[1L12-14] Hydrogen Isotope Behavior

[1L12] Effect of oxidation of co-existing metals in primary system on tritium permeation through Inconel 600 under high temperature, high pressure water environment

*Azusa Matsumoto¹, Yuji Hatano¹ (1. University of Toyama)

Keywords:tritium, tritium permeation, steam generator

T permeation through Inconel 600 under a high temperature, high pressure water environment was investigated by using two types of containers made of stainless steel 304 or Hastelloy divided into upstream and downstream chambers by an Inconel 600 sample disk. Tritiated water and light water were introduced into the upstream and downstream sides, respectively. The containers were heated at 280 ℃ for 14 to 70 hours, and the change in T concentration in the downstream water was measured. The permeation rate through Inconel 600 in the stainless steel container was significantly larger than that in the Hastelloy container. This difference was ascribed to the oxidation of inner wall of the stainless steel container and consequent generation of HT. The addition of O₂ gas in the upstream chamber resulted in reduction of the permeation rate probably due to oxidation of HT to HTO.