Development of a method to lower recontamination after chemical decontamination by depositing Pt nano particles: (I) Consideration of the suppression mechanism using a quantum dynamics calculation

The Pt coating (Pt-C) process has been developed to lower the recontamination by radioactive elements after chemical decontamination of piping surfaces. In this process, a layer of fine Pt nano particles is formed in an aqueous solution on the base metal of the piping following the chemical decontamination. In this study, we confirmed that the suppression effect by the Pt-C toward 60Co deposition on type 316 stainless steel using a 60Co deposition test under hydrogen water chemistry. Furthermore, we investigated the suppression mechanism of deposition of radioactive elements by a quantum molecular simulation. The deposition amounts of 60Co which were incorporated in oxides after 1000 h with and without the Pt-C process were about 90 and 10.2 Bq/cm2, respectively. The amount of 60Co deposition with Pt-C is about 10% that of non-coated specimens. The 60Co incorporation for the Pt-C specimen was suppressed by decreasing the formation of oxides. We considered this phenomenon using a quantum dynamics calculati...