Availability of and Solicitation of Public Comments on Report on Seismic Considerations for the Transition Break Size

Riepilogo

On November 7, 2005, the Nuclear Regulatory Commission (NRC) published for public comment a proposed rule in the Federal Register (70 FR 67598) on Risk-Informed Changes to Loss-of-Coolant Accident Technical Requirements. Under the proposed Sec. 50.46a rule, nuclear power plant licensees would be allowed to implement a voluntary, risk- informed alternative to the current requirements for analyzing the performance of emergency core cooling systems (ECCS) during loss-of- coolant accidents (LOCAs). In addition, the proposed rule would establish procedures and criteria for requesting changes in plant design and procedures based upon the results of the new analyses of ECCS performance during LOCAs. In the Federal Register notice associated with the publication of the proposed alternative Sec. 50.46a rule, the Commission noted that the potential for seismically- induced pipe breaks was not considered in determining the area of the transition break sizes \1\ (TBSs). The Commission stated that work was ongoing to investigate the possible effect of seismically-induced pipe breaks on the TBS selections and committed to put a report on the NRC Web site to facilitate public comment on the techn