TEPCO Eyes a New Plan
TOKYO, Aug. 31 (Kyodo) — Tokyo Electric Power Co. said Wednesday that it plans to take out the melted nuclear fuel from inside the crippled reactors at the Fukushima Daiichi power plant after repairing the reactor containers and filling them up with water.
But the plant operator did not go further into details, only saying that the plan, unveiled during a meeting of a government panel on nuclear energy policy, is just "an image at the current moment."
The process is expected to start with the removal of radioactive substances inside the plant's buildings housing the reactors, which would be followed by repair work on the primary containment vessels.
Workers are then expected to fill each primary containment vessel with water to a level above the fuel and open the lid of the inner pressure vessel holding the fuel.
Flooding the primary containment vessel with water is a method Tokyo Electric tried to employ in the past as part of efforts to stably cool the fuel, although it gave up doing so because one container appeared to have been leaking massive amounts of water injected into the reactor.
The utility known as TEPCO said it believes that flooding the container is necessary before removing the fuel because water would help block the radiation so that workers will be able to pinpoint the position of the melted fuel.
The process would take place without stopping the water currently being injected into the crippled reactor cores under a water circulation system created after the nuclear crisis, TEPCO said.
But the company also noted that it may have to seek alternatives because an "advanced technological development" is likely to be required to carry out the planned procedures.
On March 11, a magnitude 9.0 earthquake and tsunami waves led the six-reactor nuclear complex to lose nearly all of its power sources and caused the cooling functions of the reactors and spent nuclear fuel pools at the Nos. 1 to 4 units to fail.
The Nos. 1 to 3 reactor cores are assumed to have suffered meltdowns in the early days of the crisis, possibly damaging the bottom of each reactor pressure vessel and partially accumulating in the outer primary container.