105 CMR 120.651
Control of Source Movement
(A) The mechanism that moves the sources of a panoramic irradiator must require a key to
actuate. Actuation of the mechanism must cause an audible signal to indicate that the sources
are leaving the shielded position. Only one key may be in use at any time, and only operators
or facility management may possess it. The key must be attached to a portable radiation survey
meter by a chain or cable. The lock for source control must be designed so that the key may not
be removed if the sources are in an unshielded position. The door to the radiation room must
require the same key.
(B) The console of a panoramic irradiator must have a source position indicator that indicates
when the sources are in the fully shielded position, when they are in transit, and when the sources
are exposed.
(C) The control console of a panoramic irradiator must have a control that promptly returns the
sources to the shielded position.
(D) Each control for a panoramic irradiator must be clearly marked as to its function.