The nuclear-energy storage integrated lead-based reactor with an autonomous load-following function includes a reactor core, a phase change energy storage device, and a thermal energy utilization device; the reactor core is configured for heating a coolant, and the thermal energy utilization device is configured for absorbing heat in the coolant; the phase change energy storage device is provided at an inlet side of the reactor core, and configured for exchanging heat with the coolant, and a phase change temperature of the phase change energy storage device is consistent with a preset inlet temperature of the reactor core. The nuclear-energy storage integrated lead-based reactor has a natural circulation flow rate that is not easy to oscillate and diverge, the fuel assembly does not have the risk of overheating and melting, and the structural components are not easy to suffer from thermal fatigue, and it has high safety performance.

The nuclear-energy storage integrated lead-based reactor with an autonomous load-following function includes a reactor core, a phase change energy storage device, and a thermal energy utilization device; the reactor core is configured for heating a coolant, and the thermal energy utilization device is configured for absorbing heat in the coolant; the phase change energy storage device is provided at an inlet side of the reactor core, and configured for exchanging heat with the coolant, and a phase change temperature of the phase change energy storage device is consistent with a preset inlet temperature of the reactor core. The nuclear-energy storage integrated lead-based reactor has a natural circulation flow rate that is not easy to oscillate and diverge, the fuel assembly does not have the risk of overheating and melting, and the structural components are not easy to suffer from thermal fatigue, and it has high safety performance.

Provided is a nuclear reactor unit that can reduce a temperature increase in a reactor core at the occurrence of an abnormality with a simple structure. Included are a reactor core having radioactive fuel and causing the radioactive fuel to cause a nuclear reaction and a nuclear reactor vessel housing the reactor core and hermetically sealing the reactor core. The nuclear reactor vessel includes an inner shroud covering the entire periphery of the reactor core and an outer shroud covering the entire periphery of the inner shroud. A first space formed by the outer shroud and the inner shroud is in a vacuum condition. The inner shroud includes a main body and a communicating part placed in part of the main body and communicating the first space to a second space, which is a space inside the inner shroud, when the reactor core reaches a threshold temperature or higher.