Effect of oxygen and nitrogen impurities on the thermodynamic properties of uranium-plutonium mixed carbide fuel

Theoretical study of actinide monocarbides (ThC, UC, PuC, and AmC)

“…5 The main advantage of the carbide fuels compared with the widely used UO 2 and MOX (mixed U-Pu oxide) fuels is their higher heavy metal density, higher thermal conductivity, 6 and thus higher breeding gain and smaller plutonium inventory. 7 Currently only one reactor, the Indian fast breeder test reactor is operated with a (mixed U-Pu) carbide fuel. For safe application, additional extensive research elucidating all of the relevant properties of these potential fuels is required.…”

Experience on mixed carbide fuels with high ‘Pu’ content for Indian fast breeder reactor – An overview

“…The results of these studies have been summarized in Ref. [23][24][25][26]. These data were helpful to substantiate the compatibility experiments.…”

“…Pu 2 C 3 phase has lower carbon potential than that of U 2 C 3 at all temperatures and with SS-316 up to 978 K [24]. Saibaba et al [25] carried out some theoretical calculation based on thermodynamic data of free energies of formation of PuC, PuO and Pu 2 C 3 and predicted that both 'C' potential and P CO pressure decreases with increase in 'Pu'. Hence MK I and II are less carburizing than 'U' rich fuel [26].…”

Plutonium and the Indian atomic energy programme

“…However, the measured carbon monoxide pressures indicated that they were too low to cause gas phase carburization. Besides these measurements, modeling activities were carried out to provide a thorough understanding of the chemistry of the carbide fuel and its thermochemical behaviour [8,9]. Loss of plutonium by volatilization during the fabrication of the carbide fuel by carbothermic reduction route and the final oxygen content of the fuel are highly dependent on the equilibrium pressures of CO, U(g) and Pu(g) over the Mark-I and Mark-II fuel compositions.…”