Governments have a huge role in the development and deployment of new nuclear plants, but ultimately a “collective funding mechanism” is needed to pull together capital and make it profitable for private investors to support first-time projects, a nuclear conference in London heard.

Charles Oppenheimer, grandson of J. Robert Oppenheimer, who oversaw the development of the first atomic bomb under the Manhattan Project, told the Economist Impact Nuclear Summit that most of the capital that has gone into the nuclear field is from venture capital, which is a small slice of the financial world, and it tends to fund projects between “a few million and maybe 50, 100 million” US dollars.

“And that is not enough to get a nuclear project going,” Oppenheimer said. He said this means first-time nuclear technologies face a “valley of death”.

Oppenheimer, who wrote in Time magazine last year that nuclear energy can be a source of hope for international cooperation – not just “weapons and fear”, said a key question for the nuclear industry is whether reactor developers can get their demonstration plants suitable for institutional capital.