1. NAME AND TITLE

TERFOC-N: Terrestrial Food-Chain Model for Normal Operations.

2. CONTRIBUTOR

Japan Atomic Energy Research Institute, Tokai-mura, Naka-gun, Ibaraki-ken, Japan.

3. CODING LANGUAGE AND COMPUTER

FORTRAN 77; FACOM M-380, FACOM M-780, Sun SPARCstation.

4. NATURE OF PROBLEM SOLVED

TERFOC-N calculates radiation doses to the public due to atmospheric releases of radionuclides in normal operations of nuclear facilities. The code estimates the highest individual dose and the collective dose from four exposure highways: internal doses from ingestion and inhalation, external doses from cloudshine and groundshine.

5. METHOD OF SOLUTION

A food chain model according to the U.S. NRC Regulatory Guide 1.109 has been improved to apply to not only LWRs but also other nuclear facilities. The transfer of H-3 and C-14 in the foodchain is estimated by the revised specific activity method. Boone's model is used in the assessment of other radionuclides. 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 cloudshine and groundshine are computed on the basis of the submersion model and the finite plane model, respectively.

6. RESTRICTIONS OR LIMITATIONS

Data for edible crops should be given on wet-weight basis, but data for feed crops may be given on either dry or wet basis. Data for crops must be in the order of feed crops and edible crops.

7. TYPICAL RUNNING TIME

The sample problem only took about 21 seconds on a Sun SPARCstation SLC.

8. COMPUTER HARDWARE REQUIREMENTS

TERFOC-N runs on the FACOM M-380, FACOM M-780 and Sun SPARCstation family.

9. COMPUTER SOFTWARE REQUIREMENTS

The code was written in FORTRAN 77 and was tested using the Sun FORTRAN Version 1.2 compiler.

10. REFERENCES

a. Included in the documentation:

Orihiko Togawa, A Computer Code TERFOC-N to Calculate Doses to the Public Due to Atmospheric Releases of Radionuclides in Normal Operations of Nuclear Facilities, JAERI- memo 02-426 (January 1991).

b. Background information:

Orihiko Togawa, ``Computer Code TERFOC-N to Calculate Doses to Public Using Terrestrial Foodchain Models Improved and Extended for Long-Lived Nuclides,'' J. Nucl. Sci. Technol. 27[4], pp.360-374 (April 1990).

11. CONTENTS OF CODE PACKAGE

Included are the referenced documents and a 5.25-in. DS/HD (1.2 MB) diskette which includes source codes, sample input and output.

12. DATE OF ABSTRACT

October 1991.