Two remote-controlled robots from iRobot found high radiation levels in reactor buildings 1 and 3 Monday.

The finding could make it impossible for workers to enter the Fukushima plant to carry out crucial fixes under a a six-month “road map” for bringing radioactivity under control, Christian Science Monitor reported Monday.

The robots detected radiation leaking at a rate of 49 millisieverts per hour in the No. 1 reactor and  57 millisieverts per hour in the No. 3 reactor.

Officials said the water was more than 40 feet deep in the basement of the No. 4 reactor building and about 3 feet deep in several other buildings.