Dynamic Probabilistic Risk Assessment Methodologies Workshop

A new generation of methodologies is starting to receive attention for nuclear reactor probabilistic risk assessment (PRA). Often referred to as dynamic PRA (DPRA) methodologies, these methodologies explicitly account for the time element in the probabilistic system evolution and heavily incorporate plant analysis tools (e.g., RELAP, MELCOR, MAAP5) to model possible dependencies among failure events that may arise from  hardware/software/firmware/process/ human interactions. DPRA methodologies are also capable of quantifying the effects of phenomenological variability and model uncertainties on the consequences of upset conditions.   They can be particularly useful for the PRA modeling of passive safety systems, including representation of aging effects.

As shown in the attached table, four plant level applicable DPRA tools will be demonstrated in the workshop:

The Dynamic Probabilistic Risk Assessment (DPRA) Methodologies Workshop is scheduled from 9:00pm to 4:30pm on Sunday, April 28, 2019 with a one-hour break for lunch. The DPRA Methodologies Workshop fee includes handouts and Sunday lunch. Registration for PSA 2019 is required to participate in this Workshop.

Workshop Coordinator: Professor Tunc Aldemir, The Ohio State University

SAPHIRE Computer Code Tutorial Workshop

The SAPHIRE tutorial is scheduled from 1:00pm to 5:00pm on Sunday, April 28, 2019. It will consist of three parts:

1. Introduction to SAPHIRE and its primary capabilities:
2. SAPHIRE’s primary capabilities are the development of logic models that will be solved to obtain minimal cut sets. Here we will discuss the creation of an event tree and fault tree logic model. The basic event parameters will be input (failure rates and failure probabilities). These logic models will be solved to obtain their minimal cut sets and then discuss the different risk metrics (i.e., importance measures and parameter uncertainty).
3. Advanced features of SAPHIRE used for more detailed analysis:
4. This part will look at the use of top event substitution (link rules and graphically). Post-processing rules will also be discussed on how to manipulate the minimal cut sets generated by the logic models. Lastly, some of the advanced basic event options will be presented (i.e., common cause failure calculators, human reliability analysis, and convolution correction factor). Time permitting, end state analysis and different quantification options available will be discussed.
5. Open discussion on use of SAPHIRE for personal applications.
6. Workshop Presenter: James K. Knudsen, Idaho National Laboratory
7. The SAPHIRE Tutorial Workshop fee includes tutorial handouts and Sunday lunch. The lunch is available thirty minutes prior to the start of the Workshop. Registration for PSA 2019 is required to participate in this Workshop.

MACCS Computer Code Training Workshop

The MACCS computer code is an atmospheric transport and dispersion software tool used to support Level 3 PRA and other types of radiological consequence analyses. The MACCS Training Workshop provided here as part of the PSA 2019 Conference is comprised of two half-days. The training is intended to have a hands-on component. Current MACCS users are recommended to bring a laptop with WinMACCS 3.11.2 installed so they can participate in the exercises; prospective MACCS users are also invited to attend the workshop to learn more about the MACCS models and capabilities.

The first portion of the training, on Friday afternoon (1:00pm to 5:00pm) following the final PSA sessions, is fundamental in nature and is intended to describe many of the MACCS input parameters and provide guidance in choosing values for those input parameters. This material covers all three MACCS modules, ATMOS, EARLY, and CHRONC. The format of this training is lecture with time for questions and answers plus one or two hands-on exercises employing MACCS.

The second half of the training, on Saturday morning (8:00am to 12:00pm), is focused on a more advanced topic, how to use the relatively new features in MACCS to perform the consequence analysis portion of a multi-unit, Level 3 PRA. This portion of the training includes a discussion of strategies for keeping the consequence analyses to a practicable number when more than two units (or combinations of units, spent fuel pools, and other sources) are treated in the PRA. It also includes hands-on exercises to make the concepts practical.

The MACCS Workshop fee includes training handouts, Friday lunch and Saturday breakfast. Each meal will be available thirty minutes prior to the start of each session. Registration for PSA 2019 is required to participate in the Workshop.

Workshop Facilitator: Dr. Nathan E. Bixler, Sandia National Laboratories