NORMALYSA – a software for radiological assessments of NORM and legacy sites

The NORMALYSA (NORM And LegacY Site Assessment) software tool is designed to simulate radionuclide transport from a source (e.g., radioactively contaminated land) to relevant receptors in the environment (e.g., residential areas, agricultural areas, water bodies, etc.), and to calculate radiation exposure doses to humans.

NORMALYSA was developed by Facilia AB (Sweden) with support from the International Atomic Energy Agency (IAEA) and has been tested and benchmarked with other similar software tools (e.g., RESRAD) in the frame of the IAEA MODARIA project (Modelling and Data for Radiological Impact Assessments) Work Group 3 (NORM and Radioactively Contaminated Legacy Sites) activities.

NORMALYSA consists of a Simulator program engine that allows performing deterministic and probabilistic model simulations.The Simulator has a Graphical User Interface, which is available in English, Russian and Spanish languages. The Simulator is integrated with a set of models organized in five libraries: ‘Sources’, ‘Cover Layers’, ‘Transports’, ‘Receptors’ and ‘Doses’. Specific modelling cases can be constructed by selecting the appropriate models and setting up data exchanges between these. The software architecture allows easily configuring a variety of “source -> transport pathway -> receptor environment -> exposed reference individual” combinations, providing essential flexibility in accounting for site specific conditions and exposure situations.

NORMALYSA implements relatively simple environmental transport and exposure assessment models that have been previously recommended and documented. In particular, NORMALYSA uses models that have been used in safety assessment of radioactive waste disposal facilities performed by the Swedish Nuclear Fuel and Waste Management Company (SKB) and generic models recommended by the IAEA (e.g., from IAEA SRS-19 report). These models can be especially useful in early stages of a safety assessment, as well as for conservative radionuclide transport and dose assessment analyses (e.g., for getting upper bound estimates of radiological impacts from a contaminated land).

The model libraries are supplied with default values for all parameters that are needed for running the models. The default parameter values are taken from reputable parameter compilations (e.g., IAEA TRS-472 report and SKB parameter databases).