(1) During each radiographic operation, the radiographer or radiographer's assistant shall maintain a direct surveillance of the operation to protect against unauthorized entry into a high radiation area, as defined in ARM Title 37, chapter 14, subchapter 1, except:

(a) where the high radiation area is equipped with a control device or alarm system as described in ARM 37.14.725(3) (b) , or

(b) where the high radiation area is locked to protect against unauthorized or accidental entry.