Компьютерное моделирование экспериментов по физическому моделированию многофазных систем в аппаратах радиохимического производства

Abstract

Manuscript represents results of testing the code MCNP forMonte Carlosimulation of neutron measurements in physical model experiments with plutonium distribution through liquid multi-phase systems with radiochemical vessels. Satisfactory convergence of calculated and experimental data has been demonstrated. In order to assess applicability of the MCNP code for multivariate calculation modeling of nuclear-physical measurements at remote analytical monitoring of fissile materials its testing was performed for Monte-Carlo computer modeling of neutron measurements in the experiments aimed at physical modeling of plutonium distribution in liquid multiphase subcritical systems in the radiochemical plant tanks. The work studied calculation modeling of neutron radiation transfer through the use of Monte-Carlo method. The choice of MCNP code for modeling was justified. The work describes physical modeling facilities of plutonium distribution in solutions with concentration of up to several units g/l and the corresponding three-dimensional computer models. Physical modeling of the solution with plutonium concentration of up to 1 g/l was carried out at the facility consisting of the cylindrical tank filled with water, the plutonium-beryllium fast neutron source of IBN type and the measuring equipment. The computer model incorporated the cylindrical tank filled water, the helium counter tube and the ambient air. Physical modeling of plutonium distribution in the solutions with concentration of several units g/l was performed at the facility consisting of the cylindrical tank filled with water, special cuvettes filled with plutonium nitrate solution and the measuring equipment. The computer model included the cylindrical tank filled with water, the cuvettes with plutonium nitrate solutions, the helium counter tube and the ambient air. The results of comparison of "physical" and "computer" measurements of neutron field distributions are provided. The obtained satisfactory agreement of the calculated and the experimental results proves applicability of the MCNP code for modeling of neutron measurements in the multiphase systems with fissile materials. Key words :Monte Carlo method, simulation, plutonium, neutron count rate, slow neutron counter. (Russian) DOI: http://dx.doi.org/10.15826/analitika.2014.18.2.004 M.R. Khusainov, E.A. Parfentiev Federal State Unitary Enterprise MAYAK Production Association, Ozersk, Russian Federation