Speaker
Description
In the context of the development of Gen. IV nuclear reactors, the GIF (Generation IV. International Forum) has selected six innovative technologies. Among them, one can highlight the concept of breeding for $^{232}$Th/$^{233}$U and $^{238}$U/$^{239}$Pu fuel cycles. But those nuclei, crucial for such cycles, suffer from a lack of precise knowledge (nuclear structure, reaction cross sections). In particular, it has been demonstrated that neutron inelastic scattering reaction cross sections are not precise enough for the isotope $^{238}$U and $^{239}$Pu, and not known at all experimentally for the nucleus of $^{233}$U. In order to perform simulations of reactor cores for the development of those technologies, new measurements have to be done. The GRAPhEME (GeRmanium array for Actinides PrEcise Measurements) experimental setup, developed by the IPHC from the CNRS, installed at the GELINA facility is a powerful tool to answer this need [1,2]. Combining the prompt $\gamma$-ray spectroscopy and the time-of-flight methods, it measures partial (n,xn$\gamma$) reaction cross sections. This paper presents on one hand main challenges which represent experiments on high activity actinides, especially on $^{233}$U and $^{239}$Pu and on the other hand results obtained so far for the measurements of partial (n,xn$\gamma$) reaction cross section for the nucleus $^{233}$U.
Exploring a more theoretical aspect of nuclear data, the LEPh and the SPN from the CEA work, among other nuclear fields, on the evaluation of nuclear data. Using nuclear calculation codes such as TALYS [3] and experimental data, they aim to provide new evaluated data. In particular, a new evaluation of the neutron inelastic scattering on $^{238}$U is in progress. It is based on a recent set of experimental data, namely results on $^{238}$U partial (n,xn$\gamma$) reaction cross sections obtained with GRAPhEME and a updated version of TALYS, with new models recently added into this code.
References
[1] : M. Kerveno, G. Henning, C. Borcea, P. Dessagne, M. Dupuis, S.Hilaire, A. Negret, M. Nyman, A. Olacel, E. Party and A. Plompen; How to produce accurate inelastic cross sections from an indirect measurement method ?; EPJ N - Nuclear Sciences & Technologies, Vol. 4; 2018; https://hal.archives-ouvertes.fr/hal-02109918.
[2] : M. Kerveno, M. Dupuis, C. Borcea, M. Boromiza, R. Capote}, P. Dessagne, G. Henning, S. Hilaire, T. Kawano, A. Negret, M. Nyman, A. Olacel, E. Party, A. Plompen, P. Romain and M. Sin; What can we learn from (n,xn$\gamma$) cross sections about reaction mechanism and nuclear structure ?; ND 2019 : International Conference on Nuclear Data for Science and Technology; 2019; https://hal.archives-ouvertes.fr/hal-02957494.
[3] : A.J. Koning, D. Rochman, J. Sublet, N. Dzysiuk, M. Fleming and S. van der Marck; TENDL: Complete Nuclear Data Library for Innovative Nuclear Science and Technology; Nucl. Data Sheets; Vol.155; 2019.
