**
1. NAME AND TITLE**

QAD-CGGP-A: Point Kernel Code System for Neutron and Gamma-Ray Shielding Calculations Using the GP Buildup Factor.

**2. CONTRIBUTOR**

AECL Research, Reactor Technology Branch, Pinawa, Manitoba.

**3. CODING LANGUAGE AND COMPUTER**

FORTRAN 77; UNIX workstations and IBM PC's/compatibles (C00645/MNYCP/00).

**4. NATURE OF PROBLEM SOLVED**

QAD-CGGP-A is a point-kernel code for calculating fast-neutron and gamma-ray penetration through various shield configurations defined by combinatorial geometry specifications. AECL developed this release by modifying the CCC-493/QAD-CGGP package. The major improvements to the new version include the incorporation of a cubic spline interpolation scheme for the gamma attenuation coefficients, an added capability for source translation and rotation, correction of a potential error in evaluation of buildup factors at very deep penetration, and the adoption of complete free-format input reading routines from KENO-IV.

CCC-493/QAD-CGGP was based on CCC-307/QAD-CG contributed by Bechtel Power Corporation, Gaithersburg, Maryland and modified by Japan Atomic Energy Research Institute, Tokai-mura, and Oak Ridge National Laboratory. The GP parameters were determined by the Tokyo Institute of Technology, Tokyo, Japan and JAERI. In August 1986, double precision combinatorial geometry routines from CCC-203/MORSE-CG replaced the older geometry routines provided in the original QAD-CGGP from Japan. The code was modified in October 1988 to accommodate the ANS-6.4.3 1988 buildup factor compilation (26 materials).

The G-P buildup factor coefficients for the elements molybdenum to uranium were updated in July 1990 from new PALLAS calculations based on DLC-136/PHOTX. The DLC-129/ANS643 package was also updated with data from the PALLAS calculations.

**5. METHOD OF SOLUTION**

QAD-CGGP-A uses a point-kernel ray-tracing technique for gamma-ray calculations and either a modified Albert-Welton kernel or kernels obtained from the moments method solution of the Boltzmann equation for neutron penetration calculations. The GP version optionally makes use of the Geometric Progression (GP) fitting function for the gamma-ray buildup factor.

**6. RESTRICTIONS OR LIMITATIONS**

A math coprocessor is required for the PC version.

**7. TYPICAL RUNNING TIME**

Using the sample UNIX script, QAD-CGGP-A ran all the sample problems in a total of 5 minutes 14 seconds on an IBM RS/6000-590 running AIX 3.2.5.

**8. COMPUTER HARDWARE REQUIREMENTS**

QAD-CGGP-A has run on HP 9000, IBM RS/6000-590, and on an IBM PC compatible. In general the code should run on almost any machine equipped with a Fortran 77 compiler.

**9. COMPUTER SOFTWARE REQUIREMENTS**

A FORTRAN 77 compiler is required to compile the code on UNIX workstations. An executable for the PC created with MicroSoft Fortran 5.1 is included.

**10. REFERENCES**

**a. Included in the documentation:**

K.A. Litwin, I.C. Gauld, G.R. Penner, "Improvements to the Point Kernel Code QAD- CGGP: A Code Validation and User's Manual," RC-1214, COG-94-65, AECL Research (August 1994).

"Informal Notes on Neutron Source Normalization," (November 1988).

V. R. Cain, "A Users Manual for QAD-CG, the Combinatorial Geometry Version of the QAD-P5A Point Kernel Shielding Code," NE007, Bechtel Power Corp. (July 1977).

D. K. Trubey, Informal Notes--Part I, ORNL (December 1988).

D. K. Trubey, Informal Notes--Part II, ORNL (March 1989).

**b. Background information:**

Y. Harima, Y. Sakamoto, S. Tanaka, and M. Kawai, "Validity of the Geometrical Progression Formula in Approximating Gamma-Ray Buildup Factors," Nucl. Sci. Eng. 94, 24-35 (Sept. 1986).

D. K. Trubey, "New Gamma-Ray Buildup Factor Data for Point Kernel Calculations: ANS- 6.4.3 Standard Reference Data," NUREG/CR-5740, ORNL/RSIC-49/R1 (August 1991).

Y. Sakamoto, S. Tanaka, "QAD-CGGP2 and G33-GP2: Revised Versions of QAD-CGGP and G33-GP Codes with Conversion Factors from Exposure to Ambient and Maximum Dose Equivalents," JAERI-M 90-110, Japan Atomic Energy Research Institute (June 1990).

**11. CONTENTS OF CODE PACKAGE**

Included are the referenced documents in 10.a and one DS/HD 3.5-in. diskette written in DOS format which contains the source code, sample input and output, a DOS executable, information files, and script files to run the code under UNIX.

**12. DATE OF ABSTRACT**

December 1995.

**KEYWORDS: **GAMMA-RAY; NEUTRON; KERNEL; COMPLEX GEOMETRY;
COMBINATORIAL GEOMETRY; MICROCOMPUTER; WORKSTATION