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:

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:

The expert group will:

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.B. Briggs from INL, USA.

Current activities

The group is currently:

The following type of measurements are included:

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.

2015 edition and availability

The International Reactor Physics Evaluation (IRPhE) Project was initiated as a pilot in 1999 by the Nuclear Energy Agency (NEA) Nuclear Science Committee (NSC). The project was endorsed as an official activity of the NSC in June 2003. While the NEA co-ordinates and administers the IRPhE Project at the international level, each participating country is responsible for the administration, technical direction and priorities of the project within their respective countries. The information and data included in this handbook are available to NEA member countries, to all contributing countries and to others on a case-by-case basis.

The IRPhE Project is patterned after the International Criticality Safety Benchmark Evaluation Project (ICSBEP). It closely co-ordinates with the ICSBEP to avoid duplication of efforts and publication of conflicting information. Some benchmark data are applicable to both nuclear criticality safety and reactor physics technology. Some have already been evaluated and published by the ICSBEP, but have been extended to include other types of measurements in addition to the critical configuration.

Through this effort, the IRPhE Project will be able to 1) consolidate and preserve the existing worldwide information base; 2) retrieve lost data; 3) identify areas where more data are needed; 4) draw upon the resources of the international reactor physics community to help fill knowledge gaps; 5) identify discrepancies between calculations and experiments due to deficiencies in reported experimental data, cross-section data, cross-section processing codes and neutronics codes; 6) eliminate a large amount of redundant research and processing of reactor physics experiment data, and 7) improve future experimental planning, execution and reporting.

This handbook contains reactor physics benchmark specifications which have been derived from experiments that were performed at various nuclear facilities around the world. The benchmark specifications are intended for use by reactor designers, safety analysts and nuclear data evaluators to validate calculation techniques and data. Example calculations are presented; these do not constitute a validation or endorsement of the codes or cross-section data.

The 2015 edition of the International Handbook of Evaluated Reactor Physics Experiments contains data from 143 experimental series performed at 50 nuclear facilities. To be published as approved benchmarks the experiments must be evaluated against agreed technical criteria and reviewed by the IRPhE Technical Review Group. A total of 139 of the 143 evaluations are published as approved benchmarks. The remaining four evaluations are published as draft documents only. Draft documents have been reviewed by the IRPhE Technical Review Group (TRG); however, all action items could not be completed or reviewed in time for the final publication or, in most cases, the TRG felt it necessary to review the revised evaluations before final approval.  The handbook is organised in a manner that allows easy inclusion of additional evaluations as they become available. 

Comments (recommendations, additions, deletions and corrections), which may be of use in improving this handbook, should be addressed to:

John D. Bess
Idaho National Laboratory
2525 North Fremont
Idaho Falls, ID  83415-3855
United States of America


Jim Gulliford
NEA Division of Nuclear Science
Le Seine-Saint Germain
12 boulevard des ČŠles
92130 Issy-les-Moulineaux, France

The Handbook is published in electronic format (pdf files), where the experiments are grouped into evaluations, categorised by (1) Reactor Name, (2) Reactor Type, (3) Facility Type, and (4) Measurement Type.

The Handbook was prepared by a working party comprised of experienced reactor physics personnel from 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.

The IRPhEP Handbook, featuring the IRPhEP Database and Analysis Tool (IDAT), is distributed on DVD and online. It can be requested by completing the request form.

The IRPhEP Handbook is available to authorised requesters from the OECD member countries and to contributing establishments from non-OECD countries. Other requests are handled on a case by case basis. Find out more about the restrictions, the disclaimer, and providing feedback



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.

Last reviewed: 1 June 2015

Next meeting
  • Week of 19 October 2015