Fukushima: fuel rods exposed, fuel melted, reactor vessel has holes…

This is probably the worst news about Fukushima yet, but it seems to be getting little media play. The short version, Reactor 1 has totally exposed fuel rods, melted fuel pooling at the bottom and holes in the reactor containment vessel. It is exactly similar to Chernobyl, with reactor fuel directly exposed to the environment outside the containment vessel. High radiation in the Reactor 1 is making it very difficult to perform any sort of repair work. Workers who enter into the area will be exposed to th maximum limit doses of radiation in minutes.

Bloomberg reports:

Fuel rods in the core of the No. 1 reactor are fully exposed, with the water level 1 meter (3.3 feet) below the base of the fuel assembly, Junichi Matsumoto, a general manager at the utility known as Tepco, told reporters at a briefing in Tokyo. Melted fuel has dropped to the bottom of the pressure vessel and is still being cooled…

“What this means is this is probably going to be a much more difficult cleanup than they originally planned for,” said Paul Padley, a particle physicist at Rice University in Houston. The government and Tepco “have consistently appeared to be underestimating the severity of the situation.”

The company doesn’t know how long the rods have been exposed, it said in the briefing. It’s likely they’ve been uncovered since the first days of the disaster…

Fuel rods are submerged in water to prevent overheating that would crack the casing and release radiation…

Holes have been found in the base of the pressure vessel, and most of the fuel has likely melted, Kyodo News reported yesterday, citing the utility. It’s possible the fuel has leaked into the containment vessel, which was damaged in the explosion, according to the report.Flooding the chamber was one of the steps Tepco outlined in April to bring the crisis under control.

“The plan needs to be revised,” Matsumoto said. “We can’t deny the possibility that a hole in the pressure vessel caused water to leak.”