If the reactor vessel was breached, it will be much harder to contain radioactive contaminants, as the radioactive steam inside the pressure vessel could leak into the air. If the reactor suffers a partial meltdown, liquefied nuclear fuel could also escape.
At a press conference on Friday morning (Japan time) Hidehiko Nishiyama, deputy director-general of the Japan Nuclear and Industrial Safety Agency, said when three workers entered the turbine building at the number 3 reactor, they stepped in to water that was highly radioactive. The workers suffered burns and were hospitalized. The water was 10,000 times more radioactive than it would normally be, according to Asahi Shinbun.