ORION-WIN; A Computer code to estimate environmental concentration and radiation dose due to airborne discharge of radioactive materials from nuclear facilities

Takeyasu, Masanori ; Onuma, Toshimitsu; Sumiya, Shuichi 

A computer code, ORION-WIN, has been developed to estimate environmental concentration and radiation dose to the public due to the airborne release of radioactive materials from multiple sources of nuclear fuel cycle facilities. The modified Gaussian plume model is applied to calculate atmospheric dispersion of the released radioactive material. The plume depletion processes such as gravitational settling, dry deposition, precipitation scavenging and radioactive decay are considered, and re-suspension from the ground and the produce of progeny from the parent radionuclides are also considered. Inhalation and oral intake are considered as internal pathways, and submersion in the radioactive cloud and external exposure to contaminated ground surface are considered as external pathways, respectively. Radiation dose to an individual is calculated.