Neutron spectra measurement and calculations using data libraries CIELO, JEFF-3.2 and ENDF/B-VII.1 in iron benchmark assemblies

Abstract

Abstract. The leakage neutron spectra measurements have been done on benchmark spherical assembliesiron spheres with diameter of 20, 30, 50 and 100 cm. The Cf-252 neutron source was placed into the centre of iron sphere. The proton recoil method was used for neutron spectra measurement using spherical hydrogen proportional counters with diameter of 4 cm and with pressure of 400 and 1000 kPa. The neutron energy range of spectrometer is from 0.1 to 1.3 MeV. This energy interval represents about 85 % of all leakage neutrons from Fe sphere of diameter 50 cm and about of 74% for Fe sphere of diameter 100 cm. The adequate MCNP neutron spectra calculations based on data libraries CIELO, JEFF-3.2 and ENDF/B-VII.1 were done. Two calculations were done with CIELO library. The first one used data for all Fe-isotopes from CIELO and the second one (CIELO-56) used only Fe-56 data from CIELO and data for other Fe isotopes were from ENDF/B-VII.1. The energy structure used for calculations and measurements was 40 gpd (groups per decade) and 200 gpd. Structure 200 gpd represents lethargy step about of 1%. This relatively fine energy structure enables to analyze the Fe resonance neutron energy structure. The evaluated cross section data of Fe were validated on comparisons between the calculated and experimental spectra.

Use of nickel sphere and copper cube with 252Cf neutron source in the centre for test of nuclear data libraries ENDF/B-VII.1, ENDF/B-VIII.0, JEFF- 3.3, BROND- 3.1

“…4. The proton recoil method was used for neutron leakage spectrum measurement using spherical hydrogen proportional detectors (HPD) with pressure of 400 (K4) and 1000 kPa (K8) with diameter of 4 cm [5] and scintillation stilbene (ST) detector with dimensions of 1x1 cm [4], see Fig. 5.…”

“…Neutron nuclear data libraries for transport were tested in RC Rez for these elements: Fe, O, H, D, Ni and Na as well as benchmarks. Sodium fast reactor mock-up, i.e., full scale, was studied in cooperation with FEI Obninsk (Russia) [2][3][4]. Materials that are of current interest are: Cu, Ni and stainless steel (SS).…”

Analysis of cross sections on iron and oxygen using Cf-252 neutron source

“…4 and also around 600 keV by about 12-15 %. The C/E around 300 keV grows with iron thickness, B. Jansky [2], [3]. R. Capote, A. Trkov and S. Simakov from IAEA-NDS changed cross-section of 56 Fe producing new ND library IND-R22 and IND-R34 (IND -INDEN conference 2018, [4]) to test influence of such change.…”