AS the focus on net zero sharpens it may be time to revisit attitudes to nuclear energy that developed before the scale of the threat posed by emissions-related climate change was realised.

Nuclear has long been the bete noire of environmentalists who have highlighted the risks associated with plants and the toxic waste resulting from the generating process, which takes decades to degrade.

Disasters such as Chernobyl in the former USSR, Three Mile Island in the US and Fukushima in Japan helped to reinforce opposition.

But supporters have been emboldened by the growing awareness of the urgency of the need to cut emissions associated with power generation.

The Scottish Government has set the target to reduce emissions to zero net of amounts absorbed by 2045. The UK Government targets 2050.

The big advantage of nuclear plants is that they can be used to generate huge amounts of power without burning fossil fuels.

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The director of Torness nuclear power station, Tamer Albishawi, noted recently that the East Lothian plant generated enough electricity in 2020 to power all the homes in Scotland carbon free. He said this was the equivalent of taking 1.7 million cars off the road.

Torness recently celebrated a record performance by one of its two reactors, which operated continuously for 865 days between shut-downs, beating the previous best by six days.

Inspections have shown the graphite cores at Torness are in good shape, leaving its owner EDF confident the plant can continue operating until 2030. When the plant started generating in May 1988, it was expected to shut down in 2018.

By contrast, EDF, recently decided to move Dungeness B in Kent into the defuelling phase early after spending years grappling with technical challenges.

Supporters of nuclear say it has come into its own in the age of renewables by providing a source of base load capacity that is always available. This can be drawn on to make up for shortfalls when the wind isn’t blowing hard enough to power windfarms or there is not enough rain for hydro schemes.

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The Nuclear Industry Association said recently that its research showed that regions with both nuclear and wind power are already reaching 2030 decarbonisation targets.

The industry body said Southern Scotland produced the cleanest power in the UK in 2020, hitting the UK’s 2030 electricity decarbonisation target of 50-100g CO2 per kWh of electricity on more than 85 per cent of days.

The NIA noted that Southern Scotland has the Hunterston nuclear plant in Ayrshire as well as Torness, alongside substantial renewable capacity.

It has also highlighted the potential for nuclear to support the production of low carbon hydrogen fuel, without having to rely on gas.

HeraldScotland: Station director Tamer Albishawi inside the turbine hall at Torness nuclear power plant in East LothianStation director Tamer Albishawi inside the turbine hall at Torness nuclear power plant in East Lothian

“ Either through electrolysis, or from the use of primary heat from nuclear power stations, nuclear offers an efficient, carbon-free alternative to producing hydrogen, one that doesn’t rely on unproven technologies,” says the association.

The arguments in favour of nuclear appear to have convinced people who are leading the UK effort to reduce emissions.

The Climate Change Committee, which advises the UK and devolved governments on emissions targets and monitors progress, underlined recently that its Balanced Pathway assumes that two new nuclear power stations will be in operation by 2035. These would be in addition to the Hinkley Point C plant that EDF is building in Somerset.

All seven existing gas cooled reactor plants are due to shut down by 2030. Hunterston is due to enter the defuelling process later this year.

Some fear the UK could be left increasingly reliant on fossil fuels and/or imported energy unless the generating capacity of the plants is replaced.

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The UK Government appears convinced by the arguments in favour of nuclear.

In the Ten Point Plan for a Green Industrial Revolution published in November it said: “We will generate new clean power with offshore wind farms, nuclear plants and by investing up to half a billion pounds in new hydrogen technologies.”

Noting that Hinkley Point C is due to come online in the mod 2020s, it said: “Whether a large-scale power plant, or next generation technologies such as Small and Advanced Modular Reactors, new nuclear will both produce low carbon power and create jobs and growth across the UK.”

The Government said the nuclear industry employs 60,000 people in the UK. Work on a new large-scale plant could support a further 10,000 jobs.

The SNP Government in Scotland appears resolute in its opposition to building new nuclear plants in Scotland although trades unions have underlined the importance of the jobs provided by the industry.

It says: “We recognise the significant contribution that nuclear generation makes to the current energy mix in Scotland; however, we expect its contribution will decrease as we increase electricity generation from renewable and other low carbon sources.”

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The SNP is relying on the support of the Green Party in its attempt to separate Scotland from the rest of the UK.

The renewables lobby in Scotland has played up the potential for windfarms and the like to meet all the country’s energy needs.

In March Scottish Renewables celebrated the release of figures that showed 97.4% of Scotland’s electricity demand was met by renewable sources.

However the organisation noted that figure lagged the target set in 2011 for renewables to cover 100% of demand by 2020.

It noted that the electricity concerned only accounted for 25% of the energy used in Scotland in 2020. The rest is required for domestic and commercial transport and for heat.

“Currently 6.5% of our non-electrical heat demand is generated from renewable sources,” noted Scottish Renewables.

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With such a big gap to fill can we afford to do without nuclear?

The likes of Greenpeace insist nuclear still does not make sense, and not just because of an ideological attachment to energy sources such as wind power.

The costs of developing new large-scale facilities are likely to be immense but are notoriously hard to estimate with much certainty.

In January the expected cost of the Hinkley Point C plant was increased by £500m to £23bn. The expected date for the start of generation was pushed back to 2026 from 2025.

The costs will be paid ultimately by consumers through their bills.

The UK Government is considering using a new model under which firms could recoup some of their costs through energy bills before plants are completed.

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The Regulated Asset Base model could make it easier for firms to raise finance for plants, from the likes of pension companies. This could help cut the funding costs.

However the proposal has sparked outcry from firms that supply renewable electricity.

Doug Parr, chief Scientist for Greenpeace UK, reckons nuclear is not a great technology if you want affordable, rapid decarbonisation.

Insisting that reactors take ages to build and are invariably delayed, he notes: “The nuclear industry always claims that the next reactor will be cheaper because, mysteriously, the cheapest reactors are always the ones that haven’t been built.

“But we know how much electricity from the UK’s next reactor will cost, because the government has already signed the contract.

“It will cost double the price of the electricity from the renewable contracts we signed just a couple of years later … the offshore wind farms we commissioned will be generating much earlier.”

The question of how best to store the waste from plants in the long term still exercises experts. The Nuclear Decommissioning Authority has spent years considering the idea of developing Geological Disposal Facilities beneath Cumbria but has run into vocal opposition.

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In May it welcomed the start of tunnel excavation in Finland on the world’s first GDF, which is due to come into operation in the mid 2020s.

In the NDA’s latest accounts, which were published on Tuesday, the organisation notes: “Current plans indicate it will take more than 100 years to complete our core mission of nuclear clean-up and waste management.”

Smaller modular reactors could provide a more affordable way of developing capacity with less waste.

Nuclear fusion, which involves forcing atoms together rather than tearing them apart, may be the ultimate prize.

In December the UK Government launched a search for a site on which a pioneering fusion plant could be built. However, the New Scientist magazine noted that month: “No fusion reactor has yet produced more power than it consumed.”

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Against that backdrop some may feel it make more sense to focus on technologies that can be used to produce power on demand that have proved to be effective and could entail less risk.

These include pumped storage hydro schemes such as the ‘Hollow Mountain’ Cruachan plant in Argyll, which Drax is eager to expand.