Thoughts on the Needed Focal Areas in the Research and Understanding of In-Reactor Corrosion, Hydrogen Absorption, and Hydrogen Migration in Zirconium Alloys

Author(s):  
Bruce F. Kammenzind
2020 ◽  
Vol 86 (8) ◽  
pp. 32-37
Author(s):  
V. V. Larionov ◽  
Xu Shupeng ◽  
V. N. Kudiyarov

Nickel films formed on the surface of zirconium alloys are often used to protect materials against hydrogen penetration. Hydrogen adsorption on nickel is faster since the latter actively interacts with hydrogen, oxidizes and forms a protective film. The goal of the study is to develop a method providing control of hydrogen absorption by nickel films during vacuum-magnetron sputtering and hydrogenation via measuring thermoEMF. Zirconium alloy E110 was saturated from the gas phase with hydrogen at a temperature of 350°C and a pressure of 2 atm. A specialized Rainbow Spectrum unit was used for coating. It is shown that a nickel film present on the surface significantly affects the hydrogen penetration into the alloy. A coating with a thickness of more than 2 μm deposited by magnetron sputtering on the surface of a zirconium alloy with 1% Nb, almost completely protects the alloy against hydrogen penetration. The magnitude of thermoemf depends on the hydrogen concentration in the zirconium alloy and film thickness. An analysis of the hysteresis width of the thermoEMF temperature loop and a method for determining the effective activation energy of the conductivity of a hydrogenated material coated with a nickel film are presented. The results of the study can be used in assessing the hydrogen concentration and, hence, corrosion protection of the material.


2006 ◽  
Vol 45 ◽  
pp. 1980-1985
Author(s):  
Kazuo Kakiuchi ◽  
Kazutoshi Okubo ◽  
Noboru Itagaki ◽  
Akihiro Miyazaki ◽  
Yoshiaki Ishii ◽  
...  

Latest post-irradiation experiment results of Zry-2 and HiFi alloy (0.4%Fe-Zry2) showed that iron addition reduces the hydrogen pickup by these alloys compared to oxidation amount. In order to clarify the mechanism of reduced hydrogen absorption rate, (1) autoclave test, (2) surface potential measurement and (3) hydrogen absorption test of the intermetallic compound were carried out. Based on these results, a tentative mechanism for hydrogen absorption by zirconium alloys is proposed, taking into account of both the electrical potential gradient over the oxide film as well as the SPP window for hydrogen absorption.


Author(s):  
Kittima Khumsa-Ang ◽  
Stephane Rousseau ◽  
Oksana Shiman

Abstract Canadian Nuclear Laboratories (CNL) has an on-going Research & Development programme to support the development of a scaled-down 300 MWe version of the Canadian Super-Critical Water Reactor (SCWR) concept. The 300 MWe and 170-channel reactor core concept uses low enriched uranium fuel and features a maximum cladding temperature of 500°C. Our goal is to test surfacemodified zirconium alloys for use as fuel cladding. Zirconium alloys are attractive as they offer low neutron cross section thereby allowing the use of low enriched fuel. In this paper, we report on the results of general corrosion experiments used to evaluate chromiumcoated zirconium-based alloys in the two chemistries (630 ug/kg O2 in both deaerated and lithiated supercritical water). These experiments were conducted in a refreshed autoclave at 500°C and 23.5 MPa. After exposure, the weight gain and the hydrogen absorption were examined. At adequate coating thickness, longitudinal and transverse coupons show similar corrosion behaviour with improved corrosion resistance compared to uncoated coupons. The measured concentrations of hydrogen absorption are higher for the transverse coupons. Alkaline treatment resulted in higher weight gains than was found in pure oxygenated supercritical water.


Author(s):  
K Kakiuchi ◽  
N Itagaki ◽  
T Furuya ◽  
A Miyazaki ◽  
Y Ishii ◽  
...  

2008 ◽  
Vol 70 (3-4) ◽  
pp. 149-162 ◽  
Author(s):  
M. Grosse ◽  
M. Steinbrueck ◽  
E. Lehmann ◽  
P. Vontobel

2005 ◽  
Vol 66 (2-4) ◽  
pp. 308-311 ◽  
Author(s):  
Kazuo Kakiuchi ◽  
Noboru Itagaki ◽  
Takemi Furuya ◽  
Akihiro Miyazaki ◽  
Yoshiaki Ishii ◽  
...  

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