NEA Mandates and Structures

Technical Review Group for the International Criticality Safety Benchmarks Evaluation Project (ICSBEPTRG)

Mandate (Document reference):

• Summary Record of the 4th meeting of the Working Party on Nuclear Criticality Safety held on 15 September 2000 [NEA/SEN/NSC/WPNCS(2001)1]
• Summary Record of the 18th meeting of the Nuclear Science Committee held on 13-15 June 2007 [NEA/SEN/NSC(2007)3]
• Summary Record of the 21st meeting of the Nuclear Science Committee held on 9-11 June 2010 [NEA/SEN/NSC(2010)3]
• Summary Record of the 23rd meeting of the Nuclear Science Committee held on 13-15 June 2012 [NEA/SEN/NSC(2012)3]
• Summary Record of the 16th meeting of the Working Party on Nuclear Criticality Safety held on 21 September 2012 [NEA/NSC/WPNCS/DOC(2013)6] – Change of name from “WPNCS Expert Group on Criticality Safety Benchmarks” to “Technical Review Group for the International Criticality Safety Benchmarks Evaluation Project”
• Summary Record of the 21st meeting of the Working Party on Nuclear Criticality Safety held from 26 to 30 June 2017 [NEA/NSC/WPNCS/DOC(2017)2] 
• Summary Record of the 25th meeting of the Working Party on Nuclear Criticality Safety held on 8-9 July 2021 [NEA/NSC/WPNCS/DOC(2021)16]
• Summary Record of the 31st meeting of the Working Party on Nuclear Criticality Safety held on 27 September 2024 [NEA/NSC/WPNCS/DOC(2024)XX, forthcoming]
• Mandate of the Technical Review Group for the International Criticality Safety Benchmark Evaluation Project (ICSBEPTRG) [NEA/SEN/NSC/WPNCS(2024)2]

Mandate (Document extract):

Extract from document [NEA/SEN/NSC/WPNCS(2024)2]

Mandate

Scope

Under the direction of the Nuclear Science Committee’s (NSC) Working Party on Nuclear Criticality Safety (WPNCS), the Technical Review Group for the International Criticality Safety Benchmark Evaluation Project (ICSBEPTRG) co‑ordinates the programme of the International Criticality Safety Benchmark Evaluation Project (ICSBEP) and the development of the ICSBEP handbook and database. These comprise an evaluated set of benchmark specifications derived from experiments performed at various nuclear facilities around the world. The benchmark specifications are primarily intended for use by criticality safety practitioners to validate nuclear data and calculational techniques used to establish minimum subcritical margins for safe operations with fissile material, as well as other calculations of relevance to the field of nuclear criticality safety such as associated fundamental physics or alarm placement.

The ICSBEPTRG will also steer the development of the Database for ICSBEP (DICE) tool to facilitate user access to the ICSBEP benchmarks.

Objectives

The main objective of the ICSBEPTRG is to provide the nuclear community with an evaluated set of benchmark specifications by collecting integral experiment data from the nuclear laboratories worldwide. More specifically the objectives are as follows:

• identify and evaluate a comprehensive set of critical and sub-critical benchmark experiment data, as well as associated fundamental physics or alarm placement relevant data;
• verify the data, to the extent possible, by reviewing original and subsequently revised documentation, and by communicating with the experimenters or individuals who are familiar with the experimenters or the experimental facility;
• evaluate the experimental data and uncertainties;
• transform evaluated measurements into benchmarks that are appropriate for validation of calculation methods, adjust measurement results and uncertainties accordingly;
• compile the benchmark data into a standardised format;
• perform calculations of each benchmark with standard criticality safety codes;
• formally document the work into a single source of verified benchmark data (the ICSBEP Handbook).

Working methods

The ICSBEPTRG will report to the WPNCS. The ICSBEPTRG will meet once per year. Additional ad-hoc meetings in support of particular tasks and activities may be organised as needed.

Membership

The ICSBEPTRG is both a forum for international exchanges between experts and a task-oriented technical review group that is composed of a diverse range of specialists in the field of criticality safety, integral experiments, associated modelling and simulation.

The ICSBEPTRG will continue to invite and co-operate with experts from non-member countries, based on mutual benefit, and upon agreement by the ICSBEPTRG members.

Interactions

The ICSBEPTRG will closely co-ordinate its work with other subsidiary bodies of the NSC developing databases of integral experiments. In particular, there will be close links with the Working Party on Scientific Issues and Uncertainty Analysis of Reactor Systems (WPRS) Expert Group on Physics of Reactor Systems (EGPRS) and the International Reactor Physics Experiments Evaluation Project Technical Review Group (IRPhETRG); as well as with the International Radiation Shielding Experiments Database (SINBAD). Links will also be maintained with the NSC Working Party on International Nuclear Data Evaluation Co-operation (WPEC) and the Joint Evaluated Fission and Fusion (JEFF) Nuclear Data Library of the Management Board for the Development, Application and Validation of Nuclear Data and Codes (MBDAV). The Handbook will be distributed on a per request basis by the NEA Data Bank, and DICE will be developed jointly with the NEA IT team.

A key element of the evaluation process is a rigorous analysis of the uncertainties, including quantification of correlations between experiments. There will be strong linkage between the ICSBEPTRG and the WPNCS activities on integral experiment uncertainties and covariance data in criticality safety validation.

Deliverables

The deliverables of the ICSBEPTRG are benchmark technical reports compiled in the ICSBEP Handbook and the DICE database, under both downloadable and DVD format, as well as technical or collective opinion papers. The detailed list of deliverables will be tracked in the semi-annual NSC progress reports.