In-pile electrochemical measurements were performed in order to investigate the effect of radiation on the electrochemical corrosion behaviour of AISI 304 and AISI 316. The tests have been carried under PWR primary water conditions i.e. a temperature of 300 °C, a pressure of 150 bar and small additions of lithium hydroxide and boric acid (2 ppmLi and 400 ppmB respectively). The corrosion potential was continuously monitored during the whole irradiation period. Polarization resistance measurements and electrochemical impedance spectroscopy were performed at regular intervals. Polarization curves were measured halfway through and at the end of each reactor cycle. The variables in the experiment were the flux level and the 2 materials (AISI 304 and AISI 316). The flux level is varied by putting the specimens at different positions in the irradiation rig. Two platinum high temperature reference electrodes and two Yttrium Stabilized Zirconia (YSZ) electrodes were used to measure the corrosion potentials in and out of the neutron flux. Special connectors (electrical feed-through) were used to electrically insulate the specimens from the rig structure. The first results showed that the influence of radiation on the corrosion potential is small. However, the impedance data showed a difference between the in-flux and out-of-flux specimens. Based on the general shape of the Nyquist diagram the in-flux impedance is larger and the electrochemical reactions are (slightly) different as compared to the out-of-flux impedance.
|Title of host publication||In-pile electrochemical measurements on AISI 304 and AISI 306 under PWR conditions: the first results|
|Place of Publication||Lisbon, Portugal|
|State||Published - 6 Sep 2005|
|Event||EUROCORR 2005 - University of Lisbon, Lisbon|
Duration: 4 Sep 2005 → 8 Sep 2005
|Period||2005-09-04 → 2005-09-08|