This publication provides a single source guidance to assist those responsible for the implementation of nuclear security measures at research reactors and associated facilities in developing and maintaining an effective and comprehensive programme covering all aspects of nuclear security on the site. It is based on national experience and practices as well as on publications in the field of nuclear management and security. The scope includes security operations, security processes, and security forces and their relationship with the State’s nuclear security regime. The guidance is provided for consideration by States, competent authorities and operators.