1. NAME AND TITLE:

SCAP: Single Scatter, Albedo Scatter, or Point Kernel Analysis Code System in Complex Geometry.

2. CONTRIBUTOR

Westinghouse Advanced Reactors Division, Madison, Pennsylvania.

3. CODING LANGUAGE AND COMPUTER:

Fortran IV; CDC-7600.

4. NATURE OF PROBLEM SOLVED:

SCAP solves for radiation transport in complex geometries using the single or albedo scatter point kernel method. The program is designed to calculate the neutron or gamma-ray radiation level at detector points located within or outside a complex radiation scatter source geometry or a user specified discrete scattering volume. Geometry is describable by zones bounded by intersecting quadratic surfaces with an arbitrary maximum number of boundary surfaces per zone. Anisotropic point sources are describable as point wise energy dependent distributions of polar angles on a meridian; isotropic point sources may also be specified. The attenuation function for gamma-rays is an exponential function on the primary source leg and the scatter leg with a buildup factor approximation to account for multiple scatter on the scatter leg. The neutron attenuation function is an exponential function using neutron removal cross sections on the primary source leg and scatter leg. Line or volumetric sources can be represented as a distribution of isotropic point sources, with uncollided line-of-sight attenuation and buildup calculated between each source point and the detector point.

5. METHOD OF SOLUTION

A point kernel method using an anisotropic or isotropic point source representation is used, line-of-sight material attenuation and inverse square spatial attenuation between the source point and scatter points and the scatter points and detector point is employed. A direct summation of individual point source results is obtained.

6. RESTRICTIONS OR LIMITATIONS

SCAP is written in complete flexible dimensioning so that no restrictions are imposed on the number of energy groups or geometric zones. The geometric zone description is restricted to zones defined by boundary surfaces defined by the general quadratic equation or one of its degenerate forms. The only restriction in the program is that the total program length plus the total data array dimension for small core memory must be less than 150 K (octal).

7. TYPICAL RUNNING TIME

SCAP computes approximately 200 source point-to scatter point-to detector point calculations per second on the CDC-7600. This running time is essentially independent of the number of energy groups and is only dependent upon the calculation of geometry dependent data.

8. COMPUTER HARDWARE REQUIREMENTS

SCAP is operable on the CDC-7600 computer.

9. COMPUTER SOFTWARE REQUIREMENTS

SCAP is operational on the Westinghouse Power Systems under SCOPE 2.1 monitor system control. A Fortran IV compiler is required.

10. REFERENCE

R. K. Disney, A. R. McIlvaine, S. E. Bevan, "SCAP Computer Program Description Single Scatter, Albedo Scatter, or Point Kernel Analysis Program in Complex Geometry," Draft (April 1980).

11. CONTENTS OF CODE PACKAGE

Included are the referenced document and one (1.2MB) DOS diskette which contains the source program, sample problem input, a photon cross section library and a program to convert the library to binary format.

12. DATE OF ABSTRACT

March 1982.