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

Plompen, A. J. M.*; Cabellos, O.*; De Saint Jean, C.*; Fleming, M.*; Algora, A.*; Angelone, M.*; Archier, P.*; Bauge, E.*; Bersillon, O.*; Blokhin, A.*; et al.

European Physical Journal A, 56(7), p.181_1 - 181_108, 2020/07

https://doi.org/10.1140/epja/s10050-020-00141-9

The Joint Evaluated Fission and Fusion nuclear data library 3.3 is described. New evaluations for neutron-induced interactions with the major actinides U, U and Pu, on Am and Na, Ni, Cr, Cu, Zr, Cd, Hf, W, Au, Pb and Bi are presented. It includes new fission yileds, prompt fission neutron spectra and average number of neutrons per fission. In addition, new data for radioactive decay, thermal neutron scattering, gamma-ray emission, neutron activation, delayed neutrons and displacement damage are presented. JEFF-3.3 was complemented by files from the TENDL project. The libraries for photon, proton, deuteron, triton, helion and alpha-particle induced reactions are from TENDL-2017. The demands for uncertainty quantification in modeling led to many new covariance data. A comparison between results from model calculations using the JEFF-3.3 library and those from benchmark experiments for criticality, delayed neutron yields, shielding and decay heat, reveals that JEFF-3.3 is excellent for a wide range of nuclear technology applications, in particular nuclear energy.

CIELO collaboration summary results; International evaluations of neutron reactions on uranium, plutonium, iron, oxygen and hydrogen

Chadwick, M. B.*; Capote, R.*; Trkov, A.*; Herman, M. W.*; Brown, D. A.*; Hale, G. M.*; Kahler, A. C.*; Talou, P.*; Plompen, A. J.*; Schillebeeckx, P.*; et al.

Nuclear Data Sheets, 148, p.189 - 213, 2018/02

https://doi.org/10.1016/j.nds.2018.02.003

The CIELO collaboration has studied neutron cross sections on nuclides that significantly impact criticality in nuclear facilities - U, U, Pu, Fe, O and H - with the aim of improving the accuracy of the data and resolving previous discrepancies in our understanding. This multi-laboratory pilot project, coordinated via the OECD/NEA Working Party on Evaluation Cooperation (WPEC) Subgroup 40 with support also from the IAEA, has motivated experimental and theoretical work and led to suites of new evaluated libraries that accurately reflect measured data and also perform well in integral simulations of criticality. This report summarizes our results and outlines plans for the next phase of this collaboration.

The CIELO Collaboration; Neutron reactions on H, O, Fe, U, and Pu

Chadwick, M. B.*; Dupont, E.*; Bauge, E.*; Blokhin, A.*; Bouland, O.*; Brown, D. A.*; Capote, R.*; Carlson, A. D.*; Danon, Y.*; De Saint Jean, C.*; et al.

Nuclear Data Sheets, 118, p.1 - 25, 2014/04

https://doi.org/10.1016/j.nds.2014.04.002

CIELO (Collaborative International Evaluated Library Organization) provides a new working paradigm to facilitate evaluated nuclear reaction data advances. It brings together experts from across the international nuclear reaction data community to identify and document discrepancies among existing evaluated data libraries, measured data, and model calculation interpretations, and aims to make progress in reconciling these discrepancies to create more accurate ENDF-formatted files. The focus will initially be on a small number of the highest-priority isotopes, namely H, O, Fe, U, and Pu. This paper identifies discrepancies between various evaluations of the highest priority isotopes. The evaluated data for these materials in the existing nuclear data libraries are reviewed, and some integral properties are given. The paper summarizes a program of nuclear science and computational work needed to create the new CIELO nuclear data evaluations.

Gas production and activation calculation in MEGAPIE

Thiolliere, N.*; David, J.-C.*; Eid, M.*; Konobeyev, A. Y.*; Eikenberg, J.*; Fischer, U.*; Grschel, F.*; Guertin, A.*; Latg, C.*; Lemaire, S.*; et al.

Proceedings of International Conference on the Physics of Reactors, Nuclear Power; A Sustainable Resource (PHYSOR 2008) (CD-ROM), 8 Pages, 2008/09

Gas measurements by spectroscopy in the MEGAwatt PIlot Experiment (MEGAPIE) project has led to the determination of main radioactive isotopes released by the LBE. Comparison with calculations performed with several validated codes supplies important volatile elements release fraction estimation in a spallation target. In addition, calculations with MCNPX2.5.0, FLUKA and SNT codes coupled with evolution programs have been performed in order to study the activation of the target and structural materials. The induced database is relevant for safety and radioprotection during operation, for the post-irradiation experiments and for target dismantlement.

SIMMER-III: A Computer Program for LMFR Core Disruptive Accident Analysis; Version 3.A Model Summary and Program Description

Yamano, Hidemasa; Fujita, Satoshi; Tobita, Yoshiharu; Kamiyama, Kenji; Kondo, Satoru; Morita, Koji*; Fischer, E. A.; Brear, D. J.; Shirakawa, Noriyuki*; Cao, X.; et al.

JNC TN9400 2003-071, 340 Pages, 2003/08

JNC-TN9400-2003-071.pdf:1.54MB

An advanced safety analysis computer code, SIMMER-III, has been developed to investigate postulated core disruptive accidents in liquid-metal fast reactors (LMFRs). SIMMER-III is a two-dimensional, three-velocity-field, multiphase, multicomponent, Eulerian, fluid-dynamics code coupled with a space-dependent neutron kinetics model. By completing and integrating all the physical models originally intended at the beginning of this code development project, SIMMER-III is now applicable to integral reactor calculations and other complex multiphase flow problems. A systematic code assessment program, conducted in collaboration with European research organizations, has shown that the advanced features of the code have resolved many of the limitations and problem areas in the previous SIMMER-II code. In this report, the models, numerical algorithms and code features of SIMMER-III Version 3.A are described along with detailed program description. Areas which require future model refinement are also discussed. SIMMER-III Version 3.A, a coupled fluid-dynamics and neutronics code system, is expected to significantly improve the flexibility and reliability of LMFR safety analyses.