1. NAME AND TITLE

AIREM: Calculation of Doses, Population Doses, and Ground Depositions Due to Atmospheric Emissions of Radionuclides.

AUXILIARY ROUTINES

EGAD: Dose converter.

ROSEAV: Utility Code.

2. CONTRIBUTOR

U.S. Environmental Protection Agency, Washington, D.C.

3. CODING LANGUAGE AND COMPUTER

FORTRAN IV; IBM 360/370.

4. NATURE OF PROBLEM SOLVED

AIREM calculates doses to the general population due to atmospheric emissions of radionuclides. It is dose model independent in the sense that dose conversion factors, provided as input data, are used for calculations of dose that are proportional to radionuclide concentrations in the cloud, and dose conversion tables obtained from a model that considers the finite extent of the overhead cloud, also required as input data, are used for calculations of whole body dose due to external gamma emitters in the cloud. A set of dose tables is obtained using one finite cloud model (CCC-206/EGAD).

5. METHOD OF SOLUTION

A standard sector-averaged Gaussian-diffusion equation is solved repeatedly for each radionuclide, wind sector, stability class and downwind distance. Radionuclide contributions to doses up to a maximum of four critical organs are summed and printed by sector and downwind distance. Population doses (person-rem) are also calculated.

The code accounts for the following physical processes: cloud diffusion, ground and inversion-lid reflections, radionuclide decay by time of flight, first daughter-product buildup, ground deposition of particulates and halogens (independently), cloud depletion, in-plant holdup and decontamination factors, and sector-to-sector contributions to external gamma dose. All significant parameters are fully dimensioned and stored during a problem run. Thus, it is normally a simple matter for the user to write out various combinations and collations of data as desired. The code is composed of two basic parts: a diffusion calculation and a dose calculation.

ROSEAV is used to reduce wind frequency data in Reg-guide-1.23 format to AIREM input format.

6. RESTRICTIONS OR LIMITATIONS

None noted.

7. TYPICAL RUNNING TIME

AIREM ran in about 20 seconds on the IBM 360 computer.

*8. COMPUTER HARDWARE REQUIREMENTS

AIREM is operable on the IBM 360/370 computers.

9. COMPUTER SOFTWARE REQUIREMENTS

A FORTRAN IV compiler is required.

10. REFERENCES

"Feedback on Use of AIREM Code," Northeast Utilities Service Company (March 1978).

J. A. Martin, Jr., C. B. Nelson, and P. A. Cuny, "AIREM Program Manual - A Computer Code for Calculating Doses, Population Doses, and Ground Depositions Due to Atmospheric Emissions of Radionuclides," EPA-520 1-74-004 (May 1974).

11. CONTENTS OF CODE PACKAGE

Included are the referenced document and one (1.2MB) DOS diskette which contains the source code and sample problem input and output.

12. DATE OF ABSTRACT

October 1975, updated September 1991.

KEYWORDS: ENVIRONMENTAL DOSE; AIRBORNE