Corrosion monitoring of high-level waste tanks

High-level nuclear wastes are currently being stored in carbon steel tanks at the Hanford Site. The wastes are stored in both single-shell tanks (SSTs) and double-shell tanks (DSTs). The SSTs have already exceeded their design life and some of these tanks have already leaked waste into the surrounding soil. The DSTs, on the other hand, were fabricated and put into operation more recently and have not been observed to show any leakage of wastes. One of the objectives at the Hanford Site is to monitor the degradation of the DSTs with the aid of in-tank corrosion probes. Outside the nuclear industry, electrochemical and resistance corrosion probes are in common use. The application of these probes to nuclear waste storage is generally complicated by the high radiation and complexed caustic environment. This paper deals with the details of a proposed development of commercial probes to monitor corrosion of the DSTs at the Hanford Site. Once the corrosion probes are successfully developed, the technology can be applied to SSTs and also transferred to other US Department of Energy (DOE) Sites