1. NAME AND TITLE

QBF: Code System to Calculate Radiation Dose Rates Relative to Spent Fuel Shipping Casks.

2. CONTRIBUTOR

The Ship Research Institute, Tokyo, Japan.

3. CODING LANGUAGE AND COMPUTER

Fortran 77; PC 386.

4. NATURE OF PROBLEM SOLVED

QBF calculates and plots in a short running time, three dimensional radiation dose rate distributions in the form of contour maps on specified planes resulting from cylindrical sources loaded into vehicles or ships. Shielding effects by steel walls and shielding material layers are taken into account in addition to the shadow effect among casks. This code system identifies the critical points on which to focus when designing the radiation shielding structure and where each of the spent fuel shipping casks should be stored. The code GRAPH reads the output data file of QBF and plots it using the HGX graphics library. QBF unifies the functions of the SMART and MANYCASK codes included in CCC-482.

5. METHOD OF SOLUTION

An analytical expression is introduced to describe radiation dose rate distribution functions around a cylindrical radiation source as a result of integration on the volume type radiation source. The concept of a shadow function is introduced to describe radiation shielding effect among sources. The introduction of the analytical shadow function expression is very effective for decreasing running time.

6. RESTRICTIONS OR LIMITATIONS

The graphics routines require the HGX library for the NEC PC-9801.

7. TYPICAL RUNNING TIME

For the two dimensional 6,000 mesh points, it takes about 20 minutes with the personal computer PC-9801 (VX-21).

8. COMPUTER HARDWARE REQUIREMENTS

QBF was developed on the NEC PC-9801 and has been ported to an IBM PC-486. HGX is available only for PC-9801 and will not run on IBM PCs. IBM compatible users of GRAPH must replace the graphics subroutine calls.

9. COMPUTER SOFTWARE REQUIREMENTS

Under DOS 5.0 the Silicon Valley Software C3 F77 compiler and linker version 2.8.2 were used to create the executable file included in the package. F77L was the compiler for this code system on the PC-9801.

10. REFERENCES

H. Yamakoshi, "Description of the QBF Code System," Informal Notes (1993).

H. Yamakoshi, "Simulation of Radiation Dose Rate Distributions Around Casks in Ships and Vehicles by Using QBF Code for PC-9801 Computer," Report for PATRAM'92 held at Yukohama, Japan, Informal Report (1992).

H. Yamakoshi, "New Principle for Efficiently Calculating Radiation Dose Rate Distributions in Ships Loading Multiple Shipping Casks Containing Spent Nuclear Fuel," J. Nucl. Sci. Technol., Vol. 25, pp 563-573 (July 1988).

11. CONTENTS OF CODE PACKAGE

Included in the package are the referenced documents and one (1.2MB) diskette with source, executable, and sample case written in DOS format.

12. DATE OF ABSTRACT

May 1993.