As it executes its national security mission, Los Alamos National Laboratory produces transuranic (TRU) radioactive waste — protective clothing, tools and equipment contaminated from nuclear weapons research and production. Handling, staging and shipping TRU waste offsite to the Waste Isolation Pilot Plant (WIPP) in southern New Mexico are all central to the Lab’s mission — and so too is mitigating hazards to workers, the public and the environment associated with these activities. To achieve that goal, Los Alamos has been looking at ways to reduce the amount of TRU waste. In 2022, Los Alamos scientists and engineers developed a new instrument for decontaminating TRU waste that is safe, efficient, and will divert waste streams away from WIPP. And that could just be the start of this promising technology.
The Los Alamos team developed Modular Electrochemical Nuclear Decontamination System (MENDS) — a self-contained, portable and modifiable system for removing radioactive contamination from lab equipment and materials. The system generates a decontamination solution that dissolves radioactive contamination bound to a surface and carries it away with a flowing solution back to an attached internal reservoir. The active agent in the decontamination solution is recycled by MENDS, which then reactivates the solution. This enables decontamination of waste materials to continue repeatedly using a small, fixed volume of solution. Depending on how MENDS is configured, this volume can be even less than a pint!
Not only does MENDS reduce the amount of waste generated during decontamination, it does so more quickly and more efficiently than current decontamination methods. In less than 30 minutes, MENDS can decontaminate equipment and materials to low-level waste limits. This reduces the risks associated with the waste and enables it to be shipped to offsite waste facilities other than WIPP.
Operating MENDS is a straightforward process and no scrubbing is required. Once activated, the solution turns bright orange, signaling that the decontamination cycle can begin. With custom components and attachments for a variety of applications, users can tailor the MENDS system to meet their specific needs. Once the cycle is complete, radioactive materials are captured in the solution reservoir. This solution — a small fraction of the once-contaminated equipment’s size — will be shipped as TRU waste to WIPP for disposal. The decontaminated equipment can then be safely disposed of as typical low-level waste.
MENDS technology dramatically increases 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 and achievable throughput,” 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 or eliminates the need for direct handling of radioactive material, drastically reducing the radioactive exposure experienced by the workforce.”
That’s good news for Los Alamos, but ancillary applications will soon have broader impacts across many facets of research and industry. One such way is using MENDS technology to recover rare earth elements from waste, such as fly ash from coal-fired power plants. Those recovered elements can then be used in components ranging from consumer electronics to the aerospace industry. MENDS can also be reconfigured to decontaminate tools and parts used in the nuclear industry by dunking equipment in what it is essentially a recirculating bath. After being soaked for a certain amount of time, the tools or parts can simply be rinsed with water to be rid of contamination.
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