CCC-0185 INREM-EXREM-3.

1. NAME OR DESIGNATION OF PROGRAM:  INREM-EXREM-3.

3. DESCRIPTION OF PROBLEM OR FUNCTION

INREM calculates the total cumulative radiation dose at a specified time to various organs of a reference man due to the inhalation and ingestion of one or more radionuclides over a specified time interval. The dose due to soluble radionuclides is calculated for all organs; the dose due to  inhalation of insoluble radionuclides is included for the lungs; the dose due to both inhalation and ingestion of insoluble radionuclides is included for the gastrointestinal tract.

Data for the organs of the reference man may be age dependent, and the intake function may be a function of time, radionuclide and  age group.

The method of estimation is based on adaptations of the models presented in Publication 2 of the International Commission on Radio- logical Protection.

EXREM-3 estimates the dose equivalent rate and the total dose equivalent from beta, positron, electron and gamma radiation resulting from submersion in contaminated water or air, or exposure  to a contaimnated surface. There can be more than one environmental  release, and the exposure can begin at any time after first release. The effects of nuclide decay chains are considered.

The data base for EXREM is available under the name DECAYREM (DLC-0030).

4. METHOD OF SOLUTION

INREM uses two models to calculate radiation dose. The gastrointestinal tract is divided into four segments: stomach, small intestine, upper and lower large intestine. The dose  to the critical segment is calculated from the ICRP maximum permitted dose and maximum permitted concentration, assuming that the dose due to other concentrations obeys simple proportionality. The dose to other organs is computed by numerically integrating, using Simpson's Rule, the analytic solution to first order differential equations describing the time dependence of the burden  of each radionuclide in each organ.

EXREM-3 numerically evaluates the analytic solution of a set of differential equations describing the time dependence of the concentration of the various nuclides in the various decay chains. The dose equivalents are then calculated from the concentrations.

5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM

Both programs are variably dimensioned to store data. The problem size is restricted by the amount of space declared in the main storage array.

6. TYPICAL RUNNING TIME:

7. UNUSUAL FEATURES OF THE PROGRAM:

8. RELATED AND AUXILIARY PROGRAMS:

10. REFERENCES:

- G.G. Killough, P.S. Rohwer, W.D. Turner:
  INREM - A FORTRAN Code Which Implements ICRP2 Models of Internal
  Radiation Dose to Man
  ORNL-5003 (February 1975).
- S.V. Kaye:
  "Updating of EXREM III"
  (June 4, 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).

11. MACHINE REQUIREMENTS:

13. OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED:

14. OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS:

15. NAME AND ESTABLISHMENT OF AUTHOR

Contributed by: Radiation Safety Information Computational Center
                Oak Ridge National Laboratory
                Oak Ridge, Tennessee, U. S. A.
Developed by:   G.G.Killough, P.S. Rohwer, S.V. Kaye
                Environmental Sciences Division
                W.D. Turner
                Computer Sciences Division
                D.K. Trubey
                Radiation Shielding Information Center
                Neutron Physics Divsion
                Oak Ridge National Laboratory
                Oak Ridge, Tennessee 37830, USA

File name	File description	Records
CCC0185_01.001	SOURCE PROGRAM (F4,EBCDIC)	2596
CCC0185_01.002	DD CARDS FOR EXECUTION	14
CCC0185_01.003	SAMPLE PROBLEM INPUT DATA	111
CCC0185_01.004	SAMPLE PROBLEM PRINTED OUTPUT	743