, FRED PEARCE,
“…….. About 30 miles northeast of Rocky Flats, out on the prairie near the small town of Platteville, is the Fort St. Vrain spent-fuel store. It resembles nothing so much as an outsize grain store, but since the 1990s it has been holding 1,400 spent fuel rods, laced with plutonium and encased in blocks of graphite. The spent fuel was left behind when the neighboring nuclear power plant shut. The plan had been to send it to another temporary store at the Idaho National Laboratory, but the governor of Idaho banned the shipment. The Fort St. Vrain facility is designed to withstand earthquakes, tornado winds of up to 360 miles per hour, and flooding six feet deep. Also time. It will be several decades at least before the federal government finds the fuel a final resting place.
The country is littered with such caches of spent fuel stuck in limbo. According to the Government Accountability Office (GAO), 80,000 metric tons of spent fuel, the most dangerous of all nuclear wastes, is stored at 80 sites in 35 states. The sites include stores at past and present power plants such as Maine Yankee, and stand-alone federal sites such as Fort St. Vrain. As the GAO puts it: “After spending decades and billions of dollars … the future prospects for permanent disposal remain unclear.” Nobody wants to give the stuff a forever home.
Nuclear waste is conventionally categorized as high-, intermediate-, or low-level. Low-level waste includes everything from discarded protective clothing to plant equipment and lab waste. It can usually be treated like any other hazardous waste, which in practice usually means burial in drums in landfills or concrete-lined trenches.
Intermediate waste contains radioactive materials with isotopes that decay with half-lives long enough to require long-term incarceration. It includes many reactor components, as well as chemical sludges and liquids from processing radioactive materials, which can often be solidified in concrete blocks. Once solid, intermediate waste can be buried safely in shallow graves, though anything containing plutonium will have to be disposed of deep underground because of the very long half-life.
Much of America’s intermediate-level waste will end up at the country’s largest deep-burial site for such radioactive material. The U.S. military’s Waste Isolation Pilot Plant in salt beds near Carlsbad, New Mexico, could eventually take 6.2 million cubic feet of waste. But it has had problems that have slowed progress and raised questions about its viability.
A chemical explosion in 2014 sprayed the tunnels dug into the salt beds with a white, radioactive foam. When a ventilation filter failed, some of the plutonium reached the surface, where at least 17 surface workers were contaminated. The military shut the tunnels for three years to clean up. While WIPP is today back in business, full operations cannot resume until a new ventilation system is in place, probably in 2021. The eventual cost of the accident, including keeping the dump open longer to catch up with the waste backlog, has been put at $2 billion.
High-level waste is the nastiest stuff. It includes all spent fuel and a range of highly radioactive waste liquids produced when spent fuel is reprocessed, a chemical treatment that extracts the plutonium. Most of America’s high-level waste liquids—and around 30 percent of the world’s total—are in tanks at Hanford.
High-level waste is either very radioactive and will stay so for a long time, or it generates heat and so requires keeping cool. Usually both. It accounts for more than 95 percent of all the radioactivity in America’s nuclear waste, and needs to be kept out of harm’s way for thousands of years.
There is general agreement that the only way to keep high-level waste safe is by turning the liquids into solids and then burying it all deep underground, somewhere where neither water nor seismic activity is likely to bring the radioactivity to the surface, and where nobody is likely to stumble on it unexpectedly. There is disagreement, however, about whether this buried waste should be kept retrievable in case future technologies could make it safer sooner, or whether accessibility simply places a burden of guardianship on future generations.
Before it can be buried, most high-level waste needs to be stored for up to a century while it cools. Unfortunately, this has encouraged countries to put off making plans. None of the world’s high-level waste currently has any permanent resting place. The planet is instead peppered with interim stores. America is no better. Its 90,000 metric tons of high-level waste—set to rise to as much as 140,000 tonnes by the time the last power plant closes—is mostly sitting in ponds at dozens of power stations or lockups like Fort St. Vrain………..https://www.theatlantic.com/science/archive/2018/05/the-60-year-downfall-of-nuclear-power-in-the-us-has-left-a-huge-mess/560945/