The Nuclear Industry's Transition to Risk Informed Regulation and Operation in the United States

Report Date: August 2005
Appendices: No

Executive Summary

This report summarizes a study of the transition of the United States nuclear industry from a prescriptive regulatory structure to a more risk informed approach to operations and regulations. The transition occurred over a 20 year period in which gradual changes were made in the fundamental regulations and the approach to nuclear safety and operations. While the number of actual regulatory changes were few but are continuing, the utilities that embraced risk informed operations made dramatic changes in the way they approached operations and outage management. Those utilities that used risk in operations showed dramatic improvement in safety and economic metrics based on INPO performance indicators. It was shown that, in general, the use of risk did not affect safety performance of the plants compared to standard prescriptive approaches despite having greater flexibility in compliance to regulatory standards.

Key factors affecting the successful transition to a more risk informed approach to regulations and operations are: strong top management support and leadership both at the regulator and the utility; education and training in risk principles and Probabilistic Risk Assessment tools for engineers, operations and maintenance staff; a slow and steady introduction of risk initiatives in areas that can show value to both the regulator and the industry; a transparent regulatory foundation built around a safety goal policy; and the development of a strong safety culture at the utility to allow for more independence in safety compliance and risk management. As Japan considers the adoption of risk informed regulation and operations, the experience of the United States shows positive results in both safety and economics. The metrics presented show that the use of risk approaches is marginally better with no degradation in safety. The use of risk informed approaches allows both the regulator and the industry to focus on truly important safety issues. The transition to risk informed regulation also required a “culture change” by both the regulators and the utilities. Caution should be taken, however, since the basis of the US transition to risk informed regulation is founded on a long history of a regulatory structure and practices that have matured the industry to a point where the next step could be taken.

Program:     NSP Nuclear Systems Enhanced Performance

Type:     PR 

RPT. No.: 19