Withdrawing from the EU without a trade deal would be the “worst-case scenario” for the nuclear industry, Tom Greatrex has warned.

The Nuclear Industry Association chief executive told a conference in London, organised by Chinese atomic energy company Ocean Energy last week, that the Brexit transition period would be “crucial” to the sector, which depended in turn on whether the UK is able to strike a trade deal with the EU.

“No deal is the worst-case scenario for our industry because of the specific nature of the Euratom treaty,” he said, referring to the EU-wide framework for safeguarding nuclear materials and labour.

Greatrex also raised alarm bells over the impact of Brexit on the industry despite the steps taken by colleges in Somerset to train local people to work in the Hinkley Point C plant.

He said: “We haven’t got enough and we have to grow that capacity quite quickly.

Labour peer Lord Hanworth echoed Greatrex’s concerns about the industry’s skilled labour pipeline, citing as a particular worry the government’s failure to make a decision so far on Rolls Royce’s bid to develop a small modular reactor programme.

Rolls Royce could “no longer sustain” the project in the face of “considerable uncertainty”, he said: “If they have to walk away from the project, Britain will lose part of its nuclear engineering competence. “

The peer also highlighted concerns expressed by Hinkley Point C’s developer EDF about the shortage of steel fixers and concrete pourers.

“These kind of workers are likely to be excluded by immigration policy that gives priority to so called tier one workers with exceptional talent who possess the right level of professional and academic qualifications,” he said, adding the government had yet to give details about how many foreign workers would be let into the UK to meet the nuclear industry’s skills requirements.

Humphrey Cadoux-Hudson, managing director of nuclear development at EDF Energy, had said earlier that the company could see a “clear path” to reducing costs on its next planned nuclear plant at Sizewell by 20 per cent.

He said this cost reduction would be achieved by reusing the reactor technology developed at Hinkley Point.

Cadoux-Hudson said developing a series of nuclear plants would be the cheapest way of delivering the nuclear programme but said that it was “fair for the UK to spread its bets on technology” by bringing forward projects by competing developers, like Horizon at Wylfa.

He said using tested technology would reduce the risk profile of nuclear projects with a knock on impact on the cost of capital.

“If we have Hinkley Point half way through its construction and a decision on Sizewell, the risk profile is much lower.”

Cadoux-Hudson said the 50 year-plus consumer price index linked bonds offered by the company would be “very attractive” to pension funds looking to match their retirement payment liabilities.