Speaker
Description
The Cross Section Evaluation Working Group (CSEWG) is actively working to assemble its next library release, ENDF/B-VIII.1. In this contribution, we will outline progress toward this release. From the neutron sublibrary, there are several new evaluations from the INDEN collaboration (Cr, Mn, Fe, Si, 235U, 233U, 239Pu, 16,18O), and from others in CSEWG (140,142Ce, 63,65Cu, 86Kr, Pb, 181Ta, 103Rh and minor revisions). With these changes, all main components of stainless steel have now been updated. In the thermal neutron scattering library, the number of changes is enormous and includes Be2C, 7LiH, 7LiD, UH3, YH2, ZrH2 and ZrHx from the Naval Nuclear Laboratory; metal Be, graphite, SiC, and UC from North Carolina State University; MgO, MgF2 and BeF2 from University of Sharjah; and more than 200 evaluations generated from the NCrystal by the European Spallation Source. These changes far exceed the number of available MAT numbers in the legacy ENDF-6 format. Several of the new TSL evaluations use the mixed mode moderator format backported to the ENDF-6 format from GNDS-2.0. Several improvements to the SFY, NFY and decay sublibraries have been made including the addition of antineutrino spectra, enabling new nonproliferation applications. There are also new alpha sublibrary additions to support nuclear safeguards applications. Other changes include several other charged particle evaluations and the full adoption of the IAEA Photonuclear Library. ENDF/B-VIII.1 will be released in both GNDS-2.0 and the legacy ENDF-6 format. Due to the COVID-19 pandemic, much of the experimental work has been delayed and in-person meetings have been canceled. As a result, the ENDF/B-VIII.1 release will be delayed until February 2024.
This work was supported by the Nuclear Criticality Safety Program, funded and managed by the National Nuclear Security Administration for the Department of Energy. The work at Brookhaven National Laboratory was sponsored by the Office of Nuclear Physics, Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-98CH10886 with Brookhaven Science Associates, LLC.