NRC: Casks would survive big blaze

Suzanne Struglinski

Thursday, Sept. 15, 2005 | 9:33 a.m.

WASHINGTON -- Transportation casks carrying used nuclear fuel would survive a fire similar to one in a Baltimore train tunnel four years ago, according to additional analysis by the Nuclear Regulatory Commission that is to be published in the Federal Register.

The 2001 train fire prompted critics of the proposed Yucca Mountain nuclear waste dump to point to the potential dangers associated with moving spent nuclear fuel by train across the country to Yucca Mountain.

The train cars in the Baltimore tunnel carried hazardous materials, but no nuclear waste.

Nevada officials and other Yucca critics believe a similar fire could cause casks to break and lead to a release of high-level radioactivity. They call for full-scale testing a casks used to move the waste to Yucca, if it were to open, and tougher regulations for casks to be approved suitable for shipping.

In an analysis completed earlier this month, the NRC found that a fire similar to the Baltimore Tunnel fire would not cause a release of spent nuclear fuel particles nor fission products from a three types of shipping casks it studied.

The NRC found that one type of cask would release a small amount of residue found on a fuel assembly, but nothing significant.

The NRC report used data from the National Transportation Safety Board and assistance from the National Institute of Standards and Technology, the Center for Nuclear Waste Regulatory Analysis and the Pacific Northwest National Laboratory.

The 78-page draft will be available for public comment and a final version will be released after the comments are evaluated, the NRC says.

The commission released a report in January 2003 that analyzed only one cask in certain scenarios and also found no radiation would be released.

Commission regulations require a cask to be designed to withstand a fully engulfing fire lasting no less than 30 minutes, with an average flame temperature of no less than 1,475 degrees, according to the report.

But in another 2001 study also completed for Nevada by Matthew Lamb and Marvin Resnikoff of Radioactive Waste Management Associates showed an analysis of a 1,600-degree fire burning for five days would result in a radiological release.

Joe Strolin, of planning division administrator for the Nevada Agency for Nuclear Projects, said the bottom line is that full-scale tests need to be done on the casks that will be used at Yucca to know for sure what they can withstand.

"This should not be just public relations tests either," Strolin said.

All other tests, for the state and for NRC, have been done with computer models.

Resnikoff continues to work on updating the calculations used in the report, and UNR Mechanical Engineering Department Professor Miles Greiner is studying other "high intensity" accidents and their effects on casks, Strolin said.

The nuclear industry says that more than 3,000 spent fuel shipments have taken place in the last 40 years with no radioactive releases, deaths or injuries.