NAC459.590. Therapeutic X-ray systems: Requirements for design of treatment room.

In addition to providing shielding adequate to meet the requirements of NAC 459.320 to 459.374, inclusive, the design of the treatment room must meet the following requirements:

     1. Treatment rooms to which access is possible through more than one entrance must be provided with warning lights in a readily observable position near the outside of all access doors, preferably at eye level, which will indicate when the useful beam is on.

     2. Provision must be made for two-way aural communication with the patient from the control room.

     3. Windows, mirror systems or closed-circuit television viewing screens or equivalent systems must be provided to permit continuous observation of the patient during irradiation and must be so located that the operator may see the patient and the control panel from the same position. When the viewing system is by electronic means, for example, television, an alternate viewing system must be available as a backup in case of electronic failure.

     4. Facilities which contain an X-ray system which may be operated above 150 kVp must:

     (a) Have all necessary shielding, except for any beam interceptor, provided by fixed barriers;

     (b) Have the control panel in a protected area which is outside the treatment room or within a protective booth which has a door electrically connected to the control panel so that X-ray production cannot occur unless the door is closed;

     (c) Have all entrance doors of the treatment room electrically connected to the control panel so that X-ray production cannot occur unless all doors are closed;

     (d) Be arranged so that if the doors referred to in paragraphs (b) and (c) are opened when the therapy tubehead is activated:

          (1) The machine will shut off within 2 seconds; or

          (2) The radiation at a distance of 1 meter from the target will be reduced to 10 mR/hr or less within 2 seconds; and

     (e) Be so designed that if the radiation output of the tubehead is affected by any door opening, the machine can be restored to full operation only by:

          (1) Closing the door; and

          (2) Subsequently reinitiating the exposure by manual action at the control panel.

     [Bd. of Health, Radiation Control Reg. §§ 6.8.2-6.8.2.4.5.1, eff. 2-28-80]—(NAC A 4-27-84; 1-18-94)