The Upcoming ENDF/B-VIII.1 Release

Nuclear reactors and other nuclear applications play a crucial role in modern society. Both the maintenance of existing systems and the development of new ones require accurate and complete Nuclear Data (ND) to ensure their safe and efficient operation. The main nuclear reaction data library in the United States, and also one of the main ones across the globe, ENDF/B, had its last release (ENDF/B-VIII.0) in 2018 [1]. It contained sub-libraries for neutron, proton, alpha, deuteron, ³He, and gamma projectiles, in addition to thermal neutron scattering law, fission product yields and three atomic sub-libraries. Many developments carried out since then led to important updates to the ND files, in particular for actinides, structural materials and light elements. Some of these contributions are part of the IAEA-coordinated International Nuclear Data Evaluation Network (INDEN) [2]. The scale and impact of these changes justify a new library release, namely ENDF/B-VIII.1, which is planned for early 2024. This upcoming release will be disseminated in both ENDF-6 and GNDS-2.0 formats. In this work we will detail the expected updates in ENDF/B-VIII.1 and discuss the quality-assurance and review methods that were developed and implemented at the National Nuclear Data Center (NNDC, BNL). We will also present and discuss preliminary validation results obtained from Beta versions recently released.

[1] D.A. Brown, et al., “ENDF/B-VIII.0: The 8th Major Release of the Nuclear Reaction Data Library with CIELO-project Cross Sections, New Standards and Thermal Scattering Data”, Nuclear Data Sheets, Vol. 148 (2018), 1-142



[2] https://www-nds.iaea.org/INDEN/