A Comprehensive Review of High Burn-Up Structure Formation in UO: Mechanisms, Interactions, and Future Directions.

In the rim zone of UO nuclear fuel pellets, high burn-up and low temperatures drive changes in the microstructure, leading to the formation of high burn-up structures (HBS). This review focuses on the formation of HBS, beginning with a description of the two contentious mechanisms-recrystallization and polygonization-that are believed to be the primary controlling factors. We discuss experimental and simulation studies that support both mechanisms, emphasizing that although each mechanism can explain certain aspects of HBS formation, neither recrystallization nor polygonization alone is sufficient to fully explain the observed phenomena.

Facile synthesis of exfoliated vermiculite nanosheets as a thermal stabilizer in polyvinyl chloride resin.

Well-defined vermiculite (VMT) nanosheets have been exfoliated from mineral VMT by a water-assisted anion-exchange approach. The resultant VMT nanosheets are utilized as a thermal stabilizer in polyvinyl chloride (PVC) to resist dehydrochlorination of PVC. As expected, the color-blackening onset of PVC is delayed after incorporating VMT nanosheets, and the thermal stability improves with reducing the particle size of the VMT nanosheets.