ML20205B429
| ML20205B429 | |
| Person / Time | |
|---|---|
| Issue date: | 03/25/1999 |
| From: | Mckenna E NRC (Affiliation Not Assigned) |
| To: | Carpenter C NRC (Affiliation Not Assigned) |
| References | |
| PROJECT-689 NUDOCS 9903310246 | |
| Download: ML20205B429 (7) | |
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UNITED STATES l
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NUCLEAR REGULATORY COMMISSION i
2 WASHINGTON. D.C. 20815 0001
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i-March 25, 1999 i-i L
- MEMORANDUM TO: Cynthia A. Carpenter, Chief
- Generic issues and Environmental Projects Branch Division of Regulatory Improvement Programs Office of Nuclear Reactor Regulation Eileen M. McKenna, Senior Reactor Engineer hh //th FROM:
Generic issues and Environmental Projects Branch D
. Division of Regulatory improvement Programs Office of Nuclear Reactor Regulation
SUBJECT:
SUMMARY
OF MARCH 23,1999, MEETING WITH THE NUCLEAR ENERGY INSTITUTE (NEI) REGARDitm UNDERSTANDING OF
" MINIMAL" INCREASES
. On March 23,1999, representatives of the Nuclear Energy Institute (NEI) met with
. representatives of the Nuclear Regulatory Commission (NRC) at the NRC's offices in Rockville, Maryland. Attachment 1 provides a list'of meeting attendees.
The purpose of the meeting was to discuss possible ways to provide greater definition or guidance on what it means to result in no more than a " minimal" increase in frequency of accidents, or likelihood of malfunctions of structures, systems, or components. The NRC has underway a rulemaking that proposes to revise 10 CFR 50.59 (Changes, tests and
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experiments), to introduce the concept of " minimal increases." The staff had indicated in SECY-99-054, dated February 22,1999, that existing guidance was more suitable for
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' implementing " negligible,' increases. This meeting was an attempt to see if other guidelines could be developed for " minimal".
The representatives from NEl opened the meeting by stating that they had consulted with the h
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industry task force on 10 CFR 50.59 about the ideas that they shared at the meeting. NEl further noted that with respect to frequency of accidents, the task force members were comfortable with a rule and guidance that results in their not having to demonstrate "zero" increase. There was little support for trying to come up with qualitative considerations for moving further. However, NEl suggested some statements to help determine if a proposed change would result in more than a minimalincrease in frequency of an accident (previously evaluated in the final safety analysis report). All of the statements would have to be true to satisfy this criterion.
The change would not result in a change in the frequency classification of the " accident" (Reactor licensing has traditionally divided postulated accidents and events into classes, based upon expected likelihood and consequences were they to occur. Thus, there are anticipated operational occurrences, infrequent events, and limiting faults. Changing from one class to another is clearly more than a minimal increase).
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- The change would not cause design stresses to exceed code allowables.
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i C. Carpenter March 25, 1 M9 If the effect of the change on the frequency of the accident can be calculated, that the result is no more than a 10% change in the frequency. It was also suggested that for lower frequency events, the amount of change that would be considered minimal could be greater po specific values were discussed).
Discussion among the group on these statements focused on the last statement. It was noted
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that in order to make this assessment, the licensee would need to know the frequency before 1
the change, and be able to calculate the effect. There were questions about what kind of analysis this would be (conservative, best-s itimate), and it was also acknowledged that for most changes, this question would not be useful in making the determination.
The staff asked if it would be helpful if instead of a change in frequency as a measure of
" minimal", if there were absolute frequencies for the particular classes of events that the licensee would have to show they met in order to satisfy this criterion. It was noted that this would take some time to develop because the staff has not previously endorsed any of_ the ANSI or other documents with such classifications. Little interest was voiced by other participants in the meeting.
With respect to likelihood of malfunctions, NEl offered the following statements:
J The change was not expected to cause the applicable maintenance rule performance criteria to be exceeded (depending on the SSC, this could be a reliability value to be met).
The change must not reduce existing design redundancy and diversity.
The change must not cause stresses to exceed Code allowables.
The change would not cause more than a 10% increase in the estimate of malfunction likelihood (as for frequency of accidents, this statement raises questions about how the assessment would be performed).
If the change was being made to conform the facility or procedures to changes to the regulations (this appeared to be a reference to new requirements that the NRC might issue, not with respect to correction of failures to meet the regulations in the first place.)
With respect to the last statement, the staff noted that often there are different ways of satisfying r regulation, and that it is the responsibility of licensees to ensure that the means they use to comply with the regulations do not adversely impact t?.a safety of the plant, and that there may be unique circumstances at their plant would suggest that a different approach is needed.
The staff offered the view that additions of ' components to a system (cabling, manual valves, protective features) would not generally be viewed as more than a minimal increase in likelihood of malfunction, provided that applicable design and quality standards are fokwed.
For example, adding protective devices to breakers, or installing an additional drain line (with appropriate isolation capability) would not be increases in likelihood of malfunction. However, l
1 C. Carpenter March 25,1999 there cou!d be situations where such additions would impact upon how the system performs
- its functions that might not satisfy the 50.59 criteria (for example, a cross-connect between trains that is not suitably isolated).
Another example was substitution of one type of component for another (as for instance, ai,-
operated valve for motor-operated valve), provided requirements for redundant motive force, quality and other requirements are met (and of course that any new failure modes are already bounded by the analysis).
The group discussion concluded with an agreement that it would be helpful to collect from the industry examples of changes that could be used to help refine these concepts. The view was that such examples should be included in the implementation guidance, and that interactions between the industry and the NRC on such examples would best occur as part of the review process for the guidance.
Project No. 689 Attachments: As stated cc w/att: See next page
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1 C. Carpenter functions that might not satisfy the 50.59 criteria (for xample, a cross-connect between trains that is not suitably isolated).
Another example was substitution of one type of component for another (as for instance, air-operated valve for motor-operated valve), provided requirements for redundant motive force, quality and other requirements are met (and of course that any new failure modes are already bounded by the analysis).
The group discussion concluded with an agreement that it would be helpful to collect from the industry examples of changes that could be used to help refine these concepts. The '<iew wa that such examples should be included in the implementation guidance, and that in'
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between the industry and the NRC on such examples would best occur as part of t eview process for the guidance.
Project No. 689 i
Attachments: As stated cc w/att: See next page DISTRIBUTION: See attached page Document Name: g:\\emm\\msum0323 PM:PGEB,h//
K:@QB OFFICE NAME EMcKenna:sw z
DATE 3/MS/99 3/M /99 I
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NRC/NEl MEETING ON MINIMAL INCREASES LIST OF ATTENDEES March 23,1999 NAME ORGANIZATION Tony Pietrangelo NEl Russ Bell NEl David Matthews NRC/NRR l
Frank Akstulewicz NRC/NRR Mark Rubin NRC/NRR Eileen McKenna NRC/NRR 4
Mary Drouin NRC/RES Chris Jacksonr NRC/NRR Tim Collins NRC/NRR 1
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Nancy Chapman SERCH/Bechtel Kim Green NUS-IS Kenneth Hutko PSE&G l
Mike Callahan (none) l Tony Hsia NRC/OCM Roger Huston Licensing Support Services Charles Brinkman ABB-CENP Rich Span Westinghouse Electric j
Mike Markley NRC/ACRS l
Jim Beall NRC/OCM Janice Moore NRC/OGC d
Nuclear Energy institute Project No. 689 cc:
Mr. Ralph Beedle Ms. Lynnette Hendricks, Director Senior Vice President Plant Support and Chief Nuclear Officer Nuclear Energy institute Nuclear Energy Institute Suite 400 Suite 400 1776 i Street, NW 1776 l Street, NW Washington, DC 20006-3708 Washington, DC 20006-3708 Mr. Alex Marion, Director Mr. Charles B. Brinkman, Director Programs Washington Operations Nuclear Energy Institute ABB-Combustion Engineering, Inc.
Suite 400 12300 Twinbrook Parkway, Suite 330 '
1776 i Street, NW Rockville, Maryland 20852 Washington, DC 20006-3708 Mr. David Modeen, Director Engineering Nuclear Energy Institute Suite 400 1776 i Street, NW Washington, DC 20006-3708 Mr. Anthony Pietrangelo, Director Licensing
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Nuclear Energy Institute Suite 400 1776 l Street, NW Washington, DC 20006-3708 Mr. Nicholas J. Liparuto, Manager Nuclear Safety and Regulatory Activities Nuclear and Advanced Technology Division Westinghouse Electric Corporation P.O. Box 355 Pittsburgh, Pennsylvania 15230 Mr. Jim Davis, Director Operations Nuclear Energy Institute Suite 400 1776 l Street, NW Washington, DC 20006-3708 i
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?0 Distribution: Mtg. Summary w/ NEl Re Minimal Increases Dated March 25. 1999 Hard Coov VCentral Files PUBLIC PGEB R/F OGC ACRS SMagruder EMcKenna EMail SCollins/RZimmerman BSheron BBoger WKane DMatthews SNewberry CCarpenter FAkstulewicz EMcKenna TCollins RCorreia MRubin CJackson MMarkley, ACRS JMoore, OGC GTracy, EDO