Hydrides and Embrittlement

Figure 1: High-resolution neutron radiographs of the duplex nuclear fuel cladding tubes (loaded with 200 wppm hydrogen) treated with various cooling rates (from Gong et al. [2]).

During operation in a nuclear reactor, zirconium based fuel cladding tubes take up a part of the hydrogen produced by the oxidation reaction between the reactor coolant water and the hot tube surface. The absorbed hydrogen, depending on concentration and temperature, in solid solution or as zirconium hydrides can be deleterious.

The high spatial resolution of the neutron imaging detectors at PSI combined with the high sensitivity of neutron imaging for hydrogen is instrumental for quantification of hydrogen concentration in nuclear fuel claddings (sub-10 μm spatial resolution and sub-10 wppm concentration resolution).

The current work focusses on the assessment of the nuclear fuel cladding tubes exposed in real conditions of Swiss nuclear power plants [1] (PhD project of Mr O. Yetik, PSI).

Examples of Publications

      1. Trtik P., Zubler R., Gong W., Grabherr R., Bertsch J., Duarte L.I., Rev. Sci. Instr. (2020)      2. Gong W., Trtik P., Colldeweih A.W., Duarte L.I., Grosse M., Lehmann E.H., Bertsch J., J. Nucl. Mater. (2019)
      3. Gong W., Trtik P., Valance S., Bertsch J., J. Nucl. Mater. (2018)


      - Nuclear Fuel Group, PSI, Switzerland

Associated Junior Researchers 

     Mr Okan Yetik, okan.yetik@psi.ch, +41 56 310 4534


     PSI CROSS – project 'NEUHERA'


     Dr. J. Bertsch, johannes.bertsch@psi.ch, +41 56 310 4173     Dr. L. Duarte, liliana.duarte@psi.ch, +41 56 310 2115     Assoc. Prof. Dr. P. Trtik, pavel.trtik@psi.ch, +41 56 310 5579