Probabilistic Analysis of Passive Safety System Reliability in Advanced Small Modular Reactors: Methodologies and Lessons Learned

Conference · Sun Jun 28 00:00:00 EDT 2015

OSTI ID:1255454

Grabaskas, David; Bucknor, Matthew; Brunett, Acacia; Grelle, Austin

Many advanced small modular reactor designs rely on passive systems to fulfill safety functions during accident sequences. These systems depend heavily on boundary conditions to induce a motive force, meaning the system can fail to operate as intended due to deviations in boundary conditions, rather than as the result of physical failures. Furthermore, passive systems may operate in intermediate or degraded modes. These factors make passive system operation difficult to characterize with a traditional probabilistic framework that only recognizes discrete operating modes and does not allow for the explicit consideration of time-dependent boundary conditions. Argonne National Laboratory has been examining various methodologies for assessing passive system reliability within a probabilistic risk assessment for a station blackout event at an advanced small modular reactor. This paper describes the most promising options: mechanistic techniques, which share qualities with conventional probabilistic methods, and simulation-based techniques, which explicitly account for time-dependent processes. The primary intention of this paper is to describe the strengths and weaknesses of each methodology and highlight the lessons learned while applying the two techniques while providing high-level results. This includes the global benefits and deficiencies of the methods and practical problems encountered during the implementation of each technique.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE Office of Nuclear Energy
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 1255454
• Resource Relation: Conference: 2015 ASME Power & Energy Conference, 9th International Conference on Energy Sustainability, 13th Fuel Cell Science, Engineering, and Technology Conference, and the inaugural Nuclear Forum, 06/28/15 - 07/02/15, San Diego, CA, US
• Country of Publication: United States
• Language: English