216 R.I. Code R. 216-RICR-40-20-5.14

Current through December 26, 2024

Section 216-RICR-40-20-5.14 - Information on Radiation Shielding Required for Plan Reviews

5.14.1All Therapeutic Radiation Machines

A. Basic facility information including:

1. Name, telephone number and Agency registration number of the individual responsible for preparation of the shielding plan;

2. Name and telephone number of the facility supervisor; and

3. The street address, including room number, of the therapeutic radiation machine facility.

4. The plan should also indicate whether this is a new structure or a modification to existing structure(s).

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.

5.14.2Therapeutic Radiation Machines Up To 150 kV (Photons Only)

A. In addition to the requirements listed in §5.14.1 of this Part, therapeutic radiation machine facilities which produce only photons with a maximum energy less than or equal to one hundred fifty (150) kV must submit shielding designs which contain, as a minimum, the following additional information:

1. Equipment specifications, including the manufacturer and model number of the therapeutic radiation machine, as well as the maximum technique factors.

2. Maximum design workload for the facility including total weekly radiation output, [expressed in gray or air kerma at one (1) meter], total beam-on time per day or week, the average treatment time per patient/human research subject, along with the anticipated number of patients to be treated per day or week.

3. A facility blueprint/drawing indicating:

a. Scale [one quarter inch (0.25") = one foot (1') is typical];

b. Direction of North;

c. Normal location of the therapeutic radiation machine's radiation port(s);

d. The port's travel and traverse limits;

e. General direction(s) of the useful beam;

f. Locations of any windows and doors;

g. The location of the therapeutic radiation machine control panel; and

h. 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 §1.7.1 of this Subchapter.

4. The structural composition and thickness or lead/concrete equivalent of all walls, doors, partitions, floor, and ceiling of the room(s) concerned.

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

6. The calculations which show 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 door(s)] and shielding material in the facility.

a. If commercial software is used to generate shielding requirements, the software and the version/revision date used must be identified.

b. If the software used to generate shielding requirements is not in the open literature, an explanation of the calculations used to verify the results obtained with the software must also be submitted.

5.14.3Therapeutic Radiation Machines Over 150 kV

A. In addition to the requirements listed in §5.14.2 of this Part, therapeutic radiation machine facilities which produce photons with a maximum energy in excess of one hundred fifty (150) kV and/or electrons must submit shielding designs which contain, at a minimum, the following additional information:

1. Equipment specifications including the manufacturer and model number of the therapeutic radiation machine, and gray at the isocenter and the energy(s) and type(s) of radiation produced [i.e., photon, electron]. The target to isocenter distance must be specified.

2. Maximum design workload for the facility including total weekly radiation output [expressed in gray at one (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.

3. Facility blueprint/drawing (including both floor plan and elevation views) indicating:

a. Relative orientation of the therapeutic radiation machine;

b. Scale [one quarter inch (0.25") = one foot (1') is typical];

c. Type(s), thickness and minimum density of shielding material(s);

d. Direction of North;

e. 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.

4. The structural composition and thickness or concrete equivalent of all walls, doors, partitions, floor, and ceiling of the room(s) concerned.

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.

6. A description of all assumptions that were in shielding calculations including, but not limited to, design energy [i.e., room may be designed for six (6) MV unit although only a four (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 useful beam will intercept each permanent barrier [walls, floor and ceiling] and "allowed" radiation exposure in both restricted and unrestricted areas.

7. The calculations 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.

a. If commercial software is used to generate shielding requirements, the software and the version/revision date used must be identified.

b. If the software used to generate shielding requirements is not in the open literature, an explanation of the calculations used to verify the results obtained with the software must also be submitted.

5.14.4Neutron Shielding

A. In addition to the requirements listed in §5.14.3 of this Part, therapeutic radiation machine facilities which are capable of operating at greater to or equal to ten (10) MV must submit shielding plans which contain, as a minimum, the following additional information:

1. The structural composition, thickness, minimum density and location of all neutron shielding material.

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.

3. At least one (1) 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.

a. If commercial software is used to generate shielding requirements, the software and version/revision date used must be identified.

b. If the software used to generate shielding requirements is not in the open literature an explanation of the calculations used to verify the results obtained with the software must also be submitted.

4. The method(s) and instrumentation which will be used to verify the adequacy of all neutron shielding installed in the facility.

216 R.I. Code R. 216-RICR-40-20-5.14

Adopted effective 11/27/2023