An autonomous facility for storing spent nuclear fuel includes a building forming an enclosed interior space containing a water-filled spent fuel pool. The pool includes fuel racks containing spent fuel assemblies which heat the water via radioactive decay. A passive cooling system includes a submerged heat exchanger in the pool and an air cooled heat exchanger located in ambient air outside the building at a higher elevation than the pool heat exchanger. A heat transfer working fluid circulates in a closed flow loop between the heat exchangers via unpumped natural gravity driven flow to cool the fuel pool. The air cooled heat exchanger may be enclosed in a concrete reinforced silo adjoining the building for impact protection. The building may include a cask pit formed integrally with the pool to allow fuel assembles to be removed from a transport cask and loaded into the fuel rack underwater.

A cooling system to remove decay heat removal from a nuclear core of a nuclear reactor when the nuclear reactor cesses to operate due to unforeseen conditions such as, for example, loss of electrical power to pumps circulating the primary coolant in the nuclear reactor. The cooling has a conduit structure that defines a sealed closed circuit through which a cooling fluid circulates through natural convection. In some embodiments, the cooling system of the present disclosure is always functioning. That is, the cooling system continuously extracts heat from the nuclear core. In these embodiments, the cooling system does not need to be actuated in any way when the nuclear reactor shuts down unexpectedly. In other embodiments, the cooling system can be turned on automatically upon loss of electrical power.

A cooling system to remove decay heat removal from a nuclear core of a nuclear reactor when the nuclear reactor cesses to operate due to unforeseen conditions such as, for example, loss of electrical power to pumps circulating the primary coolant in the nuclear reactor. The cooling has a conduit structure that defines a sealed closed circuit through which a cooling fluid circulates through natural convection. In some embodiments, the cooling system of the present disclosure is always functioning. That is, the cooling system continuously extracts heat from the nuclear core. In these embodiments, the cooling system does not need to be actuated in any way when the nuclear reactor shuts down unexpectedly. In other embodiments, the cooling system can be turned on automatically upon loss of electrical power.

An emergency spent nuclear fuel pool cooling system that requires no external electrical power source and relies on the expansion of a cryogenic fluid through an evaporator/heat exchanger submerged within the spent fuel pool, to power various components used to cool the spent fuel pool and adjacent areas and provide makeup water to the spent fuel pool. Other than the evaporator/heat exchanger to which the cryogenic fluid is connected, the remaining components employed to cool the pool and the surrounding area and provide makeup water can be contained in a relatively small, readily transportable skid.

A residual heat removal ventilation system for spent fuel dry storage facility of nuclear power plant includes a natural ventilation apparatus and a forced ventilation apparatus, comprising a cold air intake chamber, a hot air removal chamber, a pipeline, a ventilation heat shield cylinder, a heat removal fan, and an air cooling equipment having certain connecting relationships and being correspondingly arranged in a storeroom, an operating room and a ventilation equipment room. The system doesn't require storing spent fuel in a pool storage manner. The safety of the spent fuel doesn't rely on power equipment, thus not only reducing routine maintenance, saving energy, but also has inherent safety. Furthermore, the system can be used to cool spent fuel storage canisters within spent fuel storage facility of pebble bed high temperature gas-cooled reactor nuclear power plant, and discharge residual heat of spent fuel storage canisters to the external environment.

A method for encapsulating a fuel rod or a fuel rod section in a container includes inserting the fuel rod or fuel rod section into the container. One of the ends of the container is connected to a purging-gas line. The container is dehydrated and purged by use of a purging gas. The ends of the container are connected to a bypass line in such a way that a closed gas circuit is produced and a hot gas is circulated in the gas circuit until the absolute moisture content reaches an end value at which the absolute moisture content no longer rises. The container is disconnected from the gas circuit and subsequently the container is closed in a fluid-tight manner at both ends.

An autonomous self-powered system for cooling radioactive materials comprising: a pool of liquid; a closed-loop fluid circuit comprising a working fluid having a boiling temperature that is less than a boiling temperature of the liquid of the pool, the closed-loop fluid circuit comprising, in operable fluid coupling, an evaporative heat exchanger at least partially immersed in the liquid of the pool, a turbogenerator, and a condenser; one or more forced flow units operably coupled to the closed-loop fluid circuit to induce flow of the working fluid through the closed-loop fluid circuit; and the closed-loop fluid circuit converting thermal energy extracted from the liquid of the pool into electrical energy in accordance with the Rankine Cycle, the electrical energy powering the one or more forced flow units.

An autonomous self-powered system for cooling radioactive materials comprising: a pool of liquid; a closed-loop fluid circuit comprising a working fluid having a boiling temperature that is less than a boiling temperature of the liquid of the pool, the closed-loop fluid circuit comprising, in operable fluid coupling, an evaporative heat exchanger at least partially immersed in the liquid of the pool, a turbogenerator, and a condenser; one or more forced flow units operably coupled to the closed-loop fluid circuit to induce flow of the working fluid through the closed-loop fluid circuit; and the closed-loop fluid circuit converting thermal energy extracted from the liquid of the pool into electrical energy in accordance with the Rankine Cycle, the electrical energy powering the one or more forced flow units.

Disclosed is a decay heat removal system for cooling the decay heat of a reactor core and the spent fuel. The decay heat removal system including: a first heat pipe which is placed in an upper plenum of the reactor vessel and arranged in upward and downward directions corresponding to a position of an insertion hole formed on a top of the nuclear fuel assemblies; a control rod drive mechanism which is connected to an upper portion of the first heat pipe and drives the first heat pipe to move up and down so that the first heat pipe can be selectively inserted in a control rod insertion hole of the reactor core arranged in the nuclear reactor vessel; and a second heat pipe which is coupled to and in close contact with a bottom surface of the reactor vessel and removes the decay heat generated in the reactor core.

Disclosed is a decay heat removal system for cooling the decay heat of a reactor core and the spent fuel. The decay heat removal system including: a first heat pipe which is placed in an upper plenum of the reactor vessel and arranged in upward and downward directions corresponding to a position of an insertion hole formed on a top of the nuclear fuel assemblies; a control rod drive mechanism which is connected to an upper portion of the first heat pipe and drives the first heat pipe to move up and down so that the first heat pipe can be selectively inserted in a control rod insertion hole of the reactor core arranged in the nuclear reactor vessel; and a second heat pipe which is coupled to and in close contact with a bottom surface of the reactor vessel and removes the decay heat generated in the reactor core.