Across the United States, radioactive uranium rods wait in storage containers at nuclear power plants, mounting into a large waste issue for the national government and utility companies. As waste builds, many Midwestern universities, including UW-Madison, are looking to improve nuclear fuel reprocessing techniques and streamline the nuclear fuel cycle, which would reduce the overall volume of toxic waste.
'There is a lot of interest in Washington in nuclear fuel reprocessing,' said Paul Wilson, associate professor of engineering at UW-Madison. 'Specific technologies are still in question, but the fundamental idea of recycling spent nuclear fuel rods than simply burying it in the ground is one that is gaining a lot of interest right now because of the long-term consequences.'
'Spent nuclear rods' removed from reactors contain un-decayed uranium, plutonium and other radioactive byproducts which may cause cancer and other diseases. These waste products need to be stored indefinitely in metal and concrete casks to prevent catastrophe, but reprocessing the used rods would reduce waste volume and ease storage problems.
Without reprocessing nuclear fuel stored in the United States, the proposed Yucca Mountain nuclear repository would be immediately near capacity with the backlog of nuclear waste. This would create a need for a second repository, a task increasingly difficult with political opposition to nuclear technology and waste. Deep geologic repositories are currently the best method for nuclear waste disposal, but their durability over thousands of years while fuel degrades is yet to be determined.
Recycling nuclear fuel involves removing unused uranium elements from 'spent' nuclear fuel and recasting rods to be again placed inside a nuclear reactor. Current reprocessing technology can perform this task, but it is inefficient and not cost-effective for the nuclear industry.
'We want to look at the pretty gritty processing, chemical engineering, nuclear engineering and all these associated technologies to make it more efficient,' said Michael Corradini, UW-Madison engineering physics professor. 'And as you make it more efficient, meaning that you can do the task for less money or less materials, it becomes more interesting for the industry to use. And the benefit is we recycle a whole lot of stuff and we only get rid of a small fraction [of waste].'
As plants continue to produce electricity, recycling uranium resources is a great option to reduce the flow of waste to repositories. Many nuclear power plants are scheduled for renewal in coming years, ensuring the flow of radioactive waste for decades.
'When we do start [building nuclear power plants] again in five years or so, it's not clear that they need to be a lot better than they are right now for producing electricity; they're pretty good at it, in terms of making money for utilities and economically producing electricity. So what is going to drive that necessity is the issue of waste and sustainability,' Wilson said.
Instituting reprocessing and making the fuel cycle more efficient would require less uranium to be extracted from the ground, possibly the largest environmental impact in the entire nuclear industry, said Richard Shaten, UW-Madison faculty associate and instructor of Environmental Studies.
Nuclear power makes up approximately 20 percent of consumed electricity'mechanisms that make the industry more sustainable and efficient would benefit all consumers. Research at UW-Madison could improve reprocessing techniques, make recycling uranium resources viable for the nuclear industry and in turn reduce stress on national toxic waste repositories.
