FAQ
    
    AGREEMENT STATES
    
    Facility Locator
    
    What's New
    
    Site Help
    
    Index A-Z
    
    Contact Us
    
    Email Updates
      
      
      
      
       
      Report a Safety Concern
                  Search
        Nuclear Reactors
  
  Power Reactors
Research & Test ReactorsOperating Reactors
New ReactorsOperator Licensing
Research ActivitiesNuclear Reactor Quick LinksNuclear Materials
  
  Types of Nuclear Materials
Fuel Cycle Facilities
Medical, Industrial, & Academic UsesUranium Recovery
Materials TransportationMaterials Environmental Reviews
National Materials ProgramNuclear Materials Quick LinksRadioactive Waste
  
  Decommissioning of Nuclear Facilities
Low-Level Waste
Waste Incidental to Reprocessing
High-Level WasteUranium Mill Tailings
Low-Level Waste Disposal
High-Level Waste DisposalStorage of Spent Nuclear Fuel
Transportation of Spent Nuclear Fuel
Research ActivitiesRadioactive Waste Quick LinksNuclear Security
  
  Domestic Safeguards
Information Security
Radioactive Material SecurityRequired Reporting for Clearance Holders
Insider Threat Program for Licensees
CybersecurityCriminal History & Firearms Checks
Contact UsPublic Meetings & Involvement
  
  The NRC Approach to Open Government
About Meetings Open to the Public
Conferences & SymposiaDocuments for Comment
NRC Rules and Petitions
Facilitating Stakeholder InvolvementNRC Information Quality Guidelines
Subscribe to E-mail UpdatesCommission Schedule
Public Meeting ScheduleAdjudications (Hearings)
Adjudicatory SubmissionsNRC Library
  
  Basic References
Document Collections
ADAMS Public Documents
Public Document Room
LSN LibraryFOIA & Privacy Act
Photos & Videos
Records Management
Training CoursesFAQ Index
Get Copies of Documents
Withholding of Sensitive Information
Controlled Unclassified Information Program (CUI)Electronic Hearing DocketAbout NRC
  
  The Commission
Organization & Functions
Governing Legislation
Plans, Budget, & Performance
Locations
History
Values
Direction-Setting & Policymaking
Research Activities
Radiation ProtectionFire Protection
Safety Culture
How We Regulate
Emergency Preparedness & Response
Public Affairs
Congressional Affairs
Enforcement
International Programs
State & Tribal ProgramsAlternative Dispute Resolution Programs
Privacy Program
Civil Rights Program
Contact Us
Career Opportunities
Contracting Opportunities
Small Businesses
Grant Opportunities
Generic SchedulesOther Links
  
  FAQ
Glossary
Facility Locator
What's NewSite Help
Index A-Z
Contact Us
Email UpdatesNRC Facebook
NRC Twitter Feed
NRC Linkedin
NRC Youtube Channel
NRC Flickr Gallery
NRC Blog Archived
NRC Email Subscriptions - GovDelivery Home
          NRC Library  Document Collections  NUREG-Series Publications  Publications Prepared by NRC StaffIndependent Verification of the Mitigating Systems Performance Index (MSPI) Results for the Pilot Plants (NUREG-1816)

On this page: Publication Information AbstractDownload complete document NUREG-1816 (PDF - 1.33 MB)Publication Information **Manuscript Completed:**October 2004**Date Published:**February 2005 **Prepared by:** D.A. Dube (NRC Project Manager)1, C.L. Atwood2, S.A. Eide3, B.B. Mrowca4, R.W. Youngblood4, D.P. Zeek3 2Statwood Consulting 2905 Covington Road Silver Spring, MD 20910 3Idaho National Laboratory P.O. Box 1625 Idaho Falls, ID 83415-3850 4ISL, Inc. 11140 Rockville Pike Rockville, MD 20852 **Prepared for:**1Division of Risk Analysis and Applications Office of Nuclear Regulatory Research U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 NRC Job Codes J8263 and Y6370/Y6636 Availability Notice Abstract In its Reactor Oversight Process (ROP), the U.S. Nuclear Regulatory Commission (NRC) currently uses performance indicators to quantify safety system unavailability (SSU) for four important nuclear power plant systems. Over time, the NRC staff has identified a number of concerns related to the use of these indicators, including the use of short-term unavailability to approximate unreliability, the use of generic performance thresholds irrespective of variations in risk significance, and potential double-counting as a result of support system failures cascading onto front line systems. Moreover, the way the SSU indicators currently measure unavailability is inconsistent with the definition in the NRC's Maintenance Rule, as well as the indicators promulgated by the World Association of Nuclear Operators and the Institute of Nuclear Power Operations. This report describes the background, technical issues, and pilot project leading to the development of a more risk-informed performance indicator, known as the Mitigating Systems Performance Index (MSPI). The MSPI addresses most of the concerns related to the use of the current indicators. The NRC staff extensively tested and improved the MSPI methodology during a 12-month pilot plant application phase that involved 20 nuclear power plant units of varying design. The staff also evaluated technical issues related to the new indicator's sensitivity to probabilistic risk assessment (PRA) modeling detail. In addition, the staff compared the MSPI results to the existing indicators, as well as findings from the significance determination process (SDP). The analysis indicates that the MSPI appears to consistently provide a better measure of integrated system performance than the current SSU performance indicators. 
      
      Page Last Reviewed/Updated Tuesday, March 09, 2021  Home
NEWS RELEASES

EVENT REPORTS

ADAMS

OPEN GOV

DIGITAL GOVERNMENT

THE STUDENT CORNER

PHOTOS & VIDEOS

FOR DEVELOPERS
        About Us
STRATEGIC PLAN

BUDGET & PERFORMANCE

AGENCY FINANCIAL REPORT

LICENSE FEES

HISTORY OF THE NRC

CAREER OPPORTUNITIES

NRC ETHICS

AGENCY STATUS

CONTACT US
        Popular Documents
INFO DIGEST

FACT SHEETS & BROCHURES

FORMS

ELECTRONIC SUBMITTALS APPLICATION

ADJUDICATORY SUBMISSIONS

NRC REPORTS - NUREG

NRC REGULATIONS - 10-CFR

INSPECTION REPORTS

PLAIN WRITING

ENFORCEMENT ACTIONS

RULEMAKING

GLOSSARY
        Stay Connected
    
    
    
    
    United States Nuclear Regulatory Commission
    
    
    
    
    Regulations.gov

USA.gov

FOIA

Whistleblower Protection

No Fear EEO

Inspector General

Site Map

Accessibility

Privacy Policy

Site Disclaimer

For Employees