216 R.I. Code R. 216-RICR-40-20-3.13

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Current through October 15, 2024

Section 216-RICR-40-20-3.13 - Information on Radiation Shielding Required for Plan Reviews

A. All X-Ray Equipment Facilities must submit the following information for plan reviews:

1. Basic facility information including:

a. Name;

b. RPS registration number and telephone number of the individual responsible for the shielding specifications;

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

d. The street address [including room number(s)] of the facility.

e. The plan should also indicate whether this is a new structure or a modification to existing structure(s). If the facility is currently registered, the Agency registration number must be provided.

2. All wall, floor, and ceiling areas struck by the useful beam shall have primary barriers.

3. Secondary barriers, when required, shall be provided in all wall, floor, and ceiling areas.

4. Shielding in walls of diagnostic X-ray facilities shall extend to a minimum height of seven feet (7') above the floor.

B. X-Ray Equipment Facilities Up To 150 kV

1. In addition to the requirements listed in § 3.13(A) of this Part, the plans for all X-ray equipment facilities which produce only photons with a maximum energy less than or equal to one hundred fifty (150) kV shall contain, as a minimum, the following additional information:

a. Equipment specifications including the make and model of the X- ray equipment, the maximum technique factors and the energy waveform (single phase, three phase, etc.).

b. The maximum design workload for the facility in terms of milliamp minutes or milliamp-seconds per week. The total anticipated number of patients per week or number of exposures per week, as well as the type of examination(s) or treatment(s) which will be performed with the equipment, shall also be provided.

c. A facility blueprint/drawing indicating:

(1) Scale (one quarter inch (0.25") = one foot (1') is typical);

(2) Direction of North;

(3) Normal location of the X-ray system's radiation port(s);

(4) The port's travel and traverse limits;

(5) General direction(s) of the useful beam;

(6) Locations of any windows and doors; and

(7) The location of the X-ray control panel.

(8) If the control panel is located inside the X-ray room, the location of the operator's station shall be noted in the plan and the operator's station at the control panel shall be in compliance with §1.7.1 of this Subchapter.

d. In X-ray facilities designed for medical use, a window (of lead equivalent at least equal to that required for the adjacent barrier), mirror or other remote viewing system shall be provided and so placed that the operator can see the patient during the exposure without having to leave the protected area.

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

f. 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.

g. At least one (1) 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. If commercial software is used to generate shielding requirements, also identify the software used and the version/revision date.

C. X-Ray Equipment Facilities Over 150 kV

1. In addition to the requirements listed in §§ 3.13(A) and (B) of this Part, the plans for all X-ray equipment/accelerator facilities which produce photons with a maximum energy in excess of one hundred fifty (150) kV and/or electrons and/or protons or other subatomic particles shall also contain the following information:

a. Equipment specifications including: manufacturer and model number of the unit; rad (or rem) per minute at the isocenter; and the energy(s) and type(s) of radiation produced [ie: photon, electron, neutron]. The source to isocenter distance must be specified.

b. Maximum design workload for the facility including total weekly radiation output [expressed in rad (or rem)/week at one (1) meter], total beam-on time per day or week.

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

(1) Position and orientation of the X-ray/accelerator unit, scale (one quarter inch (0.25") = one foot (1') is typical);

(2) Type(s) and thickness of shielding material(s);

(3) Direction of North; and

(4) 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.

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

e. 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.

f. Description of all assumptions that were used in shielding calculations including, but not limited to:

(1) Design energy [i.e.: room may be designed for six (6) MV unit although only a four (4) MV unit is currently proposed];

(2) Presence of integral beam-stop in unit;

(3) Workload, occupancy and use(s) of adjacent areas;

(4) Fraction of time that primary beam will intercept each permanent barrier (walls, floor and ceiling); and

(5) "Allowed" radiation exposure in both restricted and unrestricted areas.

D. Neutron Shielding

1. In addition to the requirements listed in §§ 3.13(A) and (C) of this Part, X- ray equipment/accelerator facilities which are capable of operating above ten (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, 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 (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. If commercial software is used to generate shielding requirements, also identify the software used and the version/revision date.

d. 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-40-20-3.13

Adopted effective 1/1/2019
Amended effective 5/25/2022