NEA Mandates and Structures

Joint Evaluated Fission and Fusion (JEFF) Nuclear Data Library Co-ordination Group

Chair(s):	Arjan PLOMPEN, Belgium	Secretary:	Antonio JIMENEZ-CARRASCOSA (antonio.jimenez-carrascosa@oecd-nea.org)
Member(s):	Argentina, Austria, Belgium, Bulgaria, Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Italy, Japan, Korea (Rep. of), Mexico, Netherlands, Norway, Poland, Portugal, Romania, Russia (Suspended*), Slovak Republic, Slovenia, Spain, Sweden, Switzerland, Türkiye, United Kingdom
	^*Russian Federation suspended pursuant to a decision of the OECD Council.
EU participation:	The European Union (EU) takes part in the work of the NEA, in accordance with the NEA Statute and the Supplementary Protocol to the Convention on the Organisation for Economic Co-operation and Development.
Observer(s)(International Organisation):	International Atomic Energy Agency (IAEA) By agreement
Date of creation:	01 October 1981
End of mandate:	31 December 2028

Mandate (Document reference):

Established at the meeting of the NEA Steering Committee in October 1981
Extension of the mandate approved at the 15th meeting of the Executive Group on the Nuclear Science Committee [NEA/SEN/NSC/EG(2006)4]
Extension of the mandate - Progress Report for 2005, Work in Hand in 2006 and Programme of Work for 2007 [NEA/SEN/NSC/EG(2006)2]
Extension of the mandate approved at the 18th Meeting of the Executive Group of the Nuclear Science Committee [NEA/SEN/NSC/EG(2009)4]
Extension and modification of the mandate approved at the 19th meeting of the Executive Group of the Nuclear Science Committee NEA/SEN/NSC/EG(2010)4
Extension of the mandate approved at the 22nd Meeting of the Executive Group of the Nuclear Science Committee [NEA/SEN/NSC/EG(2013)4]
Extension of the mandate approved at the 23rd Meeting of the Executive Group of the Nuclear Science Committee [NEA/SEN/NSC/EG(2014)8]
Extension and modification of the mandate approved at the 24th Meeting of the Executive Group (Data Bank Management Committee) of the Nuclear Science Committee [NEA/SEN/NSC/EG(2015)6]
Extension and modification of the mandate approved at the 5th Meeting of the Management Board for the Development, Application and Validation of Nuclear data and Codes (MBDAV) [NEA/SEN/MBDAV(2018)2]
Extension and modification of the mandate approved at the Eighth Meeting of the Management Board for the Development, Application and Validation of Nuclear Data and Codes (MBDAV) [NEA/MBDAV/DOC(2021)10]
Summary Record of the 14th meeting of the MBDAV held in Paris on 30-31 May 2024 [NEA/MBDAV/DOC(2024)5]
Mandate of the Joint Evaluated Fission and Fusion (JEFF) Nuclear Data Library Co-ordination Group [NEA/SEN/MBDAV(2024)1]

Mandate (Document extract):

Extract from document NEA/SEN/MBDAV(2024)1

BACKGROUND

The objective of the Joint Evaluated Fission and Fusion (JEFF) project of the OECD/NEA is to develop and promote the use of high quality evaluated nuclear data sets in standard formats for a wide range of scientific and technical applications. The JEFF project assesses the needs for nuclear data improvements by initiating the necessary measurements, evaluations and benchmarking efforts. It is a collaborative effort between NEA Data Bank member countries. The JEFF Coordination Group (JEFF CG), whose members are nominated by the Management Board for the Development, Application and Validation of Nuclear data and Codes (MBDAV), has responsibility for the overall management of the project. The deliverable of the JEFF project is the JEFF library.

The purpose of the 2025-2028 mandate for the JEFF CG is to release JEFF-4.0; to inform the user community and stakeholders about the contents of the library, its benchmarking and validation; to collect feedback from user community and stakeholders; to set the objectives for JEFF-4.1 development, to better integrate nuclear data efforts among Databank member states and streamline the development process of the new releases of the library; to define the development plan for JEFF-4.1; and to encourage the development of evaluation skills and the engagement of new evaluators.

SCOPE

The purpose of the Joint Evaluation Fission and Fusion (JEFF) Co-ordination Group (JEFF CG) is to develop, compile, verify, validate, document, distribute and promote high-quality sets of evaluated nuclear data in standard formats for a wide range of scientific and technical applications, with an emphasis on fission and fusion applications, under the label “Joint Evaluated Fission and Fusion (JEFF) Nuclear Data Library”. Successive releases target improvement of library performance and range of application. The released JEFF libraries are publicly available without restrictions and distributed by the Data Bank in the form of computer files through a dedicated webpage.

GENERAL OBJECTIVES

The JEFF CG assesses the needs for nuclear data improvements and addresses them by initiating and promoting the necessary measurement, evaluation and benchmarking efforts. The results of these efforts contribute to the JEFF libraries. The JEFF CG aims at catering to the widest possible range of applications in NEA Data Bank participating countries with modern tools of development and dissemination.

The NEA Data Bank participating countries involved in JEFF engage nuclear data users and evaluators to provide feedback on JEFF libraries and provide improved nuclear data evaluations and services.

SPECIFIC OBJECTIVES (mandate 2025-2028)

Release JEFF-4.0 when it satisfies the quality criteria of the JEFF CG (early 2025).
Disseminate JEFF-4.0 by a combination of publications and presentations at suitable events.
Collect feedback on JEFF-4.0 for input to the development of subsequent releases.
Ensure that successive releases of the JEFF library provide fully consistent general-purpose libraries with all needed data and a proven level of performance in a large range of applications.
Create a living document of the specifications required of subsequent releases, incorporating feedback and foresight.
Continue process automation quality assurance, improved benchmarking and validation, and increase the scope of application of the database by the interfaces with user code systems.
Improve integration of efforts contributing to JEFF library development.
Investigate providing process automation for a) benchmarking, b) non-physics model fitting / data adjustment / integral data assimilation, c) physics model fitting.
Promote education and training and encourage the engagement of a new generation of nuclear data scientists and evaluators.

WORKING METHODS AND INTERACTIONS

The JEFF CG schedules, coordinates and approves all updates to the JEFF nuclear data library.

The JEFF CG collaborates with national initiatives or projects aimed at improving evaluated nuclear data and will closely co-operate with Working Parties of the NEA with interest or implication on nuclear data.

The JEFF CG co-operates with major international nuclear data projects and institutions, including:

the International Atomic Energy Agency (IAEA), through the International Nuclear Data Committee (INDC) and the Nuclear Data Section (NDS);
European Union funded activities such as the nuclear data projects for fission and fusion;
the Joint Research Centre of the European Commission (JRC);
the TENDL Nuclear Data Library initiative.

To ensure performance, the JEFF CG may choose to adopt nuclear data evaluations for its own JEFF releases from other national or international nuclear data evaluated libraries that are publicly available.

The NEA Data Bank Secretariat shall provide the following services to the JEFF CG:

Organisation of JEFF meetings and Nuclear Data Weeks in consultation with the JEFF CG.
Publication and distribution of JEFF CG documents, updating the corresponding web pages, and producing official summary records of each JEFF CG meeting.
Assemble, release and distribute the official versions of the JEFF Nuclear Data Library. Collect users’ feedback, maintain up-to-date information, and archive past file versions and records.
Implement and co-ordinate a comprehensive quality assurance (QA) process involving verification, testing and benchmarking tasks according to well-defined criteria.
As part of broader nuclear data services to the NEA Data Bank participating countries, provide a number of testing, processing and benchmarking services for evaluated nuclear data files.
Maintain and develop all JEFF-related groups and projects on the NEA GitLab platform for version control, tracking of developments, documentation, verification, checking and benchmarking and for improved developer interaction.

MEMBERSHIP

All Data Bank member countries may participate in the JEFF CG.

DELIVERABLES

A journal article describing the JEFF-4.0 library with accompanying topical papers expanding on the journal article for important aspects of the library, its benchmarking and validation.
Contributions to the 2025 Nuclear Data for Science and Technology Conference (ND2025). Present JEFF-4.0 at other major conferences and events to improve its dissemination and use.
Organise the third nuclear data stakeholder meeting in 2025 and the fourth nuclear data stakeholder meeting in 2027.
Provide a feedback report for JEFF-4.0 serving the roadmap for JEFF-4.1; Consider establishing a feedback form on the distribution page (to be delivered in 2026).
Provide an objectives document for JEFF-4.1 (to be delivered in 2025 with annual updates).
Provide a roadmap for the release of JEFF-4.1 as well as an accompanying plan for improved benchmarking & validation and the role of library adjustment (documents to be delivered in 2026).
Improved integration of nuclear data projects contributing to JEFF library development.
A strategy for the rejuvenation of the JEFF development community.
Provide a report on the prospects for and realisation of improved automation.