HTGR Knowledge Base

Conference Article: Post-irradiation heating tests of ZrC coated fuel particles

Abstract

Postirradiation heating tests of the ZrC-Triso coated UO₂ particles were performed at 1600 deg. C for 4500 h and at 1800 deg. C for 3000 h to study the release behavior of fission products. The burnup and irradiation temperature of the heated particles were 1.5%FIMA and 900 deg. C, respectively. During heating of the particles, the radioactivity in flowing helium was monitored with an ionization chamber to detect fission gas release. The radioactivity in graphite components of a cold-wall furnace was measured by y-ray spectrometry to identify and evaluate the released metallic fission products. The fission gas release monitoring and the X-ray microradiography revealed that no pressure vessel failure occurred during the tests. Diffusion coefficients of ¹³⁷Cs and ¹⁰⁶Ru in the ZrC coating layer were evaluated from the release curves based on a diffusion model. The ZrC-Triso coated fuel particles showed better cesium retention than the standard Triso-coated fuel particles. In spite of better cesium retention, the ZrC layer showed a less effective barrier to ruthenium than the SiC layer.

view the full text of this article (11 pages, format: PDF, size= 888kB)

Reference:

Technical committee meeting on high temperature gas cooled reactor technology development. Johannesburg (South Africa). 13-15 Nov 1996.

International Atomic Energy Agency, Vienna (Austria)

IAEA-TECDOC--988, pp:453-463