The delicate and dangerous operation was called “tickling the dragon’s tail,” and someone made the dragon very angry.
As part of a 1946 research experiment at Los Alamos National Laboratory, Dr. Louis Slotin was using a screwdriver — yes, just a screwdriver — to hold apart two halves of a neutron reflector sphere encasing a plutonium core. Slotin slipped. The screwdriver came out, and the reflector sphere shut around the plutonium core, blasting Slotin with a burst of nuclear radiation and bathing the room in a flash of blue light. Slotin managed to separate the sphere halves before the core went critical — saving the lives of the other scientists in the lab, but not his own. He died nine days later of radiation poisoning.
Dr. Denis Beller is familiar with the incident. “(It’s) famous among nuclear people,” he says. And it’s Beller’s job to prevent such nuclear tragedies from happening, whether sparked by human foibles or natural disasters. As director of UNLV’s nuclear safety program, he oversees a graduate curriculum — one of three in the country — that’s teaching a new generation of scientists and engineers how to prevent nuclear criticality accidents.
“The nuclear industry is very gray across the world because it is 60-70 years old,” says Beller. “Everybody who started it is now 20 years older than me, and they are still working. So we need to educate a lot of young people pretty quickly.” According to Elizabeth McAndrew-Benvides from the Nuclear Energy Institute, the industry is predicting a 38 percent potential retirement rate by 2018.
Nevada has had an often-stormy affair with all things nuclear. From the first atomic detonation at the Nevada Test Site on January 27, 1951, to the still-brewing fight over the proposed Yucca Mountain nuclear waste repository, Nevada has done duty as both nuclear testing ground and potential dumping ground. Now it’s looking to start a new chapter as UNLV partners with what is currently known as the Nevada National Security Site (formerly the Nevada Test Site). This partnership is a valuable byproduct of a program designed specifically for teaching nuclear criticality safety, an area of expertise that’s expected to be in high demand in the nuclear industry in the next decade.
In their Outlook for Energy, even ExxonMobil predicts nuclear will be a necessary source of energy to meet future demands — and demand means jobs. A 2008 report from the American Physical Society suggests that if the industry grows as anticipated, it will need to hire 300 nuclear engineers per year in the coming decades. The United States currently graduates approximately 160 each year. Citing the Nuclear Regulatory Commission, “nuclear criticality safety is one of the top two employment needs of the nuclear industry for the next decade,” says Beller.
“No fabrication site, no operating plant, no research facility runs without the criticality safety team,” says Tanya Sloma, a graduate of UNLV’s nuclear engineering program and now a criticality safety engineer for Westinghouse in South Carolina.
A booming area
Criticality safety is ensuring that fissile materials only create chain reactions when and where you want — that is, inside a reactor. Whenever the materials are not inside a reactor, a criticality safety engineer’s job is to make sure there’s no risk of a nuclear reaction, and the certification program at UNLV trains future and current engineers to do just that. Students learn things such as the Monte Carlo method — considered a cornerstone of criticality safety — which analyzes risk probability by running thousands of possible scenarios through complex algorithms. (It’s also used in predicting the stock market and traffic patterns.) Clearly, math is important, but so is history. As a final project for one course, students choose a historical criticality accident and analyze what went wrong. There are plenty of case studies to go around: Beller has a book that catalogues every criticality safety incident since the Manhattan Project. It was produced in partnership with engineers in Los Alamos and Russia, and when he pulls it off the shelf, he notes, “We did it to learn lessons, so that we wouldn’t repeat those accidents. It’s not a small book.” That means a lot of lessons learned.
“Oak Ridge, they had a pretty good one there,” he says, referring to a criticality accident at a Tennessee uranium-processing facility in 1958. “And, there is a pretty good video of it. Good for teaching people why we study this stuff, and why they do the job the way they do it.” (In case you’re wondering, nobody died at Oak Ridge.)
The graduate certificate program was the vision of Beller and Dr. Charlotta Sanders. Sanders grew up in Sweden, where a large percentage of the power is produced by nuclear plants. In fact, she grew up next to one. “We could go and visit the power plant, and that created a little bit of an interest from an early age,” she says. She came to Nevada with the Yucca Mountain Project, and UNLV invited her to help start the master’s program in nuclear engineering, which is one of only about 30 in the country.
She herself knew there was a need. While doing consulting work for URENCO, a uranium enrichment company, Sanders learned of concerns regarding the shortcomings of existing criticality safety training. “The theory and regulations can be taught in a university environment. We were thinking we can have a win-win,” she explains. URENCO could send their engineers for training at the university, and UNLV could establish a certificate program. With the help of past work from Beller, they secured a $200,000, two-year grant from the Nuclear Regulatory Commission to develop it in 2012.
[HEAR MORE: Catch up on the debate over nuclear waste in Nevada on " KNPR’s State of Nevada."]
‘Part of our future’
The program, which Sanders believes is the only fully online program available, currently has 10-15 students. Of those students, approximately 60 percent are working in the industry. Student Amber Guckes is slated to earn her master’s in materials and nuclear engineering next December.
“Originally, my biggest dream was to become a fashion designer, but I knew I was good in math and science,” says Guckes. “I didn’t think being a fashion designer would be challenging enough. I decided engineering would be a good field to get into, and I wanted to make a difference. I thought nuclear could open the doors to energy independence and efficiency. My friends always ask, ‘So, you built a nuclear bomb in class?’” Kidding aside, while she hasn’t decided her exact focus for now, she is interested in safety issues. “I wholeheartedly believe that nuclear is going to be a part of our future.”
Ideally a safer one. In the case of “tickling the dragon’s tail,” as a result of that 1946 accident, new remotely controlled machines were developed for similar experiments. One of these machines, named Godiva, is used at the Nevada National Security Site. In fact, a graduate of the certificate program works there in the criticality safety group, and National Security Technologies, the group that manages the site, also works directly with UNLV. “We have about a $185,000 contract to support their nuclear criticality safety program,” says Beller. “We are part of the review committee that looks at their nuclear criticality safety evaluations to see if they did the job right, before they’re allowed to do a new process for actual things that are getting done at the site with massive amounts of very high-level nuclear materials.”
As with Yucca Mountain, the partnership with National Security Technologies provides needed monetary support to the university and invaluable opportunities for students like Sloma to get experience both in the lab and on the job. She says, “All of the jobs that the industry provided out there were great opportunities for a young individual looking to stay near home, and between UNLV and the jobs, I have made a great career for myself.”
The nuclear criticality safety program is working to meet that need. But to Sanders, this is about more than jobs — it’s about winning the hearts and minds of an American public that still seems skeptical about the safety of nuclear power.
“We contribute to making a better-qualified young workforce that has an understanding of safety in all aspects of nuclear activities,” she says. “I hope people will have more confidence in the nuclear activity that goes on in the state of Nevada, for example, in future discussions of Yucca Mountain, to know there is a strong safety program, and we’re doing everything possible to add to the education at UNLV.”