TY - GEN
T1 - In situ measurement of the effect of LiOH on the stability of zircaloy 2 surface film in PWR water
AU - Saario, Timo
AU - Tähtinen, Seppo
N1 - HUO: YDINVOIMALAITOSMATERIAALIT
Project code: MET3018341
PY - 1993
Y1 - 1993
N2 - Surface films on the metals play a major role in corrosion assisted cracking. A new method called Contact Electric Resistance (CER) method has been recently developed for in situ measurement of the electric resistance of surface films in high temperature and high pressure environments. The technique has been used to determine in situ the electric resistance of films on metals when in contact with water and dissolved anions, during formation and destruction of oxides and hydrides and during electroplating of metals. Electric resistance data can be measured with a frequency of the order of one hertz, which makes it possible to investigate in situ the kinetics of surface film related processes which are dependent on the environment, temperature, pH and electrochemical potential. This paper presents the results of the CER investigation on the effects of LiOH on the stability of Zircaloy-2 surface film in water with 2000 ppm H3BO3. At 300°C the LiOH concentrations higher than 10-2 M (roughly 70 ppm of Li+) were found to markedly reduce the electric resistance of the Zircaloy-2 surface film during a test period of less than two hours. The decrease of the film resistance is very abrupt, possibly indicating a phase transformation. Moreover, the advantages of the CER technique over the other competing techniques which rely on the measurement of current are discussed.
AB - Surface films on the metals play a major role in corrosion assisted cracking. A new method called Contact Electric Resistance (CER) method has been recently developed for in situ measurement of the electric resistance of surface films in high temperature and high pressure environments. The technique has been used to determine in situ the electric resistance of films on metals when in contact with water and dissolved anions, during formation and destruction of oxides and hydrides and during electroplating of metals. Electric resistance data can be measured with a frequency of the order of one hertz, which makes it possible to investigate in situ the kinetics of surface film related processes which are dependent on the environment, temperature, pH and electrochemical potential. This paper presents the results of the CER investigation on the effects of LiOH on the stability of Zircaloy-2 surface film in water with 2000 ppm H3BO3. At 300°C the LiOH concentrations higher than 10-2 M (roughly 70 ppm of Li+) were found to markedly reduce the electric resistance of the Zircaloy-2 surface film during a test period of less than two hours. The decrease of the film resistance is very abrupt, possibly indicating a phase transformation. Moreover, the advantages of the CER technique over the other competing techniques which rely on the measurement of current are discussed.
M3 - Conference article in proceedings
T3 - IAEA Technical Documents
SP - 207
EP - 226
BT - Influence of water chemistry on fuel cladding behaviour
PB - International Atomic Energy Agency IAEA
CY - Vienna
T2 - IAEA Technical Committee Meeting on Influence of Water Chemistry on Fuel Cladding Behaviour
Y2 - 4 October 1993 through 8 October 1993
ER -