New York Times
March 30, 2005
WASHINGTON, March 29 - A semisecret debate is raging between the National Academy of Sciences and the Nuclear Regulatory Commission about the vulnerability of nuclear wastes to terrorist attack and about how secret the debate should be.
The academy, under orders from Congress, produced a study last summer about whether the spent-fuel pools at nuclear reactors were vulnerable to terrorist attacks. The pools hold most of the radioactive material ever produced at the reactors, far more than the reactors themselves. After the attacks of Sept. 11, 2001, an independent group of scientists published a paper in a Princeton scientific journal asserting that an enemy could drain a pool and set a fire that would be "significantly worse than Chernobyl."
Academy officials say they have hit a roadblock in releasing their report. By law, the academy, which Congress charters, coordinates the work of academic experts from around the country, and it is supposed to make its findings public. In cases like the nuclear waste one, it is supposed to work with the relevant federal agency to develop a version of its report that has no information that would be useful to terrorists.
The academy sent a draft to the regulatory commission in November. But the two have not agreed on what information to release. A commission official said the problem was "aggregation." Although no secret facts appear in the academy version, piecing together the material disclosed would provide useful information.
This month, the academy took the unusual step of sending its version to members of Congress, with classified information removed but still including "safety sensitive information."
A few days later, the commission sent several lawmakers, Democrats and Republicans, a rebuttal to the classified report. A spokesman, Eliot Brenner, said this was not a response to the academy, but because Congress wanted to know what actions the commission would take.
According to the commission, the academy panel had "identified some scenarios that are unreasonable."
The rebuttal, sent by Nils J. Diaz, chairman of the commission, said using those situations could "lead to a misinterpretation of the actual risk, and this can cause confusion."
Some ideas put forward by the academy "lacked a sound technical basis," including having reactor operators move more fuel from the pools to dry casks, said the rebuttal, which was sent to Senator Pete V. Domenici, the New Mexico Republican who is chairman of a Senate subcommittee on energy and water.
Among engineers, those are fighting words. The rebuttal's characterization is "an incomplete and, consequently, less than accurate description of what our classified report had to say," the executive officer of the academy, E. William Colglazier, said in a telephone interview.
In separate interviews, two of the scientists who provided peer review of the academy study and an author of the study agreed. All three said they could not talk about what the report said because it remained classified at the insistence of the Nuclear Regulatory Commission.
When nuclear fuel is taken out of the reactor, it has to stay in the pool because it generates so much heat. After about five years, it cools enough to be put in a sealed cask of steel and concrete.
The casks are filled with inert gas to prevent rust. The fuel warms the gas, which transfers its heat to the exterior of the cask. Nearly half the reactors in the United States use such casks because they have run out of space in their fuel pools and because the government has not accepted the waste for permanent disposal. Building the casks is expensive, and the power plant operators have constructed them only as needed and not fast enough to lower the inventories in the pools.
The commission has repeatedly said cask storage and pool storage are equally safe. On March 14, Dr. Diaz told reporters at the National Press Club, "I don't see them as a significant radiological risk."
At many plants, the pools are below ground or nearly so, making attacks difficult. But at some reactors, the plants are well above grade. In Mr. Diaz's rebuttal, he refers to a recommendation by the academy that plants be analyzed individually to evaluate their vulnerability and that at some the commission "might determine that earlier movements of spent fuel from pools to dry storage would be prudent."
Frank N. von Hippel, a Princeton professor and co-author of the study that brought the issue to prominence, was also brought in as a peer reviewer of the academy study. He said it did not go nearly far enough in urging dry storage.
"I found it peculiar that the N.R.C. said they did," Dr. von Hippel said.
A declassified version might explain the apparent discrepancy. Mr. Brenner, the commission spokesman, said his agency sent a new draft to the academy on Tuesday.