Photo/IllutrationThe Asahi Shimbun

A decommissioning organization on Aug. 31 formally recommended bypassing a safety measure to remove melted nuclear fuel from crippled reactors at the Fukushima No. 1 nuclear plant.

The Nuclear Damage Compensation and Decommissioning Facilitation Corp. (NDF) urged the central government and Tokyo Electric Power Co. to use the “airborne method” in which the melted fuel is removed even when the water level in the reactor containment vessel is kept low.

Proposals have been made to fill the containment vessels with water to restrain the spewing of radioactive materials during the fuel removal process.

But the NDF said that method is currently not viable because of the difficulties in patching up the holes in the containment vessels.

The government and TEPCO are expected to decide on a fuel removal method in September and confirm the specific steps next fiscal year.

The removal of equipment and other structural objects in and around the reactors must be completed before work can start on taking out melted fuel that remains in the pressure vessels.

The nuclear fuel that has seeped through the pressure vessels and landed at the bottom of the containment vessels will be the first to be removed.

Work will also have to be done to develop a robot arm that can remove fuel from the side of the containment vessel.

Under the current schedule, removal of the melted fuel will start at one of the three, No. 1 to No. 3, reactors of the Fukushima No. 1 plant in 2021.

However, officials still do not know the exact location of the melted fuel in the reactors.

Hajimu Yamana, NDF president, pointed out there would likely be a need to combine various methods instead of pushing through with one specific procedure to meet the scheduled deadline.