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Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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No impact from Savannah River radioactive wasps
The news is abuzz with recent news stories about four radioactive wasp nests found at the Department of Energy’s Savannah River Site in South Carolina. The site has been undergoing cleanup operations since the 1990s related to the production of plutonium and tritium for defense purposes during the Cold War. Cleanup activities are expected to continue into the 2060s.
M. J. Ades, K. L. Peddicord
Nuclear Science and Engineering | Volume 81 | Number 4 | August 1982 | Pages 563-569
Technical Note | doi.org/10.13182/NSE82-A21448
Articles are hosted by Taylor and Francis Online.
An analytical method is presented to estimate the effective thermal conductivity of sphere-pac fuel during restructuring. This method is based on a unit cell model in which a sintering model is used to describe the extent of restructuring occurring between the fuel particles. As a result of sintering, a “neck” is formed between the fuel spheres. The effective conductivity of the sphere-pac bed can then be evaluated in terms of restructuring, i.e., as a function of temperature and necking between the fuel spheres. The effects of other relevant parameters such as the gas pressure in the sphere-pac pin and fission gas release are also included in the model Furthermore, a thermal conductivity criterion is used to determine the matching conductivity boundary, which is defined as the outer radial boundary where fuel restructuring is completed. Fuel restructuring is of particular importance in sphere-pac fuel because of its controlling effect on the temperature distribution. By knowing the effective conductivity, the temperature distribution of the fuel, both in its initial configuration and during restructuring, can be determined. Using the model, the temperature distribution as well as the extent of restructuring can be calculated. This model can be incorporated into computer codes to predict the overall thermal and mechanical performance of sphere-pac fuel pins.