ML993500387

Meeting Summary for 10/6/99 and 11/10/99 Meetings with Risk-Informed Technical Specifications Task Force

ML993500387
Person / Time
Issue date:	12/14/1999
From:	Beckner W Technical Specifications Branch
To:	Brooks A Nuclear Energy Institute
Gilles N, NRR/DRIP, 415-1180
References
Download: ML993500387 (3)

Text

December 14, 1999 Mr. Anthony Brooks Nuclear Energy Institute Suite 400 1776 I Street, NW Washington, DC 20006-3708 Mr. Brooks:

The purpose of this letter is to transmit the summary of two meetings with the Risk-Informed Technical Specifications Task Force. The first meeting was held at the San Onofre Nuclear Generating Station on October 6-7, 1999. The second meeting was held at the U.S. Nuclear Regulatory Commission (NRC) Headquarters offices in Rockville, Maryland, on November 10, 1999.

Sincerely, Original signed by:

William D. Beckner, Chief Technical Specifications Branch Division of Regulatory Improvement Programs Office of Nuclear Reactor Regulation

Enclosures:

1. Meeting Summary

2. Attendance List

3. October Meeting Presentations

4. November Meeting Presentations cc: See attached list

December 14, 1999 Mr. Anthony Brooks Nuclear Energy Institute Suite 400 1776 I Street, NW Washington, DC 20006-3708 Mr. Brooks:

The purpose of this letter is to transmit the summary of two meetings with the Risk-Informed Technical Specifications Task Force. The first meeting was held at the San Onofre Nuclear Generating Station on October 6-7, 1999. The second meeting was held at the U.S. Nuclear Regulatory Commission (NRC) Headquarters offices in Rockville, Maryland, on November 10, 1999.

Sincerely, Original signed by:

William D. Beckner, Chief Technical Specifications Branch Division of Regulatory Improvement Programs Office of Nuclear Reactor Regulation

Enclosures:

1. Meeting Summary

2. Attendance List

3. October Meeting Presentations

4. November Meeting Presentations cc: See attached list DISTRIBUTION: See attached.

DOCUMENT NAME: G:\RTSB\GILLES\MTGSUMRITSTF111099.WPD OFFICE NRR/DRIP/RTSB NRR/DRIP/RTSB NRR/DRIP/RTSB NAME NVGilles RLDennig WDBeckner DATE 12/14/99 12/14/99 12/14/99 OFFICIAL RECORD COPY

Multiple Addressees December 14, 1999 cc:

Mr. Alan Hackerott Mr. Dennis Henneke Omaha Public Power District San Onofre Nuclear Generating Station Ft. Calhoun Nuclear Station Southern California Edison P.O. Box 399 5000 Pacific Coast Highway Ft. Calhoun, NE 68023-0399 San Clemente, California 92674-0128 Mr. Noel Clarkson Ms. Sharon Mahler Duke Energy/Oconee Cooper Nuclear Station Mail Code: 0N03RC Nebraska Pulic Power District Highways 130 & 183 (29678) P.O. Box 98 P.O. Box 14393652 Brownville, NE 68321-0098 Seneca, SC 29679-1439 Mr. Frank Rahn Mr. Greg Krueger Electric Power Research Institute PECO Energy Company P. O. Box 10412 Mail Code 63A-3 Palo Alto, CA 94303 965 Chesterbrook Boulevard Wayne, PA 19087 Mr. Donald Hoffman EXCEL Services Corporation Mr. Wayne Harrison 11921 Rockville Pike, Suite 100 South Texas Project Electric Generating Rockville, MD 20852 Station STP Nuclear Operating Company Mr. Jack Stringfellow P. O. Box 289 Southern Nuclear Operating Company Wadsworth, TX 77483 P.O. Box 1295 Birmingham, AL 35201-1295

Multiple Addressees December 14, 1999 DISTRIBUTION:

E-Mail w/o Enclosures 3 & 4 SCollins/RPZimmerman JJohnson BWSheron DBMatthews SFNewberry GMHolahan WDBeckner RJBarrett RLDennig FMReinhart MLWohl NTSaltos TSB Staff JAZwolinski JFWilliams AWMarkley MACunningham, RES MMarkley, ACRS Staff HARD COPY FILE CENTER PUBLIC TSB R/F NVGilles

NRC/INDUSTRY MEETING OF THE RISK-INFORMED TECHNICAL SPECIFICATION TASK FORCE Meeting Summaries October 6-7 and November 10, 1999 Two meetings between the NRC staff and industry representatives comprising the Risk-Informed Technical Specifications Task Force (RITSTF) were held on October 6-7 and November 10, 1999. The attendees are listed in Enclosure 2. The meetings were a continuation of earlier meetings where the NRC staff and the industry discussed ongoing risk-informed technical specification initiatives and the creation of a fully risk-informed set of standard technical specifications (STS).

The main purpose of the October 6-7 meeting was to have a more detailed discussion of the probabilistic risk analysis (PRA) work done to support the current technical specification (TS) initiatives being prepared for submittal to the staff. There was limited RITSTF representation at this meeting. Southern California Edison has volunteered San Onofre Nuclear Generating Station (SONGS) to be the industrys lead plant for the majority of the seven initiatives currently being pursued by the RITSTF. These include:

1. Define preferred end states for TS actions (e.g., hot shutdown vs. cold shutdown)

2. Increase the time allowed to delay entering required actions when a surveillance is missed

3. Modify existing mode restraint logic to allow use risk assessments for entry into limiting conditions for operation (LCOs) with inoperable equipment based on low risk

4. Develop a risk-informed extension of current allowed outage times based on a configuration risk management program (CRMP)

5. Optimize surveillance requirements (SRs)

6. Modify LCO 3.0.3 actions and timing by extending minimum time to begin LCO 3.0.3 shutdown from 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> and allowing for a risk-informed evaluation to determine whether it is better to shut down or continue to operate

7. Define actions to be taken when equipment is not operable but is still functional The staff and the industry discussed the meaning of the term risk-informed as it relates to regulatory applications. The industry stated that it was their general philosophy to use qualitative risk assessments where they believed the benefits of a proposed change were obvious, and to use quantitative assessments where the outcome was not as obvious. The industry also stated that they take into account other aspects such as defense in depth and safety margins when considering a proposed change. The industry believed such an approach was consistent with the guidance in Regulatory Guide 1.174, An Approach for Using Probabilistic Risk Assessment in Risk-Informed Decisions on Plant-Specific Changes to the Licensing Basis, to use PRA to improve decision making and regulatory effectiveness. The staff reserved judgement of such an approach noting that benefits that are obvious to one person or group might not be obvious to another.

SONGS representatives then presented some details regarding their PRA work in support of some of the RITSTF initiatives. The San Onofre presentations are contained in Enclosure 3.

The SONGS representatives presented information regarding their living PRA and Safety Monitor, including the full power, transition, and low power and shutdown risk models. The SONGS representatives stated that they had their own transition model development document 1 Enclosure 1

that would likely be referenced or included in the SONGS plant-specific submittal for Initiative

1. 1.

The staff and the RITSTF discussed some specific submittal and implementation and technical issues related to a few of the initiatives. With regard to Initiative #1 related to safe end states, the RITSTF indicated that the Combustion Engineering Owners Group (CEOG) was preparing a draft report to support this initiative and that the report would accompany an industry request for a generic change to the STS. The RITSTF indicated that changes to the TS end states would be proposed for the vast majority of LCOs in the STS. The RITSTF indicated that uncertainties and sensitivities of PRA results will be investigated. The group discussed that additional known shutdown issues which may impact the results (e.g., external events and boron dilution) should be addressed.

Representatives from the Boiling Water Reactor Owners Group (BWROG) stated that they are still considering this initiative and that the risk of operating in hot shutdown and in cold shutdown is relatively the same, whereas for the pressurized water reactors there appears to be a clear risk benefit to operating in hot shutdown in most cases. They indicated that they would be more interested in changing the current TS to allow them to use PRA in deciding whether to stay at power or shut the reactor down. They also indicated that they may be interested in extending the time requirements for going to cold shutdown. This would allow them to operate longer in hot shutdown conditions. The BWROG is considering a pilot plant for this issue.

The RITSTF and the staff discussed how the SONGS assessment results for Initiative #1 could be applied to other plants. The Westinghouse Owners Group (WOG) indicated that they would attempt to show how the SONGS results apply using qualitative assessments and comparisons, and that they did not plan to perform any further plant-specific analyses. The Babcock and Wilcox Owners Group indicated that they intended to pursue a similar approach. The group indicated that they could use the SONGS model to help develop sensitivity studies to address some of the design differences between the plants. The staff stated that they could not make any definitive decisions on what type of submittals they would find acceptable and that the burden of proof of similarity to the CEOG work would rest with the other owners groups.

With regard to Initiative #2 related to missed SRs, the group discussed the PRA aspects of that initiative. In order to assess the increase in risk it is necessary to make an assumption about the frequency of the various expected missed surveillances. This requires an understanding of the reasons, the nature and circumstances under which surveillances are missed. The RITSTF pointed out that even if the failure rate of a component is doubled, due to the missed surveillance on that component, the plant risk would not be affected significantly. The staff agreed that most likely the risk increase would not be significant unless some licensees abuse the proposed flexibility. The development and implementation of an appropriate regulatory oversight process could address this issue. The industry and the staff agreed that the staffs review of this issue would involve more of a policy decision than a technical decision.

With regard to Initiative #3 related to mode restraints, SONGS has been studying this issue by comparing the relative importance of functions and associated systems at various modes of operation. The proposed change would allow a licensee to use a CRMP to decide whether to enter into a mode or other specified condition within the applicability with inoperable equipment.

The staff agreed that the study of conditions and risks associated with various likely transitions could help focus the issue and identify an appropriate regulatory oversight mechanism.

2 Enclosure 1

With regard to Initiative #6 related to changes to LCO 3.0.3, the RITSTF stated that this initiative is very closely tied to the maintenance rule as it addresses what actions to take for a loss of safety function. The industry indicated that the frequency of plant conditions for which this TS change is applicable is low. The staff mentioned that the identification and study of examples of plant specific LCO 3.0.3 entries and conditions that would drive the plant to shutdown, including associated risks, could help focus the issue.

The group discussed the process for plants to adopt approved changes to the STS. The staff briefly discussed processes being considered to make adoption of such approved changes more efficient.

Finally, the group discussed submittal schedules for some of the initiatives. The RITSTF stated that they expected to submit Initiatives #2 and #3 to the staff around October 30, 1999, and that they might be able to submit some of their PRA assessment for Initiative #1 by December 31, 1999. The RITSTF stated that Initiatives #4 and #6 would come sometime in 2000.

The November 10, 1999 meeting was a meeting of the full RITSTF to discuss high-level objectives and the status of the current initiatives. All presentations for the meeting are contained in Enclosure 4. The staff opened the meeting with a general discussion of the status of risk-informed regulatory activities at the NRC. The staff pointed out that there was a high level of interest in the RITSTF activities and that we needed to understand how broad the interest in the industry was. The staff presented several thoughts on a long-term vision for risk-informed TS and acknowledged that structure and resource issues will need to be worked out.

The staff also pointed out that it will need to address the four strategic performance goals identified in the Commissions Nuclear Reactor Safety Strategic Plan. Those performance goals are: (1) Maintain safety; (2) Increase public confidence; (3) Reduce unnecessary regulatory burden; and (4) Make NRC activities and decisions more effective, efficient, and realistic.

The RITSTF presented some of its thoughts on a long-term vision for risk-informed TS. Much of the discussion focused on a slide which presented the Westinghouse Owners Group (WOG) five year risk-informed TS strategy. The group discussed at what point rulemaking might be needed to accommodate all of the envisioned changes to TS. The group also discussed the issue of PRA quality and the fact that the ASME PRA standard currently being developed did not address configuration risk management tools like those envisioned as necessary to implement many of the TS changes under development.

Representatives from the South Texas Project presented a concept of a fully risk-informed set of TS that essentially relies on a CRMP as the backbone of the TS. They likened the proposed risk limits in their concept to radiation protection limits (i.e., ALARA limits). The NRC regulates ALARA limits at a high level and licensees control these limits at a lower level administratively.

The group also discussed whether there was a need for an instantaneous risk cap for TS. The RITSTF stated that the major question is the cost benefit of going to this extreme. For example, if plant PRAs essentially become the TS, then licensees would have to control changes to the PRA model to the same degree as TS changes are currently controlled.

The RITSTF presented a status of the seven initiatives currently under development. The group discussed Initiative #1 related to safe end states. The RITSTF stated that the expected results were confirmed by the PRA work done by SONGS. The group again discussed what work the other owners groups planned to do to justify the changes for their plant types by taking 3 Enclosure 1

advantage of the SONGS and CEOG work.

Updated schedules for the various initiatives were discussed. The RITSTF stated that they expected to submit Initiative #1 in February or March 2000. Initiatives #2 and #3 were expected to be submitted in the very near future. Initiative #4 was planned for submittal in late 2000.

Initiatives 5, 6, and 7 were also expected in mid to late 2000.

The group briefly discussed the staffs planned process for reviewing and adopting these initiatives as changes to the STS. The group also discussed support for the December 16, 1999 meeting with the Advisory Committee for Reactor Safeguards Reliability and PRA Subcommittee and agreed to a possible future meeting in late February 2000.

4 Enclosure 1

Meeting Attendees October 6-7, 1999 Name Affiliation Dennis Henneke Southern California Edison Sharon Mahler Southern California Edison Gary Chung Southern California Edison Brian Woods Southern California Edison Thomas Hook Southern California Edison Ed Scherer Southern California Edison Don McCamy Tennessee Valley Authority Kent Sulton Nebraska Public Power District S. Visweswaran General Electric Thomas Sihko Vermont Yankee Jerry André Westinghouse Mike Kitlan Duke Power Rick Wachowiak Nebraska Public Power District Frank Rahn Electric Power Research Institute Nicholas Saltos NRC/NRR/SPSB Millard Wohl NRC/NRR/SPSB Nanette Gilles NRC/NRR/RTSB

ÿýüûúø÷ Enclosure 2

Meeting Attendees November 10, 1999 Name Affiliation Ray Schneider ABB-Combustion Engineering Nuclear Fuel Company Alan Hackerott Omaha Public Power District Dennis Henneke Southern California Edison Sharon Mahler Southern California Edison Biff Bradley Nuclear Energy Institute Noel Clarkson Duke Power Wayne Harrison South Texas Project Rick Grantom South Texas Project Donald Hoffman EXCEL Services Jerry André Westinghouse Jim Andrachek Westinghouse Jack Stringfellow Southern Nuclear Don McCamy Tennessee Valley Authority E. D. Ingram Southern Nuclear Glenn Warren BWR Owners Group David Stellfox McGraw Hill John Fehringer INEEL J. E. Rhoads Energy Northwest Richard Harris Entergy Mike Kitlan Duke Power Rodney Johnson Detroit Edison Bert Morris Tennessee Valley Authority Gregory Norris Entergy Rick Wachowiak Nebraska Public Power District Scott Newberry NRC/NRR/DRIP Rich Barrett NRC/NRR/SPSB Mark Reinhart NRC/NRR/SPSB Mark Rubin NRC/NRR/SPSB Millard Wohl NRC/NRR/SPSB Nick Saltos NRC/NRR/SPSB William Beckner NRC/NRR/RTSB Bob Dennig NRC/NRR/RTSB Jack Foster NRC/NRR/RTSB Nanette Gilles NRC/NRR/RTSB

ÿýüûúø÷ Enclosure 2

ENCLOSURE 3 OCTOBER 6-7, 1999 MEETING PRESENTATIONS

ÿýüûúø÷ Enclosure 2

ENCLOSURE 4 NOVEMBER 10, 1999 MEETING PRESENTATIONS

ÿýüûúø÷ Enclosure 2