Melted Fuel May Be Deposited at N-Reactor Bottoms: Group

Tokyo, April 15 (Jiji Press)--Part of nuclear fuel rods has melted and stays in the form of powder at the bottoms of three reactor pressure vessels of the Fukushima No. 1 plant, a Japanese academic group has said.
The No. 1 to No. 3 reactors of Tokyo Electric Power Co.'s <9501> plant have suffered major damage to their cores because the March 11 earthquake and tsunami knocked out the plant's cooling systems, according to the outcome of analyses by a specialist group of the Atomic Energy Society of Japan.
Part of the reactors' fuel rods were exposed for a long time after the power was lost for the cooling systems, and it is highly likely that part of them has melted and been damaged, the group said.
The group said it does not favor a view among some experts that the melted fuel may destroy the reactor vessels by falling to their bottoms at extremely high temperatures.
At present, the temperatures in the lower parts of the reactor pressure vessels are low and the melted fuel is believed to have been cooled and deposited as powder, the group said.
Tokyo Electric Power is currently continuing pumping water into the three reactor vessels to cool fuel rods, and highly radioactive water is believed to be leaking from the vessels.
On this, the group said the fuel powder will not leak from the vessels because it is heavy.
In the No. 1 and No. 2 reactors, part of the fuel rods may be exposed even now as the temperatures at the tops of their pressure vessels are high.
But the group said their fuel rods will unlikely be damaged further and cause massive releases of radioactive particles since enough cooling water is injected into the pressure vessels.
Takashi Sawada, the society's vice president, said the situation of the reactors will remain stable as long as they are kept cool through water injection.
Tokyo Electric Power has to speed up its work to drain water from reactor turbine buildings and identify the places from which the contaminated water is leaking.