Therapeutic Radiation Machines; Shielding and Safety Design Requirements.
24 RCNY § 175.67
in effect§ 175.67 Therapeutic Radiation Machines; Shielding and Safety Design Requirements.
(a) Each therapeutic radiation machine subject to the requirements of 24 RCNY Health Code §§ 175.64 or 175.65 must be provided with such primary and secondary barriers as are necessary to ensure compliance with this Article.
(b) Facility design information for all new installations of a therapeutic radiation machine or installations of a therapeutic radiation machine of higher energy into a room not previously approved for that energy must be submitted for Department review prior to operation of the therapeutic radiation machine. The minimum facility design information that must be submitted to the Department is contained in Appendix A to this section:
Appendix A: Information on Radiation Shielding Required for Plan Reviews
I. All Therapeutic Radiation Machines.
A. Basic facility information including: name, telephone number and Agency 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 must have primary barriers.
C. Secondary barriers must be provided in all wall, floor, and ceiling areas not having primary barriers.
II. Therapeutic Radiation Machines up to 150 Kv (photons only). In addition to the requirements listed in Section I, therapeutic radiation machine facilities which produce only photons with a maximum energy less than or equal to 150 kV must 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/drawing indicating: scale (0.25 inch = 1 foot is typical); direction of north; normal location of the therapeutic radiation machine's radiation ports; each port's travel and traverse limits; general direction 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 must be noted on the plan and the operator's station at the control panel must be behind a protective barrier sufficient to ensure compliance with this Article;
D. The structural composition and thickness or lead/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, show distance to the closest area 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/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.
III. Therapeutic Radiation Machines Over 150 kV. In addition to the requirements listed in Section I above, therapeutic radiation machine facilities that produce photons with a maximum energy in excess of 150 kV or electrons must 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 energy and types of radiation produced (i.e., photon, electron). The target to isocenter distance must 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/drawing (including both floor plan and elevation views) 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, show distance to the closest area where it is likely that individuals may be present;
F. Description of all assumptions that were in shielding calculations including, but not limited to, design energy (i.e., room may be designed for 6 MV unit although only a 4 MV unit is currently proposed), work-load, presence of integral beam-stop in unit, occupancy and use 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/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/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.
IV. Neutron Shielding. In addition to the requirements listed in Section III, therapeutic radiation machine facilities that are capable of operating above 10 MV must 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, 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;
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/ 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.
(Added City Record 4/24/2019, eff. 5/24/2019)
Source: City of New York, Charter, Administrative Code and Rules (American Legal Publishing XML export, codelibrary.amlegal.com)URL: https://codelibrary.amlegal.com/codes/newyorkcity/latest/NYCrules/0-0-0-118155Fetched: 10/24/2026