Fuel Storage and Flask

A fuel storage block sits next to a transfer flask in the reactor hall at ANSTO HIFAR. The storage block is a slab of dense concrete, pierced with vertical tubes that held spent fuel elements while their radioactivity decayed. The transfer flask, on a wheeled trolley, is a cylindrical lead vessel about a metre and a half tall, used to move fuel safely between the reactor and the storage block. Both objects are painted the standard reactor-hall colour, a pale grey. Both are heavily built, designed to handle radioactive material without leaking radiation to operators standing nearby. The block is bolted to the floor; the flask is on locked wheels.

Fuel handling is one of the slower parts of reactor operation. After a fuel element finishes its life in the reactor core, it is highly radioactive and gives off both radiation and decay heat. The element is moved out of the reactor in the transfer flask, lowered into a tube in the storage block, and left for months or years to cool down. Only then can it be processed further. At HIFAR this cycle ran continuously for forty-nine years. The storage block in this photograph still holds elements from late in the reactor's life. They are not going anywhere quickly.