Transient analysis of nuclear power plant thermal energy storage and power cycle for future energy mix

Abstract

In 2017, South Korea announced the Renewable Energy 3020 plan. However, renewable energy is intermittent in nature, which can affect grid stability. This research predicted the demand and supply of electricity in 2030 based on the actual renewable energy generation data, and confirmed that the rapid ramp rate of exiting power generators is required due to the intermittency of renewable energy. Therefore, as a technical alternative to solve this problem, a thermal energy storage system (TES) integrated nuclear power plant is proposed. For the conceptual design and performance evaluation of the TES integrated nuclear power plant, the TES type, heat transfer and heat storage medium were first investigated, and qualitative evaluation recommended the use of two tanks TES and HITEC salt. Based on this, the performance of the TES power cycle was evaluated through the quantitative evaluation factor of round-trip efficiency, and it was confirmed that the performance of the S-$CO_2$ recompression cycle is satisfactory. The TES dedicated power cycle proposed in this research aims to reduce the burden on power generators and reduce $CO_2$ emissions by substituting LNG based power generation when rapid ramp-up is required. Therefore, a fast ramp-up capability is required for the proposed system and a transient analysis from break-even state to full power was performed to demonstrate the technical feasibility. As a result, full power can be reached within 20 minutes and this can potentially reduce 2360 tons of $CO_2$ emissions by replacing LNG power generation.