Half of the last remaining radioactive fuel elements inside the Dounreay Fast Reactor (DFR) have now been removed, Dounreay Site Restoration Ltd (DSRL) has announced. The elements had been jammed inside the reactor, and their removal has been a top priority for its decommissioning. DFR, at Dounreay in northern Scotland, achieved criticality in November 1959 and in October 1962 became the world’s first fast reactor to supply electricity to the grid. Developed at a time of uranium shortage, the reactor’s core was surrounded by a blanket of natural uranium elements that, when exposed to radiation, would “breed” to create a new fuel, plutonium. The reactor, which was cooled by a liquid sodium-potassium alloy, achieved a maximum electrical power of 14.5 MWe and was shut down in 1977. Most of the core fuel was removed from the reactor after its closure, but almost 1000 elements from the breeder zone were found to be swollen and jammed, and were left in place. Recovery of the jammed elements, using purpose-built remotely-operated tools that reached down into the reactor to cut the breeder elements free and lift them into a flask for removal to the next stage of the process, began in 2017. Locally manufactured tooling has played a big part in the successful removal of half the remaining radioactive fuel inventory inside the reactor vessel.
World Nuclear News 11th Oct 2019 read more »