Production test IP-555-A sodium silicate as a corrosion inhibitor

Abstract

The objective of this test is to operate one of the 1706-KE single pass tubes using sodium silicate rather than sodium dichromate as the corrosion inhibitor and to monitor the radioisotope concentration in the effluent. Single pass tube tests carried out under Production Test IP-484-A have demonstrated that when sodium silicate is added to process water the concentrations of significant radioisotopes in the effluent are reduced by a factor of two. At the concentrations investigated., the use of sodium silicate as an additional additive to all Hanford process water would cost in the neighborhood of two million dollars per year. If, however, sodium silicate, an excellent corrosion inhibitor for certain applications, would also serve to replace sodium dichromate, it would provide the added benefits of eliminating Cr{sup 51} and hexavalent chromium from the effluent. While still not economically attractive, the use of sodium silicate would be less unpalatable.