UW-Madison's nuclear reactor going strong after 40 years
During the 40 years that UW-Madison's nuclear reactor has operated, 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 Emeritus Professor Max Carbon.
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 college's own reactor.
A few years later, the General Electric Company 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, who also was the reactor's first director.
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. And 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 currently testing the replacement for one. And though 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 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.
And 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. They've also tested both United States- and Soviet-retrieved moon rocks, soil from former landfills, fish samples, fluid from the joints of people who have artificial joint replacements, and artifacts and pottery from all over the world. Staff 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," says Cashwell.
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 (
He also teaches a capstone-style nuclear reactor laboratory class (
The Department of Energy's reactor-sharing program provides small grants for students and teachers from other educational institutions to use the reactor. Sometimes they just visit for demonstrations; one UW-Platteville class came for a complete lab course, and for years, a Milton College (Wisconsin) chemistry class spent several weeks learning about neutron-activation analysis.
The reactor-sharing program also permits nonsponsored research. "This semester we did some samples for an elementary school in Idaho," says Cashwell. Eric Loewen, a former PhD student who volunteers at the school, initiated the project. One class grew plants on various vermiculites, while the other hunted for rock samples to analyze.
"One of the teachers wrote me a letter and said that most of the kids were really anxious to get their analyses back because most of them were prospecting for gold," chuckles Cashwell about the rock project. "That may not be good science, but it's good education."
Kids also get a reactor education through its outreach efforts. "We have always had an open-door policy toward tours," says Cashwell. Members of the college's American Nuclear Society student section lead tours and conduct demonstrations for local Boy Scouts seeking to earn their merit badges in atomic energy. And reactor staff have hosted several elementary and high school classes — even children from a day care center ("they seemed to like it," Cashwell reflects). Teachers attend reactor "classes," too. Last fall, about 120 high school science teachers attended three educational sessions at the reactor.
Cashwell, who is retiring this summer, says all of 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."