Robert H. Leyse; Denial of Petition for Rulemaking

The Nuclear Regulatory Commission (NRC) is denying a petition for rulemaking submitted by Mr. Robert H. Leyse (PRM-50-76). The petitioner requests that the NRC's regulations concerning the specified evaluation models for emergency core cooling systems (ECCS) and associated guidance documents be amended. The petitioner asserts that amendments are necessary to correct technical deficiencies in the correlations and data used for calculation of metal-water oxidation. The petitioner states that the correlations and data do not consider the complex thermal-hydraulic conditions present during a loss-of- coolant accident (LOCA), including the potential for very high fluid temperature. The Commission is denying Mr. Leyse's petition for rulemaking (PRM-50-76). None of the specific technical issues raised by the petitioner have shown safety-significant deficiencies in the research, calculation methods, or data used to support ECCS performance evaluations. NRC's technical safety analysis demonstrates that current procedures for evaluating ECCS performance are based on sound science and that no amendments to the NRC's regulations and guidance documents are necessary.