Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Plutonium's unusual interactions with clay may minimize leakage of nuclear waste

03.11.2011
As a first line of defense, steel barrels buried deep underground are designed to keep dangerous plutonium waste from seeping into the soil and surrounding bedrock, and, eventually, contaminating the groundwater.

But after several thousand years, those barrels will naturally begin to disintegrate due to corrosion. A team of scientists at Argonne National Lab (ANL) in Argonne, Ill., has determined what may happen to this toxic waste once its container disappears.

"We want to be sure that nuclides (like plutonium) stay where we put them," says Moritz Schmidt, an ANL post-doctoral researcher who will present his team's work at the AVS Symposium in Nashville, Tenn., held Oct. 30 – Nov. 4. Understanding how these radioactive molecules behave is "the only way we can make educated decisions about what is a sufficient nuclear waste repository and what is not," he adds.

Plutonium, with its half-life of 24 thousand years, is notoriously difficult to work with, and the result is that very little is known about the element's chemistry. Few labs around the world are equipped to handle its high radioactivity and toxicity, and its extremely complicated behavior around water makes modeling plutonium systems a formidable task.

Plutonium's extraordinary chemistry in water also means scientists cannot directly equate it with similar elements to tell them how plutonium will behave in the environment. Other ions tend to stick to the surface of clay as individual atoms. Plutonium, on the other hand, bunches into nanometer-sized clusters in water, and almost nothing is known about how these clusters interact with clay surfaces.

To better understand how this toxic substance might respond to its environment, the Argonne team examined the interactions between plutonium ions dissolved in water and a mineral called muscovite. This mineral is structurally similar to clay, which is often considered for use in waste repository sites around the world due to its strong affinity for plutonium. Using a range of X-ray scattering techniques, the scientists reconstructed images of thin layers of plutonium molecules sitting on the surface of a slab of muscovite.

What they found was "very interesting," Schmidt says. The Argonne scientists discovered that plutonium clusters adhere much more strongly to mineral surfaces than individual plutonium ions would be expected to. The result of this strong adherence is that plutonium tends to become trapped on the surface of the clay, a process which could help contain the spread of plutonium into the environment.

"In this respect, it's a rather positive effect" that his group has observed, Schmidt says; but, he adds, "it's hard to make a very general statement" about whether this would alter the rate of plutonium leaking out of its repository thousands of years from now.

Schmidt cautions that these are fundamental studies and probably will not have an immediate impact on the design of plutonium-containing structures; however, he stresses that this work shows the importance of studying plutonium's surface reactivity at a molecular level, with potential future benefits for nuclear waste containment strategies.

"This is a field that is only just emerging," Schmidt says.

The AVS 58th International Symposium & Exhibition will be held Oct. 30 – Nov. 4 at the Nashville Convention Center.

Presentation AC+TF-ThA-1, "Plutonium Sorption and Reactivity at the Solid/Water Interface," is at 2 p.m. on Thursday, Nov. 3.

USEFUL LINKS:

Main meeting website: http://www2.avs.org/symposium/AVS58/pages/greetings.html

Technical Program: http://www2.avs.org/symposium

Catherine Meyers | EurekAlert!
Further information:
http://www.aip.org

More articles from Physics and Astronomy:

nachricht When fluid flows almost as fast as light -- with quantum rotation
22.06.2018 | The Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Sciences

nachricht Thermal Radiation from Tiny Particles
22.06.2018 | Universität Greifswald

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Temperature-controlled fiber-optic light source with liquid core

In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.

Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...

Im Focus: Overdosing on Calcium

Nano crystals impact stem cell fate during bone formation

Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...

Im Focus: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

Graphene assembled film shows higher thermal conductivity than graphite film

22.06.2018 | Materials Sciences

Fast rising bedrock below West Antarctica reveals an extremely fluid Earth mantle

22.06.2018 | Earth Sciences

Zebrafish's near 360 degree UV-vision knocks stripes off Google Street View

22.06.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>