EPRI’s engagement with the nuclear industry on storage of used nuclear fuel dates back 40 years. Our Used Fuel & High-Level Waste Management program team recently achieved a significant milestone when the U.S. Nuclear Regulatory Commission (NRC) issued the transportation certificate supporting a long-term collaborative project with the U.S. Department of Energy (DOE) to research the storage and transportation of high burn-up fuel. This is an exciting project that holds great potential for the nuclear industry, and I’d like to review EPRI’s history with used fuel storage before I go into more detail about it.
In the early 1980s, EPRI tested a new solution for storing used nuclear fuel in dry cask storage systems, a technology originally developed in Germany. Through this technology, fuel is moved out of spent fuel pools where it has been stored and into large steel cylinders filled with an inert gas. The canister can then be moved to a concrete pad and stored until it’s ready to be moved to its final storage location.
The first demonstration of this technology was conducted with oversight from EPRI, the DOE, and Virginia Electric Power Company (later Dominion Energy). That first demonstration was successful, and this alternative storage method soon became widespread in the industry.
As time marched on, the nature of the fuel being stored changed. Operators were able to use more of the uranium in the fuel. This was a benefit because reactors could operate longer between refueling outages and use less fuel. Fuel in which more of the uranium has been used is known as high burnup fuel. That then raised the question, does loading a cask with high burnup fuel change anything? Is it still safe for storage and eventual transportation?
A 2013 DOE award enabled an EPRI-led team to conduct a demonstration project focused on the long-term characteristics and behaviors of high burnup fuel under real conditions in a full-scale dry storage system and its subsequent transportation. Other members of the project team include Orano TN, Dominion Energy, Framatome, Westinghouse fuels, and NAC International.
Dominion Energy’s North Anna Power Station agreed to host this project. An Orano TN-32B cask was loaded with high burnup fuel in November 2017. The specially prepared cask was equipped with a modified lid that was designed and built with penetrations allowing for the insertion of instrumentation to monitor the fuel as it sits in the cask. Since 2017, the cask has been stored with North Anna’s other storage casks and undergone hourly temperature measurements.
The recent receipt of the transportation certificate from the NRC will allow the cask’s shipment in the next phase of this demonstration project. The cask will be shipped using the Atlas railcar system, a 12-axle railcar developed by the DOE to transport shipments of used nuclear fuel safely and securely. The Atlas railcar received certification from the Association of American Railroads to operate on all major freight railroads in the United States earlier this year.
In 2027, the cask will be shipped to a fuel examination facility. At the facility, the cask will be opened, and the fuel will be visually examined to look for any degradation that may have occurred during loading and subsequent storage. The fuel will then be removed and further examined through both destructive and non-destructive examination.
The information gathered from this project, in conjunction with other testing and predictive models, will provide the complete technical bases for understanding the behavior of high burnup fuel during storage and transportation. It will also provide data required by aging management programs to ensure the safe, long-term storage of both low and high burnup used fuel.
Used nuclear fuel is stored at nuclear reactors across the globe. EPRI’s research in this area helps to ensure that it’s stored safely and cost-effectively. Click here to learn more about the research EPRI is conducting in used fuel and high-level waste management.