X-ray diffraction: If the radiation source is totally surrounded by a shielded enclosure with “fail-safe” interlocks on all access doors, no additional shielding is usually required. Contact the RSO for details.
Moisture/density gauges: Special consideration should be given to the storage location for such sources. Storage locations may need to be shielded or in remote locations where the exposure limits for controlled and uncontrolled areas are not exceeded. Contact the RSO for details. Adequate security measures for the storage area and transportation need to be provided to prevent unauthorized removal. A minimum of two locks should be placed between the radioactive source, and the public and transport vehicles should possess a security device (such as an alarm) to deter unauthorized use or theft of the vehicle.
CA DHS Radiation Safety Advisory of 3/6/03 – Security of Licensed Materials
Electrical equipment that produces radiation incidental to its operation for other purposes but does not produce radiation in an area likely to cause any individual to receive in excess of 500 mrem in a year does not need to be registered with the State.
17 CCR 30125 (b)