Double dome work taking place
For the first time, work is taking place on the site’s two domes at the same time after the 237-tonne structure for dome one was lifted out of bunker five by Big Carl and placed on a purpose-built, temporary support structure – including 96 jacks. The support structure will allow pipe work and HVAC systems to be installed before dome one is lifted back in to bunker five so that the painting and more sensitive pieces of electrical and mechanical equipment can be completed. With dome 1 vacating bunker five, space was created for the first dome two panels to be lifted in and assembly work to begin. Big Carl placed each of the panels onto a temporary jig structure, which allows them broadly to sit in the shape of the finished dome, ready to be assembled.
Tunnel two main drive complete
Beatrice, the third tunnel boring machine (TBM), successfully completed the main drive for the 3.5km-long intake tunnel two. This follows previous journeys taken on intake tunnel one and the outfall tunnel by TBMs Mary and Emmeline, respectively. All three tunnels form part of the water-cooling system for the power station, with intake tunnel two designed to bring water in from the Bristol Channel to cool the unit two reactor.
Huge hatch lowered into place
Big Carl has lifted the equipment hatch access (EHA) into position on unit one liner ring two, the largest single opening on the liner. The EHA forms the main access route to bring equipment, including the reactor pressure vessel and steam generators, in and out of the reactor hall and will still be in use once the power station is operational. At around 8.4m in diameter, 6m long and weighing 50 tonnes, positioning the EHA had to be meticulously planned!
Welding begins on specialist tanks
The first welds have been made by contractor EFINOR on two stainless steel ceilings that form part of the emergency boron system (RBS) tanks, a critical safeguard system in the unit one fuel building. This work follows the installation of the tanks last year and the subsequent pouring of the concrete walls within the building. Welding stainless steel is a highly specialised task and EFINOR’s welders had to complete rigorous tests that were monitored and signed off by Bylor and EDF’s quality teams.
Taken from The Point April 2022