The regulatory guide for reviewing the licensee's technical report for the extension of the operating period of commercial power reactors, enacted in November 2013, requires evaluation of the proof stress of the concrete structures of nuclear power plants operated for more than 40 years if the neutron fluence exceeds or may exceed a certain limit where neutron irradiation affects the concrete strength.

A new risk-informed and performance-based inspection program will be enacted from April 2020. A part of this program builds on the information obtained from a probabilistic risk assessment (PRA).