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Home > Nuclear Reactors > Operating Reactors > Oversight > Reactor Oversight Process

Inspection Procedures & Performance Indicators by ROP Cornerstone

ROP Regulatory Framework

The regulatory framework for reactor oversight is shown in the diagram below. It is a risk-informed, tiered approach to ensuring plant safety. There are three key strategic performance areas: reactor safety, radiation safety, and safeguards. Within each strategic performance area are cornerstones that reflect the essential safety aspects of facility operation. Satisfactory licensee performance in the cornerstones provides reasonable assurance of safe facility operation and that the NRC’s safety mission is being accomplished.

Within this framework, the NRC’s operating reactor oversight process provides a means to collect information about licensee performance, assess the information for its safety significance, and provide for appropriate licensee and NRC response. The NRC evaluates plant performance by analyzing two distinct inputs: inspection findings resulting from NRC's inspection program and performance indicators (PIs) reported by the licensees.

Regulatory Framework

Additional background information can be found on the Detailed ROP Description page. The Office of Public Affairs has published a plain language description of the ROP in NUREG-1649. The ROP-related program and policy documents are also conveniently summarized by subject area on the ROP Program Documents page.

Initiating Events - The objective of this cornerstone is to limit the frequency of those events that upset plant stability and challenge critical safety functions, during shutdown as well as power operations. If not properly mitigated, and if multiple barriers are breached, a reactor accident could result which might compromise public health and safety. Licensees can reduce the likelihood of a reactor accident by maintaining a low frequency of these initiating events. Such events include reactor trips (scrams) due to turbine trips, loss of feedwater, loss of off-site power, and other reactor transients.

Inspection Procedures - There are twenty-three attachments to the inspection procedure for the reactor safety strategic performance area, which includes the initiating events cornerstone, mitigating systems cornerstone, and the barrier integrity cornerstone:

Performance Indicators - There are three performance indicators in the initiating events cornerstone:

The NRC and Industry are working jointly to develop a replacement performance indicator for SCRAMS with Loss of Normal Heat Removal. The new draft indicator is called Unplanned Scrams with Complications.

Mitigating Systems - The objective of this cornerstone is to monitor the availability, reliability, and capability of systems that mitigate the effects of initiating events to prevent core damage. Licensees reduce the likelihood of reactor accidents by maintaining the availability and reliability of mitigating systems. Mitigating systems include those systems associated with safety injection, decay heat removal, and their support systems, such as emergency AC power. This cornerstone includes mitigating systems that respond to both operating and shutdown events. There are five indicators in this cornerstone:

Inspection Procedures - As listed above, there are twenty-three attachments to the inspection procedure for the reactor safety strategic performance area, which includes the initiating events cornerstone, mitigating systems cornerstone, and the barrier integrity cornerstone.

Performance Indicators - There are currently five performance indicators in the mitigating systems cornerstone:

The NRC and the nuclear industry have jointly implemented a replacement to the Safety System Unavailability Performance Indicators, called the Mitigating System Performance Index (MSPI). Data collection for the MSPI began in April 2006 with the first licensee submittal occurring in July 2006 (to include data up through 2Q2006).

Barrier Integrity - The objective of this cornerstone is to provide reasonable assurance that the physical design barriers protect the public from radionuclide releases caused by accidents. Licensees can reduce the effects of reactor accidents if they do occur by maintaining the integrity of the barriers. The barriers are the fuel cladding, reactor coolant system boundary, and the containment.

Inspection Procedures - As listed above under the initiating events cornerstone, there are twenty-three attachments to the inspection procedure for the reactor safety strategic performance area, which includes the initiating events cornerstone, mitigating systems cornerstone, and the barrier integrity cornerstone.

Performance Indicators - There are two performance indicators in the barrier integrity cornerstone:

Emergency Preparedness - The objective of this cornerstone is to ensure that licensees are capable of implementing adequate measures to protect public health and safety during a radiological emergency. Licensees provide reasonable assurance that their emergency preparedness program is effective through drills and exercises, participation in actual events, and testing of the Alert and Notification System (ANS). This cornerstone does not include the off-site actions, which are covered by FEMA.

Inspection Procedures - There are seven attachments to the inspection procedure for the emergency preparedness cornerstone:

Performance Indicators - There are three performance indicators in the emergency preparedness cornerstone:

Occupational Radiation Safety - The objective of this cornerstone is to ensure adequate protection of worker health and safety from exposure to radiation from radioactive material during routine civilian nuclear reactor operation. This exposure could come from poorly controlled or uncontrolled radiation areas or radioactive material that unnecessarily exposes workers. Licensees can maintain occupational worker protection by meeting applicable regulatory limits and ALARA guidelines.

Inspection Procedures - There are three attachments to the inspection procedure for the occupational radiation safety cornerstone:

Performance Indicators - There is one performance indicator in the occupational radiation safety cornerstone:

Public Radiation Safety - The objective of this cornerstone is to ensure adequate protection of public health and safety from exposure to radioactive material released into the public domain as a result of routine civilian nuclear reactor operations. These releases include routine gaseous and liquid radioactive effluent discharges, the inadvertent release of solid contaminated materials, and the offsite transport of radioactive materials and wastes. Licensees can maintain public protection by meeting the applicable regulatory limits and ALARA guidelines.

Inspection Procedures - There are three attachments to the inspection procedure for the public radiation safety cornerstone:

Performance Indicators - There is one performance indicator in the public radiation safety cornerstone:

Security - The objective of this cornerstone is to provide assurance that the licensees's security system and material control and accounting program use a defense-in-depth approach and can protect against (1) the design basis threat if radiological sabotage from external and internal threats, and (2) the theft of loss of radiological materials. Although the NRC is actively overseeing the security cornerstone, the Commission has decided that certain security related inspection and assessment information will not be publicly available to ensure that potentially useful information is not provided to a possible adversary. Therefore, the cover letters to security inspection reports may be viewed.



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Monday, July 21, 2008