1. NAME AND TITLE

WRAITH: Code System for Calculating Internal and External Doses Resulting from an Atmospheric Release of Radioactive Material.

2. CONTRIBUTOR

Battelle-Pacific Northwest Laboratory, Richland, Washington.

3. CODING LANGUAGE AND COMPUTER

Fortran IV; UNIVAC 1100/44.

4. NATURE OF PROBLEM SOLVED

WRAITH calculates the atmospheric transport of radioactive material to each of a number of downwind receptor points and the external and internal doses to a reference man at each of the receptor points.

5. METHOD OF SOLUTION

The movement of the released material through the atmosphere is calculated using a bivariate straight-line Gaussian distribution model with Pasquill values for standard deviations. The quantity of material in the released cloud is modified during its transit time to account for radioactive decay and daughter production. External doses due to exposure to the cloud can be calculated using a semi-infinite cloud approximation or a ``finite plume'' three-dimensional point-kernel numerical integration technique. Internal doses due to acute inhalation are calculated using the ICRP Task Group Lung Model and a four-segmented gastro-intestinal tract model. Translocation of the material between body compartments and retention in the body compartments are calculated using multiple exponential retention functions. Internal doses to each organ are calculated as sums of cross-organ doses with each target organ irradiated by radioactive material in a number of source organs. All doses are calculated in rads with separate values determined for high-LET and low-LET radiation.

6. RESTRICTIONS OR LIMITATIONS

Doses to only three target organs (total body, red bone marrow, and the lungs) are considered and acute inhalation is the only pathway for material to enter the body. The dose response model is not valid for high-LET radiation other than alphas. The high-LET calculation ignores the contributions of neutrons, spontaneous fission fragments, and alpha recoil nuclei.

7. TYPICAL RUNNING TIME

No study has been made by RSIC of typical running times for WRAITH. A discussion of expensive, precise vs. cheap, approximate calculations is provided in Appendix D of the referenced document.

8. COMPUTER HARDWARE REQUIREMENTS

WRAITH is operable on the univac 1100/44 computer with interactive system.

9. COMPUTER SOFTWARE REQUIREMENTS

A Fortran IV compiler is required.

Installation-dependent routines must be supplied for the following subroutines:

SECOND used to find the time of program execution

DATE used to find the date of the job run

TIME used to find the time of day of the job run

BANRF prints the banner on the title page.

Dummy routines could be substituted without affecting the calculations.

10. REFERENCE

R. I. Scherpelz, F. J. Borst, G. R. Hoenes, "WRAITH A Computer Code for Calculating Internal and External Doses Resulting from an Atmospheric Release of Radioactive Material," NUREG/CR-1690 PNL-3382 (August 1980).

11. CONTENTS OF CODE PACKAGE

Included are the referenced document and one (1.2MB) DOS diskette which contains the source code and associated libraries, plus output from the sample problems.

12. DATE OF ABSTRACT

June 1982.