Debris investigated in unit 3 pool

Wednesday, 17 October 2012

Fuel racks in the pool of Fukushima Daiichi 3 appear undamaged, despite impact by debris including large parts of a 35-tonne fuel handling machine over 18 months ago.

Top: The electric motor of the fuel transfer machine lies within the pool. Bottom: Debris and dust covers the fuel assemblies stored in the pool (Images: Tepco)

Tokyo Electric Power Co (Tepco) has released a series of photos as well as video footage taken on 11 and 12 October. These show pieces of equipment that fell into the pool following the hydrogen explosion that damaged the reactor building on 14 March 2011. The debris includes parts of a 35-tonne fuel transfer machine normally used to move fuel assemblies between the reactor and the pool. The machine's electric motor, concrete blocks and steel beams can be seen lying within the pool, which contains 566 used fuel assemblies.

"We now know approximately where the equipment fell," a Tepco spokesman was quoted as saying by The Japan Times. He added that the used fuel in the pool, located on the fourth floor of the reactor building, does not appear to have been damaged by the impact.

Last month, during an operation to remotely remove debris from the roof of the reactor building, a steel beam - about seven metres long and weighing about 470 kilograms - slipped into the pool but is not thought to have damaged the fuel.

Tepco aims to remove sufficient debris from unit 3's used fuel pool to allow the removal of the fuel assemblies to start in fiscal 2014.

Researched and written
by World Nuclear News