ML20045D094
| ML20045D094 | |
| Person / Time | |
|---|---|
| Issue date: | 03/01/1993 |
| From: | Carroll J Advisory Committee on Reactor Safeguards |
| To: | Advisory Committee on Reactor Safeguards |
| References | |
| ACRS-2852, NUDOCS 9306250319 | |
| Download: ML20045D094 (8) | |
Text
$ $ ~ $ $ck CERTIFIED BY:
DATE ISSSUED: 2/25/93
- J. Carroll - 3/1/93
SUMMARY
/ MINUTES OF THE SUBCOMMITTEE ON MAINTENANCE PRACTICES AND PROCEDURES OCTOBER 6, 1992 BETHESDA, MARYLAND i
INTRODUCTION The ACRS Subcommittee on maintenance practices and procedures held a meeting on Tuesday, October 6, 1992, in Room P-110, 7920 Norfolk Avenue, Bethesda, Maryland.
The purpose of the meeting was to discuss the NRC staff's proposed regulatory guide for implementation of the Maintenance Rule and Revision 2A of the NUMARC 93-01 document,
" Industry Guidelines for Monitoring the Effectiveness of Maintenance at Nuclear Power Plants."
The entire meeting was open to public attendance.
Mr. Herman Alderman was the Cognizant ACRS Staff Engineer for this meeting.
A copy of the presentation schedule for the meeting and a list of documents submitted to the Subcommittee are included in the attachment.
The Subcommittee had received neither written comments nor requests for time to make oral statements from members of the public.
The meeting was convened at 8:30 a.m. and adjourned at 11:50 a.m.
Carroll, Subcommittee Chairman W. Smith C.
Michelson, Member W.
Hall D.
Ward, Member i
H.
Alderman, Cognizant ACRS Staff Engineer NRC/RES 0.
Rothberg R.
Correia F. Cherney q
CHAIRMAN'S OPENING REMARKS Mr. Carroll noted that the full Committee will have a presentation on this topic during the October 1992 ACRS meeting and a report including ACRS comments and recommendations on this matter is expected to be completed during that meeting.
He mentioned that the Committee would be interested in hearing how the staff is going to integrate the Maintenance Rule implementation with the License Renewal Rule and the Reliability Assurance Program that is required for the advanced reactor plants under 10 CFR 52.
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Maint. Prac. & Proc. October 6, 1992 Summary / Minutes NUMARC Presentation-Mr.
W.
Smith, NUMARC Mr. Smith said that the industry believes that the Maintenance Rule can be implemented within the bounds of the maintenance programs that exist today.
Although some utilities will have to improve their maintenance programs, it is not expected to present a big obstacle.
originally, the NRC staff and NUMARC guidance proceeded in parallel in the development of maintenance documents.
Subsequently, the NRC staff decided to endorse the industry guidance document. and discontinued its efforts in developing a
separate guidance document.
There have been a series of meetings between NUMARC and the NRC staff to reconcile differences in language and concepts.
A number of working groups were established to resolve the issues.
The end result was an endorsed industry guidance document.
Mr. Smith discussed the methods for identifying risk significant criteria for the selection of risk significant structures, systems, and components (SSCs).
One of the methodologies is PRA and another one is the DELPHI process.
The DELPHI process involves experts looking at the overall number of systems based on a weighing criterion, assigning risk significance to the set of systems based on a set of selected functions.
Mr. Smith talked about the verification and validation (V & V) program.
He said this was needed in order to ensure themselves that the maintenance guidance document could be implemented in the way that was expected.
Nine plants were selected, representing the four nuclear steam system suppliers.
An attempt was made to have the plants of the same vintage.
1 He noted that one of the basic elements of the V & V program was the process of defining SSCs so that a decision can be made as to
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what is within the scope of the Maintenance Rule. He said that each of the program participants has completed this activity.
NUMARC has taken these lists and compared them.-
The li'sts have been j
provided to the participating plants for their evaluation of the differences between each'of the units.
Stating that the fire protection system is important to safety, Mr.
Michelson asked where the maintenance of the fire protection system is discussed.
Mr. Smith said that fire protection is treated as a non-safety related system that does not affect the safety system.
He said that it is not within the scope of the Maintenance Rule.
He noted that Appendix R and all' of the other requirements for fire protection and suppression are already covered under other regulations and maintenanca programs.
Maint. Prac. & Proc. October 6, 1992 Summary / Minutes 1
Mr. Smith identified the major project milestones of the V & V program.
Some of these were:
Identify all SSCs that are within the scope of the Maintenance Rule.
compare the selected SSCs between common NSSS participants and e
describe differences, Identify the method for identifying risk-significant criteria e
for the selection of risk-significant SSCs.
Identify the criteria selected for the determination of risk-e significant SSCs.
Identify and verify the methodology for evaluating the performance of standby systems that are risk significant or non-risk significant, Identify all SSCs included in the emergency operating e
procedures (EOPs).
Identify EOP categories to be recommended for deletion from e
the scope of the Maintenance Rule.
Mr. Carroll asked about the threshold at which something becomes safety significant, when using a PRA.
Mr. Smith said there were two methodologies.
The first uses a ranking of contribution to core-damage frequency.
The second is based on risk sensitivity measurements developed by the NRC.
Mr. Michelson asked how they identify all the components that might be important to safety, and when there might be only one component in a system.
He also noted that PRAs are not very good for pipe breaks. ' Mr. Smith said that they felt that the DELPHI process will help them get closer to a complete assessment for both of these.
Mr. Smith discussed the principal lessons learned from the V & V' program.
Some of these were:
Excluding some. SSCs used in EOPs from the scope of the Maintenance Rule' that require actions to be taken for equipment whose only purpose is to protect - the owner's investment and does not affect public health and safety.
This equipment could be excluded from the scope of the Maintenance-Rule.
Maint. Prac. & Proc. October 6, 1992 Summary / Minutes
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Determining the appropriate level for goal setting and e
monitoring.
Appropriate use of PRA results.
Some safety systems have very few components that contribute e
to the safety function.
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A "Q" classification component does not automatically indicate e
a safety or safety-related system.
i Application of industrywide and plant-specific experience.
e V & V participants recommended that industrywide performance, such as trips, be considered under the Operating Experience
- Program, but not be used as the basis for establishing specific plant goals.
Mr. Smith discussed the major project milestones.
He noted that NUMARC will issue three interim lessons learned reports, followed' by a final report in December 1992.
The V & V program is_ expected to be completed in December 1992.
The NRC expects to issue the maintenance guidance document for public comments in January 1993.
The end of the public comment period is March 1993.
The resolution of the public comments are presently expected to be available for presentation to ACRS and CRGR in May 1993.
It is expected that the final version of the maintenarece regulatory guide will be published in the Federal Register on July 10, 1993.
It is anticipated that the NUMARC-sponsored workshops will start in July 1993.
Implementation of the Maintenance Rule will be in July 1996.
The NRC staff will start a pilot inspection program sometime in 1995.
i Mr. Carroll asked Mr. Smith to comment on the integration of the Maintenance
- Rule, License Renewal Rule, and the Reliability Assurance Program.
Mr. Smith said that NUMARC always thought the License Renewal and the Maintenance Rule were related.
NUMARC has established an ad hoc advisory committee to evaluate the two rules and the potential for modifying or interpreting both of the rules as necessary, and to provide recommendations to the NRC.
Regarding reliability i
assurance, Mr. Smith said that they have worked with EPRI in terms j
of reviewing all advanced light water reactor documentation relative to their Design Reliability Assurance Programs.
Mr. Correia, NRR, said that he has the responsibility for both the I
Maintenance Rule and reliability assurance for advanced reactors.
i He noted that they have been working very closely with EPRI and the NSSS vendors for advanced reactors.
One of their key concerns is consistency between the Reliability Assurance Programs and the
r.
Maint. Prac. & Proc. October 6, 1992 Summary / Minutes Maintenance Rule.
In response to a question by Mr.
Carroll regarding license renewal, Mr. Correia said he couldn't respond to j
questions about license renewal because that wasn't in his area of responsibility.
NRC Staff Presentation-Mr. Rothbera. RES Mr. Rothberg said that the NRC Staff's intent was to endorse the NUMARC guidance document without exceptions.
He said that the V & V effort should confirm the case.
If the staff agrees with the V & V effort, there would not be any changes from the NUMARC guidance because it will incorporate the NRC staff thinking.
Mr. Rothberg said that after the Reg. Guide public comment period,-
which ends in March 1993, there may be some changes to the NUMARC 1
maintenance guidance resulting from the V & V program.
Mr. Rothberg said that one of the major elements of the industry guidance is that licensees will identify all SSCs within the scope of the Maintenance Rule.
He noted that the scope of the rule is not subject to a PRA interpretation.
He said that you cannot use PRA to exclude something from the scope of the Maintenance Rule.
Mr. Carroll noted that the personnel working on the License Renewal Rule have the view that things can be removed from the scope of the l
rule on the basis of PRA.
i Mr. Rothberg discussed the Maintenance Rule.
He said that section l
(a)1 concerns establishing goals for SSCs as appropriate.
The l
goals are based on risk significance of the SSCs.
.Section (a)2
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specifies that SSCs will perform their intended function.
Performance is defined as availability, reliability, and condition.
He said that SSCs will be monitored to ensure that the goals are met, and corrective action will be taken if they are not.
He said that enforcement action will be taken if corrective actions are not taken.
He said that the goals will be in terms of availability and reliability.
Mr. Carroll and.the other Subcommittee members asked how they plan.
to measure reliability that is 95 percent or higher.
Mr. Carroll asked how they set goals for the reactor protection system that must be 100 percent reliable and never fail.
Mr.
Smith said that you cannot rely on reliability alone or availability alone, that you have to take into consideration other factors.
He said that you can set goals for availability based on
i A
Maint. Prac. & Proc. October 6, 1992 Summary / Minutes PRA assumptions.
He said that he expected that availability and reliability for risk-significant equipment would be the initial method for goal setting and people will establish the availability to _ perform the function based on their PRA assumptions as a baseline.
Mr.
Rothberg noted that the Maintenance Rule requires that licensees perform periodic assessments of maintenance efforts to ensure maintenance effectiveness.
He said that they intend to change the assessment period from an annual basis to every refueling outage.
Mr. Carroll asked what group in a utility would do this.
Mr. Smith said that it would probably be the lessons learned group with input from the maintenance program.
ACTIONS, AGREEMENTS, AND COMMITMENTS The Subcommittee decided to bring this topic to the full Committee in October 1992, and proposed a proposed report for the Committee's consideration.
NOTE:
Additional meeting details can be obtained from a transcript of this meeting available in the NRC Public Document Room, 2120 L Street, NW, Washington, DC 20006, (202) 634-3273, or can be purchased from Ann Riley and Associates, Ltd.,
1612 K
- Street, NW, Suite
- 300, Washington, DC 20006, (202) 293-3950.
i s-1 ATTACHMENT A MAINTENANCE PRACTICES AND PROCEDURES SUBCOMMITTEE MEETING PHILLIPS BUILDING, ROOM P-110 BETHESDA, MARYLAND OCTOBER 6, 1992 TENTATIVE SCHEDULE Introductory Remarks 8:30 a.m.
(10 Min.)
- J.
Carroll,.. Subcommittee Chairman Draft Regulatory Analysis 8:40 a.m. (45 Min.)
- O.
Rothberg et. al., NRC Maintenance Rule Interrelationships 9:25 a.m. (45 Min.)
with Rules Affecting SSCs
- O. Rothberg et. al., NRC BREAK 10:10 a.m. (15 Min.)
NUMARC Industry Guidelines 10: 2 5 a.m. (30 Min. )
- W.
Smith, NUMARC NUMARC Verification and 10: 55 a.m. (30 Min.)
Validation Process
- W.
Smith, NUMARC Subcommittee Discussion 11:25 a.m. (30 Min.)
Adjourn 11:55 a.m.
l
4 s
4 ATTACHMENT B Documents provided to the subcommittee:
1.
Monitoring the Effectiveness of Maintenance at Nuclear Power Plants, NRC staff 2.
NUMARC Presentation on Maintenance Rule Implementation 3.
A Comparison of Maintenance and License Renewal Rules, J. Roe, NRR 4.
Draft Regulatory Guide for the Implementation of the Maintenance Rule, September 2, 1992 5.
NUMARC 93-01, Rev. 2A, Industry Guidelines _for Monitoring the Effectiveness of Maintenance at Nuclear Power Plants, July 1992 I.
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