Carbon monoxide formation in UO2 kerneled HTR fuel particles containing oxygen getters

Immobilization of inert TRISO-coated fuel in glass for geological disposal

“…SEM examination of the heat-treated TRISO-particle showed the absence of the OPyC layer (Fig. 3), confirming the complete oxidation to likely carbon monoxide CO [7]. EDS analysis of the particle surface showed that the SiC layer was little affected by the oxidation as indicated by presence of only traces of SiO 2 due to SiC oxidation.…”

“…Nevertheless, the SiC was prevented from rapid oxidation. All around the particles gas bubbles of CO [7] developed, thus increasing the mechanical stress at the glass/particle interface during cooling (Fig. 4(c)).…”

“…Up to today and over the last 30 years works on TRISO-fuel particles were conducted for fuel fabrication technologies, fuel testing and performance under irradiation conditions [1][2][3][4][5][6][7][8][9][10][11][12]. Hence, in Germany the fabrication process of the fuel is so strict that only about a 100 defects were found in 3.3 million particles produced [11].…”

Performance modeling of Deep Burn TRISO fuel using ZrC as a load-bearing layer and an oxygen getter

“…It also thermally decomposes significantly starting at $1700°C by transformation from b-SiC to a-SiC [15], resulting in a loss of integrity.…”

Alternative configurations for the QUADRISO fuel design concept

“…Another important material aspect is the oxygen diffusion into the carbon layer, and the carbon diffusion in the oxide layer, both leading to the formation of carbon monoxide (CO) and Carbon dioxide (CO 2 ). This has been extensively researched for UO 2 kernels in ordinary TRISO particles, [11] The U.S. Government retains for itself, and others acting on its behalf, a paid-up nonexclusive, irrevocable worldwide license in said article to reproduce, prepare derivative works, distribute copies to the public, and perform publicly and display publicly, by or on behalf of the Government. easier if an intermediate valence state forms between Ln(III) and Ln(0).…”