VVER-1000 BENCHMARK INTERPRETATION WITH MONTE CARLO CODE MCS

Fathurrahman Setiawan,Peng Zhang,Deokjung Lee,Matthieu Lemaire,Hyunsuk Lee,M Margulis,P Blaise

doi:10.1051/epjconf/202124710006

Abstract

An interpretation of the NEA-1517/82 benchmark from the SINBAD shielding database has been conducted with the MCS Monte Carlo code developed at the Ulsan National Institute of Science and Technology (UNIST) and the ENDF/B-VII.1 nuclear data library. The NEA-1517/82 benchmark corresponds to experiments on a VVER-1000 critical mock-up (thermal reactor with hexagonal fuel lattice) inside the LR-0 research reactor operated by the Nuclear Research Institute (NRI) in the Czech Republic. A new 3D model of the VVER-1000 mock-up core is developed for MCS based on the SINBAD documentation. The model includes the top and bottom parts of fuel pins, the spacer grids and core components: baffle, barrel, downcomer, tank, reactor pressure vessel (RPV) and concrete block used as biological shielding. The quality of the model is verified first by code/code comparison of MCS against MCNP6 for criticality and power distributions (pin-by-pin and axial power). The validation of MCS results is then performed against six critical cases, 260 measured pin powers and benchmark calculations of the axial power profile. Finally, a comparison of calculated and measured neutron spectra inside the mock-up core is presented as a preliminary study for upcoming works on the deep-penetration shielding capability of MCS.

Highlights

This paper presents an interpretation of the NEA-1517/82 SINBAD benchmark with the MCS Monte Carlo code, developed at the Ulsan National Institute of Science and Technology (UNIST), and the ENDF/B-VII.1 nuclear data library
A first interpretation of experiments conducted in the VVER-1000 mock-up in the LR-0 experimental reactor of the Nuclear Research Institute in the Czech Republic is conducted with the MCS Monte Carlo under development at UNIST and the ENDF/B-VII.1 nuclear data library
The interpretation is carried out with a detailed model of the VVER-1000 mock-up prepared for MCS and MCNP6 in order to provide verification and validation elements of MCS for thermal-reactor hexagonal fuel lattice geometries

Summary

INTRODUCTION

MCS photon transport kernel has been verified for shielding problems with a fixed photon source by comparison against the Monte Carlo code MCNP6 [5] and validation studies of the coupled neutron-photon transport capability have been conducted using gamma-leakage measurements from 14-MeV neutron transmission SINBAD benchmarks [6]. Additional measurements available in the literature detail six critical configurations of the VVER-1000 mock-up [7] [8] This benchmark is well suited for the criticality and deep-penetration shielding validation of MCS on thermal-reactor hexagonal fuel lattices. This paper covers the verification (against MCNP6) and validation (against measurements) of MCS for the six criticality configurations, axial and radial power distributions and the neutron spectrum measured in the dry experimental channel inside the VVER-1000 mock-up core

Description and Experimental Configuration

Criticality

Radial Pin Power

Neutron Spectrum inside the Core

CONCLUSIONS