Timothy R. McJunkin

Inspection of Used Fuel Dry Storage Casks

ABSTRACT The U.S. Nuclear Regulatory Commission (NRC) regulates the storage of used nuclear fuel, which is now and will be increasingly placed in dry storage systems. Since a final disposition pathway is not defined, the fuel is expected to be maintained in dry storage well beyond the time frame originally intended. Due to knowledge gaps regarding the viability of current dry storage systems for long term use, efforts are underway to acquire the technical knowledge and tools required to understand the issues and verify the integrity of the dry storage system components. This report summarizes the initial efforts performed by researchers at Idaho National Laboratory and Argonne National Laboratory to identify and evaluate approaches to in-situ inspection dry storage casks. This task is complicated by the design of the current storage systems that severely restrict access to the casks.

The Effects of Stress Mitigation on Nondestructive Examination

Ultrasonic volumetric and eddy current and visual profile surface inspections of the completed weld securing the outer lid of the Yucca Mountain waste package are required after stress mitigation. However, the technique implemented may affect the ability of the different evaluation techniques to properly characterize the completed weld. An evaluation was performed to determine the extent the nondestructive evaluation techniques are affected by two candidate mitigation processes: controlled plasticity burnishing and laser peening. This report describes the work performed and summarizes the results.