105 CMR 120.069
Requirements for Mobile Devices
Each licensee that possesses mobile devices containing category 1 or category 2 quantities
of radioactive material must:
(A) Have two independent physical controls that form tangible barriers to secure the material
from unauthorized removal when the device is not under direct control and constant surveillance
by the licensee; and
(B) For devices in or on a vehicle or trailer, unless the health and safety requirements for a site
prohibit the disabling of the vehicle, the licensee shall utilize a method to disable the vehicle or
trailer when not under direct control and constant surveillance by the licensee. Licensees shall
not rely on the removal of an ignition key to meet this requirement.