Cutting edge research on replacing toxic radiation materials is underway by NC State’s nuclear engineering researchers – Miss Cao, graduate student (top left), Dr. Yang, assistant professor (top right), Dr. Bourham, professor of nuclear engineering (bottom left) & Mr. Moneghan, graduate student (bottom right).
In their recent article “Gamma radiation shielding properties of poly (methyl methacrylate)/ Bi2O3 composites”, published in Nuclear Engineering and Technology, they speak to –
“Advanced radiation shielding materials play[ing] a critical role in many applications, including nuclear medical imaging and therapy, nuclear waste storage, space exploration, and high-energy physics experiments. Unwanted exposure to ionizing radiation could be biologically hazardous to both humans and the environment, as it can lead to organ damage, cell mutation, component failure, and other harmful effects.
When photon type radiation, such as gamma rays, travel through matter, there are three major interactions that can occur: the photoelectric effect, Compton scattering, and pair production (for Eγ > 1.022 MeV). All these processes lead to a partial or complete energy transfer from photons to electrons. Materials with a high atomic number (Z) have a better gamma shielding ability than lower Z materials due to their higher interaction probability with photons. 
To mitigate or eliminate the influence of gamma radiation, lead, copper, stainless steel, and other high-Z materials [1] have historically been applied as shielding materials. However, these traditional shielding materials are costly, heavy, and often toxic to the environment. There is an increasing demand for developing new radiation shielding materials that can attenuate both gamma rays and neutrons whilst mitigating the disadvantages of traditional shielding materials.”
Drs. Yang and Bourham are faculty mentors to Mr. Cao and Moneghan. Dr. Yang’s research interests have revolved around the opportunities at the intersection of nuclear engineering, materials science and engineering and electrical engineering. Special emphasis is placed on developing new materials and devices for improving radiation detection and imaging technologies, which are widely needed in medical imaging, nonproliferation, nuclear security, industrial process monitoring, environmental safety survey and remediation, astronomical observation instrumentation and high energy physics R&D. Dr. Bourham’s research interests are in plasma-matter interaction, plasma propulsion and thrusters, fusion engineering, plasma surface modification, particle accelerators and electron beam irradiation systems, x-ray sources for medical and screening imaging, materials synthesis and coatings, shielding and radiation attenuation studies, nuclear and mixed waste disposal, dry casks and high-level waste packaging studies.
A related piece on this work is available here.
American Nuclear Society (ANS) SmartBrief article is available here.