Corrosion of stainless steel under radiolysis in PWR simulating conditions

Full text of publication follows: Few data are available in the literature on the role of the water radiolysis on the corrosion of metallic reactor components in PWR operating conditions (300 C, 155 bar). The present approach uses a high energy proton beam to control the production of radiolytic species at a AISI 316L/water interface in a high temperature and high pressure (HP-HT) electrochemical cell working in the range [25 C, 1 bar] - [300 C, 90 bar]. The cell is designed to record the free potential of the AISI 316L/water interface mounted in line on the CEMHTI (CNRS-Orleans) cyclotron delivering the proton beam. The free potential evolution is compared before, during and after the proton irradiation. First results are reported where an aqueous solution (initially: [B] = 1000 ppm, [Li] = 2 ppm at 25 C, P(tot) = 1.5 bar of Ar/H2 4% i.e. [H2(aq)] = 4.7*10-5 mol.L-1) is used to model the PWR primary coolant circuit. The AISI 316L/water interfaces are irradiated between 25 C / 1.5 bar and 300 C / 90 bar with protons emerging at ∼22 MeV at the interface. The flux is varied by four orders of magnitude, from 107 to 1011 H+.cm-2.s-1. The free potential at the AISI 316L/water interfaces is highly dependent on temperature and/or pressure. For a given temperature and pressure, it evolves with the flux and the ageing of the AISI 316L/water interfaces