R 333.5294 Class AA installations.

Rule 294. (1) In class AA installations the radiation machine and objects exposed thereto shall be contained within a permanent enclosure. (2) The enclosure shall be constructed such that the radiation dose rate at a distance of 5 centimeters from any point on the external surface shall not exceed 0.02 millisievert per hour (2 mrem/h). The dose rate shall be measured with the source of radiation placed at the position of closest source-wall distance that is radiographically usable and under conditions of maximum radiation output permitted by the design or operating characteristics of the radiation machine. (3) Mechanical or electrical limiters shall limit movement or alignment of the radiation machine 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 will prevent anyone from opening the enclosure while the radiation machine is on or which will terminate machine operation should anyone open the enclosure. (6) Enclosures of sufficient size to permit human occupancy shall be provided with visible signals or audible signals, or both, within the enclosure, which are activated a minimum of 5 seconds before radiation machine activation. Individuals shall at all times be able to escape from within the enclosure. (7) Individuals shall not be permitted to remain within the enclosure while the radiation machine is in operation. (8) Protective enclosures and equipment shall be kept in good repair. (9) Industrial fluoroscopy shall meet the requirements of class AA installations. (10) Notwithstanding the provisions of subrule (2) of this rule, the enclosure for industrial fluoroscopy shall be constructed such that the radiation dose rate at a distance of 5 centimeters from any accessible point on the external surface shall not exceed 0.005 millisievert per hour (0.5 mrem/h) under conditions of maximum radiation output permitted by the design or operating characteristics of the installation. (11) Industrial cabinet radiography conducted in enclosures of insufficient size to permit human occupancy shall meet the requirements of class AA installations. (12) Notwithstanding the provisions of subrule (2) of this rule, the enclosure for industrial cabinet radiography of insufficient size to permit human occupancy shall be constructed such that the radiation dose rate at a distance of 5 centimeters from any accessible point on the external surface shall not exceed 0.005 millisievert per hour (0.5 mrem/h) under conditions of maximum radiation output permitted by the design or operating characteristics of the installation. (13) For class AA enclosures of sufficient size to permit human occupancy, a personnel radiation dosimeter shall be permanently assigned to each occupationally exposed individual. This monitoring shall be continuous during employment as a radiation worker. (14) Personnel exposure records shall be kept on permanent available file at the facility where the exposure occurs for inspection by the department. (15) Class AA approval permits unlimited use at maximum capacity.