Thermotransport of Hydrogen in Zr-1.0Nb-1.0Sn-0.1Fe Alloy

Abstract

Hydrogen redistribution caused by thermotransport in the Zr-1.0Nb-1.0Sn-0.1Fe alloy under the temperature gradient which is likely to be encountered between nuclear fuel cladding and primary cooling water (300-340) was investigated. The heat of transport (Q*) of hydrogen was determined by using a steady state technique to evaluate the magnitude and direction of thermotransport of hydrogen in the alloy. The values of Q∗ were 23.1, 23.7 and 27.1 KJ/mol for the hydrogen concentration of 73.4, 75.8 and 94.3 ppm by weight respectively. In other words, hydrogen was transported from hot region to cold region and the value of Q∗ increased with increasing overall hydrogen concentration. The Zr-1.0Nb-1.0Sn-0.1Fe alloy had the smaller Q∗ value than that of Zircaloy-4 when compared with same overall hydrogen concentration. Thus, Zr-1.0Nb-1.0Sn-0.1Fe alloy has better resistance to the formation of hydride due to thermotransport than Zircaloy-4 does.