A classified report by nuclear experts assembled by the National Academy of Sciences has challenged the decision by federal regulators to allow commercial nuclear facilities to store large quantities of radioactive spent fuel in pools of water.
The report concluded that the government does not fully understand the risks that a terrorist attack could pose to the pools and ought to expedite the removal of the fuel to dry storage casks that are more resilient to attack. The Bush administration has long defended the safety of the pools, and the nuclear industry has warned that moving large amounts of fuel to dry storage would be unnecessary and very expensive.
The report was requested by Congress after the terrorist attacks of Sept. 11, 2001, as homeland security officials sought to understand the potential consequences of a Sept. 11-scale attack on a nuclear facility.
Because the report is classified, its contents were not made public when it was delivered to the Nuclear Regulatory Commission (NRC) last summer. Even a stripped-down, declassified version has remained under wraps since November because the commission says it contains sensitive information.
However, the commission made excerpts of the report public when Chairman Nils Diaz sent a letter to Congress on March 14 rebutting some of the academy's concerns. His letter also suggested that the academy had largely backed the government's views about the safety of existing fuel storage systems.
E. William Colglazier, executive officer of the academy, said the letter was misleading and warned that the public needs to learn about the report's findings.
"There are substantive disagreements between our committee's views and the NRC," he said in an interview. "If someone only reads the NRC report, they would not get a full picture of what we had to say."
Although the commission said it is keeping the report under wraps for security reasons, some officials who have seen the document suggest that the NRC is merely suppressing embarrassing criticism.
"At the same time that the NRC is saying that the National Academy's study is classified and not releasable to the public, it has somehow managed to send a detailed rebuttal of the report's conclusions to Congress in unclassified form," said Rep. Edward J. Markey (D-Mass.), who has seen the report.
"I am concerned that the totality of the Commission's actions reflect a systemic effort to withhold important information from . . . the public, rather than a genuine effort to be protective of national security," Markey said in a March 21 letter to the commission's inspector general.
NRC spokesman Eliot Brenner countered that the commission is "a very open agency" and that regulators are working with the academy to make the report public.
"Our core concern is making sure that information that could reasonably be expected to be available to a terrorist is not publicly available," he said. "We are continuing to work with them on finding the right balance."
The report was solicited by Congress to study how best to store spent nuclear fuel -- tons of rods containing radioactive byproducts of nuclear fission reactions are produced each year by the nation's 103 electricity-generating nuclear reactors. Spent fuel rods generate intense heat and dangerous long-term radiation that must be contained.
Most of the spent rods are stored in large swimming-pool-like structures called spent fuel pools, said David Lochbaum, a nuclear safety engineer at the science and advocacy group Union of Concerned Scientists, who has worked at several plants. The pools are about 45 feet deep and 40 feet square and are filled with about 100,000 gallons of circulating water to remove heat and serve as a radiation shield, he said.