Corrosion and Hydrogen Pickup – Volume I

Corrosion and hydrogen pickup (HPU) mechanisms of Zr alloys remain a top priority of the nuclear industry. Commercial Zr alloys have today adequate in-reactor corrosion properties. However, hydrogen in fuel components limits the fuel performance today during normal operation and accident conditions as well as during transport of spent fuel, as follows:

  • Loss of Coolant Accidents (LOCA)
  • Reactivity Initiated Accidents (RIA)
  • BWR Channel Distortion
  • PWR Fuel Assembly Distortion
  • Hydrogen Embrittlement / Hydride-induced Cracking
  • Seismic Events
  • Primary Hydriding & Secondary Degradation
  • Dry Cask Storage and Transportation

The HPU in Zr alloys can be reduced by decreasing the Hydrogen Pickup Fraction (HPUF) and/or the corrosion rate since it reduces the amount of hydrogen that can be picked up by the Zr alloy. The best would of course be, to both reduce the corrosion rate as well as the HPUF. The Study of Hydrogen Impacts in Zirconium Alloy Materials (SHIZAM) managed by Dr. Erik Mader has been formed within EPRI’s Fuel Reliability Program (FRP) to get a better understanding of how the hydrogen is absorbed in the Zirconium material and hydride consequences.

Despite more than 50 years of research, the corrosion and HPU mechanisms are still not clear. Improved understanding of the in-reactor oxidation and hydrogen pickup mechanisms are thus required. To shed light on these complicated mechanisms, A.N.T. International will publish a set of two reports (Vol. I and II) with the focus on explaining the very complicated corrosion and hydrogen pickup mechanisms in an understandable manner.


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Corrosion and Hydrogen Pickup – Volume II will be available soon!