NEA Mandates and Structures

Expert Group on the Recommended Definition of a General Nuclear Database Structure (EGGNDS)

Mandate (Document reference):

• Agreed at the 28th meeting of the Working Party on International Nuclear Data Evaluation Cooperation in May 2016 [NEA/SEN/NSC/WPEC(2016)2]
• Approved at the meeting of the NEA Nuclear Science Committee in June 2016 [NEA/SEN/NSC(2016)2]
• Mandate revised and extended at the 30th meeting of WPEC held on 17-18 May 2018 [NEA/SEN/NSC/WPEC(2018)2] and endorsed by the 29^th NEA Nuclear Science Committee in June 2018 [NEA/SEN/NSC(2018)6]
• Mandate of the Expert Group on the Recommended Definition of the General Nuclear Database Structure (EGGNDS) [NEA/SEN/NSC/WPEC(2018)3]
• Revised and extended at the 32^nd meeting of the Working Party on International Nuclear Data Evaluation Co-operation [NEA/SEN/NSC/WPEC/DOC(2020)11]
• Mandate of the Expert Group on the Recommended Definition of the General Nuclear Database Structure (EGGNDS) [NEA/NSC/WPEC/DOC(2020)12]
• Mandate of the Expert Group on the Recommended Definition of the General Nuclear Database Structure (EGGNDS) [NEA/NSC/WPEC/DOC(2023)2]

Mandate (Document extract):

Extract from document [NEA/NSC/WPEC/DOC(2023)2]

Background

The Evaluated Nuclear Data File format (ENDF-6) has had a long and fruitful history as the preferred format for storing and exchanging evaluated nuclear data. Together with processing codes, it plays a pivotal role connecting nuclear physicists and reactor physicists, allowing them to exchange data between different computer codes. Today, however, it is showing signs of age. In particular, the ENDF-6 format places unnecessary limitations on the types of reactions and the level of precision at which data can be stored, making it more difficult to ensure the quality and consistency of data. Modern users are applying nuclear data towards solving a broad range of problems (in medical physics, global security and advanced detector designs, among others) that stretch the ENDF-6 format beyond its original design.

The Subgroup 38 (SG38) of the Working Party on International Nuclear Data Evaluation Cooperation (WPEC) was formed to solicit feedback from international stakeholders and develop a new General Nuclear Database Structure (GNDS) for storing nuclear data to replace the legacy ENDF-6 format. The SG38 has met its stated goal to develop a nuclear data structure definition that can meet the needs of a broad set of nuclear data users and providers.

The Expert Group on the Recommended Definition of a General Nuclear Database Structure (EGGNDS or Expert Group) was established in 2016 and became the steward of a new international definition for the modern nuclear database structure. EGGNDS delivered the first public specifications for GNDS-1.9 in 2020. The group has finalized the GNDS-2.0 specifications (to be published in 2023) and is beginning to work on changes for the next version of the specifications.

Mandate

EGGNDS is an international expert group, under the WPEC, aiming to endorse, promote, and maintain the new format as the GNDS international standard for disseminating nuclear reaction databases.

Objectives

This Expert Group will make the GNDS:

1. easier for new users, as well as current users, to contribute to the community;
2. general and useful enough that it could also be used to organise nuclear structure data, experimental data, and other nuclear data products;
3. capable of addressing physics and formalism needs beyond those of ENDF-6; and
4. adhere to high quality assurance and documentation practices.

Other goals of the EGGNDS include the development of better open source infrastructure to manipulate, search, plot, process, translate and check nuclear data and the development of new nuclear data products heretofore not possible. The EGGNDS will ensure that important and useful tools for using the new recommended definition are developed and maintained.

The EGGNDS will also guide the creation of new infrastructure and promote better evaluation practices. It is anticipated that it will release new GNDS versions with appropriate documentation as necessary, without overburdening stakeholders.

Deliverables

The Expert Group will ensure the recommended definition of the GNDS meets the needs of major international nuclear data communities. In addition, the EGGNDS will aim to do the following during the mandate period:

• develop and release periodic updates of the GNDS specifications that incorporate approved format proposals; and
• organise workshops and other outreach activities to train evaluators and other members of the nuclear data community, especially users, on the new scheme, its physics, and structural advantages.