Microscopic Examination of Inner Containers from 3013-Container-Packages Storing Plutonium-Bearing Materials

Abstract The 3013-container-package consists of a convenience, inner, and outer container and is used for long-term storage of plutonium-bearing materials. A Destructive Examination (DE) protocol has been developed to examine the container package visually and with optical microscopy to determine if there are any corrosion conditions present that could result in the loss of the integrity of the container package. Through-wall penetration of the inner container is considered a potential problem since it could allow the leakage of corrosive gases into the outer container of the 3013-container package. Any corrosion of the outer container would be considered significant because it is the last barrier preventing potential release to the environment. In this work, an inner container lid was examined at the inner container closure weld region (ICCWR). This region was characterized to observe the extent of corrosion, specially localized corrosion features. To accomplish this, the ICCWR was imaged by a stereomicroscope, a Scanning Electron Microscopy (SEM), a Laser Confocal Microscopy (LCM) and a Wide-Angle 3D Measurement System (WAMS) to measure significant corrosion features including dimensions and depth. The results were used to determine if further characterizations to look at the subsurface are needed such as subsurface X-ray computed tomography (XCT) and Focus Ion Beam (FIB) 3D-tomography.