High-level radioactive or nuclear waste is “spent” uranium fuel used in nuclear reactors. This spent fuel is thermally hot and highly radioactive, usually in the form of uranium 235 contained in ceramic pellets inside metal rods. What do we do with this spent fuel? Right now, nothing really, presumably we are waiting for a future generation to figure out where to safely store it all. It will only be rendered harmless through a process of decay that can take thousands of years. The US, which had over 72,000 tons of nuclear waste as of 2011, has no long-term facility for storing high-level nuclear waste. The interim answer is either to store this spent fuel in water-cooled pools on the site of the reactor, or to transfer it temporarily to dry casks. With the exception of the expensive endeavor of reprocessing this spent fuel to extract plutonium for commercial use, there is no known alternative to burying nuclear waste in massive underground facilities, which currently do not exist. Throwing it in the Ocean is clearly not recommended, though that hasn’t stopped governments in the past. Here’s what we’re doing with it now:
Temporary Spent Fuel Pools
Much of the US’ nuclear waste is being stored in large water-cooled pools onsite at nuclear power plants. This is not the safest method: The release of radiation at Japan’s Fukushima plant came from fuel stored in pools. This poses a particular problem for the state of Minnesota, where nuclear power plants were not designed to take on nuclear waste storage. Designers were banking on the construction of a large long-term nuclear waste storage facility at Yucca Mountain, Nevada, which never materialized due to fears of ground-water contamination.
Temporary Dry Cask Storage
In some cases, after waste is cooled in spent fuel pools it is transferred and sealed dry casks, which are steel and concrete containers. The problem is that dry-casking is much more expensive than pool storage, but it is also much safer. Dry casks are much less vulnerable to fire, flooding, earthquakes or other machinations of Mother Nature. Scientists say they have never leaked radiation.
The US Department of Energy is constructing a $12.2 billion facility to process excess radioactive waste. The biggest question on everyone’s mind, of course—is it safe? Well, Energy Secretary Steven Chu, who visited the construction site in Hanford, Washington, last week, isn’t entirely convinced. He and a panel of experts are reviewing the safety of the waste storage rooms at the massive 65-acre site. This has not gotten off to a brilliant start at the site (incidentally, where the US used to produce plutonium for atomic weapons, rendering Hanford one of the most toxic areas in the country). Reviewers found leaks of radioactive material in the walls of one of the newer storage tanks and threaten to run into the Columbia River. In August, a DOE official brought up concerns about the company contracted to lead the design of the facility, Bechtel National Inc., saying it was incompetent in comparison to the task at hand. The plant is scheduled to be completed by 2022 and to store some 56 million gallons of radioactive and chemical waste for a period of 40 years, at which time it will be shut down. Then what? The Nuclear Regulatory Commission allows spent nuclear fuel to be stored at reactor sites for up to 60 years after the plant shuts down. Presumably another generation will be able to figure out what to do with all that radioactive waste.
Constructing a long-term storage facility for radioactive waste is an exercise in clever public relations and subtle politics. There must also be a trade-off for the community. The Yucca Mountain nuclear waste storage facility never got off the ground because it failed on a public relations level and was allowed to become an election campaign tool. The federal government forced the facility on the state of Nevada, against strong objections from within the state. Nevada fought back politically and the Obama administration was eventually forced to scrap the project altogether in 2010. It was a battle that lasted for over two decades.
Reprocessing for Plutonium
In terms of energy, reprocessing fuel for plutonium is rather efficient as it effectively uses fuel twice. It is not economical, however, and the process itself is very expensive. Additionally, there are some safety issues in that plutonium renders fuel from a reactor hotter and negatively affects the capacity of spent fuel pools. With plutonium, there are also greater risks of contamination.
The European Space Agency is piloting a £1 million program to use civil plutonium for nuclear batteries to power ships on deep space missions.
Britain’s nuclear waste could be used to power spacecraft as part of government attempts to offset the huge cost of the atomic clean-up by finding commercial uses for the world’s largest stock of civil plutonium. The UK, which has the world’s largest stock of civil plutonium, is the focus of these efforts. The Sellafield waste facility ponds contain some 100 tons of plutonium. Nuclear batteries can be made from an isotope (americium-241) in decaying plutonium at the UK’s Sellafield waste storage site. The UK is also eyeing the possible export of its plutonium stores to the US, which can produce plutonium-238 (which can be replaced by americium-241) only in nuclear weapons-grade reactors. Without a commercial use for the UK’s plutonium, it will cost the government an estimated £4 billion to clean up.
Of course, this does little to resolve the nuclear waste problem and space batteries alone will hardly scratch the surface of the disposal problem.
Dumping it in the Sea
Out of site out of mind. This is what the Soviets did with their decommissioned nuclear reactors and radioactive waste, massive amounts of which are now sitting at the bottom of the Kara Sea in the Arctic Ocean. To wit, some 17,000 containers of radioactive waste, 19 ships with radioactive waste, 14 decommissioned nuclear reactors, a nuclear submarine and a host of other nefarious materials. If the nuclear reactors from the sunken submarine explode under water, the consequences would be unspeakable. Regardless, decontaminating the sea will be challenging at best. This nuclear waste will also prove a major hindrance in Russia’s efforts to explore for oil in the Arctic Ocean, which is exactly why this story—an old story from the late 1990s—is now resurfacing. The Russian’s want help cleaning it up so they can get to the Arctic oil. The Soviets, of course, were not the only ones to dump oil in the world’s bodies of water: The French, British and Americans have done so as well in the past.
By. Jen Alic of Oilprice.com