WPNCS Expert Group on Criticality Excursions Analyses (CEA)
The Expert Group on Criticality Excursions Analyses was created with the aim of providing scientific knowledge on criticality excursions (accidents, experiments and simulation). Under the guidance of the Working Party on Nuclear Criticality Safety, the major assignments of the expert group include:
identifying and compiling criticality transient data from experimental programmes and from accident data;
evaluating the main transient experimental programmes and creating a database to store and disseminate the data;
identifying and highlighting experimental needs for criticality accidents analyses;
identifying and compiling available models and computer codes for transient analyses;
defining benchmark exercises to compare the computer codes used for criticality accidents analyses;
identifying modelling needs.
Current programme of work
The expert group's work currently addresses the following areas:
The evaluation of criticality excursion experiments. A draft format
was designed by extending and adapting the International Criticality Safety Benchmark Evaluation Project evaluation format.
The organisation of inter-code comparison exercises. Benchmark proposals based on experiments performed in SILENE and TRACY solution reactors. Five phases are envisaged:
Phase I report (2009) discusses the performances of four transient codes: AGNES, CRITEX, INCTAC, and TRACE to simulate experimental results from two experimental facilities SILENE and TRACY;
Phase II exercise will cover slow transients from the TRACY experimental reactor;
Phase III will study code performances to simulate long-duration experiments;
Phase IV will examine dilute Pu-solutions;
A final Phase V will consist of a detailed analysis of postulated accident conditions.
For more information on CEA activities please contact .