1. NAME AND TITLE

INDOS: Conversational Computer Code Systems to Implement ICRP-10-10A Models for Estimation of Internal Radiation Dose to Man.

2. CONTRIBUTOR

Oak Ridge National Laboratory, Oak Ridge, Tennessee.

3. CODING LANGUAGE AND COMPUTER

FORTRAN IV; PDP-10.

4. NATURE OF PROBLEM SOLVED

INDOS computes, as functions of time, the radiation dose rate and dose to an organ of the body of Reference Man resulting from a deposition in the organ of a specified quantity of any one of a number of radionuclides. The models employed are essentially those of Publications 10 and 10A of the International Commission on Radiological Protection (ICRP); the three basic models assume excretion rates which are, respectively, (1) exponential, (2) power function, and (3) a combination of the two. The two patterns of intake simulated are as follows:

INDOS 1 depends entirely on input by the user, whereas INDOS2 and INDOS3 access on-line data-base files for parameter values associated with the radionuclide and organ under study. INDOS1 provides only tabular output of dose rate (rems/day) and dose (rems) as functions of time. INDOS2 offers the foregoing tabulation and graphs of dose vs time. INDOS3 gives only punched-card output of organ burden and dose as functions of time. INDOS2 and INDOS3 consider two modes on intake; inhalation and ingestion.

5. METHOD OF SOLUTION

Routine evaluations of closed-form solutions of the differential equations which define the models are used. The power-function models require the calculation of integrals. Standard numerical methods are employed to approximate these integrals. Any portion of the range of integration beyond t = 65 is truncated and an asterisk is printed in the table to signal such truncation.

In general, if the input data and parameter values are assumed exact, six-significant-digit accuracy is believed to be obtained when the supporting machine precision is eight decimal digits.

6. RESTRICTIONS OR LIMITATIONS

User-entered inputs are checked for gross errors (e.g., negative or zero values of quantities that must be positive). When such are detected, a message is typed, and the user is given the opportunity to enter corrected information. No checking of information read from the direct-access data-base file (INDOS2 and INDOS3) is done.

The user is not protected from the accidental specification of an excessive number of lines of tabulation (INDOS1 and INDOS2).

The INDOS codes have been prepared and tested with the general assumption that time ranges covered by the simulations do not exceed 18,250 days; there are, however, no inherent limitations which preclude longer ranges.

7. TYPICAL RUNNING TIME

INDOS runs in approximately 2 minutes.

8. COMPUTER HARDWARE REQUIREMENTS

INDOS runs on the PDP-10 computer.

9. COMPUTER SOFTWARE REQUIREMENTS

A FORTRAN IV compiler is required.

10. REFERENCE

G. G. Killough and P. S. Rohwer, "INDOSConversational Computer Codes to Implement ICRP-10-10A Models for Estimation of Internal Radiation Dose to Man," ORNL-4916 (March 1974).

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.

12. DATE OF ABSTRACT

August 1975; reviewed February 1983.