Tag Archives: nuclear waste

A New Organic Compound has Potential in Removing Nuclear Uranium Wastes

          On September 20, 2018, Mohammad Chaudhry, a Ph. D student at the University of British Columbia and his team of researchers have produced a new chemical compound known as an expanded campestarene. This new compound is a large, cyclic molecular structure that possesses the unique property of binding strongly to uranium ions. This can have real-world applications in the future as a tool to manage nuclear waste since the uranium by-product produced by nuclear reactors is a growing concern. Expanded campestarenes’ ability to strongly bind to uranium ions can be used to specifically remove dangerous, radioactive uranium waste.

The hollow cavity of expanded campestarene in the middle will hold the uranium ion.

The Campastarene Creation:

          The process for making such a compound is not an easy process. It requires a lot of trial and error, and an extensive knowledge of macrocycle chemistry, a subsection of chemistry. Despite being an expert on this subject, it still took Chaudhry a lengthy time to obtain enough of these molecules to call it a success. According to Chaudhry, “I basically went through the periodic table, and I went through a list of which elements would make sense to work in this type of reaction, and uranium was one I thought would work.” Overall, this process took about eight months.

          After selection of uranium ion, a reflux reaction was used to produce the compounds. A reflux reaction is simply heating a bunch of chemical compounds in order to input energy and make the reaction more likely to happen. “Basically, you mix it and you heat it and then you purify it, and that’s it,” says Mohammad.

          The following video contains the journey that Chaudhry and his colleagues have taken to create this molecule.

SO Project Group 5 Video” by Group 5 is licensed under YouTube.

The Uranium Situation and the Campastarene Solution

          The expanded campestarenes produced by Chaudhry’s team are very unique molecular compounds. The most notable property is its ability to bind strongly to uranium ions. The expanded campestarenes have an internal cavity that can specifically bind to uranium ions, forming a very stable complex. As a result, it is a useful uranium sequestering agent. Uranium sequestration describes the process of removing uranium ions from solution by strongly binding to it.

          This property can be extremely useful when it comes to managing uranium waste produced by nuclear reactors. With our increasing need for nuclear energy, more uranium waste is being produced. There are two types of uranium waste produced from these power plants: non-radioactive and radioactive uranium.  Radioactive uranium is dangerous to humans and the environment. It can damage one’s DNA, cells, tissues, and organs, and can also contaminate groundwater and soil, drastically impacting the environment. In addition, uranium waste is very difficult to get rid of because it takes hundreds-of-thousands of years to decompose naturally

          However, removing radioactive uranium is not as easy as it may seem. It is hard to differentiate the safe, non-radioactive uranium from the harmful, radioactive uranium. Therefore, by creating an expanded campestarene that can specifically bind to dangerous, radioactive uranium, it can be safely removed. This binding process is called chelation, where a molecule with specific structure allows it to target specific metal ions (like uranium).

         The following podcast by SCIE 300 Group talks about the daily-used chelating agents, such as chelating food additives and chelating agents in water purification. Also, the podcast contains an interview with Mohammad Chaudhry about the practical implication of expanded campestarene.

SCIE 300 SO Project Podcast” by Group 5 is licensed under YouTube

          Although uranium sequestration has practical applications, especially when it comes to nuclear waste, modifications to Chaudhry’s expanded campestarenes still need to be made before it can be used for practical use. “This experiment was mostly an academic curiosity,” Chaudhry says. However, Chaudhry’s discovery has set the foundation for future research on the topic of expanded campestarenes. Perhaps in the future, the specific binding nature of expanded campestarenes can be put to applicable use, especially in dealing with the radioactive uranium waste problem.

The Technical and Social Issues of Nuclear Waste

As nuclear generators around the world continue to produce large volumes of nuclear waste, scientists and engineers are scrambling to find a way to deal them. Dr. Ramana explores the various issues in handling nuclear waste in his paper.

One of the most iconic and unsettling images of Chernobyl 30 years later. Photo Credit: The Atlantic

In the process of creating nuclear power, uranium is put into high energy generators where the atoms are split through a process called fission. The resulting byproduct is an extremely hot and radioactive waste called spent fuel. Currently, the only existing solution is to dig deep holes and isolate this waste in what are called geological repositories. However, we have learned that these repositories themselves present a slew of issues.

This video discusses the technical issues of nuclear waste with UBC’s nuclear energy specialist: Dr. Ramana.

The first issue is that the waste remains radioactive for up to one million years. In order for the spent fuel to remain safely isolated, engineers have to construct a canister capable of containing the waste for the entire duration. Furthermore, as most metals are susceptible to rusting, the repository site must somehow remains dry for the entirety of the decay period.

Assuming that the aforementioned complications can be dealt with, the waste must then be transported from the nuclear generators to the repository. One can expect accidents to occur during this transportation period. In 2014, a drum exploded at the Waste Isolation Pilot Plan (WIPP) location in New Mexico. This incident was caused by a seemingly minor mistake, yet was one of the costliest accidents in U.S. history.

The next concern comes with selecting the actual location for the geological repository. Seeing how there are currently zero running geological repositories, the governments have had a 100% fail rate at convincing residents why they should want to live near a nuclear waste facility.

10,000’s people protest nuclear energy in Japan. Photo Credit: CNN

Dr. Ramana stated that the only effective solution to this nuclear waste problem is to phase out the usage of nuclear energy entirely. As mentioned in his paper, Will Rogers states, “If you find yourself in a hole, stop digging.”. Initially, nuclear energy was a means to reduce carbon emissions. However, it has become clear that this solution has created more issues than it solves.

“Electricity is but the fleeting byproduct from atomic reactors. The actual product is forever deadly radioactive waste.” – Kevin Kamps, Environmental activist

Even for the most brilliant scientists, designing an operational canister has been a fruitless endeavour. Dr. Ramana mentions during the podcast that the greatest misconception regarding nuclear waste is that people think they can just “wish away” this inherent, radioactive property of spent fuel. In B.C., more than 85% of our electricity is sourced from hydro-dams. In fact, we produce so much electricity that we export it to the states and rest of Canada.

Renewable energy trend and forecast. Photo credit: International Energy Agency

Rest assured, with hydro, solar and wind options becoming cheaper and more readily available, the global usage of renewable energy sources is on the rise. It may be possible that Dr. Ramana’s idea of a world without nuclear energy is something we may get to look forward to.

Written by: Julia Lee, Jerry Chen, Anna Han, James Wang