so that TEPCO can conserve water that is being injected into the RPVs.
The robot "Quince" went to the 2nd floor of Reactor 3's reactor building at Fukushima I Nuclear Power Plant on July 26 and measured the radiation. It was as high as 75 millisieverts/hour on the 2nd floor. To help "Quince", 6 TEPCO employees went to the reactor building (I don't think they were inside the building), and received maximum 2.22 millisieverts of radiation.
TEPCO's handout for the press on July 27, radiation measurement by Quince:
No radiation level is too high for carbon-based workers in the time of crisis, and TEPCO is sending 6 of them up the stairs to the 2nd and 3rd floors of Reactor 3 on July 27. However, the amount of time the workers spend inside the reactor building will be limited, according to TEPCO. The workers are to conduct the survey to determine whether it is possible to hook up the water injection system to the ECCS (emergency core cooling system) pipe, so that the water could be poured directly over the melted fuel (if there's melted fuel left in the RPV, that is) and thus more efficient (i.e. using less water) in cooling the fuel.