International Reactor Physics Experiment Evaluation (IRPhE) Project

The International Reactor Physics Experiment Evaluation (IRPhE) Project aims to provide the nuclear community with qualified benchmark data sets by collecting reactor physics experimental data from nuclear facilities, worldwide. More specifically the objectives of the expert group are as follows:

  • maintaining an inventory of the experiments that have been carried out and documented;
  • archiving the primary documents and data released in computer-readable form;
  • promoting the use of the format and methods developed and seek to have them adopted as a standard.

For those experiments where interest and priority is expressed by member countries or working parties and executive groups within the NEA provide guidance or co-ordination in:

  • compiling experiments into a standard international agreed format;
  • verifying the data, to the extent possible, by reviewing original and subsequently revised documentation, and by consulting with the experimenters or individuals who are familiar with the experimenters or the experimental facility;
  • analysing and interpreting the experiments with current state-of-the-art methods;
  • publishing electronically the benchmark evaluations.

The expert group will:

  • identify gaps in data and provide guidance on priorities for future experiments;
  • involve the young generation (Masters and PhD students and young researchers) to find an effective way of transferring know-how in experimental techniques and analysis methods;
  • provide a tool for improved exploitation of completed experiments for Generation IV reactors;
  • co-ordinate closely its work with other NSC experimental work groups in particular the International Criticality Safety Benchmark Evaluation Project (ICSBEP), the Shielding Integral Benchmark Experiment Data Base (SINBAD) and others, e.g. knowledge preservation in fast reactors of the IAEA, the ANS Joint Benchmark Activities;
  • keep a close link with the working parties on scientific issues of reactor systems (WPRS), the expert group on reactor-based plutonium disposition (TFRPD), now integrated into WPRS, scientific issues of the fuel cycle (WPFC) and the working party on international evaluation co-operation (WPEC).

The Secretariat of the group is provided by the OECD/NEA Data Bank, who is in charge of the management of the material released to the project. The Technical Review is chaired and co-ordinated by J.D. Bess from INL, USA.

Current activities

The group is currently:

  • maintaining an international inventory of relevant reactor physics experiments and measurements, preserving in computer readable form the primary documentation and data describing the facilities, characterising the experimental techniques, the experimental results and interpretation thereof;
  • developing and maintaining an international database containing a sub-set of high priority reactor physics benchmark specifications derived from the experiments performed at various nuclear facilities around the world, relevant for or including data from power reactors (e.g. Advanced Gas Reactors, Fast Reactors, Generation-IV Reactors, Water Reactors, etc.)

The following type of measurements are included:

  • fundamental mode lattice experiments;
  • heterogeneous core configurations;
  • power reactor start-up data;
  • core follow experiments;
  • specific applications experiments (e.g. fission product integral data, irradiation experiments).

The benchmark specifications and experimental data are intended for use by nuclear reactor physicists and engineers to validate current and new calculational schemes including computer codes and nuclear data libraries, for assessing uncertainties, confidence bounds and safety margins, and to record measurement methods and techniques.

2019 edition and availability

For more information about the 2019 edition, please visit the following page.


  • IRPhE co-operates and co-ordinates its work with the ICSBEP: International Criticality Safety Benchmark Evaluation Project.


Much of the work so far realised by the International Reactor Physics Experiment Evaluation (IRPhE) Project, in particular, the evaluation and review of selected benchmark experiments, was possible thanks to substantial funding provided by the Government of Japan. Other countries, currently Argentina, Belgium, Brazil, Canada, P.R. of China, Czech Republic, France, Germany, Hungary, Italy, Japan, Republic of Korea, Russian Federation, Serbia, Slovenia, South Africa, Sweden, Switzerland, United Kingdom, and the United States have contributed evaluations, reviews and data at their own expense. Overall technical coordination of the IRPhEP is directly supported by the United States Department of Energy's Office of Nuclear Energy with significant in-kind contributions from the parallel OECD NEA International Criticality Safety Benchmark Evaluation Project (ICSBEP), supported in the United States by the Department of Energy's Office of Facility Management and ES&H Support.


For questions or more information, please send an e-mail to .

Last reviewed: 11 December 2019