The NAS report found that another method of storing spent fuel, called "dry cask" storage, did not require on complex power systems. Dry-cask storage involves putting older spent fuel into concrete- and steel-lined cylinders to allow natural air circulation for cooling. Dividing up spent fuel among a large number of such cylinders also makes "it more difficult to attack a large amount of spent fuel at one time" and also reduces "the consequences of such attacks," the report found.
Echoes of that report could be heard in Congress Wednesday, with several experts testifying that finding a new way to deal with spent fuel was a key takeaway from Fukushima.
For instance, the Fukushima General Electric Mark 1 Boiling Water Reactor design, which has a spent-fuel pool near the top of the building where it's easy for loading cranes to access, is one of the most vulnerable reactor designs, some experts say. At least 28 of America's 104 reactors are of that type.
The Fukushima problems of spent-fuel pools located on the same site with the reactors "will undoubtedly lead to a reevaluation of spent nuclear fuel management strategy," said Professor Moniz.
David Lochbaum, a nuclear engineer who spent years working in power plants with the same design as the Fukushima plant, told the Senate Energy and Water Development Appropriations subcommittee today that spent fuel was a huge risk.
While nuclear fuel in the reactor is carefully safeguarded with heavy shielding and multiple redundant cooling systems, that all changes once the still highly radioactive fuel is no longer productive, he said.
"Irradiated fuel sits in temporary spent-fuel pools with almost no protection," he said. "For unfathomable reasons, irradiated fuel is considered benign after it is taken out of the reactor core" even though it will be many years before a final repository can be agreed upon and built.