DES and CES Faculty receive $500,000 to improve treatment of radioactive wastewater

BATON ROUGE - In March of 2011, a 15-meter tsunami damaged the power supply at the Fukushima Daiichi nuclear power plant in Japan, triggering an accident that nuclear regulators eventually rated a seven, the highest level on the International Nuclear and Radiological Event Scale, created by the International Atomic Energy Agency.

During the crisis, workers used water to prevent the core meltdowns from progressing further, and, to this day, water is used to keep the reactors cool. While essential for safety, this process has generated more than a million tons of radioactive wastewater that must be stored and treated onsite before it can be released.

Nuclear accidents on this scale are highly unlikely. However, the storage of liquid radioactive waste and its associated hazards can create issues in many settings, and better treatment methods are needed. Yong-Ha Kim, an assistant professor in the Department of Environmental Sciences, or DES, has received a $500,000 grant from the Nuclear Regulatory Commission, or NRC, to investigate two new methods for treating radioactively contaminated water.  

DES Professor Ed Laws and Center for Energy Studies Professor Wei-Hsung Wang, director of Radiation Safety Office, will also work on the 3- year project, which will examine the feasibility of two novel methodologies: microalgae cultivation and capacitive deionization.

“Our ultimate goal is to better protect people and the environment from accidental radiation exposure,” Kim said. “By combining the two methods, we are developing a novel radionuclide separation system that can make radioactive water less radioactive. We are hoping that the radionuclide separation system can be used to better address safety issues of radioactive water.”

The methods the team is using take very different approaches to the treatment of the water. The first, microalgae cultivation, is a bioremediation strategy that involves using a variety of microalgae that can consume, or capture radioactive ions, such as strontium and cesium.

Capacitive deionization is a novel electrosorption process. Charged porous electrodes are used to capture radioactive ions from the solution. This method has also been used to desalinate water, implying it might work as well for treating radioactive wastewater. It also has the potential advantage of portability and scalability, as the process can be modularized.

Over the course of the grant, the team will treat radioactive water using both methods separately, and then attempt to combine them, in order to increase the treatment capacity and efficiency.

An effective process would not just be used to treat radioactive wastewater in the event of a nuclear spill or accident. It could also be used to facilitate decommissioning of nuclear facilities, in the management of liquid waste from medical facilities and research institutes, and even in treating wastewater produced by hydraulic fracking, which can become radioactive due to naturally occurring radioactive materials.

This is Kim’s second grant from the NRC. In 2022, he and Wang, along with faculty in the LSU College of Engineering and Center for Energy Studies, received $199,998 as a multidisciplinary scholarship grant to develop nuclear workforce for nuclear and nuclear-related industries.