I assume, sounds nothing live is supposed to be in there, that the level might be pretty high.
According to a discussion thread on Quora, cabinet-type X-Ray scanners for security applications use a continuous beam that's not very strong, presumably because of advances in detector technology.
According to the discussion, one pass through a cabinet-type scanner delivers approximately the dosage of a chest X-Ray, about 2 millisieverts.
This is considerably less than one receives while taking a transcontinental trip on a high-flying passenger aircraft.