The following are technical justifications and commitments which are acceptable to exempt licensees from specific sections of 10 CFR Part 36. Acceptable license conditions are also shown below. For converted teletherapy units, the use of a single key or even several keys on a key-ring may be impractical.
Power is required to move collimators, activate field lights, align system, etc.
Requiring a single key would not allow the licensee to operate these powered systems. Therefore, a licensee may be exempted from this requirement, provided that the licensee commits to have the operator present for the entire period of time that the key is in the control panel. A working electrical interlock system on each entrance suffices to prevent personnel entry while the source is exposed. In addition, the licensee should commit to having an operator present during the entire irradiation who can visually observe the entrance, and to having a radiation monitor that can be read before entering the radiation area. Alteration of the interlock system to meet this requirement would prevent entry to the treatment room to remove a patient in the event of a stuck source.