I-Corps: Using waste heat generated by spent nuclear fuel (SNF) to dry wastewater sludge

Award ID: 2101320

The broader impact/commercial potential of this I-Corps project is the development of a system that uses waste heat generated by spent nuclear fuel (SNF) to dry biosolids, a byproduct of wastewater treatment. The technology may create a virtuous cycle whereby two currently existing sources of waste spent nuclear fuel and biosolids are associated to create a valuable product a sustainable biomass. An estimated $180,000 and 4,000 metric tons of carbon dioxide may be saved yearly per nuclear fuel/biosolids dryer compared to the alternative drying system which uses natural gas. The United States market, which has a total of 90 spent nuclear fuel (SNF) storage sites and 14,748 wastewater plants is a potential market since current SNF is not recycled. An initial analysis revealed 26 SNF storage sites situated within 10 miles of wastewater treatment plants. The proximity of the SNF storage sites and wastewater treatment plants will significantly reduce the transportation costs of the biosolids. This I-Corps project is based on the development of a system that uses waste heat generated by spent nuclear fuel (SNF) to dry biosolids, a byproduct of wastewater treatment. The system collects decay heat from nuclear fuel stored in concrete dry casks and connects existing nuclear waste storage technology with existing wastewater sludge drying technology. In existing dry casks, the nuclear fuel is sealed within steel canisters, which are then placed in a concrete overpack. The canisters are cooled by natural convection. Air enters the casks from the bottom, pulls heat from the canister, and exits from the top of the cask. The heated air is collected by the system and directed into a biosolid dryer. This approach avoids two main problems associated with the storage of nuclear waste: designing, licensing, and constructing completely new nuclear waste storage solutions, and transporting nuclear waste. This approach also provides a much-needed, year-round biosolid disposal service to wastewater treatment plants and creates a sustainable biomass from the biosolids. Additionally, this system is flexible and could be used in other applications requiring low-grade heating, such as landfill leachate treatment, carbon capture systems, and more. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

NSF Program Director: Ruth Shuman