Drying of Spent Nuclear Fuel


Much of the spent nuclear fuel currently stored at DOE sites is stored underwater. These fuels now need to be prepared for long-term dry storage. Through funding provided by Lockheed Martin Idaho Technologies Co. (LMITCo.), the SiMM Lab is currently in the process of validating methods of drying some of the more fragile fuel assemblies. This project has been undertaken in anticipation of movement of these fuels to more permanent dry storage.


Two views of a mock ATR fuel element. ATR type fuels consist of aluminum-clad uranium plates in a frame (as shown). The mock version is solid aluminum, containing no radioactive material.

This research is being conducted under the direction of Rebecca Lords and Will Windes of the Spent Nuclear Fuel (SNF) Group of LMITCo., and we herein gratefully acknowledge their guidance and support.


A Tour of the Process


The two pieces of equipment central to this research are the drying station and the thermogravimetric analyzer (TGA).

The drying station is a vacuum and heating system. A stainless steel cylinder is connected to a vacuum pump and wrapped with three band heaters. The heaters and cylinder are wrapped in a layer of insulation. The entire system is monitored and controlled by a data acquisition and control system whose brain is a Macintosh Quadra 650 running LabVIEW interface control software.

The thermogravimetric analyzer is a dinosaur of the pre-DOS days of the early '80s that was resurrected from an Idaho National Engineering & Environmental Laboratory (INEEL) warehouse. While the computer controller/recorder connected to the TGA is ancient by computing standards, the system is a very accurate method of verifying levels of dryness obtained in the drying station.

In the picture on the left, a mock fuel element is coated with a mixture of aluminum oxide and clay soils like those found at the INEEL. This element is then placed in the drying station to be dried. Samples before and after drying are taken and fed into the TGA for analysis.


To get acquainted with those who inhabit the SiMM Lab, or learn about other projects under investigation in the laboratory, return to the SiMM Lab main page.

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For more information, questions, or comments: Drying Studies