1. NAME AND TITLE

DUST: Albedo Monte Carlo Simulation of Neutron Streaming Through Multilegged Ducts.

2. CONTRIBUTOR

Reactor Research Centre, Kalpakkam, Tamil Nadu, India.

3. CODING LANGUAGE AND COMPUTER

Fortran IV; IBM 370/155-II and IBM 3033.

4. NATURE OF PROBLEM SOLVED

DUST simulates the thermal neutron streaming through multilegged square concrete ducts.

5. METHOD OF SOLUTION

DUST uses the albedo Monte Carlo method. The albedo data used are in the form of empirical formulae based on the measured doubly differential albedo data. Sampling of the reflected polar and azimuth angles is done by the rejection method. Variance reduction devices such as Russian Roulette are used.

6. RESTRICTIONS OR LIMITATIONS

The albedo data and the subroutines for sampling the reflected polar and azimuth angles are specific for concrete ducts. The maximum number of legs (as specified by dimension statements) is 5 and the maximum number of dose points is 50. The dose points considered are only in the last leg of the multilegged duct.

7. TYPICAL RUNNING TIME

For a square duct, 40 feet in length, DUST takes .05 seconds per history. Eight thousand histories give the dose within a 15% statistical error in the case of straight ducts. The sample problem required 29.32 cpu seconds in the GO step on the IBM 3033 computer.

8. COMPUTER HARDWARE REQUIREMENTS

DUST was developed on the IBM 370/155-II computer and tested at RSIC on the IBM 3033 computer.

9. COMPUTER SOFTWARE REQUIREMENTS

The IBM 370, on which DUST was developed, runs IBM OS/VS, and the IBM 3033 used for testing runs the IBM OS/VS2 operating system. At RSIC, DUST was compiled using the IBM Fortran H Extended Enhanced compiler.

10. REFERENCE

R. Indira, K. P. N. Murthy and R. Shankar Singh, "Albedo Monte Carlo Simulation of Thermal Neutron Streaming Through Multilegged Ducts," FRG/01100/RP-217 (January 1982).

11. CONTENTS OF CODE PACKAGE

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

12. DATE OF ABSTRACT

March 1984.