University of Mississippi physicists have been awarded $3 million by the U.S. Department of Energy to conduct Nuclear fuel storage research over the next three years on ways to assess the internal components of a dry cask storage.
According to the U.S. Nuclear Regulatory Commission, by the end of 2009 there were more than 62,000 tons of spent fuel accumulated in the United States. That amount of accumulated fuel increases by 2,000 to 2,400 tons annually.
Spent nuclear fuel is stored in spent fuel pools under water for a little more than a year, after which time the fuel can be moved to dry cask storage.
Dry cask storage allows spent fuel that has already been cooled in the spent fuel pool for at least one year to be surrounded by inert gas inside a container called a cask. The casks are typically steel cylinders that are either welded or bolted closed. The steel cylinder provides a leak-tight confinement of the spent fuel. Each cylinder is surrounded by additional steel, concrete, or other material to provide radiation shielding to workers and members of the public, according to The Nuclear Regulatory Commission’s website
Josh Gladden, executive director of the University’s Jamie L. Whitten National Center for Physical Acoustics and associate professor of physics, is the principal investigator for the project.He is assisted by co-principal investigator Joel Mobley, as well as several other research scientists and graduate students at the University.
The problem with the casks is they cannot be opened— they must be analyzed without actually looking inside.
“The main goal of the research is to assess the structural health of the internal components of a dry nuclear fuel rod storage cask,” Gladden said. “They are sealed and it is not impossible to open them, but it is a very big deal to open them. The hope is to develop a technology that will allow you to get some sense of what’s going on inside these things without having to open it.”
The casks are about 20-25 feet tall, 6 or 7 feet wide and extremely heavy. Gladden said it’s important to have a system that allows researchers to get a reading on what is going on inside the cask and move to the next one.
Another reason for researching the casks is transportation. The casks were originally intended to serve as temporary storage for the spent nuclear fuel, so they will eventually need to be transported to a permanent storage location by trains or barges. Since the casks are encased in concrete and steel, it’s difficult to determine if there have been any internal changes during transport.
“Eventually these things are going to have to get moved,” Gladden said. “There really is no place to move them to now, but eventually there will be. So from our perspective, we would like to develop the technology to do an assessment before it’s moved and then repeat the assessment after it’s moved so that you can get a sense of if there is any damage or any major changes caused during the transportation process.”
The idea to conduct research on the dry casks came about a year and a half ago after speaking with James Tulenko, senior faculty member of the University of Florida’s nuclear engineering department. After developing a plan, an in-depth proposal was submitted to the Department of Energy, and the University of Mississippi was chosen to lead the research of the dry casks as part of their Nuclear Energy University Program.
“After a few conference calls, it was decided that UM should take the lead,” Gladden said. “At the National Center for Physical Acoustics, we have a lot of experience in project management, especially large projects like this. So we had the personnel, staff and experience to make sure that a large project like this is run properly.”
The University is working with several other schools and organizations to conduct research. The University of Florida, University of South Carolina, Oregon State University and two private sector organizations, Electric Power Research Institute and AREVA, are all working alongside Gladden and his team.
While each team is working toward the same end result, they all have distinct duties and goals within the larger project.
“The hope is that at the end of the day, the things that work from all of these projects will get merged together and will result in an assessment tool that regulators and operators can use,” Gladden said.
– Blake Alsup
