Nondestructive Evaluation of Concrete Radioactive Waste Tanks

Abstract

Partially or totally buried concrete hazardous-waste tanks pose a difficult problem when evaluation of their integrity and concrete quality is required. A visual survey is very limited, and destructive sampling is usually not practical because of poor access to the tank walls and the risk of spillage from the tank into the surrounding environment. This paper introduces several nondestructive testing (NDE) techniques to overcome the foregoing difficulties, including ultrasonic pulse velocity, impulse response, parallel seismic, and cross-hole sonic logging. These test methods are described, and their application is illustrated by case records from a tank evaluation program implemented at Los Alamos National Laboratory, New Mexico, to determine the residual life of 14 low-level nuclear waste tanks, most of which have been in service for more than 30 years.