Part 305: Classification of Restricted Versus Unrestricted Areas and Uses
- 305.10 Introduction
- 305.20 Restricted Area or Use Requirements
- 305.30 Unrestricted Area or Use Requirements
- 305.40 Release of Items or Equipment for Unrestricted Use
- 305.50 Termination Surveys
The Nuclear Regulatory Commission bases many of its radiation safety requirements on the concept of restricted versus unrestricted. An authorized user will determine if their area will be classified as a restricted area or unrestricted area by following the requirements described below. The main differences between the two classifications is whether or not radioactive materials are used or just stored, the level of control needed for preventing access to radioactive materials by unauthorized personnel, and the limits allowed for radioactive contamination and exposure to radioactive materials.
There may be a hybrid of the two, where during the actual use of radioactive materials, the area is considered a restricted area. After the use is completed, if contamination levels and airborne concentrations of radioactive materials are below the unrestricted limits and access to the radioactive materials is controlled, the area can then be considered an unrestricted area.
- Use or Storage - Radioactive materials may be used or stored in a restricted area.
- Access - Access to a restricted area must be controlled by the authorized user. If access is controlled, such as by locking the laboratory door(s) or by maintaining constant surveillance of the area, then radioactive materials within the area do not need to be secured (e.g., within locked cabinets, freezers, refrigerators, etc.).
- Training - All personnel who enter a restricted area must receive training at a level appropriate to their duties within the restricted area (see Part 600.20 (A) and (C)).
- Contamination Limits - Allowable contamination limits in a restricted area are specified in Part 900. Contamination levels exceeding these limits must be decontaminated.
- Airborne Radioactive Material Concentrations - Allowable airborne radioactive material concentrations are specified in Part 900.
- Use or Storage - Only storage of radioactive materials is allowed in an unrestricted area.
- Access - Radioactive materials present in an unrestricted area must not be accessible to the public, either by placing the radioactive materials in a locked area or by maintaining surveillance of the area.
- Training - No specific training is required for unrestricted areas.
- Contamination Limits - Contamination levels must not exceed the limits specified in Part 900 for unrestricted areas.
- Airborne Radioactive Material Concentrations - Airborne radioactive material concentrations must not exceed the limits specified in Part 900 for unrestricted areas.
- Exposure Limits - Radiation levels may not exceed 2 millirems per hour in an unrestricted area.
Items or equipment that had been previously used with radioactive materials must meet the decontamination requirements of Part 900 for unrestricted use. Work involving radioactive materials should plan to use items that can be disposed of as radioactive waste whenever possible.
When the use of radioactive materials is to be terminated within a laboratory or space due to users leaving the university, the work requiring the use of radioactive materials is completed and radioactive materials are not anticipated to be used again, a change in location from one space to another, or for some other reason, then a termination survey must be conducted by the radiation safety officer or designee.
A laboratory or other space may not be used until a termination survey has been completed by the radiation safety officer or designee and all contaminated areas have been cleaned.
The authorized user must account for all radioactive materials, including wastes, decontaminate any contaminated areas found during the termination survey, have all the required paperwork completed, return any radioactive waste containers and shields borrowed from the radiation safety officer or designee, and return all radiation monitoring badges.
It is the responsibility of the department head/chair to verify that the radiation safety officer or designee has been contacted prior to any of the above changes, that a termination survey has been conducted, and that the laboratory or space will not be used until approved by the radiation safety officer or designee.