Steady-state neutronic measurements and comprehensive numerical analysis for the BME training reactor

This paper describes steady-state reactor physics measurements and calculations that were performed for the Training Reactor of Budapest University of Technology and Economics (BME TR) with the purpose of benchmarking. Based on the available geometry specifications and material compositions a model of BME TR was created with the well-validated, general-purpose Serpent 2 Monte Carlo code. Uncertain parameters (such as fuel density and control rod positions) were adjusted to related measurements. The Serpent 2 model was used for the generation of group constants, examining several homogenization schemes. Models were created in the PARCS diffusion code, the SPNDYN diffusion and SP3 code and the PARTISN discrete ordinates code. Various Monte Carlo and deterministic calculations were performed with the adjusted models and the results were then compared with actual measured data. The calculations and measurements show good agreement, this way the Serpent model was successfully validated, while the deterministic models make a good basis for more complex benchmarks in the future, such as transients with thermal-hydraulic feedback. (C) 2021 The Author(s). Published by Elsevier Ltd

Neutron activation and prompt gamma intensity in Ar/CO2-filled neutron detectors at the European Spallation Source

Monte Carlo simulations using MCNP6.1 were performed to study the effect of neutron activation in Ar/CO2 neutron detector counting gas. A general MCNP model was built and validated with simple analytical calculations. Simulations and calculations agree that only the Ar-40 activation can have a considerable effect. It was shown that neither the prompt gamma intensity from the Ar-40 neutron capture nor the produced Ar-41 activity have an impact in terms of gamma dose rate around the detector and background level