Benchmark Problem for Calculating Oxygen Potential in High Burnup LWR Fuel using the THERMOCHIMICA Module in Moose/Bison

Acceleration of Thermochimica Calculations in Bison

“…Thermochimica is a software library that determines the equilibrium combination of phases and compositions of those phases given input temperature, pressure, and concentrations of chemical elements. Thermochimica and the development of Thermochimica as well as its integration into the MOOSE/Bison framework have been well-documented in previous technical reports [7,14,13,12], and journal articles [11,8,10,9], as well as in the Thermochimica documentation (available on GitHub).…”

“…The implementation of Thermochimica re-initialization in Bison builds upon previous efforts to couple Thermochimica calculations into the MOOSE framework [14,13,12]. In addition to the creation of new interfaces to accommodate re-initialization, the existing Thermochimica implementations were generalized and recast into the form of a UserObject during this work.…”

“…Previous coupling of Thermochimica to Bison has focused on calculations of the distribution and chemical potential of oxygen within the fluorite phase of uranium dioxide (UO 2±x ) nuclear fuel [14,13] for Light Water Reactor (LWR) applications. These example Bison calculations extend this work and demonstrate the reduction in simulation time for Bison objects that call Thermochimica when the re-initialization algorithm is employed.…”

Thermochemically-Informed Mass Transport Model for Zr in U-Zr Fuel

“…Thermochimica is a software library that determines the equilibrium combination of phases and compositions of those phases given input temperature, pressure, and concentrations of chemical elements. Thermochimica and the development of Thermochimica as well as its integration into the MOOSE/BISON framework have been well-documented in previous technical reports [29,39,38,37,40,34], and journal articles [33,30,32,31], as well as in the Thermochimica documentation (available on GitHub [26]).…”

“…The coupling of Thermochimica with BISON for Zr transport in metallic fuel builds upon previous efforts to couple Thermochimica calculations into the MOOSE framework [39,38,37,40,34], including the use of the re-initialization algorithm [34]. The classes implemented to complete this work also build on those implemented in those previous efforts.…”