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Operating Reactor Oversight
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Detailed ROP Description
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Industry Trends

The NRC initiated the Industry Trends Program (ITP) to monitor trends in indicators of industry performance as a means to confirm that the safety of operating power plants is being maintained. Should any long term indicators show a statistically significant adverse trend, the NRC will evaluate them and take appropriate regulatory action using its existing processes for resolving generic issues and issuing generic communications. The NRC formally reviews these indicators as part of the Agency Action Review Meeting (AARM) each year, and any statistically significant adverse trends are reported to Congress in the NRC's Performance and Accountability Report.

No statistically significant adverse trends have been identified through the end of fiscal year (FY) 2007, based on the ITP indicators and the Accident Sequence Precursor (ASP) program.

The objectives and details of the ITP are contained in NRC Inspection Manual Chapter (IMC) 0313 . The annual results of the ITP are available in the SECY Commission Papers as summarized below.

Time Period Commission Paper
FY 2007 SECY-08-0041
FY 2006 SECY-07-0063
FY 2005 SECY-06-0076
FY 2004 SECY-05-0069
FY 2003 SECY-04-0052
FY 2002 SECY-03-0057
FY 2001 SECY-02-0058
Program Development SECY-01-0111

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Performance Indicators Used in the ITP

The NRC currently uses 4 distinct sets of indicators to assess trends in industry performance as described below. The specific indicators included in the ITP are highlighted below in bold text.

The definition and description of the indicators currently qualified and used in the ITP are available in Appendix A of IMC 0313.

(1) ITP Performance Indicators - For many years, the NRC's former Office of AEOD published indicators in several NUREGs, including NUREG-1187 (series), "Performance Indicators for Operating Commercial Nuclear Power Reactors," using information derived from Licensee Event Reports (LERs) and plant Monthly Operating Reports (MORs). The ITP Indicators consist of the Ex-AEOD indicators and include (with affected cornerstones in parenthesis):

  • Automatic Reactor Scrams While Critical (IE)
  • Significant Events (IE)
  • Safety System Actuations (MS)
  • Safety System Failures (MS)
  • Forced Outage Rate (MS)
  • Equipment Forced Outage Rate/1000 Critical Hours (MS)
  • Collective Radiation Exposure (OR)

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(2) ROP Performance Indicators - Industry averages for the plant-level performance indicators under the Reactor Oversight Process (ROP), using data submitted by individual plants. The ROP indicators include (with affected cornerstones in parenthesis):

  • Unplanned Scrams (IE)
  • Unplanned Scrams with Complications(IE)
  • Unplanned Power Changes (IE)
  • MSPI – Emergency AC Power Systems (MS)
  • MSPI – High Pressure Injection System (MS)
  • MSPI – Heat Removal System (MS)
  • MSPI – Residual Heat Removal System (MS)
  • MSPI – Cooling Water Systems / Support Cooling Water Systems (MS)
  • Safety System Functional Failures - PWR (MS)
  • Safety System Functional Failures - BWR (MS)
  • Reactor Coolant System Activity (BI)
  • Reactor Coolant System Leakage (BI)
  • Drill/Exercise Performance (EP)
  • ERO Drill Participation (EP)
  • Alert & Notification System Reliability (EP)
  • Occupational Exposure Control Effectiveness (OR)
  • RETS/ODCM Radiological Effluent Occurrences (PR)

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(3) Accident Sequence Precursor (ASP) Program - ASP events are documented in the NUREG-4674 (series), "Precursors to Potential Severe Core Damage Accidents." The most recent status of the ASP program was reported to the Commission in SECY 07-0176, “Status of the Accident Sequence Precursor (ASP) Program and the Development of Standardized Plant Analysis Risk (SPAR) Models. The ASP indicators, include (with affected cornerstones in parenthesis):

  • Precursor Occurrence Rate (IE & MS)

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(4) Baseline Risk Index for Initiating Events (BRIIE)

The NRC has developed another tool in the Industry Trends Program (ITP) for assessing nuclear industry safety performance.  The Baseline Risk Index for Initiating Events (BRIIE) monitors the first (“initiating”) event in a series of unlikely failures that have the greatest potential to lead to damage of the reactor fuel.  These initiating events are not common but do occur with some regularity over time.  While plants are designed to have multiple means of stopping (mitigating) these series of events prior to damage to the reactor fuel, the NRC still wants to monitor the frequency of initiating events.  The NRC would take action if the frequency exceeds certain pre-determined levels. 

A description of BRIIE is provided in NRC Inspection Manual Chapter (IMC) 0313 and the BRIIE page.

The BRIIE is intended to enhance and complement the ITP, not as a replacement, and was implemented as part of the ITP starting in January 2008.

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Industry Trend Charts by Cornerstones of Safety

Physical Protection information not publicly available.

Data Source
Initiating Events
Mitigating Systems
Barrier Integrity
Emergency Prepared-
ness (EP)
Occupational Radiation Safety (OR)
Public Radiation Safety (PR)

ASP Program LT PDF Icon LT PDF Icon



ST(Tier 1 annual prediction limit)

LT (Tier 2 BRIIE graph)


LT = long term (10-year Industry Average Trend)
ST = short term (Annual Industry Average vs. Prediction Limit)

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Friday, August 22, 2008