| 摘要 |
<p>PURPOSE:To improve the corrosion prevention effect of a material so as to suppress the diffusion of radioactive materials to the outside of a plant by leading the NOX gas produced when nitric acid decomposition is performed in the plant to process equipment used in a highly corrosive environment in the plant. CONSTITUTION:A spent fuel assembly is dissolved in nitric acid after cutting. The nitric acid dissolving the fuel is sent to a primary decontamination process and separated into a U-Pu solution and high-level waste nitric acid solution containing most of fission products. The waste nitric acid solution is condensed by evaporation in a high-level waste solution condensing process to reduce the volume and waste solution discharge quantity is lowered by recovering nitric acid for long-period preservation. The NOX gas produced in the dissolving process is led to a high-level waste solution condensing apparatus after iodine is removed from the gas. Since the NOX gas preserved together with the waste solution reduces highly oxidized ones of the ions existing in the waste nitric acid solution and suppress a corrosion accelerating effect, corrosion of the waste solution condensing apparatus can be reduced. Moreover, since the NOX gas is recycled, the quantity of the processed gas to be discharged into air can be reduced.</p> |
