Each entrance or access point to a high or very high radiation area must be:
equipped with a control device that causes the level of radiation to be reduced so that an individual cannot receive a dose in excess of 100 millirems (1.0 mSv) in one hour upon entry into the area;
equipped with a warning device that energizes a visible or audible alarm to alert an individual entering the high or very high radiation area and other nearby nonoccupationally exposed workers;
kept locked except during periods when access to the area is required; or
monitored or supervised.
When a high or very high radiation area is established for 30 calendar days or less, direct surveillance to prevent unauthorized entry may be substituted for the devices required by this subpart.
The devices required by this subpart must not prevent an individual from leaving a high or very high radiation area.
MS s 144.12
32 SR 777
December 10, 2007