Ingestion model of COSYMA

One of the aims of the COSYMA ingestion model design was to cope in a flexible manner with the various food chain related data and results at different stages of an accident consequence assessment. Since dynamic food chain transport models themselves are normally rather complex and require significant computing times they are usually not included in ACA codes, but are used to calculate and tabulate the needed information in the data library form. Such data files contain specific activity concentrations in the foodstuffs and their time integrals normalized to unit deposit or unit air concentration for a series of times after the accident to allow for calculations taking account the food restrictions. In an ACA run, the actual specific concentrations in the foodstuffs are obtained by multiplying the normalized concentrations taken from the data library by the ground or air concentrations in each grid point predicted with an atmospheric transport and deposition model. The paper presents the ingestion model: structure, methods and libraries used for a nuclear accident consequence assessment. For the dose and risk calculations, both the 'Local production and consumption approach', where the doses are calculated for an average adult member of the population, and 'Agricultural production approach, where the collective ingestion dose is estimated from the amount of activity deposited, the concentrations of radioactivity in the foodstuffs per unit deposit, the annual amount of produce taken from the agricultural production data grid and the committed dose equivalent per unit intake of activity are presented. (author)