Autonomous self-powered system for removing thermal energy from pools of liquid heated by radioactive materials, and method of the same

A method of cooling a pool of liquid heated by radioactive materials comprising:

• flowing a working fluid having a boiling temperature that is less than a boiling temperature of the liquid of the pool through a closed-loop fluid circuit that, in accordance with the Rankine Cycle:
• (1) extracts thermal energy from the liquid of the pool into the working fluid;
• (2) converts a first portion of the extracted thermal energy into electrical energy that is used to power a hydraulic pump that forces flow of the working fluid through the closed-loop fluid circuit;
• and (3) transfers a second portion of the extracted thermal energy to a secondary fluid;
• wherein the radioactive materials are comprised of spent nuclear fuel immersed in the pool of liquid;
• wherein thermal energy is extracted from the liquid of the pool into the working fluid by an evaporative heat exchanger having a tube bundle comprising a plurality of heat exchange tubes at least partially immersed in the liquid in which an outside of the heat exchange tubes is in direct contact with the liquid of the pool;
• wherein the working fluid flows through the tubeside of the plurality heat exchange tubes inside the heat exchange tubes and operates to absorb heat from the pool of liquid, the working fluid inside the tubes being fluidly isolated from the liquid in the pool;
• wherein the second portion of the extracted thermal energy is transferred to air by an induced-flow air-cooled condenser;
• wherein the induced-flow air-cooled condenser comprises a housing defining a bottom cool air inlet, a top warmed air outlet at a top, and a blower disposed in the warm air outlet, the blower operably coupled to the air-cooled condenser to draw cool air vertically upwards through the housing from the bottom cool air inlet, over heat exchange tubes disposed in the housing below the blower, and discharge heated air through the top warmed air outlet of the housing, the working fluid being a tube-side fluid flowing vertically downwards through the heat exchange tubes of the air-cooled condenser, wherein the air flows in a first vertical direction from the bottom cool air inlet to the top warmed air outlet and the working fluid flows in a second vertical direction through the heat exchange tubes, the second vertical direction being opposite to the first vertical direction;
• wherein the working fluid in the air-cooled condenser flows in toroidal path via a horizontal working fluid inlet header comprising a first plurality of concentrically arranged toroidal tubes and a horizontal working fluid outlet header comprising a second plurality of concentrically arranged toroidal tubes, the inlet and outlet headers spaced vertically apart in the housing, the inlet and outlet headers fluidly coupled to closed-loop fluid circuit;
• wherein the heat exchange tubes of the air-cooled condenser are straight tubes each having a first end coupled to the horizontal working fluid inlet header and an opposite second end coupled to the horizontal working fluid outlet header, the heat exchange tubes each being vertically oriented and extending in a vertical direction between the horizontal working fluid inlet and outlet headers, and wherein the vapor phase of the working fluid enters the air-cooled condenser at an inlet and the liquid phase of the working fluid exits the air-cooled condenser at an outlet, wherein the inlet of the air-cooled condenser is located at a greater elevation than the outlet of the air-cooled condenser.