Saturday, March 5, 2011

International Topical Meeting on Probabilistic Safety Analysis - PSA 2011

The International Topical Meeting on Probabilistic Safety Analysis (PSA 2011), sponsored by the American Nuclear Society and Sandia National Laboratories, along with a variety of commercial sponsors, will be underway next week in Wilmington, North Carolina from March 13 to March 17, 2011. Dr. George Apostolakis of the US NRC is the Honorary Chair of the Organizing Committee, while the Technical Committee has four Co-Chairs, one each from the US, Europe, Japan and Korea.

A truly large number of technical sessions are planned, and include several sessions on PSA of New Reactors from internal initiating events (including a very interesting paper on incorporating PSA principles into fusion reactor design, and papers on both gas-cooled and sodium-cooled fast reactors). Also PSA of a variety of hazards including fire, seismic, and flood; as well as PSA of non-reactor nuclear applications. There are sessions on incorporating digital information & control (I & C) systems into nuclear plant PSA; sessions on dynamic PSA (incorporating the dynamic, i.e., changing aspects of a system in to the probabilistic safety assessment [including a very interesting paper using genetic algorithms to explore the space within the failure domain where at least one safety limit is violated].

Several sessions explore Ageing in PSAs - one very interesting paper interpolates state transition probabilities in a Markov Model for estimating reliability of passive components such as metal pipes using physics-based models of weld degradation, instead of in-service failure data for the entire piping component. The paper finds that incorporating such time-inhomogeneous and stochastic transition rates into the Markov Model causes it to become non-Markov.

Interesting panel discussions are planned on: Alternative Risk Metrics, which will consider, among other things, how the promised lower risk numerics for new reactors will be maintained over their reactor life; and how risk profiles will be affected by multiple units in a suite of SMRs (small modular reactors); PRA Standards Development (which will examine, among other things, how the regulatory endorsement of PSAs as a risk management tool impacts the development of risk informed applications).

The conference brings together practitioners of PSA from a variety of disciplines and countries, and promises to be very interesting indeed.