Abstract
The majority of the next generation of nuclear power plants (GEN-IV) will work in the fast-neutron-energy region, as opposed to present day thermal reactors. This leads to new and more accurate nuclear-data needs for some minor actinides and structural materials. Following those upcoming demands, the Organisation for Economic Cooperation and Development Nuclear Energy Agency performed a sensitivity study. Based on the latter, an improvement in accuracy from the present 20% to 5% is required for the $^{242}\mathrm{Pu}(n,f)$ cross section. Within the same project both the $^{240}\mathrm{Pu}(n,f)$ cross section and the $^{242}\mathrm{Pu}(n,f)$ cross section were measured at the Van de Graaff accelerator of the Joint Research Centre at the Institute for Reference Materials and Measurements, where quasimonoenergetic neutrons were produced in an energy range from 0.3 MeV up to 3 MeV. A twin Frisch-grid ionization chamber has been used in a back-to-back configuration as fission-fragment detector. The $^{242}\mathrm{Pu}(n,f)$ cross section has been normalized to three different isotopes: $^{237}\mathrm{Np}(n,f), ^{235}\mathrm{U}(n,f)$, and $^{238}\mathrm{U}(n,f)$. A comprehensive study of the corrections applied to the data and the uncertainties associated is given. The results obtained are in agreement with previous experimental data at the threshold region up to 0.8 MeV. The resonance-like structure at 0.8 to 1.1 MeV, visible in the evaluations and in most previous experimental values, was not reproduced with the same intensity in this experiment. For neutron energies higher than 1.1 MeV, the results of this experiment are slightly lower than the Evaluated Nuclear Data File/B-VII.1 evaluation but in agreement with the experiment of Tovesson et al. (2009) as well as Staples and Morley (1998). Finally, for energies above 1.5 MeV, the results show consistency with the present evaluations.
Highlights
For the generation of nuclear power plants (GEN-IV), four of the six designs currently under study are based on a fast neutron-energy spectrum instead of a thermal one
Within the same project both the 240Pu(n,f ) cross section and the 242Pu(n,f ) cross section were measured at the Van de Graaff accelerator of the Joint Research Centre at the Institute for Reference Materials and Measurements, where quasimonoenergetic neutrons were produced in an energy range from 0.3 MeV up to 3 MeV
The neutron-induced fission cross section of 242Pu has been measured in the neutron-energy range from 0.3 MeV up to 3 MeV, following the requests based on the High-Priority Request List of the OECD-Nuclear Energy Agency (NEA)
Summary
For the generation of nuclear power plants (GEN-IV), four of the six designs currently under study are based on a fast neutron-energy spectrum instead of a thermal one. There are upcoming needs for the nuclear-data community to meet more stringent requirements in order to improve the accuracy on the performance of simulations codes in this energy region. To address these aspects, a sensitivity study was performed by the Nuclear Energy Agency (NEA) [1] with the outcome of a list of high priorities of the most important isotopes and their relevant quantities. Within the high-priority list it is requested to improve the accuracy of the neutron-induced fission cross section of 242Pu from the current 20% to a target of 5%.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
