The Melt Refining of Irradiated Uranium: Application to EBR-II Fast Reactor Fuel. VIII. The Behavior of Rare Earths, Yttrium, Barium, Strontium, and Cesium

Regulatory Technology Development Plan - Sodium Fast Reactor. Mechanistic Source Term - Metal Fuel Radionuclide Release

“…At 1200°C, the volatilization of cesium appears to depend on time at temperature and initial concentration. Subsequent operational experience at the FCF found that essentially complete cesium volatilization occurred during actual melt refining conditions, which were at slightly higher temperatures (~1400°C for 3 -4 hours) [6].…”

“…As Table 2-5 shows, very high retention of noble metals within the fuel matrix was observed. 1 Variation believed to be due to variation in initial charge (fuel) geometry [6]. The melt refining experiments conducted as part of EBR-II reprocessing raised questions regarding the chemical form of iodine when volatized from melted metal fuel.…”

Regulatory Technology Development Plan Sodium Fast Reactor. Mechanistic Source Term Development

“…While past experiments have investigated the release of rare earths from U-Fs alloy melt in a crucible [73], the presence of oxygen in the crucible caused the formation of rare earth oxides and is not indicative of metal fuel behavior during an accident. Cerium has a relatively low melting point (795 °C) but it increases when in solution with uranium [74].…”