Melting behavior of MgO-based inert matrix fuels containing (Pu,Am)O2−x

The melting behavior of MgO-based inert matrix fuels containing (Pu,Am)O2−x ((Pu,Am)O2−x–MgO fuels) was experimentally investigated. Heat-treatment tests were carried out at 2173 K, 2373 K and 2573 K each. The fuel melted at about 2573 K in the eutectic reaction of the Pu–Am–Mg–O system. The (Pu,Am)O2−x grains, MgO grains and pores grew with increasing temperature. In addition, Am-rich oxide phases were formed in the (Pu,Am)O2−x phase by heat-treatment at high temperatures. The melting behavior was compared with behaviors of PuO2−x–MgO and AmO2−x–MgO fuels.