1. NAME AND TITLE

IDC: ICRP Dosimetric Calculational System.

AUXILIARY ROUTINES

SEE: Calculation of Specific Effective Energies.

MODSEE: Modified SEE for SEE Organ Pairs.

ICRP-TIMED: Models Transfer of Cumulated Activity in the Body.

DOSE: Calculation of Dose and Annual Dose Limits on Intake for ICRP-30.

CORE: Assembler Routine for In-Core Reads-Writes.

DATA LIBRARIES

SAF: Specific Absorbed Fractions for Source-Target Pairs for Use in SEE.

SEE MN52M TITLEMN2: Decay Data for SEE.

SEE INPUT SECT2: Decay Data for SEE.

The auxiliary routine, ICRP-TIMED, is a revision of CCC-292/TIMED, revised to correspond with guidelines provided by Committee 2 of the International Commission on Radiation Protection (ICRP).

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

The IDC calculational system was developed to implement the recommendations of ICRP Committee 2 (ICRP Publication 30) for computing limits for occupational exposure to radionuclides.

The first two routines listed above emphasize the ICRP Committee 2 recommendations for computing specific effective energy and cumulated activity. The third is concerned with criteria for calculating the tables of committed dose equivalent, weighted committed dose equivalents, annual limit of intake, and derived air concentration.

5. METHOD OF SOLUTION

SEE consists of 13 routines using methods described in the background references (Snyder, et al.). TIMED computes the cumulated activity of a radionuclide in the organs of a human body at a specified time after intake. DOSE combines the values computed by the first module and the cumulated activities calculated by the second module to calculate dose equivalent. Using the dose equivalent values, the program determines the annual limit on intake (ALI) and the derived air concentration (DAC) for a given chain of radionuclides.

6. RESTRICTIONS OR LIMITATIONS

SEE allows for a maximum of 30 source organs and 40 target organs.

ICRP TIMED is limited to 6000 nonzero elements in the coefficient matrix, 15 radionuclides to a chain, and 52 nonzero elements per row of the matrix. The user is also limited to 10 source organs other than lungs and gastrointestinal tract.

DOSE is limited to 15 radionuclides in the chain. A maximum of 3 oral and 3 inhalation classes may be used.

7. TYPICAL RUNNING TIME

SEE requires about 16 seconds to compile on the IBM 360/91. Execution time depends upon the number of radionuclides for which SEE values must be calculated and the number of radiations per radionuclide.

The Fortran routines of ICRP TIMED require about 20 seconds to compile; the Assembler routines about 0.7 second. Execution time depends upon the number of differential equations, the number of nonzero entries in the coefficient matrix, the length of time period of integration, etc.

The DOSE routines require about 70 seconds to compile. Execution time varies with the number of radionuclides in the chain, the number of source organs in the metabolic model, number of inhalation and oral classes, etc.

8. COMPUTER HARDWARE REQUIREMENTS

IDC is operable on the IBM 360/370 computers. The following amounts of core storage are required for execution:

SEE about 200 K

ICRP TIMED about 400 K

DOSE about 500 K

9. COMPUTER SOFTWARE REQUIREMENTS

The Fortran IV codes have been compiled on a Fortran H compiler; the Assembler routines require an IBM System 360 Assembler F.

10. REFERENCE

a. Included in documentation:

S. B. Watson and M. R. Ford, "A User's Manual to the ICRP Code A Series of Computer Programs to Perform Dosimetric Calculations for the ICRP Committee 2 Report," ORNL/TM-6980 (February 1980).

b. Background information:

W. S. Snyder, et al., "A Tabulation of Dose Equivalent Per Microcurie-Day for Source and Target Organs of an Adult for Various Radionuclides," ORNL-5000, Part 1 (November 1974) and Part 2 (November 1975).

11. CONTENTS OF CODE PACKAGE

Included are the referenced document in (10.a) and one (1.2MB) DOS diskette which contains the source codes and sample problem input and output.

12. DATE OF ABSTRACT

February 1982; revised December 1983.

KEYWORDS: RADIONUCLIDES; MODEL MAN; GAMMA-RAY; BETA-RAY; INTERNAL DOSE