Testing Oxygen Nuclear Data Libraries in Research Center Rez

Martin Schulc,Luiz Leal,Jan Šimon,Michal Košťál,Evžen Novák

doi:10.1115/1.4048763

Abstract

Abstract Oxygen belongs to the group of the most important isotopes in the nuclear data field. The aim of this paper is validate various oxygen nuclear data libraries in different scenarios with high content of oxygen. For this purpose, fast neutron spectra were measured by a stilbene scintillation detector in the region of 1–10 MeV in the three model cases involving 252Cf neutron source and light water reactor. The cases include measurements of leakage spectra using 252Cf neutron source placed in the centers of the light water and heavy water spheres of 0.30 m diameter. Following measurements were carried out inside the concrete biological shielding of the VVER-1000 mock-up simulator in the LR-0 reactor and in the dry channel located in the center of the special core placed in the LR-0 reactor. In the case of the special core, symmetric active core consisted of six standard fuel assemblies which surround the experimental dry module, where the fast neutron spectrum was measured. The measured neutron spectra were compared with MCNP6 transport code calculations in ENDF/B-VII.1, ENDF/B-VIII.0, JENDL-4.0, and IRSN 16O nuclear data evaluations. Experimental results for all cases follow similar trend. All considered libraries underestimate experimental measurement in the region of 3–4 MeV in all cases.

Highlights

Oxygen is one of the most important isotopes in the nuclear data field
The agreement is best for the ENDF/B-VIII.0 and IRSN oxygen evaluation
The presented work focused on the validation of the different oxygen évaluations by means of comparison of the calculated and measured neutron spectra in the range of 1-10 MeV

Summary

Introduction

Numerous nuclear data applications require an excellent knowledge of oxygen cross-sections. As oxygen is abundant in concrete, light water, heavy water and nuclear fuel, the accurate knowledge of cross-section data and related uncertainties is crucial for the nuclear reactor analysis and design and nuclear criticality safety as well as for the processing and disposai of nuclear waste. Cross section for 16O(n,a)13C reaction affects the reactivity of light water reactors and is responsible for the production of helium in fuel pins and claddings and is important for the behavior of these parts. The set of experiments was performed to validate oxygen evaluation for ENDF/B-VII.1 [1], ENDF/B-VIII.0 [2], JENDL-4.0 [3] and IRSN [4] nuclear data libraries in three different scenarios situated into a high oxygen content environment.

Objectives

Results

Conclusion