The Coast Guard and a special police assault team were among the agencies involved, Kyodo News reported. The drill took place at Fukushima No. 2, which is about 6 miles away and is also operated by the Tokyo Electric Power Co.
Fukushima No. 1 was heavily damaged by the March 2011 earthquake and tsunami. Officials say its condition could make it an inviting target for terrorist groups.
The drill involved two potential scenarios. In one, terrorists were hiding in a cargo ship docked at the plant and in the other they attempted ot enter it in a vehicle loaded with explosives.