NEA Mandates and Structures


Expert Group on Physics of Reactor Systems (EGPRS)

Chair(s): Hakim FERROUKHI, Switzerland
Robert E. GROVE, United States
Secretary:  Oliver BUSS
(oliver.buss@oecd-nea.org)
Member(s):All NEA member countries*
Russia (Suspended*)
*Russian Federation suspended pursuant to a decision of the OECD Council.
Full participant(s): European Commission
Under the NEA Statute
Observer(s)(International Organisation): International Atomic Energy Agency (IAEA)
By agreement
Date of creation:01 April 2021
End of mandate:31 March 2026

Mandate (Document reference):

  • The NSC Working Party on Scientific Issues of Reactor Systems (WPRS): Proposal for Prioritisation and Restructuring [NEA/NSC/WPRS/DOC(2020)19]
  • Summary record of the 31st meeting of the Nuclear Science Committee held on 23-25 September 2020 [NEA/SEN/NSC(2020)20] 
  • Mandate of the Expert Group on Physics of Reactor Systems (EGPRS) [NEA/NSC/WPRS/DOC(2021)1]
  • Summary record of the 4th meeting of the Expert Group on Physics of Reactor Systems held on 22 February 2024 [NEA/SEN/NSC/WPRS(2024)X] (forthcoming)
  • Mandate of the WPRS Expert Group on Physics of Reactor Systems (EGPRS) [NEA/NSC/WPRS(2024)4]

Mandate (Document extract):

Extract from document  [NEA/NSC/WPRS(2024)4]

Background

As a result of the prioritisation process, a reorganisation of the Nuclear Science Committee (NSC) activities was performed in 2020 under the guidance of the NSC Bureau. This has resulted in the disbandment of the NSC Expert Group on Multi-Physics Experimental Data, Benchmarks and Validation (EGMPEBV), the Expert Group on Radiation Transport and Shielding (EGRTS), the Expert Group on Reactor Physics and Advanced Nuclear Systems (EGRPANS) and the Expert Group on Uncertainty Analysis in Modelling (EGUAM). Two new bodies have been created to replace them: the Expert Group on Physics of Reactor Systems (EGPRS) and the Expert Group on Reactor Systems Multi-Physics (EGMUP).

Scope

Under the guidance of the Working Party on Scientific Issues and Uncertainty Analysis of Reactor Systems (WPRS), the Expert Group on Physics of Reactor Systems (EGPRS) will perform specific tasks associated with neutronics, radiation transport, reactor physics and nuclear fuel feedback along with uncertainty analysis of present and future nuclear power systems.

Reactor types considered include, but are not limited to the following:

  • Current fleet of light-water and heavy water reactors (LWRs/HWRs) as well as present generation of fuel designs.
  • Evolutionary and innovative LWR/HWR systems along with advanced designs, accident tolerant fuel designs.
  • Reactor cores with advanced fuel designs including high assay low enriched uranium (HALEU).
  • Next generation reactor systems including high temperature gas cooled reactor (HTGR), sodium fast reactor (SFR), lead fast reactor (LFR), gas fast reactor (GFR), and molten salt reactor (MSR) systems.
  • Reactor systems of different scales including large scale reactors, small modular reactors (SMRs), and micro-reactors.
  • Nuclear systems for space applications.
  • Accelerator driven (sub-critical) and critical systems for wide range of non-power applications.
  • Fusion systems.

Objectives

The objective of the EGPRS is to provide expert advice to the WPRS and the nuclear/accelerator community on the development needs (data and methods, validation experiments, scenario studies) for neutronics, fuel feedback, and radiation transport issues of different reactor systems, accelerators, irradiation, and fusion systems.

The fulfilment of this objective notably entails providing specific technical information on:

  • core reactivity characteristics, including fuel depletion effects;
  • core power/flux distributions;
  • core dynamics and reactivity control;
  • fuel physics feedback modelling and effects;
  • fluence, shielding and dosimetry aspects of reactors, accelerators and target irradiation facilities;
  • verification and validation and uncertainties quantification (VVUQ) related to the above;
  • artificial intelligence and machine learning applications related to the above.

This technical information will generally be derived from a combination of direct experimental evidence and/or the results of theoretical benchmark analyses using accurate, validated modelling and simulation (M&S) methods. In either case, the availability of suitable experimental data is a fundamental requirement. The EGPRS will monitor gaps and steer development of the International Radiation Shielding Experiments Database (SINBAD) in collaboration with the United States’ Radiation Safety Information Computational Centre (RSICC).

Working methods                                            

The EGPRS will report to the WPRS. The EGPRS will meet once per year, with additional meetings in support of particular activities such as task forces reporting to the EGPRS.

Deliverables of the EGPRS will be developed in task or benchmark groups, whose work will be organised in a project-like manner with outcomes and milestones.

Interactions

The EGPRS will maintain close collaboration with the Expert Group on Reactor Systems Multi-Physics (EGMUP), the Expert Group on Reactor Fuel Performance (EGRFP), the Working Party on Materials Science Issues in Nuclear Fuels and Structural Materials (WPFM), as well as the Working Party on Nuclear Criticality Safety (WPNCS). Close links will be maintained with other data preservation projects notably the International Reactor Physics Experiments Evaluation Project Technical Review Group (IRPhETRG) and the Technical Review Group for the International Criticality Safety Benchmarks Evaluation Project (ICSBEPTRG) as well as with the International Fuel Performance Experiments (IFPE) database supervised by EGRFP. The EGPRS should also work in co-ordination with the Joint Evaluated Fission and Fusion Nuclear Data Library Co-ordination Group (JEFF) under the Management Board for the Development, Application and Validation of Nuclear Data and Codes (MBDAV) and with the Shielding Aspects of Accelerators, Targets and Irradiation Facilities (SATIF) community of accelerator shielding specialists. Where required, the EGPRS will provide safety scenario studies for advanced systems and fuels. In this context, it will liaise closely with the Working Party on Scientific Issues of Advanced Fuel Cycles (WPFC).

Deliverables

The deliverables of EGPRS are technical reports, proceedings of seminars or workshops, state-of-the-art reports, and technical or collective opinion papers, and comparison or benchmark studies. This work will be done in task or benchmark groups, whose work will be organised in a project-like manner with outcomes and milestones. The EGPRSwill also organise specialist meetings and workshops to further its objectives. The detailed list of deliverables will be tracked in the semi-annual NSC progress reports.

Priority for the 2024-2026 period is given to the finalization of the benchmarks and developments set forth hereunder :

  • Continued development of SINBAD via its EGPRS Task Force,
  • Uncertainty Analysis in Best-Estimate Modelling for Design, Operation and Safety Analysis of Light Water Reactors (LWR-UAM) Phase II;
  • Uncertainty Analysis in Modelling (UAM) for Design, Operation and Safety Analysis of Sodium-cooled Fast Reactors (SFR-UAM) Phases I-II;
  • Fluoride-salt-cooled High temperature Reactor (FHR);
  • Deterministic Time-Dependent Neutron Transport Benchmark C5G7-TD without Spatial Homogenisation (C5G7-TD) Phases I-IIa;
  • Lead-cooled Fast Reactor (LFR) Benchmark.