1. NAME AND TITLE
PLACID: Monte Carlo Simulation of Gamma Streaming Through Straight Cylindrical Ducts.
Reactor Research Centre, Kalpakkam, Tamil Nadu, India.
3. CODING LANGUAGE AND COMPUTER
Fortran IV and Assembler language; IBM 370 and 3033.
4. NATURE OF PROBLEM SOLVED
PLACID simulates gamma streaming through straight cylindrical ducts in shields using the Monte
5. METHOD OF SOLUTION
Monte Carlo simulation is employed with variance reduction devices such as Russian Roulette and
cutoff weight for history termination. Photon point total cross sections are used. Klein Nishina
formulae are used for differential scattering cross section. The Kahn double rejection technique is used
for sampling the scattered photon energy and the scattering angle. Next event estimation is used for
scoring the streaming flux.
6. RESTRICTIONS OR LIMITATIONS
Only straight cylindrical ducts in shields are simulated.
7. TYPICAL RUNNING TIME
Simulation of Cs-137 photon streaming through a cylindrical duct of 100 cm length and 5 cm
radius takes 76 milliseconds per history. About 6400 histories give the total dose at the duct exit within
a 10% statistical error. The sample problem included in the package required 63.93 cpu seconds to
compile and execute on the IBM 3033 computer.
8. COMPUTER HARDWARE REQUIREMENTS
PLACID was developed on the IBM 370/55-II computer and modified to run on the IBM 3033
9. COMPUTER SOFTWARE REQUIREMENTS
The IBM 370 computer on which PLACID was developed runs IBM OS/VS and the IBM 3033
used for testing runs IBM OS/VS2. At RSIC, PLACID was compiled using the IBM Fortran H
Extended Enhanced compiler.
R. Indira and K. P. N. Murthy, "Monte Carlo Simulation of Gamma Streaming Through Straight
Cylindrical Ducts," FRG/01100/RP-219 (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
KEYWORDS: MONTE CARLO; DUCT GEOMETRY