The International Handbook of Evaluated Reactor Physics Benchmark Experiments contains reactor physics benchmark specifications that have been derived from experiments that were performed at 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. While co-ordination and administration of the International Reactor Physics Evaluation (IRPhE) project is undertaken by the OECD Nuclear Energy Agency (NEA) at the international level, each participating country is responsible for the administration, technical direction and priorities of the project within their respective countries.