(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 chapter 246-220 WAC except:

(a) Where the high radiation area is equipped with a control device or alarm system as described in WAC 246-221-120 (1)(e)(ii); or

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

(2) When not in operation or when not under direct surveillance, radiation machines shall be secured to prevent use by unauthorized personnel.