3. DESCRIPTION OF PROGRAM OR FUNCTION
ORION-II has been developed to estimate environmental concentration and dose due to airborne release of radioactive material from multiple sources of nuclear fuel cycle facilities.
The modified Gaussian plume model is applied to calculate atmospheric dispersion. The plume depletion models such as gravitational settling, dry deposition, precipitation scavenging and radioactive decay are considered as the causes of the depletion and deposition on the ground and vegetation.
Inhalation and oral intake are considered as the internal exposure pathways, and submersion in the radioactive cloud and external exposure to ground surface contamination are considered as the external exposure pathways.