ML20126H283
| ML20126H283 | |
| Person / Time | |
|---|---|
| Issue date: | 12/23/1992 |
| From: | Taylor J NRC OFFICE OF THE EXECUTIVE DIRECTOR FOR OPERATIONS (EDO) |
| To: | Rogers, Selin I, The Chairman NRC COMMISSION (OCM) |
| References | |
| NUDOCS 9301050129 | |
| Download: ML20126H283 (5) | |
Text
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UNITED STATES n
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December 23, 1992 MEMORANDUM FOR:
The Chairman Commissioner Rogers Commissioner Curtiss Commissioner Remick Commissioner de Planque FROM:
James M. Taylor Executive Director for Operations
SUBJECT:
RISK INSIGHTS IN TECHNICAL SPECIFICATIONS The purpose of this memorandum is to provide a report on risk applications for technical specifications. This action was originally prompted by a question in a Staff Requirements Memorandum, dated June 28, 1990, regarding the provisions to address shutdown risk in the development of risk-based technical specifications, in memoranda dated July 27, 1990 and May 23, 1991, I provided interim status reports on the activities related to the Technical Specification Improvement Program (TSIP).
The Commission issued its interim " Policy Statement on Technical Specification Improvements for Nuclear Power Reactors" on February 6, 1987. The policy statement provides an environment in which risk insights can be applied to modify technical specification requirements which themselves are retained in a deterministic framework. Based on the policy statement, each of the four nuclear steam supply system (NSSS) owners groups proposed to the staff which requirements in their current standard technical specifications (STS) could be relocated to licensee-controlled documents.
The staff reviewed the proposals against the interim policy statement criteria, which include qualitative and semi-quantitative risk considerations, and determined which requirements of greater safety significance must be retained in the-new STS. The application of the criteria in the policy statement resulted in relocation of about forty percent of the original Limiting Conditions for Operation (LCOs) to licensee controlled documents.
A number of completion times and surveillance intervals 'in technical specifications have been relaxed based on NRC staff-approved topical reports and on draft NUREG-1366, " Improvements to Technical Specifications Surveillance Requirements,"
In their topical reports justifying the relaxations, the NSSS vendors based their conclusions on quantitative risk insights.
NUREG-1366 used qualitative rather than quantitative risk insights to support such relaxations.
These and other technical specification improvements have been, and will continue to be, offered as line-item-
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improve e t eneric implementation.
Contact:
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1 The Commissioners December 23, 1992 Risk insights will be used by licensees in implementing the Maintenance Rule.
Probabilistic safety assessment (PSA) will be used to balance reliability with availability as a performance goal within the framework of this rule, PSA will be used to establish goals and to monitor achievements with respect to these goals to determine the effectiveness of maintenance activities.
In this regard, PSA may al a be used to rank systems, structures, and components (SSCs) in order of risk-importance.
The performance of SSCs could then be evaluated with respect to PSA-based performance goals.
An example of a similar application is the use of the PSA-structured Essential Systems Status Monitor (ESSM) at the Heysham B plant in the United Kingdom.
ESSM is a quasi-real-time configuration management and risk analysis system.
One use of the system is as a maintenance planning tool to prevent and control high plant risk configurations.
Southern California Edison is developing a similar system for trial use at San Onofre Units 2 and 3 which will include maintenance planning uses.
The staff will continue to monitor industry efforts to apply risk insights.
Future efforts and new initiatives in these areas will be integrated into any recommendations from the Regulatory Review task group described in my December 4, 1992 memorandum. A proposed final policy statement on technical specification improvements will be provided to the Commission in February 1993.
Or%)ttel signed by James M. Taylor James M. Taylor Executive Director for Operations cc:
SECY OGC DI STR lLU.J_LON:
See next page Document Name:
G:\\RISKINSI.REV OFC C:0TSB:00RS D: DORS NAME CIGrimes*
BKGrimes*
- See previous concurrence DATE 12/17/92 12/17/92
-~il OfC D:PMAS ADT:NRR ADP:NRR D:NRR ED0g l
NAME FPGillespie*
WTRussell*
JGPartlow*
TEMurley*
JMT lor DATE 12/17/92 12/18/92 12/18/92 12/21/92 12/Q/92 4
DISTRIBUTIQH:
PDR CEJohnson, Jr.
Central files Elois OTSB Staff JHConran JMTaylor VMMcCree JHSniezek JLieberman TEMurley ELJordan FJMiraglia PABoehnert JGPartlow MESchwartz BKGrimes ESBeckjord ClGrimes NRR Mailroom (WITS #9000169)
WIRussell CSGrimes, SECY (M900608)
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,a The-Commissioners December 23, 1992 Risk insights-will be used by licensees in implementing the Maintenance Rule.
Probabilistic safety assessment (PSA) will.be used to balance reliability with availability as a performance goal.within the framework of-this rule.
PSA-will be used to establish goals and to monitor achievements with respect to-these goals to determine the effectiveness of maintenance activities, in this regard, PSA may also be used to rank systems, structures, and components (SSCs) in order of risk-importance. The performance of SSCs could then be evaluated-with respect to PSA-based performance goals.
An example of a similar application is the use of the PSA-structured Essential Systems Status Monitor (ESSM) at the Heysham B plant in the United Kingdom.
ESSM is a quasi-real-time configuration management and risk analysis system.
One use of the system is as a maintenance planning tool to prevent and control high plant risk configurations.
Southern California Edison is developing a similar system for trial use at San Onofre Units 2 and 3 which will include maintenance planning uses.
The staff will continue to monitor industry efforts to apply risk insights.
Future efforts and new initiatives in these areas will be integrated in_to any recommendations from the Regulatory Review task group described in my December 4, 1992 memorandum.
A proposed final policy statement on technical specification improvements will be provided to the Commission in february 1993.
Originalsigned by James M. Taylor James M. Taylor Executive Director for Operations cc:
SECY OGC DISTRIBUTION:
See next page.
Document Name:.G:\\RISKINSI.REV 0FC C:0TSB:00RS D: DORS
.NAME CIGrimes*
BKGrimes*
- See previous concurrence DATE 12/17/92 12/17/92 f UFC D:PMAS ADT:NRR ADP:NRR D:NRR E00g NAME FPGillespie*
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JMT lor DATE
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Q1STRIBUTION; PDR-CEJohnson, Jr.
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WTRussell 000 rimes, SECY (M900608)
DMCrutchfield ORSB R/F SAVarga DORS R/F JWRoe EDO R/F ACThadani JERichardson CERossi FJCongel BABoger FPGillespie ATGody, Sr.
JAcalvo GClainas JAZwolinski MJVirgilio JANorberg GCagchi CHBerlinger CEMcCracken RCJones-WDBeckner:
KMCampe GGZech SFNewberry JSWermiel RMGallo LCunningham-GHMarcus AEChaffee SHWeiss TLKing-