The overall objective of the CIELO Pilot Project (OECD/NEA WPEC SG-40) is to test the scheme of broad international collaboration to improve evaluated nuclear data files of the major nuclides: H-1, O-16, Fe-56, U-235, U-238 and Pu-239. The collaboration scheme is similar to that employed in the IAEA CRP on Evaluated Nuclear Data for the Th-U Fuel Cycle, which resulted in a very successful new evaluation of Th-232 and improvements to the evaluations for other relevant nuclides. Production of improved and validated evaluated nuclear data files is the main goal of the project.
U-235 file: u235ib46o28t6DNcnu5ef0STz3 ENDF file (ACE file )
are updates to the U-235 evaluation. It includes complete covariance matrices of the cross sections, nu-bar, mu-bar, PFNS(thermal) and PFNS(fast). This file is the updated proposal for the the ENDF/B-VIII.0.beta5 evaluation.
U-238 file: u238ib58lrlFsfaST4m ENDF file (ACE file )
are updates to the U-238 evaluation. It includes complete covariance matrices of the cross sections, nu-bar, mu-bar, PFNS(fast) and PFNS(high_energy). This file is the updated proposal for the the ENDF/B-VIII.0.beta5 evaluation.
Fe-56 (26FEB) Version: fe56ib20w
compressed ENDF file and
compressed ACE file
Fe-minor isotopes (28FEB) Version: e80b4 compressed ENDF files and compressed ACE files
Version: 10B_ENDF-VIII_b4 (as received from G. Hale on 1 March), consistent with STD2017
Au-197 (01MAR) Version: n-079_Au_197_STD17_ENDF (as received from A. Trkov on 1 March), consistent with STD2017
Li-6 (07FEB) Version: 6Li_ENDF-VIII_b4 (as received from G. Hale on 8 February), consistent with STD2017
H-1 (27JAN) Version: h1hale17 (as received from G. Hale on 26 January), consistent with STD2017 (comments need update)
Pu-239 was evaluated by Los Alamos National Laboratory, and is provided for convenience of validation. The file was made consistent with Standards_2017 above the resonance region. PFNS were missing for Einc = 17.5, 20 and 30 MeV in the file submitted on February 17.Pu-239 Version: pu239e80b4_5_corDN (as submitted by D. Neudecker on 22 February) compressed ENDF file
The Standards were modified slightly (final release Standards 2017, February) and they affected benchmark performance. The U-238(n,f) cross section below the Standards region was defined on a finer mesh, so it was decided to adopt it (previously the ENDF/B-VI.8 was taken). The cross sections were made consistent with the new Standards in the "Standards" region, as well as in the region of "recommended" cross sections (pointwise or group-wise). This meant that U-235 and U-238 evaluations needed additional tuning. Small changes to nu-bar were made. The new PFNS of U-235 by D. Neudecker are included, as well as the fission gamma data from Stetcu (LANL).
Files available for downloading:
U-235 Version: u235_CIELO20170215 compressed ENDF file (internal IAEA designation u235ib36o28t6DNcnu5ef0STs), SUPERSEDED
U-238 Version: u238_CIELO20170215 compressed ENDF file (internal IAEA designation u238ib54lrlFsfaST4d)
Files are available for downloading:
The archive of data including processed ACE libraries and selected analysis reports are available from the tabs below.
Note: The U-233, Cu-63,65, Au-197 and Fe-54,57,58 are not CIELO evaluations, but they affect benchmarking and have been included in the list.
The evaluation of nuclear reaction data for U-235 is strongly linked to the IAEA CRP on Prompt Fission Neutron Spectra and the IAEA DDP on Neutron Cross Section Standards. Much of the work at the IAEA on U-235 was performed within these two projects.
The primary repository for the iron evaluations is the NNDC Gforge repository. The data files are also available from the links below for convenience.
Additional information can be found on the NEA Data Bank CIELO web site.
Due to compensating effects the Fe-56 evaluation cannot be separated from the evaluations for the minor isotopes, therefore trial evaluations for these isotopes were also performed.
There are also strong compensating effects with alloying elements in stainless steel, like Cr and Mn. Due to time and manpower constraints a re-evaluation of the corresponding isotopes was not included.
Additional information is available in the NEA Data Bank CIELO web site.
Thermal scattering law data (TSL) may have significant impact on thermal reactor benchmarks. A new WPEC Subgroup-42 is being established to investigate the problem that has been neglected for several years. Two research groups are known to work on the evaluation of thermal scattering law data for hydrogen bound in water:
The Neutrons for Science Laboratory at the Institut Laue-Langevin is involved in the nausicaa project. The reference to the published article and a link to the data is available from the web page. The status of the data is "proof-of-principle" and are not ready for extensive benchmarking.
The research group from the Neutron Physics Department at the Centro Atomico Bariloche produced a TSL library for hydrogen bound in water, aimed at improving the reliability of the evaluation in the cold neutron range, and performed a considerable amount of benchmarking in collaboration with external partners. Details will be presented at the forthcoming WPEC Meeting. Some preliminary results of calculations performed at the IAEA have shown that the new data will not introduce a significant bias into the benchmarking. For more details please contact the author Ignacio Marquez .
The thermal scattering law libraries (including hydrogen bound in water) are available from the CAB web site (site address updated in Feb.2016)Data files available for downloading:
In this folder some evaluations are collected that are not strictly CIELO, but have strong impact on the overall benchmarking of the librariesData files available for downloading: