Rutgers professor Ashutosh Goel invents way to contain radioactive iodine
How do you handle nuclear waste that will be radioactive for millions of years, keeping it from harming people and the environment?
It isn’t easy, but Rutgers researcher Ashutosh Goel has discovered ways to immobilize such waste – the offshoot of decades of nuclear weapons production – in glass and ceramics.
Goel, an assistant professor in the Department of Materials Science and Engineering, is the primary inventor of a new method to immobilize radioactive iodine in ceramics at room temperature. He’s also the principal investigator (PI) or co-PI for six glass-related research projects totaling $6.34 million in federal and private funding, with $3.335 million going to Rutgers.
“Glass is a perfect material for immobilizing the radioactive wastes with excellent chemical durability,” said Goel, who works in the School of Engineering. Developing ways to immobilize iodine-129, which is especially troublesome, is crucial for its safe storage and disposal in underground geological formations.
The half-life of iodine-129 is 15.7 million years, and it can disperse rapidly in air and water, according to the U.S. Environmental Protection Agency. If it’s released into the environment, iodine will linger for millions of years. Iodine targets the thyroid gland and can increase the chances of getting cancer.
Among Goel’s major funders is the U.S. Department of Energy (DOE), which oversees one of the world’s largest nuclear cleanups following 45 years of producing nuclear weapons. The national weapons complex once had 16 major facilities that covered vast swaths of Idaho, Nevada, South Carolina, Tennessee and Washington state, according to the DOE.
The agency says the Hanford site in southeastern Washington, which manufactured more than 20 million pieces of uranium metal fuel for nine nuclear reactors near the Columbia River, is its biggest cleanup challenge.
Hanford plants processed 110,000 tons of fuel from the reactors. Some 56 million gallons of radioactive waste – enough to fill more than 1 million bathtubs – went to 177 large underground tanks. As many as 67 tanks – more than one third – are thought to have leaked, the DOE says. The liquids have been pumped out of the 67 tanks, leaving mostly dried solids.
The Hanford cleanup mission commenced in 1989, and construction of a waste treatment plant for the liquid radioactive waste in tanks was launched a decade later and is more than three-fifths finished.
“What we’re talking about here is highly complex, multicomponent radioactive waste which contains almost everything in the periodic table,” Goel said. “What we’re focusing on is underground and has to be immobilized.”
Goel, a native of Punjab state in northern India, earned a doctorate in glasses and glass-ceramics from the University of Aveiro in Portugal in 2009 and was a postdoctoral researcher there. He worked as a “glass scientist” at the Pacific Northwest National Laboratory in 2011 and 2012, and then as a senior scientist at Sterlite Technologies Ltd. in India before joining the Rutgers faculty in January 2014.
The six projects he’s leading or co-leading are funded by the DOE Office of River Protection, National Science Foundation and Corning Inc., with collaborators from Washington State University, University of North Texas and Pacific Northwest National Laboratory.
One of his inventions involves mass producing chemically durable apatite minerals, or glasses, to immobilize iodine without using high temperatures. A second innovation deploys synthesizing apatite minerals from silver iodide particles. He’s also studying how to immobilize sodium and alumina in high-level radioactive waste in borosilicate glasses that resist crystallization.
At the Hanford site, creating glass with radioactive waste is expected to start in around 2022 or 2023, Goel said, and “the implications of our research will be much more visible by that time.”
“It depends on its composition, how complex it is and what it contains,” Goel said. “If we know the chemical composition of the nuclear waste coming out from those plants, we can definitely work on it.”
As hazard warnings increase, experts urge better decisions on who and when to warn
A group of risk experts is proposing a new framework and research agenda that they believe will support the most effective public warnings when a hurricane, wildfire, toxic chemical spill or any other environmental hazard threatens safety. Effective warnings are a growing need as expanding global populations confront a wide range of hazards.
Right now, “the potential for errors is high” when officials decide when to issue emergency warnings, who to send them to, and what safety measures to urge the public to take, says Thomas Cova, a professor in the University of Utah geography department.
That’s because “researchers tend to focus on one or two of those questions,” Cova says. “But it’s a challenge to think about all three,” which is necessary to avoid such errors as deciding the right time and right action but wrong target group or the right group and right time but wrong protective action, he adds. Emergency managers must contend with uncertainty about how the three components interact, and have to consider how likely and how costly it might be to make “false positive” decisions to issue a warning when hazards don’t occur or “false negative” decisions to continue normally when hazards do occur.
Cova and colleagues have published a paper called “Warning triggers in environmental hazards: Who should be warned to do what and when?” that proposes a way forward in improving emergency warning by thinking constructively and critically about all three issues. The paper, published in the online version of Risk Analysis, a publication of the Society for Risk Analysis, was co-authored by Cova with colleagues Philip E. Dennison, Dapeng Li, and Frank Drews, also of University of Utah, as well as Laura K. Siebeneck of University of North Texas and Michael K. Lindell of University of Washington.
Essential to improving emergency warning practices is research into the most effective methods for alerting the public. But, currently, public warning researchers are each carving out little hazard niches (hurricanes, wildfires, hazmat), as well as single dimensions of the warning problem (timing them, delimiting risk zones, selecting protective actions). “The end result is that no one is taking on the big question of simultaneously asking: who should do what when?” Cova explains. The authors’ goal is to sound a “wake up call” that they hope will lead to an improved understanding of how warnings are formulated and implemented across hazards, which in turn could lead to improved training methods, warning system innovations, and synergy between researchers and practicing emergency managers. “We’re not proposing a new approach to warnings, we’re proposing a new approach to public warning research,” Cova says, but adds, “The results may have beneficial feedbacks into public warning improvements and innovations.”
Today’s guidance on emergency warnings is not optimal. In light of the many global environmental hazards, experts are developing new procedures to simplify the warning process, aiming to prevent casualties and increase transparency about the decision making process. Widely used “warning triggers” are a decision rule that links an environmental condition to “protective action recommendations” for a specified target group, helping answer the questions: “Who should take what action and when?” For example, fire occurrence is a common qualitative trigger condition, but a more specific indicator would be a flame front crossing a prominent ridgeline, river, or road toward a community. Rainfall rates and duration can serve to define a threshold value that, once exceeded, results in a warning for flooding or landslides. Triggers aid managers in deciding when to change from “wait and see” to “take immediate action,” thereby helping them stay ahead of the emergency’s advancing curve.
But, even though warning triggers are used often, little research has been done on how emergency managers set them or how effective they are when combined with integrated early warning systems, the authors write. In an overview of key warning trigger issues, the authors discuss the critical importance of an “unambiguous trigger condition” when deciding when to issue a warning, as well as methods for defining the condition, such as directly observed environmental cues or measurements from sensors. They also discuss issues pertaining to deciding which population to warn, including the use of “emergency planning zones” such as “everyone on Manhattan Island,” a physical feature, or “south of Central Park,” a built feature that includes apartment buildings and stores. And they review challenges of deciding on the most effective actions to recommend, such as evacuating or sheltering in place.
The problem of effective warnings “has dimensions that are geographic, temporal, cognitive, and perceptual, particularly in how the public might respond,” says Cova. “So it’s an ideal challenge for interdisciplinary research” that addresses all three of the key systems at work (natural, built, social) and their interactions across different types of hazards. Emergency managers simultaneously deal with who, what, and when issues every day, and therefore so should research to improve warnings, the authors suggest.
The University of North Texas (UNT), based in Denton, is a public institution of higher education and research committed to a wide array of sciences, engineering fields, liberal arts, fine arts, performing arts, humanities, public policy, and graduate professional education.
Ten colleges, two schools, an early admissions math and science academy for exceptional high-school-age students from across the state, and a library system comprise the university. Its research is driven by nearly 50 doctoral degree programs. During the 2012–2013 school year, the university had a budget of $870 million, of which $30 million was allocated for research. North Texas was founded as a nonsectarian, coeducational, private teachers college in 1890; and, as a collaborative development in response to enrollment growth and public demand, its trustees ceded control to the state in 1899. In 1901, North Texas was formally adopted by the State.
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Farmers can use fewer resources to grow food
With the world’s population exploding to well over 7 billion, feeding the human race is getting even more challenging. Increasing the yield from crops such as wheat, maize, rice and barley, is paramount to growing enough food.
In addition, crop production is now affected by stressors such as drought, climate change and the salinization of fields — presenting obstacles to our future food supply.
Researchers with Arizona State University’s School of Life Sciences, University of Arizona, University of North Texas and with the USDA/ARS Children’s Nutrition Research Center, Baylor College of Medicine, have discovered a way to enhance a plant’s tolerance to stress, which in turn improves how it uses water and nutrients from the soil. These improvements increase plant biomass and yield.
The study’s findings are published in the scientific journal Trends in Biotechnology.
Associate professor Roberto Gaxiola with ASU School of Life Sciences said this discovery could be instrumental in agriculture and food security by improving crop sustainability and performance.
“‘We have learned how to modify the expression of a gene that codes for a plant proton pump,” said Gaxiola, lead author of the study. “This gene helps to move photosynthates — or molecules made by photosynthesis in the leaves — to the places plants need them in order to grow better roots, fruits, young leaves and seeds. This gene is called type 1 H+-PPase and is found naturally in all plants.”
Current agricultural methods often overuse fertilizer, causing environmental problems by polluting water with phosphates and creating dead zones in oceans downstream. Over-fertilization can also cause plants to have small roots — something that was not anticipated when fertilizers were developed in the early 1900s.
By changing how effectively a plant uses water and nutrients, famers would be able to use fewer resources to grow their crops.
“Larger roots allow plants to more efficiently acquire both nutrients and water. We can optimize inputs while minimizing environmental impacts. This is advantageous for our environment and for all consumers,” said Gaxiola.
Altering the expression of this gene in rice, corn, barley, wheat, tomato, lettuce, cotton and finger millet caused better growth in roots and shoots, and also improve how the plants absorbed nutrients. These crops also saw improved water use and tolerance to salt. In finger millet, researchers also discovered an increase in antioxidants, but further studies would be needed to know whether this is the case with other crops as well.
An international team of scientists has developed what may be the first one-step process for making seamless carbon-based nanomaterials that possess superior thermal, electrical and mechanical properties in three dimensions.
The research holds potential for increased energy storage in high efficiency batteries and supercapacitors, increasing the efficiency of energy conversion in solar cells, for lightweight thermal coatings and more. The study is published today (Sept. 4) in the online journal Science Advances.
In early testing, a three-dimensional (3D) fiber-like supercapacitor made with the uninterrupted fibers of carbon nanotubes and graphene matched or bettered–by a factor of four–the reported record-high capacities for this type of device.
Used as a counter electrode in a dye-sensitized solar cell, the material enabled the cell to convert power with up to 6.8 percent efficiency and more than doubled the performance of an identical cell that instead used an expensive platinum wire counter electrode.