R 333.5438 Class AA installations.

Rule 438. (1) In class AA installations the accelerator and objects exposed thereto shall be contained within a permanent enclosure. (2) The enclosure shall be constructed so that the dose equivalent rate as measured in air at a distance of 5 centimeters from an accessible point on the external surface shall not exceed 2 millirems per hour under conditions of maximum radiation output permitted by the design or operating characteristics of the accelerator. (3) Mechanical or electrical limiters shall limit movement or alignment of the accelerated beam within the enclosure if necessary to comply with subrule (2) of this rule. (4) A personnel barrier posted pursuant to R 333.5067 to R 333.5072 restricting access to the roof of the enclosure shall meet the requirement of subrule (2) of this rule. (5) Reliable interlocks shall be provided which prevent an individual from opening the enclosure while the accelerator is in operation or which terminate machine operation if an individual opens the enclosure. These interlocks shall meet the requirements of R 333.5448. (6) Enclosures of sufficient size to permit human occupancy shall be provided with visible or audible signals or both within the enclosure which are activated a minimum of 5 seconds before accelerator operation. Individuals shall at all times be able to escape from within the enclosure. (7) An individual shall not be permitted to remain within the enclosure while the accelerator is in operation except as a human patient undergoing radiation treatment. (8) Protective enclosures and equipment shall be kept in good repair. (9) Electron beam welders shall meet class AA requirements. (10) Class AA approval permits unlimited use at maximum capacity.