In her excellent article on the Hinkley C nuclear plant financial fiasco (The long read, 21 December), Holly Watt mentions the innovative insight of Sussex University academics Prof Andy Stirling and Dr Phil Johnstone, who have identified the central importance of expansion of the skill base of the new nuclear build programme – headed by Hinkley C – for the Trident military nuclear renewal programme. Watt also mentions the first nuclear plant built on the same site, Hinkley A. What is barely acknowledged about this reactor is it was both built and operated to manufacture plutonium for British nuclear warheads, and probably some plutonium it created was sent to the US for use in its military stockpile too.

I have dug up considerable evidence that demonstrates this beyond any doubt. The first public hint came with an announcement on 17 June 1958 by the Ministry of Defence, on “the production of plutonium suitable for weapons in the new [nuclear] power stations programme as an insurance against future defence needs”.

The Conservative government’s paymaster general, Reginald Maudling, told parliament a week later: “At the request of the government, the Central Electricity Generating Board has agreed to a small modification in the design of Hinkley Point … so as to enable plutonium suitable for military purposes to be extracted should the need arise. The government made this request in order to provide the country, at comparatively small cost, with a most valuable insurance against possible future defence requirements.”

And that is exactly what they did. The nuclear world has thus turned full circle, as the atomic conjoined twins that had been painfully separated for nearly 50 years are being rejoined in an insidious way by this new Conservative government.

Dr David Lowry

Senior research fellow, Institute for Resource and Security Studies

• Join the debate – email guardian.letters@theguardian.com

• Read more Guardian letters – click here to visit gu.com/letters