Nuclear fuel decay heat utilization system

Patent metadata

Field	Value
Publication number	US-2025292921-A1
Application number	US-202418967795-A
Country	US
Kind code	A1
Filing date	Dec 4, 2024
Priority date	Apr 22, 2021
Publication date	Sep 18, 2025
Grant date	—

Abstract

A nuclear fuel decay heat utilization system usable for space heating in one embodiment comprises a nuclear generation plant building housing a spent fuel pool containing submerged fuel assemblies which emit decay heat that heats the pool. Plural fluidly isolated but thermally coupled heat removal systems comprising pumped flow loops operate in tandem to absorb thermal energy from the heated pool water, and transfer the thermal energy through the systems in a cascading manner form one to the next to a final external heat sink outside the plant building from which the heat is rejected to the ambient environment. A programmable controller operably regulates the intake and flowrate of water from the heat sink into the heat removal systems and monitors ambient air temperature inside to building. The flowrate is regulated to maintain a preprogrammed building setpoint air temperature by increasing fuel pool water temperature to a maximum permissible limit.

First claim

What is claimed is:

1 . A nuclear fuel decay heat utilization system for space heating comprising:
a building; a fuel pool disposed in the building, the fuel pool containing pool water and a plurality of nuclear fuel assemblies submerged in the pool water which emit decay heat that heats the pool water; a first cooling system disposed in the building and comprising a first closed flow loop fluidly coupled to the fuel pool, the first cooling system configured to circulate the pool water through the first closed flow loop and a first heat exchanger fluidly disposed in the first closed flow loop; a second cooling system disposed in the building and comprising a second closed flow loop thermally coupled to the first closed flow loop through the first heat exchanger, the fuel second cooling system configured to circulate cooling water through the second closed flow loop and a second heat exchanger fluidly disposed in the second closed flow loop, and also circulate the cooling water through the first heat exchanger in which the cooling water absorbs heat from the heated pool water which cools the heated pool water and heats the cooling water; a third cooling system comprising an external heat sink located outside the building and a third flow loop thermally coupled to the second closed flow loop through the second heat exchanger, the third cooling system configured to circulate raw water from the heat sink through the second heat exchanger in which the raw water absorbs heat from the cooling water in the second closed flow loop which cools the cooling water and heats the raw water; the third cooling system further configured to circulate the heated raw water back to the external heat sink which rejects heat absorbed from the cooling water to the external heat sink; an air temperature sensor disposed in the building and configured to measure a real-time air temperature inside the building; a throttle valve fluidly interposed between the external heat sink and the second heat exchanger in the third flow loop, the throttle valve configured to regulate a flowrate of the raw circulated through third flow loop from the heat sink and the second heat exchanger; a programmable controller operably coupled to the throttle valve and the air temperature sensor, the controller configured to: monitor the real-time air temperature inside the building; compare the real-time air temperature to a preprogrammed building setpoint air temperature; and control the flowrate of the raw water to maintain the building setpoint air temperature.

2 . The system according to claim 1 , wherein the first and second closed flow loops each comprise a piping network extending throughout the building, the piping networks including at least some bare piping sections operable to radiate heat from the heated pool water and cooling water flowing in the first and second closed flow loops respectively which heats ambient air inside the building.

3 . The system according to claim 2 , wherein portions of the bare piping sections in the first and second closed flow loops comprise external fins configured to radiate heat to the ambient air inside the building for space heating.

4 . The system according to any one of claims 1-3 , further comprising a fuel pool temperature sensor operably coupled to the controller and configured to measure a real-time pool water temperature, the controller configured to regulate the flowrate of raw water in the third flow loop via throttling the throttle valve when the pool water temperature to keep the pool water temperature below a preprogrammed maximum pool water setpoint temperature.

5 . The system according to claim 4 , wherein the maximum pool water setpoint temperature is 150 degrees F.

6 . The system according to claim 4 or 5 , wherein the controller is configured to prioritize maintaining the fuel pool temperature below the maximum pool water setpoint temperature over maintaining the building setpoint air temperature.

7 . The system according to claim 1 , wherein the system is configured such that as the throttle valve decreases the flowrate of the third liquid coolant extracted eternal from the external heat sink, the real-time air temperature inside the building increases.

8 . The system according to any one of claims 1-7 , wherein the external heat sink is selected from the group consisting of a river, a lake, a cooling pond, and the sea.

9 . The system according to any one of claims 1-7 , wherein the external heat sink is selected from the group consisting of a natural draft cooling tower, a mechanical draft cooling tower, and an air-cooled condenser.

10 . The system according to claim 1 , wherein the third flow loop is a closed flow loop which recirculates the raw water between the external heat sink, the external heat sink operable to received heated raw water discharged by the second heat exchanger, and return cooled raw water to the second heat exchanger.

11 . The system according to claim 1 , wherein the first closed flow loop and second closed flow loops are fluidly isolated from each other, and the second closed flow loop and third flow loop are fluidly isolated from each other.

12 . The system according to claim 1 , wherein the second cooling system is a component cooling water system, the second heat exchanger is a component cooling water heat exchanger, and the cooling water is component cooling water which circulates through a plurality of auxiliary components fluidly disposed within the second closed flow loop and housed within the building.

13 . The system according to claim 12 , wherein the component cooling water extracts heat from the auxiliary components which heats the component cooling water.

14 . The system according to claim 13 , wherein the component cooling water leaving the second heat exchanger has a temperature than the component cooling water entering the first heat exchanger, and the component cooling water has a higher temperature leaving the first heat exchanger than the component cooling water entering the first heat exchanger.

15 . The system according to claim 14 , wherein the component cooling water has a higher temperature entering the second heat exchanger than the component cooling water leaving the second heat exchanger.

16 . The system according to claim 1 , wherein the fuel assemblies are disposed in a plurality of fuel racks seated on a floor of the fuel pool and submerged in the pool water.

17 . The system according to claim 1 , wherein a maximum temperature of the pool water circulating through the first closed flow loop is higher than a maximum temperature of the cooling water circulating through the second closed flow loop, and the maximum temperature of the cooling water circulating through the second closed flow loop is higher than a maximum temperature of the raw water circulating through the third flow loop.

18 . The system according to any one of claims 1-17 , further comprising a flow meter configured to measure the flowrate of the raw water circulating in the third flow loop, the flow meter operably coupled to the controller which monitors a change in the flowrate when the throttle valve is throttled between a fully open position and a fully closed position.

19 . The system according to any one of claims 1-18 , wherein the first heat exchanger is a spent fuel pool cooler and the second heat exchanger is a component cooling water heat exchanger.

20 . The system according to any one of claims 1-19 , wherein each of the first closed flow l

Assignees

• Holtec International

Inventors

• Singh Krishna P

Classifications

• G21D9/00

  Arrangements to provide heat for purposes other than conversion into power, e.g. for heating buildings · CPC title

• G21C19/07 Primary

  Storage racks; Storage pools · CPC title

• F24V99/00

  Subject matter not provided for in other main groups of this subclass · CPC title

• Y02E30/00

  Energy generation of nuclear origin · CPC title

• G21D3/001

  Computer implemented control · CPC title