Methods and tools

-The proposed deterministic approach:

-based on the use of a two-step expertise methodology already in place and operational for French PWR, the 3D3P method (triple diagnosis triple prognosis, IRSN-EDF)

-supported by existing fast-running source term evaluation tools (PERSAN, IRSN) that will also be extended to all European reactors

 

-The proposed probabilistic approach:

-based on the use of the existing Bayesian Belief Network (BBN) tool (RASTEP, SSM). The key is to produce a specific ranking of plausible scenarios from a pre-computed database of European reference accident scenarios and the BBN tool RASTEP

-complemented by automatic post-processing tools being able to rank scenarios based on external constraints such as the protection of the surrounding population

 

-These two methods will be developed:

- extending the BBN capabilities from static to dynamic representation of inferences for complex network

-including deterministic information coming from specific models or severe accident code evaluation

-extending the set of plant types on which they can be applied

- extending the deterministic methods to all European reactors such as the 3D3P one which has already been extended from PWR to BWR and VVER through the FP5 ASTRID project (2001-2005)

- including functionalities to produce or integrate environmental releases data at a standard format (IRIX, IAEA) in order to link them with other initiatives focused on atmospheric transport, radiological consequence assessments and data assimilation