Release of Fission Products from CANDU Fuel in Air, Steam and Argon Atmospheres at 1500 1900 C: The HCE3 Experiment

Abstract

Fission-product release from Zircaloy-sheathed segments of CANDU fuel was measured in the six HCE3 tests in argon, steam and air environments at peak temperatures between 1510 and 1930 degrees C. On-line y-spectrometry showed significant fractional releases for Xe, Kr, I, Cs, Te and Ru. Post-test deposition measurements also detected releases of Sn, Sb, Ag, Ba, Zr and Nb. The release rates of Kr, Xe, I and Cs were very low before complete sheath oxidation; their peak release rates in steam after complete sheath oxidation were not very temperature-dependent. Ru release was delayed by more than 2000 s after oxidative releases of the volatile fission products.