Winter 2007
In This Issue:
Focus On Energy
Going Nuclear: A Visit to Penn State's Source for Neutron Radiation
by Walt Mills
On the eastern edge of campus, tucked away behind a tall wire fence, stands the half-century-old Breazeale Nuclear Reactor. Built when Dwight Eisenhower was U.S. president and his brother Milton was president of Penn State, and frequently updated since, Breazeale is the longest-operating university nuclear reactor in the country.
The blue glow is the Cerenkov Radiation from Penn State's TRIGA Mark III nuclear reactor, the only research reactor in Pennsylvania.
Once past the concrete vehicle barriers and the guarded gate, with an ID tag and a radiation dosimeter hanging around my neck, I found little to raise my anxiety level. This is a teaching and research reactor, not a power plant. No large concrete containment units or men in white radiation suits. In fact, a major part of the staff's function is in the education of upward of 3000 visitors a year from outside the university. High school students, elementary students and their teachers, boy scouts and girl scouts earning merit badges tour the reactor building, which is officially known as the Penn State Radiation Science and Engineering Center (RSEC).
Whether in short tours of a half hour or week-long workshops for teachers, the RSEC introduces visitors to some fundamentals of nuclear technology and demonstrates how nuclear radiation is used to improve our lives. Among these practical uses are sterilization of foods, medical treatments, product improvements, and research into materials.
For materials scientists, one of the advantages of neutrons is their ability to look through metals. This means that neutrons can show liquids flowing through pipes, and see details of objects that would be invisible to x-rays. At the RSEC, materials researchers such as Dr. Matthew Mench study the insides of fuel cells with neutron beams to understand water-flooding problems in automotive fuel cells that lead to performance loss.
Students and faculty researchers from across campus, as well as researchers from more than two dozen companies and universities, use the facilities each year. Some electronics makers and defense contractors bombard their miniaturized electronic devices with neutrons to simulate cosmic radiation, which can cause transient hardware failures called soft errors in computer memories and integrated circuits. A new research tool for soft error study has been developed in the Neutron Beam Laboratory by a group of Penn State faculty and their colleagues to provide data and processes to assess the soft error problem, which can affect crucial systems such as aircraft electronics and implanted cardiac defibrillators.
A tour of the reactor building
Dr. C. Frederick Sears, director of the Breazeale facility, met me at the front desk and after a short orientation in his office, took me on a tour of the RSEC. Much of the building remains as it was in the 1950s when Penn State brought Dr. William Breazeale from Oak Ridge Laboratory in Tennessee to build the first civilian research reactor, as part of Dwight Eisenhower's Atoms for Peace initiative. “Bill Breazeale had boasted that he could build a reactor for $300,000 and he set out to prove it, using Penn State scientists and engineers to design and build the entire structure. He didn't quite meet his budget, but he came in only a few thousand over,” Sears told me.
(Another Breazeale story explains how he came to acquire his license to operate a nuclear reactor. Prior to 1955 no such license existed. Breazeale sat down and wrote the first operator license exam, answered the questions, graded himself, and gave himself a passing mark.)
We passed through a secure door into the high-ceilinged reactor room. The reactor itself sits in a pool containing 71,000 gallons of demineralized water. The water is so free of impurities that it does not conduct radiation or electricity. Visitors are able to lean over the wall and look down into the pool, where they can see the source of the neutron beams. The water is used for both shielding and cooling the reactor core.
The reactor building is a sheet metal structure rather than a concrete containment unit. It is maintained under negative air pressure to prevent any leakage of radiation to the outside. The reactor produces both fast neutrons, which can be hard to handle, according to Sears, and slower thermal neutrons, which are more easily used. The facility also produces gamma rays in a separate pool containing Cobalt-60.
Along with studying the dynamics of reactors, students in the RSEC can also learn how to operate the reactor first hand. On my visit, the control room was staffed by undergraduate students who had undergone a formal RSEC training program and received their Senior Operators License from the Nuclear Regulatory Commission; these students had also already gained nuclear experience while serving in the nuclear navy. The students sit in a glass booth overlooking the reactor pool in front of computers that, for security purposes, are not connected to the outside world and therefore cannot be hacked. There are several high-tech labs and multimedia-enhanced classrooms.
Elementary school students peer down into the reactor pool
“Students can get practical training here,” Sears remarked. “We train by doing experiments. We irradiate materials and watch the decay to determine the chemical content. We can detect materials in the parts per million down to the parts per billion. We look at soft materials for contamination, such as in filters, and also look at contaminants in semiconductor materials. We enhance the behavior of electronic components through a process called neutron doping, which is similar to but in many ways better than the more familiar chemical doping of semiconductor materials.”
According to Sears, there is a growth in the need for nuclear engineers. “The existing workforce is retiring — 30 to 40 percent will retire in the next few years. If the number of nuclear plants expands as we expect, we will soon be right back in the heyday of nuclear education.”
Graduates from the Mechanical and Nuclear Engineering program are sought after by industry, Sears told me. Because the program offer practical knowledge that is well suited to the utilities industry, Penn State is a “targeted university,” and students typically receive high-wage offers upon graduation.
The case for nuclear energy
The tour completed, we returned to Dr. Sears' office where I questioned him about the future of nuclear energy. Having spent his adult life with nuclear energy, Sears has an undiminished passion for his subject.
“I hope we will get our energy from nuclear,” he said. “I'm a firm believer. In a practical sense it is benign, nonpolluting. There really is no such thing as having no residue from energy production. But with nuclear, the amount is very small, and all of it could be contained in a space about the size of Beaver Stadium. It has to be shielded, but that's a problem that has been solved.”
We may have the technical knowledge to dispose of nuclear waste safely, but do we have the political will? He thinks not. “No one wants it in their backyards. However, if you've ever been to Yucca Mountain (the nation's proposed repository for spent nuclear fuel in southern Nevada), you won't find a more desolate place or better place to put it.”
Sears believes that if we could get past the correlation of nuclear power to nuclear weapons we would be able to find a political solution. “Hiroshima and Nagasaki stick in people's minds when they hear the word nuclear. The first word that comes to mind is bomb.” In their reactor tours, his staff explains that radioactivity is a natural part of the world around us, which includes those cosmic rays that can damage electronics but mostly pass right through our bodies. On average, he said, we receive 360 millirems a year of radioactivity exposure, of which 5 or 10 millirems are from medical procedures. “Why, just lying in bed next to your wife will expose you to 10 or 11 millirems from the potassium in her body,” he told me with relish.
He continued. “I have been in the nuclear business for almost 50 years, and in all that time my total occupational exposure only amounts to four or five times my normal annual exposure. We control radioactivity extremely well.”
Every technology must be carefully utilized, Sears argued. Although he admits there could be other accidents with nuclear energy, what is unique, he says, is that there are so many safeguards built into the system. Even at Three Mile Island the public was protected. “Our technology is nothing like Chernobyl.” (At the time of the accident, the type of reactor involved in the 1986 disaster in the USSR was already widely known to be unsafe.) “Even so, we cannot deploy nuclear power with a sense of complacency. Part of our role is to teach students and the public how to safely deploy nuclear technology.”
Sears emphasized that every technology has its downsides, including such “green” alternatives as hydro, wind, and solar. “How reliable is the power of alternative energy systems? Do they need back-up storage systems for when the sun is not shining and the wind is not blowing? Nuclear is a valid base-load power source that can be safely operated with a proper amount of dedication,” he said.
As for fossil fuels, they are “too valuable to be burned.” Sears believes they should be made into plastics. “Nuclear is cost competitive when politics doesn't draw out the construction process,” he told me. Unlike gas-fired plants, the cost of the fuel is small compared to the capital costs. For this reason, nuclear could be the base load — operated full time. Alternative sources would supply off-peak power and remote power that can't connect to the grid. “Softer technologies are specialties, not likely to meet base-load needs.”
When I pointed out that experts in every energy field believe the future belongs to their particular energy source, Sears cheerfully admitted his bias. “It's true, we all tend to ignore the warts on our own energy sources and see them clearly on the other person's. That colors the perspective. Nuclear can't supply everything, but I don't expect to see soft technology become cost effective anytime soon, whereas nuclear could go forward today without tax breaks.”
“The Japanese can build a nuclear plant in 48 months or less. We can take 20 years. But 48 months is possible, and would make it cost effective. A large part of the costs for building plants is the interest on capital. That was especially true in the 1970s when interest rates were in the 20 percent range. In the past the PUC made it difficult to build new plants. It wasn't profitable for utilities to invest in nuclear. There are new steps in place to make it possible to begin 10 to 20 nuclear plants in the next year at a cost of $1-$3 billion per plant.”
Asked about reports of a shortage of fissile material, Sears disagreed. “We have enormous amounts of uranium. I see no lack of availability of uranium in the future. The cost is still low. If necessary, you can recycle the fuel for fast reactors. France and Japan already do this. The arguments for not reprocessing are going away, though it is too expensive to do right now.”
I handed over my dosimeter (no change) and ID tag, and walked out of the interview convinced of one thing: In this climate of uncertainty over the price and availability of oil, count on nuclear to make a comeback.
Dr. Fred Sears can be reached at Validate to view address - Send Email via form.
