Trawsfynydd nuclear power station flasks were transported to Trawsfynydd on a section of the former Bala to Blaenau Ffestiniog railway that had been closed in January 1961. A single track was restored northwards with an entirely new line through the centre of Blaenau Ffestiniog that connected to the Conwy Valley branch. In 1963-4 a "Goliath" gantry crane was installed over sidings about east of the power station. Beginning on 20 April 1964, nuclear flasks could be transported by rail between destinations such as Sellafield in Cumbria. The last regular departure was on 8 August 1995. The last train to carry nuclear material from Trawsfynydd
Hartlepool Nuclear Power Station for a prototype fluidised bed combustion (FBC) coal station at Grimethorpe in Yorkshire. Because of this, the UK missed out on pioneering FBC technology, before it became internationally recognised as the best way of burning coal. Sited from Seaton Carew, and in the middle of the industrial complex of Teesside, the station was to be built closer to any major urban area than any nuclear power station site had been. To make this acceptable, the station's reactors were to be housed in prestressed concrete pressure vessels. The construction of the power station which was undertaken by Nuclear Design & Construction