TERFOC-N, Radiation Doses in Food Chain from Atmospheric Release

1 - Description of program or function: TERFOC-N calculates radiation doses to the public due to atmospheric releases of radionuclides from nuclear facilities in normal operations. This code estimates the highest individual dose and the collective dose from four typical exposure pathways: internal doses from ingestion and inhalation, external doses from cloud-shine and ground-shine. 2 - Method of solution: A food chain model, which is originally referred to in U.S. NRC Regulatory Guide 1.l09, has been improved to apply not only to LWRs but also to other nuclear facilities. The transfer of 3H and 14C in the food chain is estimated by the revised specific activity method. The model based on the Boone's model is used in the assessment of radionuclides except 3H and 14C. Internal doses due to ingestion and inhalation can be estimated by multiplying the annual intake of radionuclides by dose conversion factors. External doses due to cloud-shine and ground-shine are computed on the basis of the submersion model and the finite plane model, respectively. 3 - Restrictions on the complexity of the problem: In the preparation of input data, a user of the code may arbitrarily select the kinds of crops and animal products to be involved. Data for edible crops should be given on wet-weight bases, but data for feed crops may be given on either dry - or wet - bases. Data for crops must be in the order of feed crops and edible crops