Chemical Interactions Between UO₂ and Zircaloy-4 from 1000 to 2000°C

Overview of high-temperature fuel behaviour with relevance to CANDU fuel

“…The UO 2 and Zr can interact chemically at temperatures as low as 1273 K, leading to a complex series of reaction layers [168] where, from both internal and external oxidation, the following reaction layers can be formed [168], and the AECL experiments were conducted at an overpressure of 1 MPa [169]. In the CANDU fuel design, the thin sheath will creep down onto the fuel under the conditions of the high pressure coolant.…”

Overview of experimental programs on core melt progression and fission product release behaviour

“…2) [93][94][95][96][97][98][99][100][101]. For instance, $45% of the fuel in the TMI-2 core was liquefied in the accident [102], while smaller amounts were observed in the integral tests including 15-18% in the four PBF SFD tests and 15% in the LOFT FP-2 test [42].…”

New modelling of the U–O–Zr phase diagram in the hyper-stoichiometric region and consequences for the fuel rod liquefaction in oxidising conditions

“…These melts may have more likely their origin in an incomplete oxidation of the cladding before the high temperature phase of the VERCORS tests in spite of the oxidation plateau performed at 1770 K or in a solid state interaction between UO 2 and Zr during the oxidation plateau. Concerning the latter phenomenon, Dienst et al [47] experimentally showed that the reduction of uranium dioxide by zirconium occurred in case of contact between both solids. At 1773 K, they showed that this interaction decisively depends on the contact between both solids, what could explain why these mixtures may be present in VERCORS 5 (Fig.…”