1. NAME AND TITLE

EGAD: Calculation of Dose from External Gamma-Ray Emitters.

2. CONTRIBUTOR

Savannah River Laboratory, Aiken, South Carolina.

3. CODING LANGUAGE AND COMPUTER

FORTRAN IV; IBM 360/370.

4. NATURE OF PROBLEM SOLVED

EGAD calculates gamma-ray dose integrals to a ground level receptor (for incremental values of the vertical dispersion parameter sigma_z), as a function of gamma-ray energy and spatial distribution of the radioactive material. The dose integrals are representative of sector averages since the distribution of material is assumed to be Gaussian in the vertical, homogeneous in the horizontal, and bounded between ground level and an inversion lid. Calculated dose integrals are independent of radioactive decay, transport velocity, down-wind distance, and sector width. Space attenuation and buildup are accounted for.

5. METHOD OF SOLUTION

The plume of radioactive material is assumed to remain constant in shape and size during passage over a receptor point. The space distribution of material is then represented as parallel line sources. The line contributions are integrated analytically by transforming to Bessel and related functions, reducing the spatial distribution to a vertical plane at the receptor point. Plane integrations are then performed by Gaussian quadratures.

6. RESTRICTIONS OR LIMITATIONS

EGAD requires 40 K bytes of storage.

7. TYPICAL RUNNING TIME

Running time to evaluate integrals is typically less than 30 msec for each energy and receptor point.

8. COMPUTER HARDWARE REQUIREMENTS

EGAD is operable on the IBM 360/370 computers. It required 50 K bytes of storage for the GO step on the IBM 360/91.

9. COMPUTER SOFTWARE REQUIREMENTS

A FORTRAN IV compiler is required.

10. REFERENCE

R. E. Cooper, "EGADA Computer Program to Compute Dose Integrals from External Gamma Emitters," DP-1304 (September 1972).

11. CONTENTS OF CODE PACKAGE

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

12. DATE OF ABSTRACT

May 1975.