This article is dated 2009. I wonder if much has changed since it was written. Click here to read the full article or an excerpt below.
This involves immersing the radioactive used rods in helium or some other inert gas and slotting them into a steel container that is further encased in a concrete cask—at a cost of roughly $1 million per cask. The encased rods still manage to emit roughly one millirem of radiation per hour and heat the outside of the 100-plus ton concrete casing to as much as 90 degrees Fahrenheit (32 degrees Celsius).
“These are placed in rows on a concrete pad for stability. They’re essentially out in the air,” says NRC’s McIntyre. “Generally, they are putting them within the controlled area of the reactor site so they are protected under the physical security of the plant.”
Some 9,000 metric tons of spent fuel rods are already stored encased in some 900 such casks—the bulk of them stored vertically in concrete casks but some placed horizontally into concrete bunkers. Their makers—companies like New Jersey-based Holtec International and AREVA’s Transnuclear, Inc.—and the NRC maintain that such dry cask storage will last for at least a century, if not longer. “They’ve had an excellent safety record over the past 22 years they’ve been in use,” McIntyre says. “All signs are that they are safe and secure.”
The other nuclear waste
The U.S. produces as much as 160,000 cubic feet (4,530 cubic meters) of radioactive material from its nuclear power plants annually—a number that spikes higher dramatically when old nuclear plants are decommissioned, such as Maine Yankee in Wiscasset, Me., in 1997. Ranging from workers’ coveralls to water filters, some of this stream of nuclear waste no longer has a place for its disposal either—particularly the highly radioactive materials rated as classes B and C, such as reactor vessel heads. “That stuff has only one place it can go,” says Ralph Andersen, chief health physicist at NEI, “a deep geologic repository,” like Yucca Mountain.
The national nuclear dump in Barnwell, S.C., was closed to shipments of such waste from nuclear power plants in 36 states in July 2008. A new dump in Texas, granted a license by the state this month, will only accept low-level leavings from that state and Vermont, alongside similarly restricted dumps in Utah and Washington State. This has also left users of nuclear products such as hospitals and universities scrambling to find a place to dispose of their radioactive residue.
So now the waste from the majority of reactors on the east coast and Midwest typically sits alongside the spent nuclear fuel in dry casks on-site. In terms of safety, it’s the best that can be done at present.