Neutronics experiments for uncertainty assessment of tritium breeding in HCPB and HCLL blanket mock-ups irradiated with 14 MeV neutrons

Abstract

Two neutronics experiments have been carried out at 14 MeV neutron sources on mock-ups of the helium cooled pebble bed (HCBP) and the helium cooled lithium lead (HCLL) variants of ITER test blanket modules (TBMs). These experiments have provided an experimental validation of the calculations of the tritium production rate (TPR) in the two blanket concepts and an assessment of the uncertainties due to the uncertainties on nuclear data. This paper provides a brief summary of the HCPB experiment and then focuses in particular on the final results of the HCLL experiment. The TPR has been measured in the HCLL mock-up irradiated for long times at the Frascati 14 MeV Neutron Generator (FNG). Redundant and well-assessed experimental techniques have been used to measure the TPR by different teams for inter-comparison. Measurements of the neutron and gamma-ray spectra have also been performed. The analysis of the experiment, carried out by the MCNP code with FENDL-2.1 and JEFF-3.1.1 nuclear data libraries, and also including sensitivity/uncertainty analysis, shows good agreement between measurements and calculations, within the total uncertainty of 5.9% at 1σ level.

A study of 239Pu production rate in a water cooled natural uranium blanket mock-up of a fusion–fission hybrid reactor

“…For the present study, the neutronics experiments have been extended to include blanket materials and coolant to replicate the blanket structure in a mock-up. Similar experiments have previously been performed by European groups on mock-ups of tritium producing fusion reactor blankets [18][19][20]. Therefore, some fusion-fission blanket mockups should be established and 239 Pu production rates can be obtained in more detail.…”

Comments on the status of modern covariance data based on different fission and fusion reactor studies

“…The SUSD3D code was used since early 1990s for very various applications, such as: reactor pressure vessel surveillance dosimetry [3]: uncertainty in predicted dosimeter reaction rates and pressure vessel exposition, determination of realistic safety margins and consequently the reactor lifetime predictions; -fission shielding benchmarks [3]: sensitivity and uncertainty in the measured reaction rates were calculated for the several benchmarks from the SINBAD database, such as the ASPIS Iron, ASPIS Iron88 and VENUS-3 pressure vessel dosimetry benchmark; sensitivity/uncertainty pre-and post-analysis of the fusion shielding benchmarks performed at the Frascatti Neutron Generator (FNG) at ENEA Frascatti (sensitivity/uncertainty of the measured fast/thermal activation rates and the tritium production in FNG-Bulk Shield benchmark, FNG-Streaming, FNG-SiC, FNG-Tungsten [5], FNG HCPB and FNG-HCLL tritium breeding modules [6,7] and FNG Copper [8,9] benchmarks); criticality benchmarks (sensitivity to k eff and b eff ): many benchmarks from IRPhE and ICSBEP (KRITZ-2 [10], SNEAK-7A and À7B [11], VENUS-2, etc. ), MYRRHA reactor [12], etc.…”

Nuclear data for fusion technology – the European approach

“…The HCPB and HCLL benchmark experiments, performed previously at the Frascati Neutron Generator (FNG) [19] were re-analyzed with the state-of-theart nuclear data libraries JEFF-3.2, FENDL-3.1b, and ENDF/B-VII.1 with focus on the tritium production. It was found that all three evaluations produce similar results.…”