Method and system for extending response time during a power plant blackout.

System for Extending Response Time to Nuclear Power Plant Blackouts Using Surplus Steam Self-Generation

This technology is a system that, during a Station Blackout (SBO) at a nuclear power plant, uses steam from the steam generator to drive a Turbine-Driven Pump (TDP) module to supply auxiliary feedwater, while simultaneously using a generator connected to the same turbine to charge a DC module battery, thereby providing power to control valves and other components.

In scenarios like the Fukushima accident, where earthquakes and tsunamis damage a plant's power and cooling systems, there is a risk of nuclear fuel melting and hydrogen explosions. During a sudden blackout, plants typically rely on batteries that last only about 8 hours, making it a critical challenge to secure additional response time to prevent major accidents caused by subsequent malfunctions.

This technology regulates feedwater flow to maintain the steam generator water level within the WR range of 76.8% to 90%, allowing surplus steam beyond what is needed for pump operation to be used for power generation. The electricity produced continuously charges the battery, extending the response time to approximately 20 hours if there is RCP seal leakage, and up to 32 hours if there is not. It can be applied to upgrading emergency auxiliary feedwater systems in pressurized water reactors and reinforcing the safety of aging plants, significantly increasing the time available to maintain core cooling until external power is restored.

‍

‍

Key Features:

• A power plant blackout response system including a steam generator and an auxiliary cooling water tower that supplies cooling water to the steam generator
• A TDP module including a turbine that generates energy from steam, a pump driven by the turbine to supply cooling water to the steam generator, and a generator connected to the turbine
• A DC module including a battery that is charged by electricity generated by the generator and supplies operating power to various components such as the plant's control valves
• A control configuration that supplies 70% of normal feedwater if the WR level is below 25% after an SBO occurs, and subsequently regulates the feedwater flow to maintain the WR level between 76.8% and 90%

‍