UO2/Zircaloy-4 chemical interactions from 1000 to 1700°C under isothermal and transient temperature conditions

Microstructure studies of interdiffusion behavior of U3Si2/Zircaloy-4 at 800 and 1000 °C

“…It has been shown in many out-of-pile and in-pile experiments that UO 2 fuel can be reduced by Zry-4 cladding at high temperatures under good solid state contact conditions to form oxygenstabilized -Zr(O) and metallic U [17][18][19]. Similar to the interaction between UO 2 and Zry-4 system, the solid state interaction between U 3 Si 2 and Zry-4 could lead to the formation of Zr-Si compounds and U.…”

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

“…The liquidus temperature was measured in agreement with the modeling of the U-O-Zr phase diagram as presented in [23]. By contrast, the solidus temperature values, in both studies, were found at an unexpected high temperature (about 2600 K) considering the experimental results of Hofmann and KerwinPeck [1] which put in evidence, at temperatures as low as 1423 K, the formation of a liquid phase resulting of a solid state interaction between UO 2 and Zry. The erroneous detections of the solidus temperature in [30,31] could be due to the heterogeneous nature of the interfacial reaction between UO 2 and Zry [33] which make difficult the visual detection of solidus by RLS or VPA.…”

“…This interaction was studied by Hofmann [1] in the temperature range 1273-1973 K and by Hayward [2][3][4][5], Olander [6][7][8][9][10] and Veshchunov [11] from 2273 to 2673 K. The UO 2 /Zry interaction reaction starts at T $ 1273 K when expansion of materials leads to a close contact between fuel and cladding. At T $ 2023 K, the cladding melts and at 2173 K, it forms eutectics according to the UO 2 -(a-Zr(O)) pseudo binary phase diagram [12].…”

Microstructural Changes of Fuel Claddings for Pressurized Water Reactors Fuel after Irradiation

“…At high burn-up conditions, fuel can come into contact with cladding due to fuel swelling, which results in a chemical interaction between the fuel and cladding (FCCI). There have been many studies on FCCI to investigate fuel rod behaviour [1][2][3] . Because Zr is thermodynamically reactive with oxygen, this chemical interaction leads to the oxidation of the inner surface of the cladding.…”