Variance reduction adjustment in Monte Carlo TRIPOLI-4® neutron gamma coupled calculations

Petit, Odile; Lee, Yi-Kang; Diop, Cheikh M’Backé

doi:10.15669/pnst.4.408

Cited by 16 publications

(5 citation statements)

References 2 publications

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“…The importance map generator INIPOND module of TRIPOLI-4 can also be used to improve the variance reduction performance and to reduce the user involvement, especially for the neutron deep penetration cases [3][4][5][6][7][8]. The generated important map is then used by TRIPOLI-4 in the same run to perform importance sampling through the exponential transform method, quota sampling, splitting and Russian roulette, and source biasing.…”

Section: Tripoli-4 Variance Reduction Techniquesmentioning

confidence: 99%

Neutron Deep Penetration Calculations in Light Water with Monte Carlo TRIPOLI-4® Variance Reduction Techniques

Lee

2017

EPJ Web Conf.

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Nuclear decommissioning takes place in several stages due to the radioactivity in the reactor structure materials. A good estimation of the neutron activation products distributed in the reactor structure materials impacts obviously on the decommissioning planning and the low-level radioactive waste management. Continuous energy Monte-Carlo radiation transport code TRIPOLI-4 has been applied on radiation protection and shielding analyses. To enhance the TRIPOLI-4 application in nuclear decommissioning activities, both experimental and computational benchmarks are being performed. To calculate the neutron activation of the shielding and structure materials of nuclear facilities, the knowledge of 3D neutron flux map and energy spectra must be first investigated. To perform this type of neutron deep penetration calculations with the Monte Carlo transport code, variance reduction techniques are necessary in order to reduce the uncertainty of the neutron activation estimation. In this study, variance reduction options of the TRIPOLI-4 code were used on the NAIADE 1 light water shielding benchmark. This benchmark document is available from the OECD/NEA SINBAD shielding benchmark database. From this benchmark database, a simplified NAIADE 1 water shielding model was first proposed in this work in order to make the code validation easier. Determination of the fission neutron transport was performed in light water for penetration up to 50 cm for fast neutrons and up to about 180 cm for thermal neutrons. Measurement and calculation results were benchmarked. Variance reduction options and their performance were discussed and compared.

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Section: Tripoli-4 Variance Reduction Techniquesmentioning

confidence: 99%

Neutron Deep Penetration Calculations in Light Water with Monte Carlo TRIPOLI-4® Variance Reduction Techniques

Lee

2017

EPJ Web Conf.

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“…These are hybrid methods, in the sense that they combine Monte Carlo simulation with a deterministic (discrete-ordinate) calculation. They have been implemented in various codes (e.g., MCNP and TRIPOLI-4) for coupled neutron-gamma simulations and shielding calculations [18,19].…”

Section: Consistent Adjoint Driven Importance Sampling Methodsmentioning

confidence: 99%

Variance-Reduction Methods for Monte Carlo Simulation of Radiation Transport

2021

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After a brief description of the essentials of Monte Carlo simulation methods and the definition of simulation efficiency, the rationale for variance-reduction techniques is presented. Popular variance-reduction techniques applicable to Monte Carlo simulations of radiation transport are described and motivated. The focus is on those techniques that can be used with any transport code, irrespective of the strategies used to track charged particles; they operate by manipulating either the number and weights of the transported particles or the mean free paths of the various interaction mechanisms. The considered techniques are 1) splitting and Russian roulette, with the ant colony method as builder of importance maps, 2) exponential transform and interaction-forcing biasing, 3) Woodcock or delta-scattering method, 4) interaction forcing, and 5) proper use of symmetries and combinations of different techniques. Illustrative results from analog simulations (without recourse to variance-reduction) and from variance-reduced simulations of various transport problems are presented.

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“…For radiation shielding problems with strong attenuation, biasing the transport of the particles emitted to the trajectories which contribute to the expected results has been employed in order to reduce calculation time and improve the efficiency of the convergence. The biasing scheme of TRIPOLI-4® is based on Exponential Transform, and it can be used for neutron transport or photon transport or both [5]. This biasing method has been used for the dogleg benchmark neutronic simulation.…”

Section: Variance Reduction Technique Of Tripoli-4®mentioning

confidence: 99%

Analysis of Dogleg Duct Experiments With 14-MeV Neutron Source Using TRIPOLI-4 Monte Carlo Transport Code

Lei

Pénéliau

Lee

et al. 2018

IEEE Trans. Plasma Sci.

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TRIPOLI-4® Monte Carlo transport code, developed by CEA, has been widely used on fission reactor physics and also can be used on fusion device neutronics. In order to verify the calculation features of TRIPOLI-4® code, a simple dogleg duct model was built to simulate the 14 MeV neutron transport based on a SINBAD fusion benchmark, called Dogleg Duct Streaming Experiment. The reaction rates in the bent duct and on the back surface of the experimental assembly for 93 Nb(n,2n) 92m Nb, 115 In(n,n') 115m In and 197 Au(n,γ) 198 Au neutron activation dosimeters were calculated with the TRIPOLI-4® code. To improve the calculation efficiency, variance reduction techniques of TRIPOLI-4® were also performed. The calculation results showed that the variances reduction methods of the TRIPOLI-4® code are helpful and obviously decrease the calculated time and increase the convergence efficiency. The calculation reaction rates results of 11 points inside and outside of the dogleg duct assembly were taken into account. Results from the TRIPOLI-4® simulation were compared with the experimental ones obtained from the measurements of FNS facility in Japan Atomic Energy Agency (JAEA). The benchmark results show that the TRIPOLI-4® code has a good potential to calculate and estimate neutron streaming effects in fusion device design.

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Variance reduction adjustment in Monte Carlo TRIPOLI-4® neutron gamma coupled calculations

Cited by 16 publications

References 2 publications

Neutron Deep Penetration Calculations in Light Water with Monte Carlo TRIPOLI-4® Variance Reduction Techniques

Neutron Deep Penetration Calculations in Light Water with Monte Carlo TRIPOLI-4® Variance Reduction Techniques

Variance-Reduction Methods for Monte Carlo Simulation of Radiation Transport

Analysis of Dogleg Duct Experiments With 14-MeV Neutron Source Using TRIPOLI-4 Monte Carlo Transport Code

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