Nuclear reactor going strong after 40 years

During the 40 years that UW–Madison’s nuclear reactor has operated in the Mechanical Engineering Building, not much has happened.

And that’s as it should be, says Dick Cashwell, the reactor’s director for all but a few years of its existence. “In reactor operations, doing great things means nobody notices you,” he says.

But that’s not to say there’s no story to tell. After World War II, researchers shifted their focus from developing nuclear weapons to designing better, more efficient nuclear power plants to generate electricity. “Many, many reactors were built in the early days, but a lot more were planned, and it was expected that many, many more were going to be needed,” says engineering physics emeritus professor Max Carbon, the reactor’s first director.

Carbon was the first chair of UW–Madison’s nuclear engineering department, hired in 1958 after an interdisciplinary group of engineering faculty recognized the trend and began planning to construct the university’s reactor.

A few years later, General Electric built the teaching-and-research pool reactor. It achieved initial criticality at 10 kilowatts, its original steady-state power level, in early 1961. At the time, only five or so such university facilities, including those at North Carolina State and Penn State, existed in the United States, says Carbon.

And now, at a time when tight budgets and funding cuts are forcing many universities to pull the plug on their reactors, UW–Madison has applied for a 20-year reactor-license renewal from the Nuclear Regulatory Commission. At the same time, the Department of Engineering Physics is gearing up for more students, drawn by renewed interest in nuclear energy.

At first glance, UW–Madison’s pool reactor appears similar to a very small, very deep swimming pool with its works snaking down the inside walls, instead of hidden beneath the concrete. Like a swimming pool, its clear, clean water is easily contaminated, though not so easily cleaned. Accessible through a small control room, where panels of gauges, dials, buttons and levers are the focal point, the reactor’s home is a cavernous multistory concrete room.

Although it was constructed some 40 years ago, the reactor has been upgraded several times. The only original control-panel parts are two solid-state instruments — and staff are testing the replacement for one. Although some aspects are computerized, students and staff still use traditional individual channels integrated into an overall control system to operate the reactor.

“We chose not to go to a completely new control system that was all computer-controlled because there’s very little teaching merit in that,” says Cashwell, who came to the university in 1962 to start a reactor-safety program.

A 1964 upgrade brought the reactor’s power level to 250 kilowatts and another improvement in 1967 raised it to 1 megawatt, where it is today. That power level makes the reactor, one of seven like it, ideal not only for education, but also research, says Cashwell.

Throughout the years, reactor staff have helped scientists study just about anything that comes to mind.

“We probably have irradiated more cow manure than any reactor in the world,” says Cashwell.

UW–Madison’s dairy science department and the U.S. Department of Agriculture initiated those studies to determine how quickly various food travels through the bovine system.

Reactor staff also have tested United States- and Soviet-retrieved moon rocks, soil from former landfills, fish samples, fluid from the joints of people with artificial joint replacements, and artifacts and pottery from all over the world. They even tested storage lengths of rhinoceros sperm for artificial insemination during an experiment to preserve the endangered animal.

“Whatever people show up with and need analysis done on, we end up doing it,” Cashwell says.

For this reactor, the work, although serious business, is a little like moonlighting. Education takes up the lion’s share of its — and Cashwell’s — time. He teaches Principles and Practice of Nuclear Reactor Operations (NEEP 234), a course that familiarizes students with operating such a complex machine in a regulatory network.

“It is essentially an operator-training course, but we try to include parallels between what we do and what would be done in a power reactor,” he says. After they’ve taken the Nuclear Regulatory Commission’s licensing exam, Cashwell hires NEEP 234 “graduates” as student reactor operators.

He also teaches a capstone-style nuclear reactor laboratory class (NEEP 428), which every nuclear engineering bachelor’s student must take. In the course, students experimentally verify that they can actually measure all the reactor characteristics they learned in their theory courses. In both courses — and anywhere else — Cashwell imparts a bit of his philosophy: Do it right because it’s the right thing to do.

The Department of Energy’s reactor-sharing program provides small grants for students and teachers from other educational institutions to use the reactor. The reactor-sharing program also permits nonsponsored research.

Kids also get a reactor education through outreach efforts. “We have always had an open-door policy toward tours,” says Cashwell. Cashwell, who is retiring later this year, says these students mark the brightest spots in his career. “A lot of them are even friends after this long of time,” he says. “To me, that’s the most worthwhile part of it.”