As French nuclear developer EDF and the UK government dispute recent assertions that the planned Sizewell C nuclear power station in Suffolk will cost £40 billion to build, a new report from the International Energy Agency is bullish on the global nuclear sector, but only if obstacles like cost overruns are addressed.

Sources “close to the negotiations” recently pegged building costs for the not-yet-approved 3.2-gigawatt station at £40 billion, double the estimate given by EDF and then-prime minister Boris Johnson’s Conservative government back in 2020, reports the Financial Times.

“Surging construction costs as well as the implications of delays and cost overruns at sister site Hinkley Point C” were cited as reasons behind the price spike, writes FT. “The higher estimate is likely to raise questions over the government’s strategy for a nuclear power revival, at a time of stretched government finances and cost-of-living concerns,” the London-based daily adds.

EDF was swift to question the £40-billion figure on grounds that it fails to capture the value of knowledge gained from building Hinkley Point, reports the BBC, citing a company media release.

Describing the £40-billion estimate as “not accurate”, EDF said it reflected neither “efficiency improvements of around 30%” achieved over the course of building Hinkley, nor that construction on Sizewell C will begin with “a completed design [and] skilled work force” ready to hand and a supply chain “ready to deliver.”

A spokesperson for the UK’s Department for Energy Security and Net Zero described the £40-billion figure as “speculative” since discussions with potential investors are ongoing.

For its part, France’s state auditor has warned EDF against making any final investment decision on Sizewell C “until it has reduced exposure” to Hinkley Point, reports City AM.

Responding to the auditor, EDF Chair and CEO Luc Rémont said the Labour government has taken charge of financing for Sizewell C, and that his company now holds less than a 20% equity share in the project.

Labour Party donor and UK wind entrepreneur Dale Vince is among those warning that Sizewell C will cost too much to build, whoever builds it, with the costs invariably passed on to the ratepayer.

Sizewell “will saddle consumers with higher bills long before it delivers a single unit of electricity,” Vince said in a recent letter to the government’s new Office for Value for Money, reports FT.

Whitehall is expected to make a final investment decision about Sizewell C later in the year.

Reports of the potential doubling of estimated costs for Sizewell C landed as the International Energy Agency issued a new report on the future of the global nuclear sector. Titled “The Path to a New Era for Nuclear Energy”, the report finds nuclear power “set to reach a new record in 2025”, with consequent improvements in energy security as electricity demand accelerates.

To achieve success, however, the report says, “Costs, project overruns, and financing must be addressed.”