EXPOSURE OF THE BIOGAS STATION OPERATORS WORKING WITH CONTAMINATED BIOMASS

The article deals with evaluation of irradiation of an operator of a 1MW biogas station (BGS), processing silage plant biomass contaminated by Cs-137 and Cs-134. External irradiation and internal irradiation by the means of aerosol particles inhalation were considered. For calculation of the external irradiation, a BGS model was created in the MCNP. The calculated total committed effective doses received by the operator during annual handling of biomass contaminated by 1 kBq per kg of Cs-137 or Cs-134 were 34 or 69 mu Sv, respectively. Three scenarios of contamination were evaluated: freshly contaminated silage after model accident, silage right after the Chernobyl accident and at the current radiation situation in the Czech Republic.