RSIC CODE PACKAGE CCC-185

1. NAME AND TITLE

INREM/EXREM: Beta and Gamma Radiation Environmental Dose Code Systems.

2. CONTRIBUTOR

Oak Ridge National Laboratory, Oak Ridge, Tennessee.

3. CODING LANGUAGE AND COMPUTER

FORTRAN IV and Assembler language; IBM 360/370.

4. NATURE OF PROBLEM SOLVED

EXREM estimates the dose equivalent rate and the total dose equivalent from electron, beta, and gamma radiation resulting from submersion in contaminated water, submersion in contaminated air, and exposure to a contaminated surface. EXREM gives estimates for daughters as well as specified radionuclides since it considers contributions from nuclide chains.

Since there can be more than one environmental release, and exposure can begin at any time after the first release, INREM was developed to estimate the cumulative dose equivalent to body organs resulting from a continuous intake. The organ parameters are dependent on the age of the individual, and the intake is a function of time after release and the individual's age.

Although the codes were originally written to estimate doses to populations from construction of a sea-level canal, they may be useful in other dose-estimation studies involving releases of radioactive materials to the environment.

5. METHOD OF SOLUTION

Evaluation of the radiation hazard to a population living in an environment contaminated with radioactive material requires estimates of the total dose equivalents received by individuals of all ages. The total dose has two components. One component results from radionuclides outside the body (external exposure), and the other one results from radionuclides deposited within the body (internal exposure). Individuals making up a population under consideration for dose estimation may be described by parameters which are either age independent or age dependent.

The generalized models and the mathematical techniques required to program the models for several types of problems are presented in the referenced document as are the computer solutions for the equations, the assumptions used by the code, the logical flow of the program, the definition of the program variables, and the input format. INREM calculates the total cumulative dose at a specified time in various organs of standard man or an individual of a specified age at the time of the first intake via either inhalation or ingestion of radionuclides which continues over a specified time interval.

EXREM III estimates the dose equivalent rate and the total dose equivalent from electron, beta, and gamma radiation resulting from submersion in contaminated water, submersion in contaminated air, and exposure to a contaminated surface. There can be more than one environmental release, and exposure can begin at any time after the first release. EXREM III considers contributions from environmental releases and from nuclide chains. For a particular problem the user may choose to calculate either the dose rates, the total doses, or both for any of the three modes of exposure.

6. RESTRICTIONS OR LIMITATIONS

None noted.

7. TYPICAL RUNNING TIME

INREM and EXREM III each ran in approximately 30 seconds on the IBM 360/91.

8. COMPUTER HARDWARE REQUIREMENTS

INREM and EXREM were designed to run on the IBM 360/370 computers. INREM uses 366K bytes of storage. EXREM II uses 358K bytes.

9. COMPUTER SOFTWARE REQUIREMENTS

A FORTRAN IV compiler and assembler are required.

10. REFERENCES

G. G. Killough, P.S. Rohwer, and W. D. Turner, "INREM - A FORTRAN Code Which Implements ICRP2 Models of Internal Radiation Dose to Man," ORNL-5003 (February 1975).

D. K. Trubey, "Note to EXREM III Users" (July 1977).

D. K. Trubey, "Updating of EXREM III" (June 1974).

D. K. Trubey and S. V. Kaye, "The EXREM III Computer Code for Estimating External Radiation Doses to Populations from Environmental Releases," ORNL-TM-4322 (December 1973).

R. C. Durfee, "FORTRAN Free-Form Input" (January 1970).

11. CONTENTS OF CODE PACKAGE

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

12. DATE OF ABSTRACT

May 1975.

KEYWORDS: ENVIRONMENTAL DOSE; GAMMA-RAY; BETA-RAY; NUCLEAR EXPLOSIVES