Nuclear waste tank and pipeline external leak detection systems

The development of two external waste tank and pipeline leak detection systems based on the electrical potential fields is reviewed. The Boeing system measured the distortion of an imposed ac potential field. The Battelle--Northwest system measured the change in the magnitude of the existing dc potential field generated by the cathodic protection system and the local electrochemical potential near the electrodes in the sediment. It was found that in a dry area the systems can detect as low as 200 liters of leakage. The engineering assistance to the tank farm management in assessing the suspected leakers is also presented.