Because of its national security mission—which includes manufacturing plutonium pits for nuclear weapons—Los Alamos National Laboratory produces a considerable amount of transuranic waste, including equipment and materials contaminated with radioactive elements. For the past 24 years, that solid waste has been packaged, shipped, and stored at the Waste Isolation Pilot Plant (WIPP) in southern New Mexico.
With an eye toward the future, Los Alamos scientists and engineers are considering ways to prevent overloading the waste repository. In 2022, a Los Alamos team developed a novel instrument for decontaminating transuranic waste. This new technology is safe, efficient, and generates low-level radioactive waste, which is cheaper to dispose of than transuranic waste and doesn’t require disposal at WIPP.
The Modular Electrochemical Nuclear Decontamination System (MENDS) is a self-contained, portable, and modifiable system for removing radioactive contamination from lab equipment and materials. The system relies on a decontamination solution that dissolves radioactive contamination bound to a surface and carries it away with the solution back to an internal reservoir. (If you’re picturing a carpet cleaner, that’s the right idea.)
MENDS recycles and reactivates the decontamination solution, allowing for a single decontamination cycle to continue using a small, fixed volume of solution. Depending on the configuration of the MENDS system, this volume can be even less than a pint.
However, MENDS doesn’t just reduce the amount of waste generated during decontamination; it’s also fast, effective, and reduces worker exposure compared to current decontamination methods. In fewer than 30 minutes, MENDS can decontaminate equipment and materials to low-level waste limits, allowing this waste to be disposed of like regular trash or lab equipment, thus dramatically reducing waste streams intended for WIPP.
Operating MENDS is very simple and requires only basic personal protective equipment, such as safety glasses, gloves, and coveralls. Once the system is activated, the solution turns bright orange, signaling the user to start the decontamination cycle. With custom components and attachments tailored for each application, users can set up the MENDS system and walk away while it runs. Instead of being stuck scrubbing a surface, users are free to accomplish other tasks while MENDS takes care of the cleaning. Once the MENDS cycle is complete, the small volume of contaminated solution is sent to a radioactive liquid waste treatment facility. The decontaminated equipment can then be safely disposed of as low-level waste.
MENDS technology dramatically increases the efficiency of decontamination, decreases generated waste, and increases worker safety by limiting radiation exposure during cleaning. “Our work is modernizing plutonium processing at Los Alamos, increasing the efficiency,” says scientist Rami Batrice of the Lab’s Biochemistry and Biotechnology group. “But most importantly—and at the heart of our research—is improving worker safety; our MENDS system reduces the need for direct handling of radioactive material, reducing the radioactive exposure experienced by the workforce.” ★