A new question adds to puzzle over Hinkley

One of the riddles of 2016 was why the Government changed its mind on easily the most costly nuclear power station in the world at Hinkley Point in Somerset.

When Theresa May entered No 10 in July, she called in for re-evaluation a scheme which had been plagued by every kind of technical and financial problem. Its design was flawed. A similar project by the same French state-owned company EDF in Normandy is running years late and billions of euros over budget.

Thanks to subsidies agreed by David Cameron and George Osborne, Hinkley’s lifetime cost was estimated at £49 billion, making it almost as expensive as the equally absurd HS2.

Very much cheaper and more reliable reactors bought from South Korea could have been onstream years earlier than Hinkley’s supposed completion date of 2023

But only weeks after the scheme was put on hold, ministers meekly gave it the go-ahead, without a word of proper explanation. And now yet another huge question mark has been raised over the project. Last month it was reported that Paris prosecutors were investigating the possibility that thousands of documents certifying the safety of key reactor components, supplied to EDF by another company, had for years been falsified.

Now France’s nuclear regulator, ASN, has said it plans a much more thorough investigation into those documents, particularly ones relating to pressure vessels, which supposedly contain so much carbon they might crack. So which now will come first? The completion of Hinkley Point (if it ever gets built at all)? Or the release in 30 years time of those secret papers explaining just why in 2016 Mrs May’s Government decided that it could not cancel this lunatic project when it had the chance to do so?