Comparison of MCNPX and FLUKA Monte Carlo codes in the simulating a nuclear gauge

Highlights: • A nuclear gauge system was simulated fully using multi-purpose Monte Carlo codes MCNPX and FLUKA. • The performance level of MCNPX and FLUKA codes have been determined in simulating the nuclear gauge system. • The comparisons show very good agreement between the simulation results and the experimental results. • This study shows the accuracy of simulation in calibration and measurement of the liquid surfaces in a nuclear gauge. In this paper, a nuclear gauge was simulated using MCNPX and FLUKA codes. This device consists of a fluid-containing vessel, three BC400 rod plastic scintillator and a⁶⁰Co gamma source. Simulation studies show that the changes in the count of each of the three detectors and the sum of their counts decrease with increasing vessel water height. The simulation results were compared with the measurement results. Comparison results show that the mean count difference between MCNPX code and experimental results is about 3% lower than FLUKA code, but the computation time using FLUKA code is approximately 2.8 times less than the MCNPX code.