This report aims to highlight the needs of integral experiments in the field of nuclear criticality safety, and to identify the available experimental facilities where such experiments could be performed.

In order to identify existing experimental needs, the NEA surveyed international nuclear criticality safety (NCS) practitioners and members of the Working Party on Nuclear Criticality Safety (WPNCS). Responses were received from eight organisations and five countries (Canada, the Czech Republic, France, Japan and the United States); additional responses were also sent by four organisations in two countries (Switzerland and the United Kingdom).

The survey results were examined by the WPNCS Subgroup on Experimental Needs for Criticality Safety Purposes (SG-5), which ranked the 25 identified needs in terms of priority as well as describing these needs in detail. A dedicated section of the report describes the existing proprietary experiments that might be used to meet some of the identified needs. Another section highlights some of the many facilities available to perform some of the prioritised criticality experiments.