[Federal Register Volume 69, Number 75 (Monday, April 19, 2004)]
[Pages 20953-20954]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-8749]



Report on the Independent Verification of the Mitigating Systems 
Performance Index (MSPI) Results for the Pilot Plants

AGENCY: Nuclear Regulatory Commission.

ACTION: Request for comment.


SUMMARY: The Nuclear Regulatory Commission is announcing the 
availability of the draft document entitled: ``Report on the 
Independent Verification of the Mitigating Systems Performance Index 
(MSPI) Results for the Pilot Plants,'' dated February 2004 for review 
and comment by external stakeholders. Interested individuals may obtain 
a copy of this document from ADAMS Accession ML040550036 via the public 
web site, or from the person identified under the caption: FOR FURTHER 

DATES: Submit comments by June 15, 2004. Comments received after this 
date will be considered if it is practical to do so, but the Commission 
is able to ensure consideration only for comments received on or before 
this date.

ADDRESSES: Submit comments to: Chief, Rules and Directives Branch, U.S. 
Nuclear Regulatory Commission, Washington, DC 20555-0001.
    Deliver comments to: 11545 Rockville Pike, Rockville, Maryland, 
between 7:30 a.m. and 4:15 p.m. Federal workdays.
    The draft document and certain other documents related to this 
action, including comments received, may be examined in the NRC Public 
Document Room, 11555 Rockville Pike, Rockville, Maryland.

FOR FURTHER INFORMATION CONTACT: Donald A. Dube, Division of Risk 
Analysis and Applications, Office of Nuclear Regulatory Research, U.S. 
Nuclear Regulatory Commission, Washington, DC 20555-0001. Telephone: 
301-415-5472, e-mail: [email protected].

SUPPLEMENTARY INFORMATION: The Reactor Oversight Process (ROP) was 
created four years ago to improve the NRC's regulatory oversight of 
licensee operation of commercial nuclear power plants. It is intended 
to better risk-inform agency actions and bring more objectivity to the 
regulatory process. The ROP is consistent with the goals of the 
Commission's Probabilistic Risk Assessment (PRA) Policy Statement and 
the NRC's Strategic Plan (NUREG-1614), which include increased use of 
the PRA technology in ``* * * regulatory matters to the extent 
supported by the state-of-the-art in PRA methods and data and in a 
manner that complements the NRC's deterministic approach and supports 
the NRC's traditional defense-in-depth philosophy.'' The ROP is 
reflective of the NRC's efforts to better risk-inform its core 
    SECY-99-007 and 99-007A, ``Recommendations for Reactor Oversight 
Process Improvements,'' described the ROP. The ROP was implemented in 
April 2000 following a six-month pilot program conducted in 1999. The 
results of this pilot program were described in SECY-00-0049, ``Results 
of the Revised Reactor Oversight Process Pilot Program.'' A fundamental 
aspect of the ROP is the use of both performance indicators and 
inspection findings to determine whether the objectives of the ROP's 
cornerstones of safety are being met on a plant-specific basis.
    In light of the movement toward more risk-informed and performance-
based oversight, draft Risk-Based Performance Indicators (RBPI) were 
developed to (1) address specific areas in the current ROP that were 
identified in SECY-00-0049 as possible enhancements and (2) potentially 
support any future development of performance indicators using improved 
risk analysis tools. NUREG-1753, ``Risk-Based Performance Indicators: 
Results of Phase 1 Development,'' discussed the technical feasibility 
of using available risk models and data to enhance the NRC's ability to 
monitor plant-specific safety performance of reactors in a risk-
informed and performance-based manner. This development activity was 
designed to fit into the ROP concept for indicators, thresholds, and 
performance monitoring while continuing to move the NRC's programs 
forward in accordance with the PRA Policy Statement and the goals of 
the Strategic Plan.
    The Mitigating Systems Performance Index (MSPI) builds upon the 
insights and findings developed in the RBPI Program as discussed in 
NUREG-1753. The MSPI is described in ``NRC Regulatory Issue Summary 
2002-14, Supplement 1 Proposed Changes to the Safety System 
Unavailability Performance Indicators,'' Attachments 1 and 2, draft NEI 
99-02, Rev. 0, ``Regulatory Assessment Performance

[[Page 20954]]

Indicator Guideline,'' Section 2.2 ``Mitigating Systems Performance 
Index'' and Appendix F ``Methodologies for Computing the Unavailability 
Index, the Unreliability Index, and Determining Performance Index 
    The MSPI was developed as a potential replacement for the Safety 
System Unavailability (SSU) performance indicator. The purpose of the 
MSPI is to ``monitor the performance of selected systems based on their 
ability to perform risk-significant functions * * *'' The NRC's Office 
of Nuclear Regulatory Research developed the MSPI to address several 
specific problems with the currently used performance indicators 
including: the use of fault exposure hours in the SSU, the omission of 
unreliability elements in the indicator, the use of mostly one-size-
fits-all performance thresholds irrespective of risk-significance of 
the system, and the cascading of support system failures onto 
mitigating system unavailability. A twelve-month pilot program on the 
MSPI consisting of twenty nuclear power plant units was initiated in 
September of 2002. For the first six months, licensees submitted system 
and component performance data, and exercised the MSPI algorithm. Over 
the second six months of the pilot, the NRC staff worked to fully 
assess the results as well as to identify technical issues and to 
provide recommendations for their resolution. Numerous meetings 
involving both internal and external stakeholders have been held to 
discuss developmental details of the MSPI. The MSPI was extensively 
tested, evaluated, and reviewed during the pilot plant trial and 
evaluation period. Although the NRC staff recently announced that use 
of the MSPI in the ROP, as piloted, would not be pursued further, the 
subject draft report is being made available to document the results of 
the NRC evaluation of technical issues and detailed proposed changes to 
the MSPI methodology. The report can be found as ADAMS Accession 
ML040550036 via the NRC public Web site at http://www.nrc.gov. 
A briefing on the results of the MSPI pilot before the Advisory 
Committee on Reactor Safeguards Subcommittee on Reliability and PRA, 
and Plant Operations, is currently scheduled for April 14, 2004 from 8 
a.m. to 11 a.m. at NRC Headquarters in T2B3 of Two White Flint, 
Rockville, MD. Separately, the Office of Nuclear Reactor Regulation 
intends to document the concerns with the piloted MSPI and conduct a 
public meeting to solicit further stakeholder input regarding the MSPI. 
Information regarding this public meeting will be provided at a later 
    At this time, we are interested in comments regarding all aspects 
of the subject report, particularly the following areas:
     Fundamental mathematical formulation of the 
     Recommended improvements to the originally 
formulated MSPI methodology per draft revision to NEI 99-02.
     Overall technical findings and results of the 
MSPI pilot, including validity of MSPI outcomes.

    Dated at Rockville, Maryland, this 7th day of April, 2004.

    For the Nuclear Regulatory Commission.
Charles E. Ader,
Director, Division of Risk Analysis and Applications, Office of Nuclear 
Regulatory Research.
[FR Doc. 04-8749 Filed 4-16-04; 8:45 am]