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 (Internet), 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.
Palmiotti, G.*; Salvatores, M.*; Yokoyama, Kenji; Ishikawa, Makoto
NEA/NSC/R(2016)6 (Internet), 42 Pages, 2017/05
Palmiotti, G.*; Briggs, J. B.*; Kugo, Teruhiko; Trumble, E.*; Kahler, A. C.*; Lancaster, D.*
Nuclear Science and Engineering, 178(3), p.295 - 310, 2014/11
The International Reactor Physics Experiment Evaluation Project (IRPhEP) and the International Criticality Safety Benchmark Evaluation Project (ICSBEP) provide evaluated integral benchmark data that may be used for validation of reactor physics / nuclear criticality safety analytical methods and data, nuclear data testing, advanced modeling and simulation, and safety analysis licensing activities. The handbooks produced by these programs are used in over 30 countries. Five example applications are presented in this paper: (1) Use of IRPhEP Data in Uncertainty Analyses and Cross Section Adjustment, (2) Uncertainty Evaluation Methods for Reactor Core Design at JAEA Using Reactor Physics Experimental Data, (3) Cross Section Data Testing with ICSBEP Benchmarks, (4) Application of Benchmarking Data to a Broad Range of Criticality Safety Problems, and (5) Use of the International Handbook of Evaluated Reactor Physics Benchmark Experiments to Support the Power Industry.
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.
Harada, Hideo; Shibata, Keiichi; Nishio, Katsuhisa; Igashira, Masayuki*; Plompen, A.*; Hambsch, F.-J.*; Schillebeeckx, P.*; Gunsing, F.*; Ledoux, X.*; Palmiotti, G.*; et al.
NEA/NSC/WPEC/DOC(2014)446, 111 Pages, 2014/02
Okajima, Shigeaki; Fougeras, P.*; Gil, C.-S.*; Glinatsis, G.*; Gulliford, J.*; Iwamoto, Osamu; Jacqmin, R.*; Khomyakov, Y.*; Kochetkov, A.*; Kormilitsyn, M. V.*; et al.
NEA/NSC/DOC(2013)3, p.265 - 278, 2013/04
The Expert Group on Integral Experiments for Minor Actinide Management (EG on IEMAM) was established under OECD/NEA/NSC. The objectives are to review integral experiments for validating MA nuclear data, to recommend additional integral experiments and to propose an international framework to facilitate them from view points of the MA management. The paper summarized the discussion results in the EG on IEMAM as follows: (1) Requirement of nuclear data for MA management, (2) Reviewing existing integral data and identifying specification of missing experimental work to be required, (3) Identifying the bottlenecks and considering possible solutions to them and (4) Proposal of action program for international cooperation.
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.
Oizumi, Akito; Hummel, A. J.*; Marshall, M. A.*; Palmiotti, G.*; Youinou, G. J.*
no journal, ,
The Idaho National Laboratory (INL) has proposed to perform measurements of the fission rate ratio and sample reactivity worth under a wide range of spectral indices created using several types of thermal neutron shielding filters in an experimental position in the Neutron RADiography (NRAD) reactor. The JAEA has a plan to perform integral experiments with fission chambers in the NRAD to further validate the nuclear data of MAs, and ultimately reduce the uncertainty in the cross-sections. In this study, the optimization of the BC filter thickness was conducted to acquire the high-accuracy and the beneficial experimental data. The optimized BC filter thickness was determined to be 3 mm based on the comprehensive evaluation from the viewpoints of the shielding ability of low energy neutrons, the level of the total neutron flux, and the influence of fabrication accuracy of the BC filter. The adoption of the tentative optimized model would be acquired the experimental data such as fission reaction rate and sample worth with the wider spectral indices because the tentative optimized model would be able to increase the ratio of the fast neutrons by almost completely eliminating the effect of the thermal neutrons.