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.

Tuesday, March 1, 2011

5th International Symposium on Supercritical Water-cooled Reactors ISSCWR-5 Vancouver

The 5th International Symposium on Supercritical Water-cooled Reactors (ISSCWR-5) begins on March 14 2011 in Vancouver. The conference gets underway with five plenary addresses by national and international program managers of respective SCWR/HPLWR programs on the morning of the first day, Monday, and then branches off into three parallel technical sessions in the afternoon: on SCWR Core Design; on Materials Issues and on General Thermalhydraulics and Safety, chaired by international authorities in these respective fields. The session on General Thermalhydraulics and Safety will be co-chaired by Sama Bilbao y Leon of Virginia Commonwealth University and Jovica Riznik of the Canadian Nuclear Safety Commission.

This pattern of technical sessions continues also on Tuesday; an important facet of the Tuesday morning sessions will be regulatory considerations: a talk by Alexandre Viktorov of the Canadian Nuclear Safety Commission will be on Regulatory Expectations for Advanced Reactors, while Ima Ituen and David Novog of McMaster University will present on Assessing the Applicability of Canadian Regulations to the SCWR.

On Wednesday morning, there are sessions on Safety Issues and non-Aqueous Fluid Heat Transfer, the latter referring especially to experiments on supercritical carbon dioxide, where considerations on fluid-to-fluid scaling are important in interpreting the results and applying them to the real working fluid, supercritical water. Of the many interesting papers, one which describes a supercritical loop for in-pile testing of materials seemed especially interesting.

On all three days, the pattern of three parallel technical sessions is maintained, testifying to the high level and quality of national and international participation in the conference, and the interesting work on the SCWR that continues apace through the Gen-IV International Forum (GIF). Canada, as the host country [and also the country that formally leads R&D on the SCWR under the GIF] has the highest number of papers - both established groups and newer ones, and both senior researchers and students are presenting papers. Importantly, the Canadian participation shows significant engagement with the SCWR concept, across all major stakeholders: by academic groups, by regulatory authorities, as well as by R&D Labs and industrial firms.

The conference closes on Thursday with a tour of TRIUMF, Canada's national laboratory for nuclear and particle physics, located on the campus of the University of British Columbia. The scenic locale of the conference in Vancouver, and the very interesting papers to be presented, and discussions to be had, plus the social and cultural programs and the tour of TRIUMF promise to make this a most memorable conference in the biannual ISSCWR series.