Huge pool lifted into place in Unit 1
Teams on Unit 1 undertook one of the largest and most challenging lifts seen so far on site. The world’s largest crane, Big Carl, successfully lifted the reactor cavity and core pool – weighing in excess of 700 tonnes – into place. The reactor cavity and core internal storage pool will provide a tank of water to completely cover the reactor during refuelling and maintenance. The Bylor Precast team began constructing the precast base unit for the pool in 2021, while Darchem built the stainless steel liners. The team then finished the pool off by installing the internal formwork and reinforcement fixings, before making the final concrete pours.
Structure built to enable crane assembly
A 20m-tall building has been constructed alongside the HPC training centre as a temporary home for the Unit 1 polar crane assembly operation. A team of 10 scaffolders spent three months turning 1,000 tonnes of materials into the massive support structure inside which the polar crane will be assembled. Around 6,000m2 of white sheeting was used to protect their work from the elements. Once the polar crane is ready to be installed, the roof of the structure will be removed so that the crane can be lifted into the Unit 1 reactor building.
New crane will be used for vital reactor building work
The Unit 1 polar crane will be transported in 32 containers from storage in Avonmouth, then assembled under the roof of the new temporary building alongside the training centre. Supplied by APCO Technologies, the crane will eventually swivel around the dome of the reactor building, while moving heavy components, such as steam generators and the reactor vessel head, during construction, maintenance and refuelling. Preparations are well under way in the reactor building to receive the finished assembly. The Unit 1 team is surveying and adjusting 45 polar brackets, weighing 4.5 tonnes each, on Liner Ring 3. The polar brackets will carry the special rail that runs the crane around the circumference of the building.
Taken from The Point April 2023
