CCC-0396 QADMOD-G.

1. NAME OR DESIGNATION OF PROGRAM:  QADMOD-G (Point Kernel Gamma-Ray Shielding Code).

3. DESCRIPTION OF PROGRAM OR FUNCTION

QAD is the generic designation for a series of point-kernel computer programs designed for estimating the effects of gamma-rays and neutrons that originate in a volume-distributed source. QADMOD is a modified version of the QAD P-5 point-kernel computer program designed to consider only gamma-ray sources. QADMOD-G has new geometry routines, additional source routines, and internal library data which make the program easier to use. Gamma-ray dose rates, energy depositions, and uncollided fluxes may be calculated. Surfaces, defined by quadric equations, are used for a three-dimensional description of the configuration.

4. METHOD OF SOLUTION

QADMOD-G calculates gamma-ray fluxes, dose rates, or heating rates at discrete locations within a complex source-geometry configuration by representing a volume-distributed source by a number of point isotropic sources and computing the distances through all regions traversed by the line-of-sight from the source points to a desired receiver point. From these distances  and the characteristics of the materials within them, energy- dependent exponential attenuation factors and energy-dependent buildup factors for gamma-rays are applied to calculate the direct gamma-ray dose and the gamma-ray dose with buildup. The responses to individual source points are summed into source-energy groups and recorded. Input data consists of the source distribution and intensity, the physical geometry, and may include tabulations of attenuation coefficients, buildup factor coefficients, and conversion factors.
Each source may be represented by a volume-distributed source or a series of up to 27 000 point sources. The source spectra are assumed to be constant for all volumes. The source may be defined in terms of a cylindrical, a Cartesian, or a spherical-geometry coordinate system.
As many as 500 point isotropic sources defined in terms of a spatial position and power density may be used in point source calculations. Each point source is represented by the same specified energy spectrum.
Shield configurations are represented in terms of a three- dimensional model which is made up of a series of material and void regions. Each region is defined by a previously-described set of surfaces.

5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM

The radiation source is represented by a series of individual point isotropic sources. For gamma-ray calculations, the direct beam component is calculated  exactly. The scattered component is calculated using buildup factors. The code is restricted to using dose buildup factors for a  single material.
The program limitations include: a single source spectrum, one source volume with up to 30 subvolumes along each major axis or up to 500 point sources, 30 source energy groups, 30 materials, 100 compositions, 250 surface boundaries, 300 shield geometry regions, 15 boundaries per region, and one set of dose buildup factors. There is no limit on the number of detectors per problem. However, only 100 may be saved for stacked problems.

6. TYPICAL RUNNING TIME

On the IBM 3033, sample problem 1 took 8.13 seconds and sample problem 2 took 8.l9 seconds. In both cases, the time is a total of the compilation, linkage, and go steps.

NEA-DB ran each of the two test cases included in this  package on a DEC VAX 6000-510 computer in less then 1 second of CPU  time.

7. UNUSUAL FEATURES OF THE PROGRAM:

8. RELATED AND AUXILIARY PROGRAMS:

10. REFERENCES:

- J.H. Price and W.G.M. Blattner:
  Utilization instructions for QADMOD-G
  RRA-N7914 (December 1979).
- J.K. Warkentin
"QADMOD-GP Notes"
Informal notes (November 2, 1990)
- J.K. Warkentin :
"Utilization Instructions for QADMOD-GP - A PC Version of
QADMOD-G with Geometric Progression Buildup Factors"
(November 1, 1990)

11. MACHINE REQUIREMENTS:  QADMOD-G is operable on the IBM 3033 and 3081 computers.

13. OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED

A FORTRAN IV compiler is required. An Assembler language ORNL-written subroutine  called TIME is part of the package. The user may choose to write a
routine for TIME.

VMS V5.4-1 (DEC VAX 6000).

14. OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS:

15. NAME AND ESTABLISHMENT OF AUTHORS

  Radiation Research Associates
  Fort Worth
  Texas, U.S.A.

File name	File description	Records
CCC0396_01.001	Information file	44
CCC0396_01.002	JCL to execute QADMODG on IBM computer	16
CCC0396_01.003	JCL and control information	7
CCC0396_01.004	QADMODG FORTRAN source program	1664
CCC0396_01.005	TIME ASSEMBLY language routine (IBM version)	28
CCC0396_01.006	Sample input problem 1	64
CCC0396_01.007	Sample input problem 2	46
CCC0396_01.008	Sample output problem 1	261
CCC0396_01.009	Sample output problem 2	906