Section 325.5294. Class AA installations.

(1) In class AA installations the source of radiation and objects exposed thereto shall be contained within a permanent enclosure.

(2)   The enclosure shall be constructed such that the  radiation   exposure rate as measured in air at a distance of 5 centimeters from any point on the external surface shall not exceed 2 milliroentgens per hour with the source of radiation placed in the shortest source-to-wall radiographically usable position under conditions of maximum radiation output permitted by the design or operating characteristics of the radiographic exposure device or radiation machine.

(3)   Mechanical or electrical limiters shall limit movement or alignment of the source of radiation within the enclosure if  necessary to  comply with subrule (2).

(4)  A personnel barrier posted in accordance   with  rules  224  to  231 restricting access to the roof of the enclosure shall meet the requirement of subrule (2).

(5)    Reliable interlocks shall be provided which will prevent anyone from opening the enclosure while the radiation machine is on or the sealed source is unshielded, or which will terminate machine operation or automatically return the sealed source to a shielded position should anyone open the enclosure.

(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 radiation machine activation or exposure of the sealed source. Persons shall at all times be able to escape from within the enclosure.

(7)   A person shall not be permitted to remain within the enclosure while the radiation machine is in operation or the sealed source is unshielded.

(8)   Protective enclosures and equipment shall be kept in good repair.

(9)   Industrial fluoroscopy shall meet class AA requirements.

(10)    Notwithstanding the provisions of subrule (2), the enclosure   for industrial fluoroscopy shall be constructed such that the radiation exposure rate as measured in air at a distance of 5 centimeters from any accessible point on the external surface shall not exceed 0.5 milliroentgens per hour 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 class AA requirements.

(12)   Notwithstanding the provisions of subrule (2), the enclosure forindustrial cabinet radiography of insufficient size to permit human occupancy shall be constructed such that the radiation exposure rate as measured in air at a distance of 5 centimeters from any accessible point on the  external surface shall not exceed 0.5 milliroentgens   per  hour  under   conditions of maximum radiation output permitted by the design or operating characteristics of the installation.

(13)   Class AA approval permits unlimited use at maximum capacity.

[Note: The requirements of this rule that pertain  to  radiation  machine registration, licensing, or compliance are under the purview of the Michigan Department of Consumer & Industry Services.]

History: 1979 AC.