Models inform worldwide nuclear energy choices
To inform nuclear-energy-related policy decisions, Engineering Physics Associate Professor Paul Wilson develops and runs complex computer simulations that provide insight into the next century of nuclear energy.
In one project, he and his students are using VISION, a piece of software developed at Idaho National Laboratory, to simulate how the nuclear fuel cycle will develop over the next 100 years. In particular, they are interested in how current nuclear waste policy might affect the amount and cost of space in the proposed Yucca Mountain long-term storage facility.
The policy creates financial disincentives for advanced fuel cycles, which include re-using spent nuclear fuel, says Wilson. “Current nuclear waste policy says that utilities only have to pay $1 per megawatt-hour of electricity; they’re absolved of all responsibility for the spent nuclear fuel and the government will take charge,” he says.
Given the high cost—about $100 per megawatt-hour—consumers pay for electricity, that $1 is a small fraction of the total cost of electricity. “It means that nobody is commercially interested in doing anything except the status quo because it’s financially the cheapest option,” says Wilson.
Additionally, most estimates indicate the government can build and operate Yucca Mountain using that spent-fuel surcharge. But given the amount of spent fuel around the country, there’s a good possibility that the country will need to start planning for an additional facility before Yucca Mountain even opens.
Faced with that possibility, Wilson and his students began a study to determine how space in a long-term repository would be priced if there were only one such facility. “At the very extreme, if you treat the space in Yucca Mountain like real estate, the last 100 meters of space is going to be very valuable,” he says. “And now it could be much cheaper to use advanced fuel cycles with reprocessing than it is to put used fuel in Yucca Mountain.”
Using a calculation they applied to the VISION code, Wilson and his students can follow spent fuel (and other material) through the fuel cycle and quickly determine, based on heat load, how much space it will need in the repository. In addition, given the current waste fee and amount of stored waste, they can study the economics of different fuel cycle choices based on the value of available space in Yucca Mountain. “Right now, we’ve got the capability to take whatever pricing scheme you want to use and see what it does to the economics of the nuclear fuel cycle,” says Wilson.
The group’s research may help inform an upcoming decision by the U.S. Secretary of Energy about whether to propose a second nuclear waste repository and where to site it.
Working with Idaho National Laboratory researchers, Wilson and his students also are developing a new software tool called GENIUS. The tool will enable them to model individual facilities throughout the global nuclear fuel cycle, and to study the flow of material among those facilities over the next 100 years.
Driven by the Global Nuclear Energy Partnership, an international initiative to promote nuclear power while reducing nuclear waste and the risk of proliferation, Wilson hopes to use GENIUS to study global interactions in the fuel cycle. “Really, we have to focus on diplomatic measures for non-proliferation,” he says. “And, so if you turn that around, alternative technology options allow you to use different diplomatic instruments. If we had full-scale reprocessing occurring in the United States, we could consider taking back people’s spent fuel and reprocessing it.”
This more finely tuned research may contribute to dialog about the economic and diplomatic feasibility of fuel-cycle services agreements among nuclear energy providers around the world. “Those things all have domestic costs, and I like to look at the notion of it being the cost of global peace, if you will,” says Wilson. “It’s sort of a tax that maybe we’re going to have to put on our industries. We’re all paying it to allow us to have nuclear energy for all of its benefits, but to minimize the proliferation risk.”