Radiolysis effect on oxide film of 316L stainless steel formed in PWR primary water under irradiation

M. Wang (1, 2) , S. Perrin (1) , C. Corbel (2) , D. Feron (1)

1 CEA-DES (ex-DEN) - CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire)
2 LSI - Laboratoire des Solides Irradiés

This work is focused on the corrosion behaviour of austenitic 316L stainless steel in PWR primary water under the influence of radiolysis. The present approach uses a high energy proton beam to control the production of radiolytic species at a 316L/PWR solution interface in a high temperature and high pressure electrochemical cell working in the range. Previous work showed that the corrosion potential of 316L stainless steel was enhanced by the radiolysis causing by high energy proton beam. A high similarity of electrochemical behaviour was also observed under electron beam.The electrochemical oxidative response of the 316L/PWR solution interface under radiolysis is related to the surface characterization analysis (SEM, XPS, Raman spectroscopy, NRA) on the oxide layers of 316L which are formed under or without irradiation. The radiolysis effect on the oxide film includes micron scale cavities which were observed in a highly irradiated oxide film. The observation of Fe$_2$O$_3$ hematite on the outer oxide film where cavities were formed is in accordance with the electrochemical oxidative response.

Keywords: radiolysis; electrochemistry; corrosion; PWR; internals; 316L

Domains: Nuclear Experiment [nucl-ex]; Nuclear Theory [nucl-th]

M. Wang, S. Perrin, C. Corbel, D. Feron. Radiolysis effect on oxide film of 316L stainless steel formed in PWR primary water under irradiation. NPC 2016 - Nuclear Plant Chemistry Conference - 11th specialist workshop on radiation chemistry and electrochemistry in the nuclear fuel cycle, Oct 2016, Brighton, United Kingdom. ⟨cea-02442342⟩