Nuclear reactors can make plutonium for the core of atom bombs, and therefore secretive work on reactors is usually interpreted as military in nature.
The Atomic Energy Commission's influential General Advisory Committee, chaired by Robert Oppenheimer, recommended that all work on reactors be concentrated at the Argonne National Laboratory, the successor to the Metallurgical Laboratory, near Chicago.
"There's nothing holding them there," said Margaret Harding, a consultant who worked on reactor designs for General Electric for 27 years.
After he left Argonne, he remained a White House adviser, formed his own consulting firm and kept working on reactor designs.
"We all want to go back, but we have to face the obvious," said Koichi Soga, 75, a retired carpenter who once worked on reactor buildings at the plant.
Hocevar had earlier been an engineer working on reactor safety at Idaho National Engineering Laboratory.
Under a reformed licensing system adopted in the 1990s, the commission is to approve a completed design before substantial work begins on reactor structures.
Work began on Reactor B, the first of six planned 250 MW reactors, on 10 October 1943.
"You're looking at several thousands of gallons a day potentially out as long as a year," said Arnold Gundersen, a former nuclear engineer who worked on reactors of the same design as those in Japan.
Work on the reactor is taking longer than expected, amid Russian complaints, sotto voce, that Iran is a bad payer.
