NHK reporting that the robot sent by the Idaho National Laboratory has measured radiation levels inside reactors 1 and 3.

The robots were sent to Japan to help deal with the damaged Fukshima Daiichi nuclear plant.

The max radiation level inside the Reactor 3 building is 57 millisieverts per hour, while max level in Reactor 1 building is at 49 millisieverts per hour.  The readings were taken on the first floor of the buildings.

Normal safe limits, for nuclear employees, are 100 millisieverts, but the Japanese government raised it to an emergency limit of 250 millisieverts.  Even at the emergency limit, a worker would exceed it within four and a half hours of exposure.

They will check Reactor 2 building next.  NHK video