Molten salt reactors reliability database: Mosard

This paper summarizes the initial effort to leverage Oak Ridge National Laboratorys legacy of the Molten Salt Reactor Experiment (MSRE) to create a reliability database for molten salt systems and components primarily source d from test programs, semi-annual reports, operational logbooks and summaries, and maintenance reports. This database will build the capability to examine the failure modes of the components such as valves, pumps, pipes, and more specifically seal leakages, and instrumentation failures during the MSRE operations and using lessons learned from the data to improve reliability performance of the next generation of salt components. Molten Salt Reactors Reliability Database (MOSARD) is a timely input for licensing efforts of the advanced molten salt reactor designs under the potential risk-informed, performance-based regulations to support (i) safety assessments (failure estimates from the database serve as PRA [input data), and (ii) process hazard assessments (inform the process with the dominant failure modes). Valve reliability data will be presented to demonstrate the capabilities of the MOSARD and to build understanding on causes of failures that lead to premature replacement of control and check valves of the off-gas, cover gas and component cooling systems. MSRE valve issues related with plugging were solved mostly with better filter designs and bigger valve replacements. For other valve failure modes expected to be similar for advanced designs, a trade-off study related with redundancy, size, diversity, location (relative to the charcoal beds, for instance) and cost, will feedback to the design and operation decisions (maintenance planning and optimization).