An MIT undergraduate course in civil and environmental engineering and engineering systems is exploring how to safely transport spent nuclear fuel from 130 sites in the United States to a high-security repository in Yucca Mountain, Nev.
Today there is a five-mile tunnel at Yucca Mountain constructed for experimental purposes, but the repository itself is not expected to open for many years. So, the fuel--the radioactive byproduct of electricity generation--is presently stored on-site at the nation's 66 operational nuclear power plants, which produce about 20 percent of U.S. electricity, and at nine plants that are no longer operational.
Joseph Sussman, the JR East Professor in the Department of Civil and Environmental Engineering and the Engineering Systems Division, served for two years on a National Research Council committee charged with solving the nation's problem of transporting nuclear waste.
Now he is applying that experience to Course 1.041/ESD.04 (Frameworks and Models in Engineering Systems). In the past, Sussman focused this course on urban transportation as an example of a complex system. Beginning in spring 2006 and again this spring, he is engaging students by presenting them with a set of very timely, complex issues to solve.
"It certainly made the course more applicable, and therefore more interesting. It was always interesting to catch the issue on the news, or some lecture at MIT, and be able to relate to it from a 'research' point of view," said Aaron Sarfati, a senior in civil engineering who took 1.041 last year and is now serving as a teaching assistant in the course.
"To be honest, I did not even know about the spent nuclear fuel problem before taking this course. I knew about nuclear technology, obviously, but I did not realize there was a problem storing its byproduct," Sarfati said.
The resurgence of the U.S. nuclear power industry is bringing with it renewed questions of what to do with the spent fuel. Continuing to store it as we do now is not a long-term solution, Sussman said. On the other hand, conveying the waste by rail and truck through populated centers to a rugged part of Nevada introduces different risks, both accidental (trains can derail, trucks can roll over) and deliberate (theft or terrorism).
"There will be risk in any case. Transporting the spent nuclear fuel redistributes the risk, perhaps equitably and perhaps not," said Sussman.
The class has two threads: the theoretical explanation of engineering systems principles and the techniques required to study complex engineering systems. Sussman teaches the students a system he calls the CLIOS (complex large-scale interconnected open socio-technical) Process, in addition to simulation modeling and stakeholder analysis. "Then we devote about half the class time to getting the students to apply the CLIOS Process to this particular system--transporting nuclear waste," he said.
Students work in two competitive groups that consolidate their findings into a formal presentation at the end of the semester. In their analyses, they consider the various stakeholders: the general public, electric utilities, railroads and trucking companies who would transport the waste, people living near power plants or along the transportation routes, and the U.S. Department of Energy, which has responsibility for safeguarding the nation against adverse uses of this material.
"I think the most interesting part of the transportation problem was dealing with terrorist attacks," said Sarfati. "To me it seemed that the casks would be safe enough to travel through the United States, unless they were specifically sabotaged. That was part of the reasoning that led to me designing an air transport system, to try and minimize the effects of terrorism through closer scrutiny and control of the packages."
The teams also consider strategic alternatives for reducing the carbon footprint involved in the generation and use of electrical energy, on the assumption that it may turn out to be impossible to deal with all the spent nuclear fuel if a large portion of U.S. electric power is produced from nuclear sources. For this, they look at alternatives such as wind power and conservation.
"It's a complex issue with many players. The students work very hard to understand all these issues and to try to figure out appropriate strategies," said Sussman, who credits the students with imaginative solutions. "We asked them to think about not only the technologies that are involved, but also the organizational change that would be required to actually make it happen."
