1. NAME AND TITLE

ACRA-TRIT: The Tritium Version of ACRA-II, Estimation of Radiation Doses Caused by a Hypothetical Reactor Accident.

2. CONTRIBUTOR

Oak Ridge National Laboratory, Oak Ridge, Tennessee.

3. CODING LANGUAGE AND COMPUTER

FORTRAN IV; IBM 360/370.

4. NATURE OF PROBLEM SOLVED

ACRA-TRIT is an atmospheric dispersion code which, using a three- (or two-) dimensional normal distribution model calculates the external dose, the internal dose due to inhalation, and the ground contamination that can be expected from the transport, fallout, and washout of the radioactive products released to the atmosphere in either a continuous fashion or an accidental short-term release. Allowance is made for elevated receptors above ground, for variable height of the plume centerline, and for reflection on the ground and on a possible inversion layer in the atmosphere.

5. METHOD OF SOLUTION

ACRA-TRIT prints out integrated doses over time as in CCC-213/ACRA-II.

It can produce concentrations instead of internal doses. This allows (a) studying the variation of the activity concentration of each radioisotope with time at a maximum of a hundred receptor locations, and (b) calculating the equilibrium concentration, for continuous releases, as a function of distance from the source.

Given the wind-rose statistical data of winds and atmospheric conditions, year averaged external and internal doses and ground contamination can be computed over a circle around the point of release.

ACRA-TRIT has a tritium oxidation modeling capability that allows a more realistic evaluation of the environmental impact of future fuel reprocessing plants and nuclear fusion power reactors.

6. RESTRICTIONS OR LIMITATIONS

None noted.

7. TYPICAL RUNNING TIME

An ACRA-TRIT case was run in 11 seconds on the IBM 360/91.

8. COMPUTER HARDWARE REQUIREMENTS

When run on an IBM 360/370, using standard I-O, ACRA-TRIT requires 500 K bytes core storage.

9. COMPUTER SOFTWARE REQUIREMENTS

A FORTRAN IV compiler is required.

Subroutine SETUP requires 350 K bytes to compile.

10. REFERENCES

P. J. Otaduy, "Tritium Oxidation and Dispersion Model," (February 1976).

F. W. Stallmann and F. B. K. Kam, "ACRAA Computer Program for the Estimation of Radiation Doses Caused by a Hypothetical Reactor Accident," ORNL-TM-4082 (April 1973).

F. B. K. Kam, "Informal Notes" (April 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 and output.

12. DATE OF ABSTRACT

December 1981; reviewed March 1982.