The International Criticality Safety Benchmark Evaluation Project (ICSBEP) Handbook contains criticality safety benchmark specifications that have been derived from experiments that were performed at various critical facilities around the world. The benchmark specifications are intended for use by criticality and safety analysts as well as nuclear data evaluators to validate calculational techniques and data. The handbook is produced by the ICSBEP working group, under the aegis of the OECD Nuclear Energy Agency (NEA). While co-ordination and administration of the ICSBEP is undertaken by the NEA, each participating country is responsible for the administration, technical direction, and priorities of the project within their respective countries. Access to some of the information and data included in this handbook may be restricted; full conditions for access are available online.