Moving nuclear waste

In the 1930s, Eastman Kodak Co. began to hear complaints that some of the X-ray plates it sold to hospitals were arriving hopelessly fogged.

A quick check showed that laborers had loaded boxes of plates onto the same boxcar that carried the containers of radium.

Thus was born what may be the earliest shipping requirement for nuclear materials: Do not ship radium in a boxcar used for shipping X-ray film.

"It was the shortest regulation in history," quips Bob Jefferson, a nuclear-materials transportation consultant.

Today, nuclear materials routinely travel across the country – and around the world.

These materials are subject to stringent shipping and security measures. But concern about them – particularly about the highly radioactive waste from nuclear-power plants – has grown with the prospect that waste shipments will become more frequent if a permanent repository is built, as many expect. Those concerns have intensified following Sept. 11. And some states are getting more vocal about having nuclear materials on their turf: Recently, South Carolina Gov. Jim Hodges unsuccessfully attempted to block waste shipments into his state.

These shipments have moved around the US from a range of sources, from the Three-Mile Island clean-up and research reactors overseas to spent fuel and other high-level waste from US Department of Energy reactors and the US Navy.

While some shipments have been involved in accidents, since the early 1960s none has led to a release of radioactivity or to radiation-related illnesses or deaths, state and federal regulators note.

Credit goes to the shipping containers, Mr. Jefferson says. Many products, ranging from radio-pharmaceuticals to home smoke detectors, which contain low-level nuclear materials, can be shipped in cardboard boxes. The most dangerous materials, such as the high-level waste from nuclear-power plants, get more-deft handling.

Spent reactor fuel is loaded into stainless-steel casks weighing from 60 to 120 tons. Casks are lined with materials including depleted uranium that keep radiation inside the cask. The design philosophy, Jefferson says, is, "you can't trust humans."

Casks are designed to withstand a 30-foot fall onto a hard surface such as concrete. A cask must withstand temperatures of 1,440 degrees F. for 30 minutes. (A blaze in a Baltimore tunnel exceeded those temperatures for longer than that in 2001, although engineers point out it's unlikely such materials will be shipped over routes currently off-limits to hazardous limits.) A fractured cask must be leakproof when immersed in three feet of water for eight hours. Newer casks must remain leakproof for eight hours at depths of 100 feet. And a cask must withstand a three-foot fall onto a steel post to simulate an accident that could puncture a cask.

Driving next to a truck and cask on the highway, or standing on the shoulder while one whizzes by, yields a brief dose of radiation indistinguishable from what humans are naturally expose to every day. By one estimate, a pedestrian watching a truck pass receives a dose equivalent to eating two extra bananas a year. Bananas contain traces of radioactive potassium.

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