After considering the heating mechanisms, casting issues, crucible design and issues related to the mass transport of americium, an ISM system was selected for melting the feedstock and casting fuel pins containing high vapor pressure actinides (americium). The finite element commercial software (FIDAP) was used to simulate the induction melting process and the casting process. Phase change is considered both in the heating and in the solidification process. Various factors and properties are studied, such as boundary conditions and initial conditions, output current, frequency of the current, main dimensions of the system, mold preheating temperature, heat transfer coefficient and mold material. As shown in simulated results, several conclusions can be drawn:
• The design of the system has great impact on the induction melting process. In order to obtain high heat efficiency, the coils group number can be designed as many as possible and the coils are located as near to the crucible as possible.
• The induction melting process is sensitive to the electrical factors and properties (Current density; frequency and output power). Through the control of these values we can control the melting process. The thermal properties of the feedstock and the crucible material are also important in the heating process.
• A direct IH has a much higher efficiency than an indirect IH. In order to form the “skull”, a low temperature and good thermal conductivity of the coolant is necessary.
• A VOF-Solidification process can be “divided” to a filling process and a solidification process and be studied respectively, especially for a case of low convective heat transfer coefficient value.
• A constant filling pressure is expected rather than a constant velocity in the casting process.
• Mold material, mold preheated temperature, inlet pressure, and heat transfer coefficient have relative large effects to the casting process.
Actinide alloys; Americium; Metal-base fuel; Metal castings; Metallurgical furnaces; Nuclear fuel rods; Transmutation (Chemistry)
Nuclear | Nuclear Engineering
Design and Analysis of a Process for Melt Casting Metallic Fuel Pins Incorporating Volatile Actinides.
Available at: https://digitalscholarship.unlv.edu/hrc_trp_fuels/16