N.D. Admin. Code tit. 33.1, art. 33.1-10, ch. 33.1-10-15, app A
1. All therapeutic radiation machines.
a. Basic facility information, including name, telephone number, and department registration number of the individual responsible for preparation of 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 structures.
b. All wall, floor, and ceiling areas struck by the useful beam shall have primary barriers.
c. Secondary barriers shall be provided in all wall, floor, and ceiling areas not having primary barriers.
2. Therapeutic radiation machines up to 150 Kv (photons only). In addition to the requirements listed in subsection 1, therapeutic radiation machine facilities which produce only photons with a maximum energy less than or equal to 150 kilovolts shall submit shielding plans which contain, as a minimum, the following additional information:
a. Equipment specifications, including the manufacturer and model number of the therapeutic radiation machine, as well as the maximum technique factors;
b. Maximum design workload for the facility, including total weekly radiation output, (expressed in gray (rad) or air kerma at 1 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;
c. A facility blueprint or drawing indicating: scale (0.25 inch = 1 foot is typical); direction of north, normal location of the therapeutic radiation machine's radiation ports, the port's travel and traverse limits, general directions 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 subsection 1 of section 33.1-10-04.2-06 [ 10 CFR 20.1201 ] of these regulations;
d. The structural composition and thickness or lead or concrete equivalent of all walls, doors, partitions, floor, and ceiling of the rooms concerned;
e. The type of occupancy of all adjacent areas inclusive of space above and below the rooms concerned. If there is an exterior wall, showing distance to the closest areas where it is likely that individuals may be present; and
f. 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, please also identify the software used and the version or revision date.
(2) If the software used to generate shielding requirements is not in the open literature, please also submit quality control sample calculations to verify the result obtained with the software.
3. Therapeutic radiation machines over 150 kilovolts. In addition to the requirements listed in subsection 1, therapeutic radiation machine facilities that produce photons with a maximum energy in excess of 150 kilovolts or electrons shall submit shielding plans which contain, as a minimum, the following additional information:
a. Equipment specifications, including the manufacturer and model number of the therapeutic radiation machine, and gray (rad) at the isocenter and the energies and types of radiation produced (i.e., photon, electron). The target to isocenter distance shall be specified; b. Maximum design workload for the facility, including total weekly radiation output (expressed in gray (rad) at 1 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;
c. Facility blueprint or drawing (including both floor plan and elevation view) indicating relative orientation of the therapeutic radiation machine, scale (0.25 inch = 1 foot is typical), types, thickness, and minimum density of shielding materials, direction of north, the locations and size of all penetrations through each shielding barrier (ceiling, walls, and floor), as well as details of the doors and maze;
d. The structural composition and thickness or concrete equivalent of all walls, doors, partitions, floor, and ceiling of the rooms concerned;
e. The type of occupancy of all adjacent areas inclusive of space above and below the rooms concerned. If there is an exterior wall, showing distance to the closest areas where it is likely that individuals may be present;
f. Description of all assumptions that were in shielding calculations, including design energy (i.e., room may be designed for 6 MV unit although only a 4 MV unit is currently proposed), workload, presence of integral beam-stop in unit, occupancy and uses of adjacent areas, fraction of time that useful beam will intercept each permanent barrier (walls, floor, and ceiling), and "allowed" radiation exposure in both restricted and unrestricted areas; and
g. 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 or leakage barriers, restricted and unrestricted areas, small angle scatter, entry doors and maze) and shielding material in the facility:
(1) If commercial software is used to generate shielding requirements, also identify the software used and the version or revision date; and
(2) If the software used to generate shielding requirements is not in the open literature, also submit quality control sample calculations to verify the result obtained with the software.
4. Neutron shielding. In addition to the requirements listed in subsection 3, therapeutic radiation machine facilities that are capable of operating above 10 MV shall submit shielding plans which contain, as a minimum, the following additional information:
a. The structural composition, thickness, minimum density, and location of all neutron shielding material;
b. Description of all assumptions that were used in neutron shielding calculations, including neutron spectra as a function of energy, neutron fluence rate, absorbed dose, and dose equivalent (due to neutrons) in both restricted and unrestricted areas;
c. 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 doors 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 or revision date; and
(2) If the software used to generate shielding requirements is not in the open literature, also submit quality control sample calculations to verify the result obtained with the software. d. The methods and instrumentation that will be used to verify the adequacy of all neutron shielding installed in the facility.
5. References.
a. NCRP Report 147, "Structural Shielding Design and Evaluation for Medical Use of X-Rays and Gamma Rays of Energies Up to 10 MeV" (2004).
b. NCRP Report 144, "Radiation Protection Design Guidelines for 0.1-100 MeV Particle Accelerator Facilities" (2003).
c. NCRP Report 79, "Neutron Contamination from Medical Electron Accelerators" (1984).
N.D. Admin Code tit. 33.1, art. 33.1-10, ch. 33.1-10-15, app A