About 15% of the UK’s energy comes from an ageing fleet of Advanced Gas-Cooled Reactors (AGRs), with nuclear cores made of thousands of interlocking graphite bricks. Fine cracks can occur over time in these bricks, which were installed in the 1970s and ‘80s. Those cracks might not have any effect on day-to-day operation, but what about during an earthquake? That might seem an unlikely eventuality, but with 200-300 earthquakes of varying intensity hitting the UK every year – and the potential for devastating damage highlighted by the Fukushima nuclear disaster – the University of Bristol and EDF Energy are not taking any risks. The partners are showing their earthquake research at the Royal Society’s Summer Science Exhibition, which opened in central London this morning (1 July) and runs until Sunday. “Learning from Fukushima we’ve got to make sure we’ve covered everything,” said Dr Jim Reed at the event. The graphite chief engineer at EDF added: “We test far beyond what we’ve ever seen in the UK.” This testing involves Bristol’s ‘shaking table’, which at 3x3m is the largest in the UK. It can carry up to 15 tonnes and reach acceleration of up to 5g, with maximum displacements of 0.15m. Researchers input different settings to the table, simulating earthquakes up to 7.2 on the Richter scale – the UK’s strongest ever quake was 6.1. It can even replicate the conditions of real-world seismic events.
IMech 1st July 2019 read more »