6 Colo. Code Regs. § 1007-1-24-A
24A.1 All Therapeutic Radiation Machines.
24A.1.1 Basic facility information including: name, telephone number and facility registration number; registration number of the individual preparing the shielding plan; name and telephone number of the facility supervisor; and the street address [including room number] of the therapeutic radiation machine facility. The plan should also indicate whether this is a new structure or a modification to existing structure(s).
24A.1.2 All wall, floor, and ceiling areas struck by the useful beam shall have primary barriers.
24A.1.3 Secondary barriers shall be provided in all wall, floor, and ceiling areas not having primary barriers.
24A.2 Therapeutic Radiation Machines Up To 150 kV (photons only).
In addition to the requirements listed in 24A.1 above, therapeutic radiation machine facilities which produce only photons with a maximum energy less than or equal to 150 kV shall develop, document, and maintain on file, shielding plans which contain, as a minimum, the following additional information:
24A.2.1 Equipment specifications, including the manufacturer and model number of the therapeutic radiation machine, as well as the maximum technique factors;
24A.2.2 Maximum design workload for the facility including total weekly radiation output, expressed in gray (rad) or air kerma at one meter, total beam-on time or monitor units (MU) per day or week, the average treatment time or monitor units (MU) per patient, along with the anticipated number of patients to be treated per day or week;
24A.2.3 A facility drawing to scale indicating: the direction of North; normal location of the therapeutic radiation machine's radiation port(s); each port's travel and traverse limits; general direction(s) of the useful beam; locations of any windows and doors; and the location of the therapeutic radiation machine control panel. If the control panel is located inside the therapeutic radiation machine treatment room, the location of the operator's booth shall be noted on the plan and the operator's station at the control panel shall be behind a protective barrier sufficient to ensure compliance with 4.6;
24A.2.4 The structural composition and thickness or lead/concrete equivalent of all walls, doors, partitions, floor, and ceiling of the room(s) concerned;
24A.2.5 The type of occupancy of all adjacent areas inclusive of space above and below the room(s) concerned. If there is an exterior wall, show distance to the closest area(s) where it is likely that individuals may be present; and
24A.2.6 At least one example calculation which shows the methodology used to determine the amount of shielding required for each physical condition (i.e.: primary and secondary/leakage barriers, restricted and unrestricted areas, entry doors) and shielding material in the facility:
(1) If commercial software is used to generate shielding requirements, the software used and the version/ revision date shall be identified; or
(2) If the software used to generate shielding requirements is not in the open literature or commercially available, quality control sample calculations to verify the result obtained with the software shall be identified.
24A.3 Therapeutic Radiation Machines Over 150 kV.
In addition to the requirements listed in 24A.1 above, therapeutic radiation machine facilities that produce photons with a maximum energy in excess of 150 kV and/or electrons shall develop, document, and maintain on file, shielding plans which contain, as a minimum, the following additional information:
24A.3.1 Equipment specifications including the manufacturer and model number of the therapeutic radiation machine, and gray (rad) at the isocenter and the energy(s) and type(s) of radiation produced (photon, electron). The target to isocenter distance shall be specified;
24A.3.2 Maximum design workload for the facility including total weekly radiation output (expressed in gray (rad) at one meter), total beam-on time per day or week, the average treatment time per patient, along with the anticipated number of patients to be treated per day or week;
24A.3.3 Facility drawing to scale [including both floor plan and elevation views] indicating relative orientation of the therapeutic radiation machine, type(s), thickness and minimum density of shielding material(s), direction of North, the locations and size of all penetrations through each shielding barrier (ceiling, walls and floor), as well as details of the door(s) and maze;
24A.3.4 The structural composition and thickness or concrete equivalent of all walls, doors, partitions, floor, and ceiling of the room(s) concerned;
24A.3.5 The type of occupancy of all adjacent areas inclusive of space above and below the room(s)
concerned. If there is an exterior wall, show distance to the closest area(s) where it is likely that individuals may be present;
24A.3.6 A description of all assumptions that were in shielding calculations including, but not limited to,
design energy [i.e. a room may be designed for a 6 MV unit although only a 4 MV unit is currently proposed], work-load, presence of integral beam-stop in unit, occupancy and use(s) of adjacent areas, fraction of time that the useful beam will intercept each permanent barrier [walls, floor and ceiling] and the radiation exposure in both restricted and unrestricted areas; and
24A.3.7 At least one example calculation which shows the methodology used to determine the amount of shielding required for each physical condition (i.e.: primary and secondary/leakage barriers, restricted and unrestricted areas, small angle scatter, entry door(s) and maze) and shielding material in the facility:
(1) If commercial software is used to generate shielding requirements, identify the software used and the version/ revision date; or
(2) If the software used to generate shielding requirements is not in the open literature or commercially available, submit quality control sample calculations to verify the result obtained with the software.
24A.4 Neutron Shielding
In addition to the requirements listed in 24A.3 above, therapeutic radiation machine facilities that are capable of operating above 10 MV shall document, develop, and maintain on file, shielding plans which contain, as a minimum, the following additional information:
24A.4.1 The structural composition, thickness, minimum density and location of all neutron shielding material;
24A.4.2 Description of all assumptions that were used in neutron shielding calculations including, but not limited to, neutron spectra as a function of energy, neutron fluence rate, absorbed dose and dose equivalent (due to neutrons) in both restricted and unrestricted areas;
24A.4.3 At least one example calculation which shows the methodology used to determine the amount of neutron shielding required for each physical condition (i.e.: restricted and unrestricted areas, entry door(s) and maze) and neutron shielding material utilized in the facility:
(1) If commercial software is used to generate shielding requirements, also identify the software used and the version/ revision date; or
(2) If the software used to generate shielding requirements is not in the open literature or commercially available, submit quality control sample calculations to verify the result obtained with the software; and
24A.4.4 The method(s) and instrumentation that will be used to verify the adequacy of all neutron shielding installed in the facility.
6 CCR 1007-1-24-A