USING THE METHOD OF APPROXIMATE CALCULATION OF LOW-IMPORTANCE NUCLIDE CROSS SECTIONS IN THE BURNUP SIMULATION OF VVER-1000 CORE BY THE MCU MONTE CARLO CODE

Authors & Affiliations

Bikeev A.S., Kalugin M.A., Shkarovsky D.A., Shkityr V.V.
National Research Centre "Kurchatov Institute", Moscow, Russia

Bikeev A.S. – Head of Software Laboratory, National Research Center "Kurchatov Institute". Contacts: 1, Akademika Kurchatova pl., Moscow, Russia, 123182. Tel: +7(499) 196-96-43; e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it..
Kalugin M.A. – Scientific Director of the Kurchatov Nuclear Power Complex, Dr. Sci. (Tech.), National Research Center "Kurchatov Institute".
Shkarovsky D.A. – Head of the Division of Benchmark Calculations of Nuclear Reactors, Cand. Sci. (Phys. and Math.), National Research Center "Kurchatov Institute".
Shkityr V.V. – Engineer, National Research Center "Kurchatov Institute".

Abstract

In recent years, there has been a tendency in the nuclear industry to use Monte Carlo codes for burnup simulation of full-scale reactor cores or their fragments. The main difficulties of using the Monte Carlo code for burnup simulation of a full-scale core are the long calculation time and the large amount of RAM required for simulating neutron transport and changing the nuclide composition in a considered system consisting of several million burnup materials.
The purpose of the work is to study the possibility of reducing the calculation time and the amount of RAM in the burnup simulation of the VVER-1000 reactor core or its fragment using the MCU Monte Carlo code.
MCU code implements the method for approximate calculation of macroscopic cross sections of low-importance nuclides – the summary isotope method in order to reduce the calculation time and the amount of RAM while solving the problem of changing the nuclide composition of the considered system. The paper discusses the use of the summary isotope method in solving the problem of changing the nuclide composition of uranium fuel in the VVER-1000 core or its fragment.
An optimal list of low-importance nuclides for the summary isotope method was determined using the fixed-point algorithm and binary search algorithm. It is shown that the use of this list of nuclides reduces the total calculation time by 4 times while the methodological errors in estimating the neutron multiplication factor and fission reaction rate do not exceed 0.06 % and 0.16 % respectively at all time steps.

Keywords
MCU, Monte Carlo, burnup, core, VVER-1000, summary isotope method, macroscopic cross section, actinide, fission products, simulation parameters, neutron multiplication factor, fission reaction rate

Article Text (PDF, in Russian)

References

UDC 621.039.17

Problems of Atomic Science and Technology. Series: Nuclear and Reactor Constants, 2018, issue 4, 4:3