Copper benchmark experiment for the testing of JEFF-3.2 nuclear data for fusion applications

Abstract

A neutronics benchmark experiment on a pure Copper block (dimensions 60 × 70 × 70 cm 3) aimed at testing and validating the recent nuclear data libraries for fusion applications was performed in the frame of the European Fusion Program at the 14 MeV ENEA Frascati Neutron Generator (FNG). Reaction rates, neutron flux spectra and doses were measured using different experimental techniques (e.g. activation foils techniques, NE213 scintillator and thermoluminescent detectors). This paper first summarizes the analyses of the experiment carried-out using the MCNP5 Monte Carlo code and the European JEFF-3.2 library. Large discrepancies between calculation (C) and experiment (E) were found for the reaction rates both in the high and low neutron energy range. The analysis was complemented by sensitivity/uncertainty analyses (S/U) using the deterministic and Monte Carlo SUSD3D and MCSEN codes, respectively. The S/U analyses enabled to identify the cross sections and energy ranges which are mostly affecting the calculated responses. The largest discrepancy among the C/E values was observed for the thermal (capture) reactions indicating severe deficiencies in the 63,65 Cu capture and elastic cross sections at lower rather than at high energy. Deterministic and MC codes produced similar results. The 14 MeV copper experiment and its analysis thus calls for a revision of the JEFF-3.2 copper cross section and covariance data evaluation. A new analysis of the experiment was performed with the MCNP5 code using the revised JEFF-3.3-T2 library released by NEA and a new, not yet distributed, revised JEFF-3.2 Cu evaluation produced by KIT. A noticeable improvement of the C/E results was obtained with both new libraries.

The joint evaluated fission and fusion nuclear data library, JEFF-3.3

“…• JEFF- 3 [395,396]. Even if covariance data could be further improved it was concluded earlier that the uncertainties calculated using the available nuclear data were realistic ( [397], Sect.…”

Outcomes of WPEC SG47 on "Use of Shielding Integral Benchmark Archive and Database for Nuclear Data Validation"

“…Copper will be used in fusion reactors such as ITER in divertor, first wall, superconducting magnets, coils and other auxiliary systems. A neutronics benchmark experiment on a pure copper assembly [12,13] was performed at the end of 2014 -beginning of 2015 at the 14 MeV Frascati Neutron Generator (FNG) of ENEA Frascati with the objective to validate the state-of-the-art copper nuclear cross-section data and the related uncertainties. Reaction rates, neutron flux spectra and doses were measured at several locations inside the 60x70x70 cm 3 Copper block (Fig.…”

“…The neutron-leakage spectra of 75 pulsed spheres made of 20 distinct materials were simulated using ENDF/B-VII.1 and ENDF/B-VIII.0 [27]. They highlight issues in 6 Li, 12 C, 16 O, Mg, 27 Al, Ti, and Pb nuclear data. Sensitivities for some of those simulated neutronleakage spectra were calculated in [28] to better understand which nuclear data observables could potentially lead to biases in simulating these experiments.…”

Use of shielding integral benchmark archive and database for nucleardata validation

“…A neutronics benchmark experiment on a pure Copper assembly [14] was performed end 2014 -beginning 2015 at the 14-MeV Frascati neutron generator (FNG) of ENEA Frascati with the objective to provide the experimental database required for the validation of the copper nuclear cross-section data relevant for ITER design calculations, including the related uncertainties. Evaluation of the benchmark for the SINBAD database was performed in the scope of the F4E project [15] and the review is ongoing to include the data in SINBAD.…”