R313-30-10. Information on Radiation Shielding Required for Plan Reviews

  (1) Therapeutic Radiation Machines

  (a) Basic facility information including: name, telephone number and 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 external beam radiation therapy facility. The plan should also indicate whether this is a new structure or a modification to existing structures.

  (b) Wall, floor, and ceiling areas struck by the useful beam shall have primary barriers. For an adjacent area that is normally unoccupied, barrier thicknesses may be less than the required thickness, if:

  (i) That area where the exposure rates and exposures exceed the limits specified in R313-15-301(1) is permanently fenced or walled to prevent access;

  (ii) The appropriate warning signs are posted at appropriate intervals and locations on the fence or wall;

  (iii) The exposure rates and exposures outside the fence or wall are less than the limits specified in R313-15-301(1);

  (iv) Access to the area is controlled by the operator, and once access is gained, the therapeutic radiation machine cannot be operated until the area has been cleared and access is again controlled by the operator;

  (v) The ceiling is of sufficient thickness to reduce exposure due to skyshine, so that the exposure rates and exposures surrounding the facility are less than the limits specified in R313-15-301(1); and

  (vi) The primary barrier is of sufficient thickness to ensure that the exposure rates and exposures from the primary beam in spaces in adjacent buildings are less than the limits specified in R313-15-301(1).

  (c) Secondary barriers shall be provided in 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 R313-30-10(1), therapeutic radiation machine facilities which produce only photons with a maximum energy less than or equal to 150 kV 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 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.

  (c) A facility blueprint or drawing indicating: the scale of the blueprint or drawing; 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 windows and doors; and the location of the therapeutic radiation machine control panel. If the control panel is located inside the external beam radiation therapy 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 R313-15-101 of these rules.

  (d) The structural composition and thickness or the lead or concrete equivalent of walls, doors, partitions, floor, and ceiling of the rooms concerned.

  (e) The type of occupancy of adjacent areas inclusive of space above and below the rooms concerned. If there is an exterior wall, show distance to the closest areas where it is likely that individuals may be present.

  (f) At least one example calculation which shows the methodology used to determine the amount of shielding required for the physical conditions; that is the primary and secondary or leakage barriers, restricted and unrestricted areas, entry doors; and shielding material in the facility.

  (i) If commercial software is used to generate shielding requirements, please also identify the software used and the version or revision date.

  (ii) 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 kV. In addition to the requirements listed in R313-30-10(1), therapeutic radiation machine facilities which produce photons with a maximum energy in excess of 150 kV and electrons and protons or other subatomic particles 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, that is photon and electron. The source to isocenter distance shall be specified.

  (b) 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.

  (c) Facility blueprint or drawing, including both floor plan and elevation views, indicating relative orientation of the therapeutic radiation machine; scale; types; thickness and minimum density of shielding materials; direction of North; the locations and size of penetrations through shielding barriers, ceiling, walls and floor; as well as details of the doors and maze.

  (d) The structural composition and thickness or concrete equivalent of walls, doors, partitions, floor, and ceiling of the rooms concerned.

  (e) The type of occupancy of adjacent areas inclusive of space above and below the rooms concerned. If there is an exterior wall, show distance to the closest areas where it is likely that individuals may be present.

  (f) Description of assumptions that were used in shielding calculations including, but not limited to; design energy, for example a 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 permanent barriers, walls, floor and ceiling; and "allowed" radiation exposure in both restricted and unrestricted areas.

  (g) At least one example calculation which shows the methodology used to determine the amount of shielding required for the physical conditions; that is the primary and secondary or leakage barriers, restricted and unrestricted areas, small angle scatter, entry doors and maze; and shielding material in the facility.

  (i) If commercial software is used to generate shielding requirements, also identify the software used and the version or revision date.

  (ii) 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 R313-30-10(3), therapeutic radiation machine facilities which 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 neutron shielding material.

  (b) Description of assumptions that were used in neutron shielding calculations including, but not limited to, neutron spectra as a function of energy, neutron flux 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 the physical conditions, that is, restricted and unrestricted areas, entry doors and maze and neutron shielding material utilized in the facility.

  (i) If commercial software is used to generate shielding requirements, also identify the software used and the version or revision date.

  (ii) 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 which will be used to verify the adequacy of neutron shielding installed in the facility.