Grainger College of Engineering, All Events

Future Advances in Probabilistic Risk Assessment (PRA) for use in Small Modular Reactors (SMRs) and Advanced Nuclear Reactors

Abstract: When I began working in PRA in 1982 supporting the Oconee PRA (NSAC-60), the methods the industry has used, and scope of PRAs have steadily grown. Where methodology gaps existed, such as in Fire PRA, we worked on better approaches such as those documented in EPRI TR-1011989 (NUREG/CR-6850) and the associated methodology reports. Where the gaps in PRA scope existed, we have expanded the PRA scope to include extensive low power/shutdown and spent fuel pool PRA modeling. When applying PRA to new technologies, such as for the PRISM Sodium-Cooled Fast Reactor PRA (https://www.osti.gov/biblio/1352518), we developed new approaches and PRA standards for any gaps experienced.

However, we still have significant gaps; in part due to scope limitations in current PRAs being developed, and in part due to the PRA methods needed to support unique advanced reactor designs, such as evaluation of passive systems. This presentation will discuss three areas of current and future advancement, including:

1. Evaluation of Combinations of Hazards such as the type of event experienced at the Fukushima-Daichi nuclear plant (Seismic-Tsunami) or those we may experience due to climate change (rain-wind-flooding events).  

2. Evaluation of Passive Systems in support of both PRA and deterministic safety analysis with a focus on applying passive reliability modeling to PSA and DSA.  

3. Evaluation of multi-unit or multi-source radiological releases.  

The talk will introduce the above areas of advancement and provide references to more detailed discussion on each.  

Bio: Dennis Henneke has 43 years of experience in System Engineering, Design Engineering and Probabilistic Safety Assessment (PSA) for PWRs, BWRs, Advanced LWRs, and Advanced Non-LWRs including sodium and molten salt applications. Dennis is a Consulting Engineer with GE Hitachi supporting the design and safety analysis for the BWRX-300, Natrium, VTR, PRISM, ABWR and ESBWR advanced reactors. Prior to joining GEH, Dennis worked as a Senior PSA Engineer for both Duke Energy and Southern California where he supported PSA and risk-informed applications for multiple operating plants, including leading the industry efforts on risk-informed fire protection and installation of risk monitors at more than 10 sites worldwide.  Dennis is the Chair of the Joint ANS and ASME PRA Standards Committee, JCNRM, and an author or co-author of more than 150 publications including the IAEA report on Multi-Unit PSA, SR-110. Dennis was recently inducted into the US National Academy of Engineering and is a Fellow of the American Nuclear Society.