Radioactive waste from historic subterranean vaults at Berkeley nuclear power station in Gloucestershire has been put into a concrete box.
This marks a milestone step in the decommissioning of the site, the Office for Nuclear Regulation (ONR) has said.
The nuclear power station was taken offline in 1989, after 27 years of powering homes across the region – Berkeley was the first commercial nuclear power station in the UK to be decommissioned.
The ONR confirmed that the first concrete box of radioactive waste has now been filled and safely stored at the Gloucestershire site, pending long-term disposal in a future geological disposal facility.
It is expected to take between four and five years to remove the full waste from the vaults at Berkeley, authorities have said.
David Hubbard, Magnox’s Programme Manager, said: “The innovative design cuts down the need for maintenance and reduces the amount of hands-on control needed to provide a safe and secure environment for the waste containers for up to 150 years.”