The cause of aluminum material degradation inside spent nuclear fuel dry storage containers when exposed to heat for extended periods has been identified at the nano scale. A methodology to predict material performance changes decades into the future using only short-term high-temperature testing has also been presented, and it is reported that this will be applied to long-term safety evaluation and licensing procedures for domestic dry storage systems.

The research team conducted prolonged thermal aging experiments lasting up to 10,000 hours to analyze the material degradation mechanism, and on this basis derived a prediction method to calculate long-term property changes from short-term high-temperature test results.

Through this, the institute explained that it has identified the fundamental causes of mechanical property degradation such as material strength and ductility as thermal aging progresses.

Since dry storage containers must maintain stable performance over decades, technology to pre-evaluate material behavior over the entire actual operational period is essential.

The institute stated that this achievement can contribute to establishing licensing and safety evaluation standards for domestic spent nuclear fuel dry storage systems.

The research was conducted by Lee Jun-ho, senior researcher of the Nuclear Safety Research Division at the Korea Institute of Materials Science.