Wednesday, March 7, 2018

Grad Students Harish Gadey (L) and Steven Czyz (R) work with Associate Professor Abi Farsoni in the Radiation Detection Lab. Czyz took top honors for the School of Nuclear Science and Engineering (NSE) at Oregon State's 2018 Graduate Research Showcase. Gadey placed second for NSE.

Nuclear nonproliferation, homeland security, and reprocessing nuclear fuel were the big picture topics encapsulating the best student research that the School of Nuclear Science and Engineering (NSE) had to offer at the College of Engineering’s 2018 Graduate Research Showcase.

The annual showcase offers graduate student from across the college’s five engineering schools a chance to take their research out of their labs and, via poster presentations, explain it to the public, peers, professors, and their school’s judging panels. This year, 150 students presented. The top three students from each school were recognized for their achievements.

Steven Czyz took top honors for the NSE with his research on radiation detectors.  “There are radiation detectors placed all around the world that are constantly monitoring the atmosphere of the earth for radioxenon signatures- a tell-tale sign of a nuclear detonation,” he said. “I work on making detectors that are smaller, more power efficient, more durable, faster, and more economical than the current state-of-the-art detection systems, without sacrificing performance.”

These types of detectors are used in the International Monitoring System, which informs nuclear nonproliferation efforts around the world. Current detectors cost around $500,000 while the ones that Czyz is working on would run between $20,000 and $50,000. Czyz is pursuing a doctorate in nuclear engineering and works in the Oregon State Radiation Detection Group under Abi Farsoni, associate professor of radiation health physics. (See his poster for full details and technical specs.)

Harish Gadey, another graduate student in the Radiation Detection Group, took second place. His research looked at improving detection capabilities for radiation detectors using metal-loaded plastic scintillators. These types of loaded plastic scintillators promise to be easier and cheaper to manufacture than traditional detectors. This would be a boon as homeland security utilizes radiation detectors at borders and airports and these detectors must be large, easy to manufacture and low cost.

Detectors work by picking up the photon(s) emitted by radioactive isotopes also known as radionuclides. These photos act as signatures in identifying radionuclides. One of the problems with metal-loaded plastic detectors is that when a radionuclide is detected it generates a large Compton continuum. Compton continuums occur when the photon(s) interacts with the detector and scatters without depositing all of its energy. This is a problem, because full energy depositions help researchers like Gadey determine which radionuclide is being detected. The Compton continuum interferes with the data, because when a photon(s) with higher energy is detected it makes it difficult to see other photons with lower energy. In other words, it’s hard to tell which radionuclides are being detected.

Gadey’s work uses digital algorithms to discriminate pulses based on the element the photon is interacting with in the metal-loaded scintillator, leading to more accurate identification of the radionuclide. These digital algorithms are called spectrum enhancement techniques. “This research has not been explored before, so right now it’s the first step in a long journey. In the future, we might be able to use plastic detectors for border protection while applying the spectrum enhancement techniques,” he said. (See his poster for full details and technical specs.)

Third place went to Yana Isaichykava. Working in the Radiochemistry Group under Alena Paulenova, associate professor of radiochemistry, Isaichykava’s research informs nuclear fuel reprocessing. In order for nuclear power to be cost effective and competitive with other energy sources, it’s necessary to reprocess nuclear fuel after it’s gone through a burn cycle to recover useful elements like actinides that can be burned again, and to reduce nuclear waste.

Fuel reprocessing is done through a variety of chemical extraction processes. One of these is called the Actinide Lanthanide Separation Process or ALSEP, which was proposed by Argonne National Laboratory in 2013. Lanthanides are all natural elements and only one, promethium, is radioactive. Actinides, on the other hand, are very chemically similar to lanthanides but are all radioactive elements and some of them are human made. ALSEP extracts and separates actinides from lanthanides in nuclear fuel for more efficient and safer reprocessing. “There is a global need for separation of actinides,” said Isaichykava. One of the main reasons for this is the “possibility to reuse the separated actinides in so-called fast reactors thereby, eventually, closing the nuclear fuel cycle,” she said. Isaichykava’s research investigated how to “better understand and to possibly predict the extraction and stripping behavior of actinides and lanthanides” during the ALSEP process. ALSEP shows great promise for being an ideal way to reprocess nuclear fuel and work like Isaichykava’s helps improve it by exploring non-predicted effects in extraction behavior. (See her poster for full details and technical specs.)

Yana Isaichykava explains her research at the 2018 Graduate Research Showcase

Yana Isaichykava explains her research at the showcase. 

The showcase gives students like Czyz, Gadey, and Isaichykava the chance to explain their research to a broad audience and show its impact both in the real world and in further academic pursuits. This helps close the knowledge gap between researchers and the public.

“I think research can sometimes feel like an echo chamber: talking about your work with your peers, presenting work to your peers, reading work by peers and for peers,” Czyz said. “Winning something like this tells me that I've become quite proficient at conveying my work to a wider audience in a clear and concise way. I remember my first poster presentation and my first conference talk, less than two years ago- I couldn't even watch the recording of that talk, it's so painful. This is something I'm going to be doing for the rest of my life, and it's a wonderful thing to know that I've improved so much.”

— Jens Odegaard.