An impartial Board was set up in 1980 at the Atomic Weapons Research Establishment to review the health and safety aspects of the design and operation of nuclear chemical processing plant. Its primary aim is to provide considered advice to the Director of the Establishment that a facility or project was acceptably safe to operate, so that he could then authorise such operation. The examinations by the Board now scan the full life of facilities from conception, through design, construction, commissioning, operation, modification, to eventual decommissioning and disposal, and include safety management aspects. Throughout, the Board seeks evidence of the application of sound safety principles which minimise health and safety risks to employees, other persons on site, the general public and the environment. The formal safety assurance procedure, including the archive of documentation called for by the Board and the minutes of its meetings record the justification for design and operating decisions made on safety grounds. The procedure has had a profoundly beneficial effect on safety awareness on the site. As an example of the documentation provided in 1984, a summary from a safety submission on the ventilation system of a plutonium processing facility is included which illustrates the use of target design values for radiation exposure which are well below national limits.