The third part of the“Advanced Nuclear Reactors and Power Systems” sessions during the 2020 ANS Virtual Winter Meeting featured an examination of the status of various advanced reactors. The sessions were sponsored by the Operations and Power Division and chaired by Piyush Sabharwall of Idaho National Laboratory.
Presentation topics in the third and final session included using Modelica for system-level modeling and simulation of advanced reactors; the testing of fast-spectrum reactors’ gears and bearings in liquid sodium; and the creation of a simple core analysis tool called the Thermal hydrAulic COre Calculations using the single heAted channel meThod (TACOCAT) code.
Here are some of the highlights:
Modeling and simulation: M. Scott Greenwood, of Oak Ridge National Laboratory, provided information about Transient Simulation Framework of Reconfigurable Models (TRANSFORM), an open-source Modelica-based library developed at ORNL. Modelica programming language is an object-oriented, declarative, multi-domain language for component-oriented modeling of complex systems.
TRANSFORM focuses on dynamic, system-level modeling that enables the rapid development of advanced energy systems (nuclear and otherwise) in a collaborative and adaptable framework. Being collaborative is a key concept for TRANSFORM, which Greenwood said is part of what he calls “an economy of modeling.”
“TRANSFORM-type solutions are not meant to be siloed,” he said. “They’re meant to be built and shared and distributed across a variety of applications.”
Some examples provided by Greenwood for projects that have leveraged TRANSFORM include the Transformational Challenge Reactor and the Eastman Chemical Company integrated energy system investigation.
Gear Test Assembly: Edward Kent, of Argonne National Laboratory, presented information on the Gear Test Assembly (GTA), an experimental apparatus designed to test mechanical components used in advanced fuel handling systems of liquid-sodium cooled fast-spectrum nuclear reactors.
The first GTA experimental campaign was completed in 2019 and operated around the clock until a drive shaft seized in the assembly. GTA operated at 250 oC for 19,600 cycles, equivalent to 9,800 fuel-assembly removal-and-insertion operations. A second experimental campaign was completed in 2020, but was interrupted by nearly two months due to COVID-19 shutdowns. Kent said that he intends to conduct a third experimental campaign in the future
Python code: Sierra Tutwiler, of Virginia Commonwealth University (VCU), completed the session with a presentation about TACOCAT, a python code, single-heated channel analysis tool under development at VCU. Tutwiler found that TACOCAT could be useful for preliminary design studies of advanced reactor concepts and for educational purposes in academia and research. In her presentation, TACOCAT was shown to work for a lunar fast reactor with a liquid metal or molten salt coolant.