Project RISE (Risk-Informed System Engineering): An Enterprise Infrastructure for a Smart Safety Case Design of Nuclear Power Plants

FPoliSolutions has developed a service called Risk-Informed System Engineering (RISE) digital infrastructure. The development was motivated by the need to address difficulties associated with the practical implementation of NEI 18-04 originally for the advanced reactor developer industry. However, the framework is generic and intended to orchestrate complex modeling and simulation workflows for a realistic characterization of the frequency- consequence (risk) envelop of any nuclear power plant. This presents an opportunity that such infrastructure could be easily and efficiently updated or re-directed toward the LWR use case described in this solicitation. FPoli intends to leverage the existence of the RISE platform to address the three areas of interest listed in the call: (1) Dynamic risk modeling with physics-based assessments integrated into the scenario progression simulation; (2) Evaluation of a release of radiological constituents from nuclear fuel damaged during simulated accidents (source terms analysis); and (3) Evaluation of phenomena of radiological material distribution from a nuclear facility to the environment. The objective of the Phase-II project is to update the RISE platform to be able to fully analyze a reactor design using Risk Informed Performance Based methodology. This includes automation of event sequence simulation from thermal hydraulic system response to dose consequence analysis. The capabilities of the platform will be demonstrated with an end-to-end analysis for a typical PWR safety case. Scenario progressions are physics-based and can be simulated with RELAP5-3D. For the evaluation of the release of radiological constituents from nuclear fuel damaged during simulated accidents (source terms analysis), FPoli is considering using RADTRAD or other tools available in the industry. Radiological consequence analysis is one key objective of this project. We believe that the project could have a significant impact on reducing generating costs of the US LWR fleet in the years to come. When risk-informed analysis are pursued to the full extent, including a realistic calculation of the radiological consequences, significant margin can be gained by coupling the evaluation of design basis accidents/events with the quantification of the radiological consequences, by considering the actual frequency of a spectrum of events rather than limiting the analysis to a superabounding MHA event for the purpose of quantifying radiological consequences and/or moving toward a mechanistic (with uncertainty propagation) source terms and activity calculations. As an example, FPoli believes that this technology may lead to a significant reduction in EZP sizing or how it is defined as well as more realistic estimates of on-site exposures. This can have an important economical and societal impacts considering that these analyses and limits have a direct influence on the public acceptance and economical operation of nuclear power plants. Given the existing framework, FPoli can achieve a beta release of the RISE product by the completion of Phase-II.