System Modeling-Based Investigation of SMR Operations Using Variable T-avg Control for Cost-Effective Electricity Generation in a Grid

Given the importance of nuclear power as low carbon energy source, this study conducted techno-economic evaluation of flexible use (baseload as well as load-following) of small modular reactors (SMRs) in an electric grid. The load-following operation of SMR (SMART-100) was restricted to the use of variable T-avg control, a least disruptive and cost minimizing method of load follow control. A system model was developed to describe the reactivity feedback effects of coolant temperature variations due to electric demand-based turbine load changes. Using the system model, conservative output ranges and maximum ramp rates that allow load-following operation without violating axial offset limits were derived. Assuming the introduction of SMR in Jeju Island in South Korea, a semi-independent grid region, with highly dependency on fossil fuel energy and power imports along with significant renewable energy generation (15–20 %), as a test case, this study evaluated the economic contribution of SMR using LPM to minimize the grid electricity generation costs. The results indicate that in regions with a high penetration of renewable energy in their grid systems, flexible energy generation of SMR can make a significant contribution in reducing electricity generation cost and carbon emissions.