Radiation Safety

Authorized Users should minimize their exposures to keep their occupational doses As Low As Reasonably Achievable (ALARA) using the three principles:

• Time: The shorter the time spent around an X-ray machine, the lower the radiation dose.
• Distance: Radiation levels decrease significantly with increase in distance from the source of radiation. The use of distance is one of the easiest and most effective methods for radiation protection.
• Shielding: Lead shielding should be used to reduce radiation levels below 2 mR/hr. Most machines have built-in shielding, some will require additional shielding placed around the machine.

The RSO requires all Principal Investigators and Authorized Users of radioactive material, Class 3b and 4 lasers, X-ray machines, and other ionizing radiation producing devices requiring registration to complete the applicable radiation safety course. The training will be consistent with the Texas Hazard Communication Act, reviewing the hazards associated with radiation. Completion of a radiation safety course does not automatically qualify someone as an Authorized User (AU). To receive authorization to work with specific radioactive material and/or radiation producing devices, you must be added to a PI's sublicense or subregistration through an amendment application. How to complete the training will be communicated once the subregistration application is received. Contact the EHS Office for further information at ehs@uhd.edu.

Annual Radiation Safety Refresher Training courses shall be completed by all persons authorized to work with radioactive materials, X-ray machines, and Class 3b and 4 Lasers. PIs and AUs may receive notification of required refresher training. Non-completion of the refresher training by not completing or passing the required exam shall lead to suspension from working with any source of radiation. Inactive PIs and their authorized users shall be exempted from annual refresher training requirements. However, completion of appropriate training shall be required prior to reinstatement from inactivity. The RSO shall recommend the applicable training when the request is received.

Start up, shut down, alignment, and emergency procedures for all X-ray machines (except for minimal threat devices) must be readily available to and acknowledged by all users. The safety and basic operations sections in the manufacturer’s manual should include much of the necessary information for the standalone document. X-ray machines classified as minimal threat devices only require the availability of the manual for compliance.

Radiation badges (dosimeters) are provided to primary users of X-ray diffraction machines and other such potentially high exposure units. Not all X-ray users will be required to use a dosimeter. Users should keep their dosimeters in an area of low exposure away from the X-ray machine when not in use. If assigned, dosimeters must be worn while working with X-ray machines. Notify the Radiation Safety Officer if your dosimeter is lost or damaged; do not use someone else’s. PIs and/or Authorized Users who do not promptly report lost badges or return old badges may be charged for the cost of the badge plus administrative fees. PIs must also immediately report when their Authorized Users terminate and arrange to return the badge promptly to the RSO.

Survey meters are required for potential high exposure units. Survey meters must be kept calibrated and should not be used after the calibration due date has passed. Radiation safety personnel conduct required inspections of all X-ray machines at the initial setup, after modifications, calibrations, and moving. Radiation safety personnel also perform routine inspections and exposure surveys of the X-ray machines.

Required X-ray use location door signage and postings will be provided by the Radiation Safety Officer to assure standardization and compliance. At a minimum, all X-ray labs must have a “Caution Radiation Area” sign posted at each entrance, a Notice to Employees, and an emergency contact sign. A “Caution Safety Device Not Working” sign must be used whenever the interlocks are bypassed for alignments and equipment changes, as pre-approved by the RSO.

Certain records are required to be maintained by all X-ray PIs and readily available for internal and/or external inspections. All records should be maintained in one central location in the lab. Applicable records are outlined in the “Receipt, Document and Set up” section of this manual. X-ray machines shall also have a use log, to be filled out each time the machine is used. The log shall include, at a minimum, the user’s name, date of use, and settings or description of use.