The ASME (formerly the American Society of Mechanical Engineers) code titled Operation and Maintenance of Nuclear Power Plants (OM Code), Division 1, “Section IST: Rules for Inservice Testing of Light-Water Reactor Power Plants,” defines a post-2000 plant as a nuclear power plant that was issued (or will be issued) its construction permit or its combined license for construction and operation by the applicable regulatory authority on or after January 1, 2000. The New Reactors OM Code (NROMC) Task Group (TG) of the ASME OM Code Committee is assigned the task of ensuring that the preservice testing (PST) and inservice testing (IST) provisions in the ASME OM Code are adequate to provide reasonable assurance that pumps, valves, and dynamic restraints (snubbers) for post-2000 plants will operate when needed. The NROMC TG has prepared updated guidance for pumps and pyrotechnically operated (squib) valves in new reactors that has been incorporated in the ASME OM Code. Currently, the NROMC TG is preparing proposed guidance for surveillance of safety-significant pumps, valves, and dynamic restraints in nonsafety systems at post-2000 plants that employ passive safety-related post-accident heat-removal systems (referred to as passive post-2000 reactors).
The NROMC TG is also evaluating pump and valve surveillance provisions that would ensure that safety-significant components in small modular reactor (SMR) designs are verified to be operationally ready while providing flexibility to accommodate potentially extended refueling cycles associated with these post-2000 plants. There are several other changes and evaluations being performed by the NROMC TG to provide reasonable assurance of the operational readiness of safety-significant pumps, valves, and dynamic restraints while still weighing the cost-effectiveness of the requirements. The NROMC TG also considers risk insights in its evaluation of PST and IST provisions for post-2000 plants. This paper discusses the NROMC TG activities to develop the recent and planned improvements to the PST and IST provisions in the ASME OM Code to address pumps, valves, and dynamic restraints in new reactors.
Paper published with permission.