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POLICY ISSUE
NOTATION VOTE

SECY-07-0184

October 22, 2007

• PURPOSE
• SUMMARY
• BACKGROUND
• DISCUSSION
• COMMITMENTS
• RESOURCES
• COORDINATION

PURPOSE:

To request Commission approval to implement the Baseline Risk Index for Initiating Events (BRIIE), a new performance indicator for the Nuclear Regulatory Commission's (NRC) Industry Trends Program (ITP).

SUMMARY:

The staff proposes to implement the BRIIE, a new performance indicator in the ITP.  NRC staff developed the BRIIE indicator to provide a risk-based index which will serve to assess overall industry performance with regard to the frequency of selected initiating events.  The BRIIE will monitor a number of risk-significant initiating events, assign an importance measure to each event according to the relative contribution of the event to industry core damage frequency, and calculate an integrated, industry-level, risk-based indicator for the initiating events cornerstone.  Once implemented, the staff will include BRIIE results in the annual Commission paper on the ITP results.

BACKGROUND:

Since the ITP was initiated, the staff has looked to incorporate risk information into the ITP.  In SECY-01-0111, "Development of an Industry Trends Program for Operating Power Reactors," the staff stated that they were working to develop a more objective, predictable approach to establishing risk-informed thresholds used to assess trends in indicators and to determine the appropriate agency response.  In the staff requirements memorandum related to SECY-01-0111, dated August 2, 2001, the Commission directed the staff to develop risk-informed thresholds for the industry-level indicators "as soon as practicable."

In SECY-02-0058, "Results of the Industry Trends Program for Operating Power Reactors and Status of Ongoing Development," dated April 1, 2002, the staff reported on the development of additional risk-informed indicators for the initiating events cornerstone, consisting of multiple indicators of initiating events for both pressurized water reactors (PWRs) and boiling water reactors (BWRs). This effort involved updating the data that were most recently published in NUREG/CR-5750, "Rates of Initiating Events at U.S. Nuclear Power Plants: 1987B1995."

At this point, the staff determined that a single indicator, which combines the initiating events, would be more effective than having numerous indicators for each type of initiating event.  During Fiscal Year (FY) 2002, the staff built on the prior work by developing an overall industry-level indicator. This overall indicator of initiating events, initially called the Industry Initiating Events Performance Indicator (IIEPI), consisted of an index of the most risk-significant industry initiating events.  This set of events is defined in NUREG-1753, "Risk-Based Performance Indicators:  Results of Phase 1 Development," as those events that contribute more than one percent to industry core damage frequency and that have occurred at least once between 1987 and 1995.

The electric grid blackout event of 2003 temporarily redirected staff attention and suspended development work.  Work resumed in FY 2006.  The result of the staff's efforts was the development of:  (1) an index for BWRs that monitors nine risk-significant initiating events; and (2) a similar index for PWRs that monitors 10 events (the additional event category is steam generator tube rupture).  The index weighs each initiating event according to its relative contribution to industry core damage frequency.  The indicator was renamed BRIIE, the baseline risk index for initiating events.

The BRIIE development effort has benefited from stakeholder interaction which included:  (1) a request for public review of a draft version of the BRIIE and the resolutions of comments received through the public review process; (2) a detailed presentation to the Advisory Committee on Reactor Safeguards on May 7, 2003, on the draft BRIIE methods and results with additional comments and suggestions for final development of the BRIIE; and (3) a public workshop on the draft BRIIE methodology held at NRC Headquarters on July 30, 2003.  That interaction also resulted in stakeholder feedback concerning the draft BRIIE.

In addition, the BRIIE benefited from work leading up to implementation of the Mitigating System Performance Index in 2006.  The MSPI included a significant effort to address issues related to the quality of licensee probabilistic risk assessment models and the NRC's Standardized Plant Analysis Risk (SPAR) models.  That work led to a comprehensive program to upgrade the SPAR models based on cut-set-level comparisons with licensee risk models.  This helped to improve the Birnbaum importance measures (a measure of the risk of each initiating event) used in the BRIIE and ensured that they are adequate for this application.

DISCUSSION:

The NRC staff implemented the ITP in 2001 and uses the ITP industry-level indicators to monitor for adverse trends in industry performance.  Should adverse trends arise, further staff evaluation of the likely causes would follow, and if appropriate, changes to the NRC regulatory framework could be made.

The BRIIE concept uses a three-step process to enhance the ITP:

A summary description of the BRIIE is provided in the enclosure .  A detailed description and the technical basis for the BRIIE is in NUREG/CR-6932 (INLEXT-06-11950), "Baseline Risk Index for Initiating Events (BRIIE)," published in June 2007.  The BRIIE has now been developed to the point that it is ready to be incorporated into the ITP.  Data collection for the BRIIE has been ongoing as part of the development effort.

One important output of the ITP is the annual agency performance measures reported to Congress on the number of statistically significant adverse industry trends in safety performance.  This outcome measure is part of the NRC Performance and Accountability Report.  The threshold for reporting BRIIE results to Congress as part of the adverse industry trends metric has been set at a value of 1x10^-5 per reactor critical year and it is associated only with the ΔCDF BRIIE calculations for industry-wide results. This threshold value was arrived at from considerations of the NRC safety goals, RG 1.174, and consistency with the ROP and Accident Sequence Precursor (ASP) programs.  As an industry-wide indicator, the BRIIE is not an input to the Reactor Oversight Process (ROP) Action Matrix, and will not directly affect NRC oversight of individual plants.

NRC Inspection Manual Chapter 0313, "Industry Trends Program," contains ITP details, including program descriptions and definitions of the indicators.  BRIIE will be included in this Inspection Manual Chapter.

As part of BRIIE implementation, the staff has also developed a communication plan to inform NRC internal and external stakeholders of the use of BRIIE as a new, industry-wide indicator. 

The staff will use available NRC communication tools such as Congressional Reports (NUREG-1100 and NUREG-1542), Commission Papers, Public Meetings/Workshops, the Regulatory Information Conference, and the NRC Web site.  These will ensure that the following key messages are clearly communicated:

• The NRC's highest priority is protection of public health, safety, and the environment.

• The BRIIE is intended to enhance and complement the ITP, not as a replacement for the ITP.

• The NRC staff has undertaken efforts that will enhance the accuracy, effectiveness, and efficiency of the ITP and the process to evaluate nuclear industry safety performance.

• The BRIIE indicator of nuclear industry safety performance provides a mechanism for determining the risk significance of changes in industry performance at both the individual initiating event level and at the integrated cornerstone of safety level.

• The BRIIE concept consists of a two-tier process. The first tier provides short-term trending information and an action point for NRC engagement. The second tier provides a risk perspective of industry performance as a change from a baseline CDF value.

The communication plan includes a matrix that identifies:  (1) the internal and external stakeholders; (2) the information needs of the various stakeholders; (3) the way the information will be communicated to the stakeholders; (4) the date and frequency at which the information will be communicated; and (5) the person(s)/groups responsible for communicating the information to the stakeholders.  This communication plan is currently available on the NRC internal Web page at http://www.internal.nrc.gov/communications/plans/active-plans.html.

COMMITMENTS:

Upon Commission approval, the staff will incorporate the BRIIE into NRC Inspection Manual Chapter 0313 and will formally use BRIIE results as an ITP indicator, starting with the annual Commission paper on the FY 2007 ITP results (to be issued in early 2008).

RESOURCES:

The data needed for BRIIE calculation are already being collected as part of the ITP.  No new data collection is necessary.  In FY 2008, for the Office of Nuclear Reactor Regulation, $450,000 and 0.5 full-time equivalents (FTE) are needed to support ITP and BRIIE implementation.  Currently, $325,000 and 0.5 FTE are budgeted.  The remaining $125,000 needed for contractor support of the ITP will be reallocated from lower priority work in the ROP.  For FY 2009, approximately $475,000 for contractor support and 0.5 FTE are needed and are included in the FY 2009 budget request.  The NRC Office of Nuclear Regulatory Research (RES) provides indirect support to the ITP in the areas of operating experience data, and models developed and budgeted under other RES programs such as the SPAR Program and the Reactor Operating Experience Data Collection and Analysis Program.

COORDINATION:

The Office of the General Counsel has reviewed this paper and has no legal objection.  The Office of the Chief Financial Officer has reviewed this paper for resource implications and concurs.

Enclosure:

Baseline Risk Index for Initiating Events

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