DMTR became Scotland’s first operating reactor when it achieved criticality in 1958. It was used for irradiation tests on materials until its shutdown in 1969. In 2018 a contract was awarded to Cavendish Nuclear Limited to dismantle and demolish the reactor. The fuel, heavy-water coolant and some redundant plant have been removed, leaving the reactor vessel, supports and containment shell ready for final demolition. Work is currently focused on the fuel element storage block (FESB), where irradiated fuel was stored after its removal from the reactor. The 8.9 tonne lid, known as the top plate, …