Science: Britain Can Make It

Britain passed an atomic milestone last week by announcing the existence of its first home-made plutonium. It was not much: a small amount of greyish solution, now stored in a vault. But it was made from uranium in Britain's own nuclear reactors at Harwell, Berkshire, and separated chemically from the dangerous "hot" uranium. Except for a microscopic quantity that may have been contributed by Canada, it is the first plutonium that British scientists have had to work with.

Soon they should have plenty, probably enough for bomb production. At Sellafield in Cumberland, two big plutonium reactors are now close to completion. They...