12.0 Sealed Source Use Procedures
In the use of sealed sources the primary safety consideration is to control external radiation exposure to the human body from gamma rays and neutrons. A secondary consideration is to prevent contamination and exposure if a sealed source should leak.
12.1 Sealed Source Use Procedure
- Remote handling equipment appropriate to the source shall be used if the radiation exposure one inch from the surface is greater than 10 mrem/hr. For long periods of handling (greater than one hour) remote equipment should be used to keep dose rates low. Shielding shall be used whenever possible to further reduce personnel exposure.
- Personnel monitoring equipment (dosimeters) is provided by EH&S shall be used if an individual is likely to receive a dose in excess of 10% of the applicable value specified in NAC 459.325.
- Radiation surveys with a calibrated detector shall be conducted of all general use areas to determine radiation levels. The radiation level in an uncontrolled area shall be less than 2 mrem/hr and 50 mrem/yr. Records shall be maintained of these surveys.
- Mark the use area with the appropriate caution signs as specified in NAC 459.355-3575.
- Post State Radiation Control Program Office Form NRC-1 "Notice to Employees."
- Sources must be secured from unauthorized access or be attended at all times.
- Leak testing of each sealed source not exempted from licensing shall be performed in accordance with Chapter 17 of this Manual.
- Notify EH&S immediately if a sealed source is lost or damaged, found to be leaking, or used in such a manner that human exposure above 100 mrem is a possibility.
- If a source is found to be leaking (0.005 uCi or more of removable contamination), the Radiation Safety Staff will remove the source from use until properly resealed. A report will be filed with the State Radiation Control Program Office within five days (NAC 459.307). Sources found with detectable amount of removable contamination will be examined, cleaned, and resurveyed. If necessary, a qualified outside vendor will be called for repair and/or maintenance of a source. Follow-up surveys will be conducted to determine the degree of contamination spread. Action will be taken to minimize personnel and property contamination. Documentation of the resolution of all leaks shall be provided to, and maintained by, the EH&S Department.
NOTE: Any leakage of sealed sources shall be reported immediately to the Radiation Safety Office.