PNNL

Abstract

This work focuses on a method for detecting liquid water inside of dry cask storage systems (DCSSs). Ideally, the environment inside of a DCSS confinement is inert and free of water to prevent potential corrosion of used fuel cladding or other internal hardware. However, there is some uncertainty about the amount of residual water potentially left behind in a DCSS after drying processes. Considering the complex spatial and time-dependent temperature profiles in dry storage casks, water may be in liquid or gas phase depending on location inside of the cask and how long the cask has been in storage. This paper describes development of an ultrasonic technique for sensing liquid water inside of a Transnuclear TN-32 DCSS. This system is being used in a demonstration of the efficacy of dry storage of high burnup fuel in DCSSs in collaboration between the United States nuclear power industry and the United States Department of Energy.