NRC Commissioner Gregory Jaczko told Congress today that:
that the commission believed that all the water in the spent fuel pool at the No. 4 reactor of the Fukushima Daiichi Nuclear Power Station had boiled dry, leaving fuel rods stored there exposed and bleeding radiation.
Tokyo Electric Power Co. disagrees:
On Thursday morning [Japan is 13 hours ahead of Eastern Daylight Time], a spokesman for Tokyo Electric Power, the Daiichi plant operator, and a spokesman for Japan’s nuclear regulatory agency, denied Mr. Jaczko’s account, saying the situation at reactor No. 4 had not changed and that water remained in the spent fuel storage pool. But both officials said the situation was changing and that the reactor had not been inspected in recent hours.
"We can’t get inside to check, but we’ve been carefully watching the building’s environs, and there has not been any particular problem," said Hajime Motojuku, the spokesman for Tokyo Electric.
A little more:
Takumi Koyamada, the spokesman at Japan’s nuclear regulator, said that as of 12 hours ago water remained and the temperature reading was 84 degrees Celsius and that no change had been reported since then.
84 degrees C means the water is not boiling.