Dupont, E.*; Bossant, M.*; Capote, R.*; Carlson, A. D.*; Danon, Y.*; Fleming, M.*; Ge, Z.*; Harada, Hideo; Iwamoto, Osamu; Iwamoto, Nobuyuki; et al.
EPJ Web of Conferences, 239, p.15005_1 - 15005_4, 2020/09
Fleming, M.*; Chadwick, M.*; Brown, D.*; Capote, R.*; Ge, Z.*; Herman, M.*; Ignatyuk, A.*; Ivanova, T.*; Iwamoto, Osamu; Koning, A.*; et al.
EPJ Web of Conferences, 239, p.15003_1 - 15003_5, 2020/09
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
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.
Trkov, A.*; Griffin, P. J.*; Simakov, S. P.*; Greenwood, L. R.*; Zolotarev, K. I.*; Capote, R.*; Aldama, D. L.*; Chechev, V.*; Destouches, C.*; Kahler, A. C.*; et al.
Nuclear Data Sheets, 163, p.1 - 108, 2020/01
The version II of the International Reactor Dosimetry and Fusion File (IRDFF-II) has been released as a consistent set of nuclear data for fission and fusion neutron metrology applications up to 60 MeV neutron energy. The library is intended to support: (a) applications in research reactors; (b) safety and regulatory applications in the nuclear power generation in commercial fission reactors; and c) material damage studies in support of the research and development of advanced fusion concepts. The paper describes the contents of the library, documents the thorough verification process used in its preparation, and provides an extensive set of validation data gathered from a wide range of neutron benchmark fields. The new library is expected to become the international reference in neutron metrology for multiple applications.
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
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.
Chadwick, M. B.*; Capote, R.*; Trkov, A.*; Kahler, A. C.*; Herman, M. W.*; Brown, D. A.*; Hale, G. M.*; Pigni, M.*; Dunn, M.*; Leal, L.*; et al.
EPJ Web of Conferences, 146, p.02001_1 - 02001_9, 2017/09
The CIELO collaboration has studied neutron cross sections on nuclides (O, Fe, U and Pu) that significantly impact criticality in nuclear technologies 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.
erovnik, G.*; Becker, B.*; Belgya, T.*; Genreith, C.*; Harada, Hideo; Kopecky, S.*; Radulovi, V.*; Sano, Tadafumi*; Schillebeeckx, P.*; Trkov, A.*
Nuclear Instruments and Methods in Physics Research A, 799, p.29 - 36, 2015/11
The methodology to derive cross section data from measurements in a cold neutron beam was studied. Mostly, capture cross sections at thermal energy are derived relative to a standard cross section, and proportionality between the standard and the measured cross section is often assumed. Due to this assumption the derived capture cross section at thermal energy can be biased by more than 10%. Evidently the bias depends on how much the energy dependence of the cross section deviates from a direct proportionality with the inverse of the neutron speed. The effect is reduced in case the cross section is not derived at thermal energy but at an energy close to the average energy of the cold neutron beam. Nevertheless, it is demonstrated that the bias can only be avoided in case the energy dependence of the cross section is known and proper correction factors are applied. In some cases the results can also be biased when the attenuation of the neutron beam within the sample is neglected in the analysis. Some of the cross section data reported in the literature suffer from such bias effects.
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
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.
Chadwick, M. B.*; Herman, M.*; Obloinsk, P.*; Dunn, M. E.*; Danon, Y.*; Kahler, A. C.*; Smith, D. L.*; Pritychenko, B.*; Arbanas, G.*; Arcilla, R.*; et al.
Nuclear Data Sheets, 112(12), p.2887 - 2996, 2011/12
The ENDF/B-VII.1 library is our latest recommended evaluated nuclear data file for use in nuclear science and technology applications, and incorporates advances made in the five years since the release of ENDF/B-VII.0. These advances focus on neutron cross sections, covariances, fission product yields and decay data, and represent work by the US Cross Section Evaluation Working Group (CSEWG) in nuclear data evaluation that utilizes developments in nuclear theory, modeling, simulation, and experiment. It features extension of covered nuclei, covariance data for 190 nuclei, R-matrix analyses of neutron reactions on light nuclei, updates for some medium-heavy and actinoid nuclei, etc. Criticality benchmark tests with a transport simulation code MCNP shows improved performances.
Batistoni, P.*; Angelone, M.*; Carconi, P.*; Fischer, U.*; Fleischer, K.*; Kondo, Keitaro; Klix, A.*; Kodeli, I.*; Leichtle, D.*; Petrizzi, L.*; et al.
Fusion Engineering and Design, 85(7-9), p.1675 - 1680, 2010/12
The EU is developing two test blanket modules (TBM), the Helium Cooled Pebble Bed (HCPB) and the Helium Cooled Lithium Lead (HCLL), which will be tested in ITER. Here neutronics experiments with a mockup for HCLL TBM were carried out. Detail distributions of the tritium production rate inside the mockup were measured with various methods. A lithium diamond detector developed as a neutron monitor for fusion devices has also been used as a tritium detector. Activation reaction rates inside the mockup were also measured. These measured data agreed with calculation results buy using MCNP and FENDL-2.1 within 10%, which demonstrated that the prediction accuracy was high. Sensitivity and uncertainty analyses suggested that the uncertainty of the tritium production rate from the nuclear data uncertainty was small, usually below 2%.
Kodeli, I.*; Trkov, A.*; Capote, R.*; Nagaya, Yasunobu; Maslov, V.*
Nuclear Instruments and Methods in Physics Research A, 610(2), p.540 - 552, 2009/11
The prompt fission neutron spectra covariance matrices of U, U and Pu were evaluated using the Monte Carlo method for two empirical spectra formulations, Watt and Kornilov, and compared to the existing evaluations such as JENDL-3.3. The fission spectra, together with the covariance matrices and the methods for the calculation of the corresponding sensitivity profiles were validated on several applications, including shielding (VENUS-3 benchmark, pressure vessel dosimetry) as well as on fast and thermal reactor systems (KRITZ and SNEAK critical experiments). A new set of parameters for a Kornilov model is proposed that improve both benchmark performance and the agreement with recently measured differential spectra. A recommendation to use constrained sensitivity coefficients was confirmed for the case of the fission spectrum induced uncertainty in the effective multiplication factor and in the detector responses, in order to assure the proper normalisation of the corresponding covariance matrices.
Iwamoto, Osamu; Herman, M.*; Mughabghab, S. F.*; Oblozinsk, P.*; Trkov, A.*
AIP Conference Proceedings 769, p.434 - 437, 2005/05
Entirely new evaluations for all the Ge isotopes, from thermal energy to 20 MeV, has been performed with focus on photon production. In the resonance region, parameters were improved considerably compared to earlier evaluations. In the fast region, code EMPIRE-2.19 was used. Validation was done against photon data on Fe and Nb. Isotopic evaluations for Ge were summed up and compared with available measurements on natural Ge. Various quantities related to photon production, showing strong dependence on neutron incident energy, are discussed.
Cullen, D. E.*; Blomquist, R. N.*; Dean, C.*; Heinrichs, D.*; Kalugin, M. A.*; Lee, M.*; Lee, Y. K.*; MacFarlane, R.*; Nagaya, Yasunobu; Trkov, A.*
UCRL-TR-203892, p.1 - 40, 2004/04
no abstracts in English