.
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