1. NAME AND TITLE

CONSTRIP V: Vertical Barrier-Finite Source Plane Gamma-Ray Penetration Code System.

CONSTRIP V is the successor to CONSTRIP II which was developed by C. Eisenhauer and E. E. Morris of the National Bureau of Standards, and CONSTRIP III, developed subsequently by the Research Triangle Institute.

DATA LIBRARIES

TSD: Total Scatter Data.

MSD: Monte Carlo Multiple Scatter Data.

2. CONTRIBUTOR

Research Triangle Institute, Research Triangle Park, North Carolina.

3. CODING LANGUAGE AND COMPUTER

FORTRAN IV; IBM 360/75/91.

4. NATURE OF PROBLEM SOLVED

The problem solved is that of the dose rate to a detector located behind a wall, or adjacent to the front surface of a wall, due to direct and wall scattered gamma radiation from source planes of various sizes and shapes located in front of the wall. Contributions from the source plane through various wall segments to the detector are determined through numerical integration of the dose rate arising from segments of the source field. CONSTRIP V can calculate the dose rates at the detector location due to gamma radiation which is singly scattered, multiply scattered, or that (direct) radiation which passes unscattered through the wall. No edge effects are considered and all geometrical considerations are made relating to the external face of the wall.

5. METHOD OF SOLUTION

The single scatter contribution is treated exactly with the Klein Nishina differential scatter cross section.

The multiple scatter calculation makes use of differential Monte Carlo dose transmission coefficients. These data are based upon the assumption of a uniform monodirectional flux incident on the wall. They are tabulated as a function of incident obliquity cosines, emergent obliquity cosines, and azimuthal angles of scatter. These data are three-way interpolated for the multiple scatter calculation. Both multiple scatter and total scatter Monte Carlo data are available. When total scatter data are supplied to CONSTRIP V, the single scatter calculation is bypassed. The dose transmission data are interpolated also for thickness and for energy to obtain results for arbitrary thicknesses and source energies bounded by the available Monte Carlo data.

Either Monte Carlo total scatter data, or multiple scatter data are required as input. Data suitable for this input have been generated by M. J. Berger, Charles Eisenhauer, and E. E. Morris of the National Bureau of Standards for wall thicknesses of 0.25 to 4 mean free paths of concrete for source energies of 0.2, 0.4, 0.66, 1.25, 5, and 10 MeV. These data are given as dose transmission functions for 11 source obliquity cosine base points, 11 detector obliquity cosine base points, and seven detector azimuthal angle base points.

6. RESTRICTIONS OR LIMITATIONS

The only restrictions on the calculational technique are those imposed by availability of (1) Monte Carlo data spanning the energy and wall thickness under consideration, and (2) buildup factors for the source energy employed. Currently, the buildup factor in CONSTRIP is that for the 1.25-M3V Cobalt-60 gamma. This factor must be replaced in subroutine BILDUP if another one is desired.

7. TYPICAL RUNNING TIME

For source fields in front of a shielding wall with the detector located behind the wall, typical running times are from 15 to 30 seconds per case on the IBM 360/75. When the fields are adjacent to the front of the wall and extend past either end of the wall, running times are highly dependent on the fractional integration accuracy requested.

8. COMPUTER HARDWARE REQUIREMENTS

The code system is designed for the IBM 360/75 with 300K fast core. Auxiliary equipment required is limited to an input device and a printer. The code may be loaded directly from cards, tapes, or other auxiliary storage. Problems are loaded from cards.

9. COMPUTER SOFTWARE REQUIREMENTS

CONSTRIP V may be compiled and executed on the FORTRAN IV Monitor of the IBM 360/75/91 Operating System.

10. REFERENCES

W. O. Doggett and F. A. Bryan, Jr., "CONSTRIP V, A Computer Program for the Vertical Barrier-Finite Source Plane Gamma Ray Penetration Problem," NRDL-TRC-68-55 Final Report R-OU-333 (part 1 of 2) (April 1969).

W. O. Doggett and F. A. Bryan, Jr., "Radiological Recovery Requirements, Structures and Operations Research, Volume I: Calculational Technique for Determining Importance of Limited Strip Decontamination Procedures," R-OU-266 (May 1967).

11. CONTENTS OF CODE PACKAGE

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

12. DATE OF ABSTRACT

February 1972; revised July 1982.