Under the guidance of the Nuclear Science Committee (NSC), the Working Party on Scientific Issues and Uncertainty Analysis of Reactor Systems (WPRS) studies the reactor physics, fuel performance, an...

The NEA is organising the 16^th Information Exchange Meeting on Actinide and Fission Product Partitioning and Transmutation (16IEMPT) on 24-27 October 2023. The meeting will be held at the NEA offices...

The 12th International Conference on Nuclear Criticality Safety (ICNC) will be held in Sendai, Japan on 1-6 October 2023. Twenty years after the last conference in Japan, which was held in Tokai-mura...

Knowledge of basic nuclear physics data is essential for the modelling and safe operation of all types of nuclear facilities. The de facto international standard format, Evaluated Nuclear Data File 6...

The Task Force on Dose Rate Calculations for Irradiated Fuel Assembly was launched in 2015 to assess code predictions of dose rates from bare spent fuel assemblies and to benchmark multiple codes and...

The goal of the Nuclear Energy Agency (NEA) Working Party on Nuclear Criticality Safety (WPNCS) Subgroup on Experimental Needs for Criticality Safety Purposes (SG-5) was to highlight the needs of int...

The NEA launched the Nuclear Education, Skills and Technology (NEST) Framework in partnership with its member countries to help address important gaps in nuclear skills capacity building, knowledge t...

Burn-up credit is a safety approach that accounts for the reduction in the reactivity of configurations with spent nuclear fuel due to the change in their composition after irradiation.

Image: Microscopic examination of U-bearing particles collected at Fukushima-Daiichi, JAEA

Image: Microscopic examination of U-bearing particles collected at Fukushima-Daiichi, JAEA

TCOFF Phases

First Phase (2017-2020)

The Thermodynamic Characterisation of Fuel Debris and Fission Products ...

The NEA Working Party on Nuclear Criticality Safety (WPNCS) held its bi-annual meetings in June 2023

Co-organised with the UK Atomic Energy Authority, the course took place on 20-22 June 2023.

High-temperature gas-cooled nuclear reactors are one of the next generation reactor designs. This benchmark consists of a multi-staged code-to-code-to-data thermal hydraulics code validation benchmar...

TCOFF-2 members discuss future activities.

The NEA workshop gathered experts to discuss the challenges and opportunities related to the demise of zero power reactors.

In the early decades of nuclear reactor development, many countries built and operated zero-power facilities in which many different critical arrangements of materials were studied. These flexible ex...

10-year FIDES-II strategic plan will define key research needs in a variety of technical disciplines.

Kick-off workshop of the thermal hydraulic code validation benchmark for high temperature gas-cooled reactors using High Temperature Test Facility (HTTF) data.

The first International School on Simulation of Nuclear Reactor Systems (SINUS) took place on 22-23 May 2023.

The annual WPRS Benchmarks Workshops took place on 22-26 May 2023 in Bologna, Italy.

WPFM held meetings on 23-25 May 2023.

The FIDES-II framework is designed to do more than just produce data on transient fuel behavior and safety related issues. 

The NEA Second Framework for Irradiation Experiments (FIDES-II) supports the fuel and material experimental needs of nuclear safety regulators, technical support organisations, research institutions ...

Lead-cooled Fast Reactors (LFR) are rather new concepts which have gathered increasing international attention after the Generation-IV International Forum (GIF) selected them as promising candidates ...

The NEA thermal hydraulic code validation benchmark for high temperature gas-cooled reactors using HTTF data (HTGR T/H), supervised by the Expert Group on Reactor Core Thermal-Hydraulics and Mechanic...

The Global Forum on Nuclear Education, Science, Technology and Policy acts as an inclusive network of experts in the nuclear energy sector, primarily from academia, focused on enabling the generation...

The annual Benchmark Workshops of the Working Party on Scientific Issues and Uncertainty Analysis of Reactor Systems will be hosted by the Italian National Agency for New Technologies, Energy and Sus...

Image: QUENCH facility at KIT. Court. KIT. 

The purpose of the QUENCH-ATF project is to investigate the chemical, mechanical and thermal-hydraulics behaviour of ATF claddings in Design Basis Accident...

The NEA nuclear science programme is developed and executed by the Nuclear Science Committee (NSC), comprising high-level scientific experts from all NEA member countries.

The NEA organised the first International School on Simulation of Nuclear Reactor Systems (SINUS) on the topic of Reactor single- and multi-physics simulations based on Light Water Reactor (LWR) Unce...

The Technical Review Groups for both projects met at the NEA headquarters on 3-7 April 2023.

Members of FIDES-II from 12 countries assembled in Prague, Czech Republic, on 17-21 April 2023 for meetings of its Technical Advisory Group and Governing Board.

International Fuel Performance Experiments (IFPE) is a data collection of nuclear fuel performance experiments for the purpose of code development and validation.

Since the early 2000s there is an increasing demand from nuclear research, industry, safety and regulation for best-estimate predictions to be provided with their confidence bounds. Consequently, an ...

Development started on DATIF, the DATabase for IFpe, in 2018 in order to enhance accessibility to the IFPE legacy collection of integral fuel performance experiments data, jointly put together by the...

EGPRS Task Force members met on 3 April 2023.

This report presents the results of a benchmark study on innovative fuels for fast reactors using fuel performance codes. Irradiation results were shared among participants of the expert group and co...

The WPRS met from 20-24 February 2023.

The Working Party on Scientific Issues and Uncertainty Analysis of Reactor Systems (WPRS) and its expert groups co-ordinate benchmark activities on Reactor Single- and Multi-Physics. The benchmark ac...

This benchmark is organised to examine the models for fission gas release during anticipated operational occurrences (AOOs).

Expert groups on structural and fuel materials meet to advance materials science activities

Thermodynamic databases and accident prevention

International experts gathered at the NEA for the commencement of the third phase TAF-ID on 16-17 February 2023.

Under the guidance of the Nuclear Science Committee (NSC), the Working Party on Scientific Issues and Uncertainty Analysis of Reactor Systems (WPRS) studies the reactor physics, fuel performance, an...

Monte Carlo criticality calculations involve a two-step procedure based on a stochastic implementation of the power iteration method: first, achieve convergence of the fission source distribution dur...

The understanding of nuclear physics and the associated uncertainties is essential to the modelling of all nuclear systems. Nuclear reaction probabilities, emitted particle energies and angles, fissi...

The EGMUP Task Force on artificial intelligence and machine learning will design benchmark specifications to evaluate the performance of AI/ML in multi-physics modeling and simulation of reactor syst...

This benchmark report has been compiled under the guidance of the NEA Working Party on Nuclear Criticality Safety (WPNCS) in the Subgroup on the Role of Integral Experiment Uncertainties and Covarian...

Courses were held in November 2022 in paris, France.

The 2021 edition contains data from 169 experimental series that were performed at 57 nuclear facilities.

Please note that this report was initially published in November 2022 (NEA/NSC/R(2022)3) under erroneous benchmark number IIB; in this updated version (NEA/NSC/R(2022)3/CORR) this has been corrected ...

Under the auspices of the NEA Nuclear Science Committee (NSC), the Working Party on Scientific Issues of Advanced Fuel Cycles (WPFC) was established to co-ordinate scientific activities related to ad...

MeshTal Viewer user manual

JANIS (Java-based nuclear information software) is an application designed to facilitate the visualisation and manipulation of nuclear data. JANIS will be helpful to engineers and physicists who use ...

The 2021 edition can be downloaded online.

The International Criticality Safety Benchmark Evaluation Project (ICSBEP) Handbook contains criticality safety benchmark specifications that have been derived from experiments that were performed at...

The primary purpose of the International Criticality Safety Benchmark Evaluation Project (ICSBEP) is to compile critical and subcritical benchmark experiment data into a standardised format that allo...

The International Handbook of Evaluated Reactor Physics Benchmark Experiments (IRPhE) contains reactor physics benchmark specifications that have been derived from experiments that were performed at ...

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) performs specific tasks associa...

View of Dragon Reactor. Photo: AEA Technology.

In 1959, twelve OECD countries began the Dragon Reactor Experiment (DRE) to build a reactor at Winfrith in Dorset, United Kingdom. The Dragon was the fi...

The modelling and simulation of nuclear systems allow scientists and engineers to probe aspects of the operation of these systems beyond what has been precisely measured. This has numerous applicatio...

Advanced nuclear fuel cycles to improve the safety, sustainability and economics of nuclear energy are being investigated worldwide. Partitioning and transmutation (P&T) is one of the candidate techn...

The event gathered 129 participants from 75 international institutions.

As governments around the world are committing to reaching net zero emissions by 2050, many countries are looking at the role hydrogen can play in mitigating climate change. This page provides more i...

The first QUENCH-ATF joint project test was successfully completed by the KIT team on 17 July 2022.

The Shielding Integral Benchmark Archive and Database (SINBAD) database contains compilations for 46 reactor shielding, 31 fusion neutronics and 23 accelerator shielding experiments.

Forsmark 1 and 2 Boiling Water Reactor Stability Benchmark

A number of tests with detail well documented neutronics and thermal-hydraulics measurements data have been performed at the Rostov Unit 2 (Rostov-2) nuclear power plant (NPP). The reactor type is a ...

The Expert Group on Reactor Systems Multi-Physics (EGMUP) advances the state of the art in establishing processes and procedures for certifying experimental data and benchmarking multi-physics multi-...

The NEA Data Bank organised a PENELOPE training course at the University of Barcelona in Spain on 11-15 July 2022

Over its 25 years of existence, the working party has contributed many topics and has led advances in criticality safety studies.

TVA Watts Bar Unit 1 Multi-Physics Benchmark

The Liquid Metal Fast Reactor (LFMR) is one of the next generation reactor designs. This benchmark consists of steady-state numerical predictions of Texas A&M University (TAMU) separate effect tests ...

To ensure reliable modelling of neutron physics within a state-of-the-art transient code, the neutron kinetics part of such a code should be based on the full-scale calculation of the space-time neu...

The Boiling Water Reactor Turbine Trip (BWRTT) Benchmark was established to challenge the coupled system thermal-hydraulic/neutron kinetics codes against a Peach-Bottom-2 (a GE-designed BWR/4) turbin...

The NEA Data Bank's first in-person course since the pandemic started was on FISPACT, an enhanced multi-physics platform for neutron, proton, alpha, deuteron or gamma particle interactions.

WPRS gathered 172 experts from 22 countries at the annual Benchmark Workshop.

The annual Benchmark Workshop of the Working Party on Scientific Issues and Uncertainty Analysis of Reactor Systems was hosted by CEA Cadarache in Aix-en-Provence. During the week of 30 May to 3 June...

The NEA Data Bank Nuclear Data Service (NDS) organised the Joint Evaluated Fission and Fusion (JEFF) Nuclear Data Week (NDW) on 25-29 April 2022.

 Nuclear Data Sensitivity Tool (NDaST), aims to provide rapid feedback on the effect of changes to nuclear data on integral benchmarks.

Recent meetings of groups working under the aegis of the Framework for Irradiation Experiments (FIDES) have demonstrated that the international community is enthusiastic and on a strong course to ful...

The International Criticality Safety Benchmark Evaluation Project (ICSBEP) released the first version of the Database for the International Handbook of Evaluated Criticality Safety Benchmark Experime...

Collected sources of primary documentation for reactor physics benchmarks.

The IRPhEP Database and Analysis Tool (IDAT) was first released in 2013 and is included on the IRPhE Handbook DVD. This database and corresponding user interface allows easy access to handbook inform...

Under the guidance of the  Nuclear Science Committee (NSC) , the Working Party on Scientific Issues and Uncertainty Analysis of Reactor Systems (WPRS) studies the reactor physics, fuel performance, ...

WPNCS bi-annual event brought together 80 experts from 17 member countries.

The following report is issued by the WPEC Subgroup 27, which builds upon the work of the previous Subgroups 21 and 23, critically reviewing the gamma emission data and providing recommendations to i...

The OECD Nuclear Energy Agency (NEA) Strategic Plan serves as a guiding instrument that reflects the priorities of its member countries as the Agency addresses evolving needs in the exploration and a...

Proceedings of the Fourteenth Workshop, 30 October-2 November 2018, Gyeongju, Korea.

The webinar "Research and international dialogue in technology nuclear power - What role for Italy?", was held on 17- 18 November 2021.

In the past decade, a large amount of effort has been made towards the direct simulation of the boiling transition (BT) for boiling water reactor (BWR) fuel bundles. This international benchmark, bas...

The purpose of this prismatic High Temperature Reactor (HTR) benchmark is to provide a solution set that can be used in future code benchmarking and to better understand the effects induced by the pr...

The NEA Expert Group on Innovative Structural Materials (EGISM) organised a workshop on 19-21 October 2021 together with the Spanish Center for Energy, Environmental and Technological Research (CIEMA...

ICSBEP, SINBAD AND IRPhEP Technical Review Group meetings, October 2021.

Helium-cooled very high-temperature gas reactors are highlighted as a key technology with the potential to improve the competitiveness of nuclear energy within the Generation IV International Forum (...

For nuclear utility companies that opt to reprocess spent fuel, recycle it or do both, one of the main pertinent issues is plutonium recycling.

Working Party on Scientific Issues of Advanced Fuel Cycles (WPFC) meeting, 8 June 2021.

This benchmark focuses on FHR reactors with plates and triso fuel. Several phases are planned, starting with neutronics on a simple fuel element simulation without burn-up, and gradually extending to...

In the past decade, a large amount of effort has been made towards the direct simulation of the boiling transition (BT) for Boiling Water Reactor (BWR) fuel bundles. This international benchmark, bas...

Preparatory meeting for Thermodynamic Characterisation of Fuel Debris and Fission Products Based on Scenario Analysis of Severe Accident Progression at Fukushima Daiichi Nuclear Power Station (TCOFF)...

NEA Working Party on Scientific Issues of Reactor Systems (WPRS) annual meeting, 15-19 February 2021.

A sodium-cooled fast reactor (SFR) is a fast neutron reactor that uses molten sodium metal as a coolant. Sodium-cooled Fast Reactors (SFRs) are the most promising type of reactors to achieve Generati...

New NEA task force on partitioning and transmutation kicks off

NEA Thermodynamics of Advanced Fuels International Database updates

NEA Working Party on Scientific Issues of Reactor Systems (WPRS) workshops, 7-15 December 2020.

Understanding fuel performance is a key condition for successful reactor operation. Scientific knowledge in this domain was conceived by experimental tests encoded into software routines to ensure ac...

Thermal hydraulics and mechanics deals with the physics and mechanics of the flow and energetic transfer of liquids, and its interactions with the structures around them in large complex systems, suc...

The quality of the isotopic composition of plutonium fuel degrades as the number of recycles increases in thermal reactors, requiring an increase in the total loading necessary in mixed plutonium-ura...

The ICSBEP Technical Review Group of over 65 international technical experts met remotely for the first time on 19-23 October 2020.

Radiation shielding is a protective shield that is inserted betweeen a source of ionising radiation and the object to protect to reduce the amount of damage that can happen to delicate or biological ...

State-of-the-Art Report on Multi-Scale Modelling Methods

SFCOMPO 2.0 (Spent Fuel Isotopic Composition) is a relational database designed to facilitate the search and visualisation of experimental assay data of spent nuclear fuel.

MeshTal Viewer is a Java based software which can read mesh tallies output formats of several neutron transport codes and display them graphically.

The Benchmark for Uncertainty Analysis in Best-Estimate Modelling (UAM) for Design, Operation and Safety Analysis of Light Water Reactors (LWRs) is an international high-visibility benchmark for unce...

The following report is issued by WPEC Subgroup 28, which builds upon the work of the previous Subgroup 20 for developing new methods for cross-section covariance evaluation. Subgroup 28 was tasked w...

Sensitivities Viewer is a Java based software which can read sensitivities files and plot sensitivities profiles.

Knowledge of basic nuclear physics data is essential for the modelling and safe operation of all types of nuclear facilities. The de facto international standard format, Evaluated Nuclear Data File 6...

New NEA reports on nuclear data evaluation

Sustained performance of nuclear technology depends on access to a talented and well-qualified workforce, thus it is important to ensure that adequate infrastructures exist for education and training...

The NEA Annual Report 2019 provides an overview of the status of nuclear power in NEA member countries and illustrative descriptions of the Agency's activities and international joint projects. 2019 ...

U-Zr-O system miscibility gap in the liquid state. Source: Guéneau et al. Journal of Nuclear Materials 254 (1998), 158-174.

NEA Expert Group on Fuel Recycling Chemistry (EGFRC): The International Database on Extractant Ligands (IDEaL)

Document content and format guide for the International Criticality Safety Benchmark Evaluation Project (ICSBEP) – NEA/NSC/DOC(95)03

Criticality is the state of a nuclear reactor when there is a self-sustaining chain reaction of fissionable material. Criticality experiments are controlled tests using fissile materials, like pluton...

Criticality is the state of a nuclear reactor when there is a self-sustaining chain reaction of fissionable material. Criticality safety analysis relates to evaluation approaches in data and computat...

Thermal Scattering Law S(α,β): Measurement, Evaluation and Application

Co-ordinated Evaluation of Plutonium-239 in the Resonance Region

NEA Working Party on Scientific Issues of Reactor Systems (WPRS) annual meeting, 19-21 February 2020.

Under the guidance of the Nuclear Science Committee (NSC) and under the mandate of the Working Party on Multi-scale Modelling of Materials (WPMM), the scope of the Expert Group on Multi-scale Modelli...

The Working Party on Multi-scale Modelling of Fuels and Structural Material for Nuclear Systems (WPMM) was established to deal with the scientific and engineering aspects of fuels and structural mate...

This volume is the 13b in the OECD Nuclear Energy Agency (NEA) Chemical Thermodynamics series. It is the second part of a critical review of the thermodynamic properties of iron, its solid compounds ...

Workshop Proceedings, 10-12 December 2012

Nuclear data refers to the probabilities, statistics and measurements of the physical interactions associated with atomic particles.

The nuclear fuel cycle is the chain of processes whereby nuclear fuel is prepared and managed before and after its use in a reactor.

Questions relating to the space, time end energy distribution of neutrons and radiation in different media are the domain of reactor physics.

Nuclear science is the study of the atomic nuclei and their application, including in nuclear power plants, atomic theory and radiation.

ICSBEP, SINBAD AND IRPhEP Technical Review Group meetings

The fourth international NEA workshop on Technology and Components of Accelerator‑Driven Systems (TCADS‑4), 14‑17 October 2019.

The continued evolution of fuel and materials technology, fuel performance, optimisation of operational limits, material ageing, failure limits, etc. requires experimental evidence obtained from test...

Current knowledge of the nuclear physics of fuels and materials provides an understanding and simulation of the operations of nuclear reactors and other systems, both under ordinary and exceptional c...