Nuclear power advocates believe the energy secretary, Kwasi Kwarteng, is open to extending the life of the Hinkley Point B plant to help wean the UK off gas imports and prevent a faster-than-expected decline in Britain’s fleet of atomic reactors. Soaring gas prices and the war in Ukraine have already spurred the government to ask coal power plant owners to stay open longer, while ministers also revisited their staunch opposition to fracking in the light of energy supply concerns. There is a growing feeling in the nuclear industry and its supporters that Kwarteng could also be persuaded to back an extension of up to 18 months to the life of Hinkley Point B, which is due to stop generating electricity this summer. Such a plan, which would chime with Boris Johnson’s backing for new nuclear in the recent energy security plan, would keep 1GW of electricity generation on the National Grid in the short term, replacing the need for gas-fired generation for up to 1.5m homes. The Conservative MP Ian Liddell-Grainger, whose Bridgwater and West Somerset constituency includes Hinkley, said he had spoken to Kwarteng about the possibility and that he was “definitely” open to it. “Kwasi is no fool,” he said. “He understands the stresses and strains we’re going through and that we need to look at everything we can. They are fully aware of what the [Hinkley] B station is capable of. She’s old but she’s in good health.” Hinkley’s owner, EDF Energy, would have to produce a safety case for extending the life of a power station that was hooked up to the grid in 1976 and whose closure was previously postponed by seven years in 2012. EDF would have to prove to the Office for Nuclear Regulation (ONR) that the ageing graphite rods in the plant’s reactors could be inserted, even in the event of a huge and unprecedented earthquake, to prevent a nuclear accident. One nuclear industry source said there was a “six-week window” left, during which EDF could still make that case in time for the ONR to give a verdict on the safety of the plans and postpone the scheduled end to Hinkley generating electricity on 15 July. Greg Hands, a junior minister in Kwarteng’s business and energy department (BEIS), visited Hinkley last week. Engineers there are understood to have told Hands that they expected the plant to shut as scheduled. But the nuclear industry source said that while engineers were naturally focused on shutdown plans they had been working towards for many months, senior figures at EDF were likely to be more open to extending Hinkley’s life. The ONR would ultimately decide on whether such a plan could go ahead but Kwarteng’s approval is crucial. This is because EDF would incur significant costs to put together a safety case for an extension and would need to be confident that ministers would not block it. EDF declined to comment on whether it was planning to do so. BEIS said it had not held any discussions about such a proposal. “It [extending Hinkley] would stop you having to import a chunk of gas,” said the nuclear industry source. The Guardian also understands that Torness, near Dunbar, and Heysham 2 in Lancashire could come off grid earlier than expected, depending on regular assessments of the state of their graphite rods. Their retirement has already been brought forward, with EDF saying earlier this year that they would stop generating in 2028, rather than 2030. In theory, each station that operates for a year can replace more than 1bn cubic metres of gas imports. While nuclear power is traditionally expensive, the sky-high price of gas in recent months, exacerbated by the war in Ukraine, means the £45 per megawatt hour that EDF gets from its nuclear contract is significantly below wholesale market power prices. The trade unions Prospect and the GMB have also called for the life of Britain’s nuclear fleet to be extended. Pressure on Kwarteng to signal to EDF that the government would back plans to keep Hinkley Point B open comes against the backdrop of concern that the capacity of Britain’s nuclear fleet could be declining even faster than thought. Based on current projections for the retirement of reactors and the building of new ones, UK nuclear capacity will fall from 5.8GW today to 4.4GW in 2028, factoring in the construction of Hinkley Point C but also the end of life of Torness and Heysham. However, the 2028 completion date for Hinkley Point C, which is already over budget and behind schedule is under review, with a forecast due this summer.