Qualification file of “GASRIM” for dispersion calculations of radioactive contamination in the atmosphere

The operational safety studies performed in the framework of the project of near surface disposal of category A waste (cAt project) encompass among other things dispersion calculations of radioactive contamination emanating out of the repository into the atmosphere. For these dispersion calculations, ONDRAF/NIRAS envisages using the GASRIM software package developed by the SCK•CEN. However, the Federal Agency of Nuclear Control (FANC-AFCN) requires appropriate qualification files for all simulation tools that are used in the frame work of operational and/or long-term safety assessments. Verification and validation (V&V) of computational simulations are the primary methods for building and quantifying confidence in computer codes. Verification is the process of determining that a model implementation accurately represents the developer's conceptual description of the model and the solution to the model. Validation is the process of determining the degree to which a model is an accurate representation of the real world from the perspective of the intended uses of the model. This qualification file brings together the elements that justify using the GASRIM software package for the radiological dispersion calculations in the framework of the project of near surface disposal of category A waste.