Scientists have detailed the potential implications should the ongoing Suffolk wildfires reach the Sizewell B nuclear power station, as emergency services continue to combat the blaze. The inferno has prompted a major response, forcing evacuations from campsites and leading to the nuclear site being placed on high alert as a precautionary measure.
Experts have emphasized that current indicators do not suggest the reactor itself is under immediate threat. Professor Joel Turner, Professor of Nuclear Fuel Technology at the University of Manchester's Dalton Nuclear Institute, described the high alert as a "very sensible precaution." He explained that the reactor can be rapidly shut down via a SCRAM, a process where control rods are inserted into the reactor core in under a second. "In practice a SCRAM would likely only be done because it was unsafe to keep the plant fully staffed, rather than because of physical danger to the reactor itself," Turner stated.
A primary concern would be maintaining the station's connection to the electricity grid, which is vital for its cooling systems. However, even if this connection were lost, the plant is equipped with multiple backup cooling systems and diesel-powered generators designed to ensure the reactor's safety.
The wildfire, initially covering approximately 24 acres of Dunwich Heath, has since expanded significantly. By midday, it had grown to an estimated 247.1 acres, roughly the size of 140 football pitches. The fire front is currently reported to be several miles from the Sizewell B site, which remains unaffected.
Professor Mike Bluck, Professor of Nuclear Engineering at Imperial College London, noted that while wildfires could approach the station, the industrial nature of the site and its access roads would act as natural firebreaks. He added that the reactor is designed to withstand various external hazards, including fires. The reactor core is encased within a 20cm-thick steel pressure vessel, surrounded by a heavily reinforced concrete containment building. "Breaching of the containment and pressure vessel is unimaginable," Bluck said.
In the event of closer proximity and specific concerns, the reactor could be safely shut down, with extensive backup cooling systems maintaining security. Bluck also pointed out that facilities such as spent fuel storage areas would also require protection, and the site has its own dedicated fire service and emergency personnel. He referenced France, where multiple nuclear power stations are situated near areas prone to large wildfires without recorded nuclear incidents, indicating that Britain is not facing an unprecedented situation.
Dr. Thomas Smith, Associate Professor in Environmental Geography at the London School of Economics and Political Science, echoed these reassurances. "I don't expect the fire to threaten the power plant," Smith said. He cited the current distance of the fire and the presence of non-vegetated buffer zones. Furthermore, cooler temperatures and increased humidity forecast for the evening and the following day are expected to slow the fire's spread.
Sizewell B, the UK's sole operating pressurised water reactor, has been generating electricity since 1995 and powers approximately 2.5 million homes, accounting for about 3% of Britain's electricity supply. Earlier this month, the government approved plans to extend its operating life from 2035 until 2055.