Furnace structure

Abstract

The present invention relates to a furnace structure having an upper compartment above a discharge tank compartment, wherein the upper compartment comprises a molten salt furnace (MSR) having a furnace vessel containing molten fuel salt, and a molten salt discharge system connected to the furnace vessel, and the discharge tank compartment comprises one or more discharge tanks communicating with the molten salt discharge system, and a buffer water tank surrounding the one or more discharge tanks, having an inner wall and an outer wall, and buffer water in the gap between the inner wall and the outer wall of the buffer water tank, wherein the first piping structure comprises a heat exchanger that defines a circuit for at least a portion of the buffer water and is in thermal contact with a storage water tank, and the storage water is in thermal contact with the environment, and the second piping structure comprises a heat exchanger that defines a circuit for at least a portion of the buffer water and is in thermal contact with the environment, and the seawater heat exchanger is in thermal contact with the buffer water and seawater.

Description

Technical Field

[0001] The present invention relates to a reactor structure for a small modular reactor (SMR) such as a molten salt reactor (MSR), the reactor structure comprising a system for cooling decay heat from a nuclear fission reaction. The reactor structure comprises a water tank for transferring heat in order to enable a fully passive decay heat removal system. The present invention further relates to a method of transferring heat from molten salt.

Background Art

[0002] A molten salt reactor (MSR) is based on the critical concentration of fissile material dissolved in a molten salt. The molten salt containing the fissile material is commonly referred to as the fuel salt or molten fuel salt. Research on MSRs was first carried out at Oak Ridge National Laboratory (ORNL) in the 1950s and 1960s, but has not yet been successfully commercialized. MSRs have several advantages over other reactor types, including those currently in commercial use. MSRs can breed fissile U-233 from thorium, can produce much lower levels of transuranic actinide waste than uranium / plutonium fuel reactors, can operate at high temperatures, can avoid the accumulation of volatile radioactive fission products in solid fuel rods, and can burn more fissile material than is possible in conventional reactors. Another particularly attractive feature of MSRs is that they can be operated at atmospheric or low pressure and are conventionally held in the form of salts that are strongly bound either as fluoride salts or chloride salts.

[0003] Much of the concern in reactor safety systems is focused on removing the heat generated from the decay of fission products, particularly in cases of loss-of-cooling accidents (LOCAs) that occur when a normally functioning cooling pump in a nuclear plant fails. These events can be caused by loss of external power (LOOP) or other reasons. Conventional light water reactors (LWRs) are second-generation types, with a small number being third-generation types. Second and third-generation types use active systems for cooling by residual heat removal heat exchangers. More advanced designs (third and third+ generations) rely heavily on passive safety systems, at least for a certain grace period, to allow time for active systems to become operational to remove large amounts of decay heat in the vast majority of nuclear power plants.

[0004] Molten salt reactors (MSRs), along with other advanced small modular reactors (SMRs) such as high-temperature gas-cooled reactors (HTGRs), are characterized as fourth-generation designs. These types of reactors are expected to rely indefinitely on passive and inherent safety features. Reactor vessel auxiliary cooling systems (RVACS) and direct reactor auxiliary cooling systems (DRACS) are examples of such relatively new safety systems. While RVACS and DRACS are particularly well-suited as cooling systems for SMRs, these systems are less attractive to conventional reactors where the requirements for heat removal can be orders of magnitude greater.

[0005] Non-Patent Document 1 discloses the heat removal process for the operation of the original Molten Salt Reactor Experiment (MSRE) from September 15, 1960. Non-Patent Document 1 discloses that heat is removed from the molten fuel salt after it has been discharged into multiple discharge tanks. It describes the use of 40 immersion bayonet coolers with boiling water as the coolant to remove heat as uniformly as possible throughout the tanks. Water cooling was chosen over gas, molten salt, or NaK due to its simplicity and relative independence from utility failures. However, direct immersion of water contained in the bayonet into the molten fuel salt poses a risk of sudden ejection of hot steam if the bayonet material (usually a metal alloy) breaks, as the molten fuel salt and water come into contact.

[0006] Patent Document 1 discloses a cooling system for removing decay heat from a high-temperature gas-cooled reactor (HTGR). The system aims to minimize parasitic heat loss during normal operation. Decay heat from the core is transferred to a water piping system in which water piping is air-cooled. The water piping is in thermal contact with a water storage tank via a water bath heat exchanger, and water is actively pumped through the water piping. A passive air-cooling system is used as the primary cooling system, with only the air-cooling device used during normal operation, and the water-cooled section of the system used in the event of an accident. Large-capacity passive cooling can be obtained in the event of an accident in a reactor, especially a high-temperature gas-cooled reactor, but the system also relies on active cooling to minimize parasitic heat loss during normal operation.

[0007] Patent Document 2 discloses a reactor vessel auxiliary cooling system (RVACS) for removing decay heat from MSR and for spent molten fuel salt. The cooling system comprises a conduit structure defining a sealed closed circuit through which a cooling gas or fluid circulates via natural convection. In some embodiments, the cooling system is always functioning so that the cooling system continuously extracts heat from the core. The heat is further transferred directly to the environment, such as the external environment, via heat transfer mediated, for example, by a large roof structure above the reactor building.

[0008] Patent Document 3 discloses a reactor cooling system for a reactor mounted on a ship at sea. A water storage tank is in fluid communication with the reactor vessel compartment. The tank may be periodically filled with seawater and provides a storage tank for cooling the reactor. This system is described as a passive cooling system for a floating nuclear power plant using seawater and has the advantage of improving the safety of the floating nuclear power plant by eliminating the uncertainty caused by pump equipment failure, because pumps are not required. The reactor is continuously cooled during operation. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Korean Published Patent No. 2009-0021722 [Patent Document 2] U.S. Patent Application Publication No. 2019 / 035510 [Patent Document 3] Korean Published Patent No. 2022-0106618 [Patent Document 4] U.S. Patent No. 8442182 [Patent Document 5] European Patent No. 3639279 [Non-patent literature]

[0010] [Non-Patent Document 1] ORNL-314 “MOLTEN-SALT REACTOR PROGRAM QUARTERLY PROGRESS REPORT” [Overview of the project] [Problems that the invention aims to solve]

[0011] The object of the present invention was to provide a cooling system for MSRs that enables a completely passive method of transferring decay heat from the molten fuel salts of the MSR.

[0012] A further object of the present invention was to provide a cooling system for an MSR disposed on an ocean structure with limited space.

Means for Solving the Problems

[0013] According to one aspect of the present invention, a furnace structure is provided that includes an upper compartment above the discharge tank compartment, The upper compartment · A molten salt reactor (MSR) including a furnace vessel containing molten fuel salt, · A molten salt discharge system connected to the furnace vessel, and The discharge tank compartment <� · One or more discharge tanks communicating with the molten salt discharge system, · A buffer water tank, which includes an inner wall and an outer wall and buffer water in a gap between the inner wall and the outer wall of the buffer water tank, and surrounds one or more discharge tanks, and [[ID=,26]]The first piping structure defines a circuit for at least a part of the buffer water and includes a heat exchanger in thermal contact with a storage water tank, and the storage water tank is at a level above the buffer water tank, and the storage water is in thermal contact with the environment, and / or The second piping structure defines a circuit for at least a part of the buffer water and includes a heat exchanger in thermal contact with the environment, and the heat exchanger is at a level above the buffer water tank, and / or [[ID=,32]] The seawater heat exchanger is in thermal contact with the buffer water and seawater, and the seawater heat exchanger is disposed below the sea surface outside the outer wall of the buffer water tank.

[0014] According to one aspect of the present invention, a furnace structure is provided that includes an upper compartment above the discharge tank compartment, The upper compartment · A molten salt reactor (MSR) including a furnace vessel containing molten fuel salt, · A molten salt discharge system connected to the furnace vessel, and​​ The discharge tank compartment · one or more discharge tanks communicating with the molten salt discharge system, · a tube system including an inner tube and an outer tube, the inner tube and the outer tube being joined, and the buffer water being located within the tube within the joined inner and outer tubes of the tube system and surrounding the one or more discharge tanks, comprises The first piping structure defines a circuit for at least a portion of the buffer water and includes a heat exchanger in thermal contact with the storage water tank, the storage water tank being at a level above the tube system, and the storage water being in thermal contact with the environment, and / or The second piping structure defines a circuit for at least a portion of the buffer water and includes a heat exchanger in thermal contact with the environment, the heat exchanger being at a level above the tube system, and / or The seawater heat exchanger is in thermal contact with the buffer water and seawater, and the seawater heat exchanger is disposed below the sea surface outside the outer wall of the tube system.

[0015] According to another aspect of the present invention, a method of transferring heat from molten salt is provided, the method comprising · supplying molten fuel salt to one or more discharge tanks for molten fuel salt, · surrounding the one or more discharge tanks for molten fuel salt with a buffer water tank, the buffer water tank containing buffer water in a gap between an inner wall and an outer wall of the buffer water tank, and the molten fuel salt transferring heat through at least one of thermal radiation, heat conduction, or thermal convection with the inner wall to heat the buffer water to steam, · providing a first piping structure, the first piping structure comprising at least one riser tube above at least a portion of the buffer water, the at least one riser tube collecting steam and guiding the steam to a heat exchanger in the storage water in a storage water tank above the buffer water tank to condense the steam into water, A descending pipe for guiding water from a heat exchanger in the water storage tank to a buffer water tank, It has steps, and / or The step of providing a second piping structure, wherein the second piping structure is At least one riser above at least a portion of the buffer water, the riser collects steam and leads the steam to a gas heat exchanger which is in thermal contact with a gas-containing environment, the gas heat exchanger is located above the buffer water tank and condenses the steam into water, At least one downpipe for guiding water from the gas heat exchanger to the buffer water tank, It has steps, and / or A step of providing a seawater heat exchanger that comes into thermal contact with buffer water, wherein the seawater heat exchanger is positioned below the seawater level outside the outer wall of the buffer water tank, and the buffer water circulates through the seawater heat exchanger. Includes.

[0016] (Detailed explanation) The reactor structure includes an upper compartment above the discharge tank compartment, The aforementioned upper compartment is, A molten salt reactor (MSR) having a furnace vessel containing molten fuel salt, • A molten fuel salt discharge system connected to the reactor vessel, Equipped with, The aforementioned discharge tank compartment is • One or more discharge tanks in communication with the molten fuel salt discharge system, A buffer water tank comprising an inner wall and an outer wall, with buffer water in the gap between the inner wall and the outer wall of the buffer water tank, and surrounding one or more discharge tanks, Equipped with, The first piping structure defines a circuit for at least a portion of the buffer water and includes a heat exchanger that is in thermal contact with the storage water tank, the storage water tank being at a level above the buffer water tank. and / or The second piping structure defines a circuit for at least a portion of the buffer water and includes a heat exchanger that is in thermal contact with the environment, the heat exchanger being located at a level above the buffer water tank.

[0017] The inventors have found that such a furnace structure has numerous advantages.

[0018] Most conventional reactor cooling systems are designed to cool the reactor itself. In the case of small modular reactors (SMRs), such as molten salt reactors (MSRs), the cooling system relies heavily on passive and inherent safety systems, such as directly cooling the reactor within a DRACS system or the reactor vessel within an RVACS system. In such systems, passive cooling is performed, for example, without pumps, and cooling continues while the reactor is operating. Therefore, in the above systems, the reactor is constantly being cooled, and parasitic heat loss occurs rather than the heat generated in the reactor being used for steam generation, etc.

[0019] The proposed reactor structure does not cool the reactor or reactor compartment during normal operation, thus avoiding parasitic heat loss even with a passive cooling system. Instead, after the molten fuel salt is discharged into the discharge tank, for example, during an emergency or planned maintenance operation, the decay heat is removed from the molten fuel salt.

[0020] The proposed reactor structure also addresses a specific accident event, the so-called "molten salt spill" scenario. This is a scenario in which a large amount of molten fuel salt is not contained in the reactor or discharge tank and may be accidentally caused during planned maintenance work or by extreme events such as an aircraft impact, projectile impact, or unusual hurricane. In such events, the majority of the spilled molten salt will eventually flow downwards into any structure and accumulate on the floor, etc. In the proposed reactor structure, the spilled molten fuel salt can be collected by a fuel salt catcher installed at the lowest point of the discharge tank compartment in the event of a leak. This allows the cooling system to operate within the discharge tank compartment, which is at the bottom of the reactor structure, enabling the cooling of the spilled molten fuel salt.

[0021] When cooling a reactor, especially when directly cooling the core with a coolant such as air or water, radiation exposure to the coolant is unavoidable, resulting in the handling of large amounts of contaminated coolant. The proposed system mitigates this drawback by cooling the molten fuel salt in an exhaust tank where nuclear fission does not occur, rather than the reactor itself. However, the decay process of the molten fuel salt also leads to radiation exposure and activation of the surroundings, although radiation levels decrease over time.

[0022] By providing buffer water around the discharge tank, an effective heat sink for decay heat is provided, which becomes operational immediately as the molten fuel salt begins to fill the discharge tank during the discharge of molten fuel salt from the furnace. The heat accumulation in the buffer water is further processed by at least one additional heat removal system, and as a result, the decay heat is transferred to a selected final heat sink or two types of final heat sinks operating in parallel. These transfers of heat to the final heat sinks are both passive heat transfers and are therefore very safe. Choosing buffer water (water) as the cooling medium results in a smaller volume for the cooling system compared to choosing air as the primary cooling medium.

[0023] Molten salt furnace (MSR) and molten salt Molten salt reactors (MSRs) are often based on achieving criticality using fissile material dissolved in molten salt. When an MSR uses fissile material dissolved in molten salt, this salt is called fuel salt (or molten fuel salt).

[0024] Nuclear fission typically produces energy neutrons in the energy range of 100 keV to 2 MeV. The probability of a fission event occurring depends on the neutron energy. In so-called fast reactors, unmoderated (fast) neutrons produced from fission events interact directly with other nuclei. Thermal and epithermal fission reactors, depending on a moderator, first reduce the energy of 100 keV to 2 MeV energy neutrons to thermal neutrons (kinetic energy at ambient temperature), typically said to be 0.025 eV. Such thermal neutrons have a high probability of inducing fission events in fissile material, such as U-235, a prominent example. In summary, fission reactors can therefore be operated by two different principles: fast reactors and thermal / epithermal reactors. In fast reactors, energy neutrons interact directly with fissile material to produce energy, fission products, and energy neutrons. In thermal and epithermal reactors, energy neutrons produced by nuclear fission exchange energy with moderators such as graphite, and ultimately interact with fissile material to produce energy, fission products, and higher-energy neutrons.

[0025] When using molten fuel salt, the fissile material is dissolved in a molten salt containing a carrier salt, and the carrier salt is preferably a fluoride-based salt or a chloride-based salt.

[0026] In one embodiment, the MSR includes a molten salt, which is a molten fuel salt circulating within channels or gaps in the graphite core.

[0027] Another type of reactor, also known as an MSR, is one in which the fuel is solid and a molten salt is used as a coolant to adapt to the temperature rise of the solid (pebble fuel, most frequently TRISO-type fuel). Patent document 4 describes such a reactor in which a molten salt is used as a coolant for pebble fuel immersed in a coolant.

[0028] Cooling salts are salts that do not contain fissile material.

[0029] In one embodiment, the MSR includes a molten salt, which is a molten fuel salt circulating inside and outside the reactor vessel, and the vessel includes pebbles of a solid moderator.

[0030] According to one aspect of the present invention, a furnace structure is provided which includes an upper compartment above the discharge tank compartment, The aforementioned upper compartment is, A molten salt reactor (MSR) having a furnace vessel containing molten fuel salt, • Molten salt discharge system connected to the furnace vessel, Equipped with, The aforementioned discharge tank compartment is • One or more discharge tanks connected to the molten salt discharge system, A buffer water tank that operates as a tube system comprising an inner tube and an outer tube, wherein the inner tube and the outer tube are joined together, and the buffer water is located within the tubes of the joined inner and outer tubes of the tube system, surrounding one or more discharge tanks, Equipped with, The first piping structure defines a circuit for at least a portion of the buffer water and includes a heat exchanger that is in thermal contact with a storage water tank, the storage water tank being at a level above the buffer water tank, and the storage water being in thermal contact with the environment. and / or The second piping structure defines a circuit for at least a portion of the buffer water and includes a heat exchanger that is in thermal contact with the environment, the heat exchanger being located at a level above the buffer water tank. and / or The seawater heat exchanger is in thermal contact with the buffer water and seawater, and the seawater heat exchanger is positioned below the seawater surface outside the outer wall of the buffer water tank.

[0031] According to one aspect of the present invention, a furnace structure is provided which includes an upper compartment above the discharge tank compartment, The aforementioned upper compartment is, A molten salt reactor (MSR) having a furnace vessel containing molten fuel salt, • Molten salt discharge system connected to the furnace vessel, Equipped with, The aforementioned discharge tank compartment is • One or more discharge tanks connected to the molten salt discharge system, A buffer water tank that operates as a tube system comprising an inner tube and an outer tube, wherein the inner tube and the outer tube are joined together, the buffer water is located within the tubes of the joined inner and outer tubes of the tube system, the buffer water tank surrounds one or more discharge tanks, and the joined inner and outer tubes of the tube system comprise a section where the buffer water evaporates, a section where the buffer water is insulated, and a section where the buffer water condenses. Equipped with, The first piping structure defines a circuit for at least a portion of the buffer water and includes a heat exchanger that is in thermal contact with a storage water tank, the storage water tank being at a level above the buffer water tank, and the storage water being in thermal contact with the environment. and / or The second piping structure defines a circuit for at least a portion of the buffer water and includes a heat exchanger that is in thermal contact with the environment, the heat exchanger being located at a level above the buffer water tank. and / or The seawater heat exchanger is in thermal contact with the buffer water and seawater, and the seawater heat exchanger is positioned below the seawater surface outside the outer wall of the buffer water tank.

[0032] According to one aspect of the present invention, a furnace structure is provided which includes an upper compartment above the discharge tank compartment, The aforementioned upper compartment is, A molten salt reactor (MSR) having a furnace vessel containing molten fuel salt, • Molten salt discharge system connected to the furnace vessel, Equipped with, The aforementioned discharge tank compartment is • One or more discharge tanks connected to the molten salt discharge system, A buffer water tank that operates as a tube system comprising an inner tube and an outer tube, wherein the inner tube and the outer tube are joined together, the buffer water is located within the tubes of the joined inner and outer tubes of the tube system, the buffer water tank surrounds one or more discharge tanks, and the joined inner and outer tubes of the tube system comprise a section where the buffer water evaporates, a section where the buffer water is insulated, and a section where the buffer water condenses. Equipped with, The seawater heat exchanger is in thermal contact with buffer water and seawater, and is located in a rectangular or cylindrical recess, preferably a sea chest, below the seawater surface outside the outer wall of the buffer water tank.

[0033] In one embodiment, the furnace structure includes an upper compartment above the discharge tank compartment, The aforementioned upper compartment is, A molten salt reactor (MSR) having a furnace vessel containing molten fuel salt, • Molten salt discharge system connected to the furnace vessel, Equipped with, The aforementioned discharge tank compartment is • One or more discharge tanks connected to the molten salt discharge system, A buffer water tank comprising an inner wall and an outer wall, with buffer water in the gap between the inner wall and the outer wall of the buffer water tank, and surrounding one or more discharge tanks, Equipped with, The first piping structure defines a circuit for at least a portion of the buffer water and includes a heat exchanger that is in thermal contact with a storage water tank, the storage water tank being at a level above the buffer water tank, and the storage water being in thermal contact with the environment. and / or The second piping structure defines a circuit for at least a portion of the buffer water and includes a heat exchanger that is in thermal contact with the environment, the heat exchanger being located at a level above the buffer water tank. and / or The seawater heat exchanger is in thermal contact with the buffer water and seawater, and the seawater heat exchanger is positioned below the seawater surface outside the outer wall of the buffer water tank.

[0034] In one embodiment, the furnace structure includes an upper compartment above the discharge tank compartment, The aforementioned upper compartment is, A molten salt reactor (MSR) having a furnace vessel containing molten fuel salt, • Molten salt discharge system connected to the furnace vessel, Equipped with, The aforementioned discharge tank compartment is • One or more discharge tanks connected to the molten salt discharge system, A buffer water tank comprising an inner wall and an outer wall, with buffer water in the gap between the inner wall and the outer wall of the buffer water tank, and surrounding one or more discharge tanks, Equipped with, The first piping structure defines a circuit for at least a portion of the buffer water and includes a heat exchanger that is in thermal contact with a storage water tank, the storage water tank being at a level above the buffer water tank, and the storage water being in thermal contact with the environment. and / or The second piping structure defines a circuit for at least a portion of the buffer water and includes a heat exchanger that is in thermal contact with the environment, the heat exchanger being located at a level above the buffer water tank. Optional, The seawater heat exchanger is in thermal contact with the buffer water and seawater, and the seawater heat exchanger is positioned below the seawater surface outside the outer wall of the buffer water tank.

[0035] In one embodiment, the furnace structure includes an upper compartment above the discharge tank compartment, The aforementioned upper compartment is, A molten salt reactor (MSR) having a furnace vessel containing molten fuel salt, • Molten salt discharge system connected to the furnace vessel, Equipped with, The aforementioned discharge tank compartment is • One or more discharge tanks connected to the molten salt discharge system, A buffer water tank comprising an inner wall and an outer wall, with buffer water in the gap between the inner wall and the outer wall of the buffer water tank, and surrounding one or more discharge tanks, Equipped with, The first piping structure defines a circuit for at least a portion of the buffer water and includes a heat exchanger that is in thermal contact with a storage water tank, the storage water tank being at a level above the buffer water tank, and the storage water being in thermal contact with the environment, optionally, The second piping structure defines a circuit for at least a portion of the buffer water and includes a heat exchanger that is in thermal contact with the environment, the heat exchanger being located at a level above the buffer water tank. Optionally, a seawater heat exchanger is in thermal contact with buffer water and seawater, and the seawater heat exchanger is positioned below the seawater surface outside the outer wall of the buffer water tank.

[0036] By separating the upper compartment, which is equipped with the MSR, from the discharge tank compartment below it, it becomes possible to cool molten salts such as molten fuel salt when the reactor is not operating, thereby avoiding parasitic heat loss during normal operation.

[0037] The furnace vessel has an inner surface made of a lining material. The furnace vessel can be made of any material, such as metal, metal alloy, ceramic material, or a combination thereof, and in this context, this material is referred to as the furnace vessel material. The inner surface may be the surface of the furnace vessel material, such that the lining material is the furnace vessel material, or the furnace vessel material may be coated with an additional material to serve as the lining material. For example, the furnace vessel material may be a metal alloy, such as a nickel alloy, a nickel superalloy, or Hastelloy®, or it may be nickel. In this context, a nickel alloy is an alloy having at least 50% w / w nickel.

[0038] The molten salt discharge system comprises a piping system connected to the furnace vessel and one or more opening means such as a valve or salt plug, which allows molten salt to flow when the opening means is open, thereby discharging the molten salt from the furnace vessel to one or more discharge tanks. In one embodiment, the one or more discharge tanks are one or more molten fuel salt discharge tanks. In one embodiment, the molten salt discharge system is a molten fuel salt discharge system connected to the furnace vessel and one or more molten fuel salt discharge tanks.

[0039] The piping and valves may be made from the same material as the furnace vessel, or from a metal alloy, such as a nickel alloy. The molten fuel salt discharge system includes piping connected to the furnace vessel in the upper compartment, and the piping extends to the area of ​​the discharge tank compartment, which is connected to one or more discharge tanks.

[0040] One or more opening means, such as valves, may be located on piping near the furnace vessel in the upper compartment or near one or more discharge tanks.

[0041] In one embodiment, the buffer water tank holds buffer water within a tank that partially surrounds one or more discharge tanks, for example, along 95% of the overall contour of one or more discharge tanks, or for example, along 80% of the overall contour of one or more discharge tanks. In one embodiment, the buffer water tank completely surrounds one or more discharge tanks.

[0042] In one embodiment, the water buffer tank has a substantially cylindrical inner wall and outer wall that are concentric, or a substantially rectangular inner wall and outer wall that are concentric. In one embodiment, the minimum distance between the inner wall and outer wall of the buffer water tank may be less than 3 meters, for example less than 2 meters, or for example less than 1 meter.

[0043] The first piping structure is intended to transport steam generated from buffer water in a buffer water tank to a heat exchanger in a storage water tank, and to return condensed water from the heat exchanger in the storage water tank back to the buffer water tank. This evaporation and condensation circuit provides a mechanism for removing heat from the molten salt in the discharge tank that is heating the buffer water. In one embodiment, the first piping structure defines a sealed circuit comprising a heat exchanger. The heat exchanger is located in the storage water tank to assist in the cooling process, and is preferably partially or completely immersed in the storage water tank.

[0044] In one embodiment, the water storage tank is an open tank.

[0045] In one embodiment, the water storage tank is a closed tank.

[0046] The second piping structure also aims to carry away the heat and steam generated from the buffer water in the buffer water tank and return the condensed water to the buffer water tank. In one embodiment, the second piping structure defines a sealing circuit. A heat exchanger in thermal contact with the second piping structure exchanges heat with the environment, such as the external environment, and therefore with the air. This exchange may also be with a gas, such as air, in a closed volume, in which case the gas heated in the closed volume transfers heat to the external environment in thermal contact with the closed volume. This thermal contact may occur, for example, between the casing of the closed volume and the external environment.

[0047] The use of seawater as a final heat sink provides a variety of alternatives for the final heat sink when the reactor structure is deployed in the sea, a barge, or another offshore structure. The seawater heat exchanger is connected to an offshore piping system that includes pipes in contact with the buffer water in the buffer water tank, so that buffer water can be circulated from the buffer water tank to the seawater heat exchanger in the sea. In one embodiment, the offshore piping system includes pipes running through the outer wall of the buffer water tank, which are connected to the seawater heat exchanger.

[0048] In one embodiment, the seawater heat exchanger is equipped with an anti-fouling system.

[0049] In one embodiment, the first piping structure is • At least one riser pipe, the first end of which serves as an inlet for at least a portion of the buffer water, and the second end of which is in contact with the inlet of a heat exchanger in a storage water tank, • At least one downpipe, the first end of which is in contact with the outlet of the heat exchanger in the storage water tank, and the second end of which is an outlet for at least a portion of the buffer water, It is equipped with.

[0050] The riser or descender pipe of the first piping system can have any cross-sectional shape, such as circular, elliptical, or rectangular, and can be manufactured from an alloy such as stainless steel. The minimum cross-sectional size is the diameter in the case of a circular pipe, and the minor axis in the case of an elliptical pipe.

[0051] In one embodiment, two sets of rising and descending pipes are provided, preferably, these sets facing each other along the contour around one or more discharge tanks.

[0052] In one embodiment, the first end of the rising pipe and / or the second end of the descending pipe are above the buffer water surface level.

[0053] The riser tube collects or captures buffer water vapor evaporated from the buffer water tank through its first end, and the buffer water vapor rises upward and forward through the riser tube by natural circulation. The buffer water vapor may partially condense inside the riser tube, and generally, some of the buffer water in the riser tube may be in a liquid state, some in a gaseous state, and therefore may be buffer water vapor. Similarly, some of the buffer water in the descender tube may be in a liquid state, some in a gaseous state, and therefore may be buffer water vapor.

[0054] In one embodiment, the minimum cross-section of the first end of the ascending pipe is larger than the minimum cross-section of the second end of the descending pipe.

[0055] In one embodiment, the minimum cross-section of the first end of the ascending pipe is larger than the minimum cross-section of the second end of the descending pipe, the minimum cross-section of the first end of the ascending pipe is at intervals of 1 cm to 20 cm, for example, at intervals of 1.5 cm to 10 cm, and the minimum cross-section of the second end of the descending pipe is at intervals of 0.5 cm to 15 cm, for example, at intervals of 1 cm to 8 cm.

[0056] In one embodiment, a natural convection enhancer is contained in the buffer water within a buffer water tank, and the natural convection enhancer includes a tank wall in the gap between the inner wall and the outer wall that divides the buffer water tank into an inner tank region and an outer tank region, and the tank wall extends beyond the buffer water level into a dry wall section that contacts the outer wall at the wall contact point. • Equipped with perforations that allow air circulation between the dry wall section and / or the inner wall, the inner tank area and the outer tank area, The first end of the ascending pipe is positioned above the wall contact point, and the second end of the descending pipe is positioned below the wall contact point.

[0057] In one embodiment, the end of the descending pipe, positioned below the wall contact point, has a spray nozzle capable of condensing any vapor in the gas volume above the buffer water surface.

[0058] The natural convection enhancer may be a wall structure arranged concentrically around the inner wall of the buffer water, preferably within the buffer water tank. The wall structure is preferably made of an alloy such as stainless steel. The dry wall section is preferably integrated with the wall structure and may also be made of an alloy such as stainless steel.

[0059] In one embodiment, the tank wall is substantially vertical below the buffer water level and continues above the water surface into a dry wall section which is a plate structure angled to the substantially vertical structure, preferably between 30 and 120 degrees, for example between 60 and 100 degrees.

[0060] The outer tank region has a gas volume above the buffer water surface, and this gas volume is surrounded by the dry wall section, the outer wall, and the surface of the buffer water. Perforations in the dry wall section allow gases such as steam and air to circulate and prevent pressure from accumulating on both sides of the dry wall separating the inner and outer tank regions. This prevents pressure from rising within the outer tank region, thereby preventing water from flowing freely into the outer tank region through the downpipe.

[0061] In one embodiment, no perforations are provided in the tank wall or dry wall section between the inner and outer tank regions. Maintaining a certain level of high pressure can sometimes be advantageous to facilitate the circulation of steam and condensate.

[0062] In one embodiment, a seawater heat exchanger is provided, which has an inlet for buffer water through a perforation in the tank wall and an outlet for buffer water to a buffer water tank, the outlet being located lower than the inlet.

[0063] The inlet through the perforation in the tank wall has the effect of ensuring that only the buffer water in the inner tank region begins circulation through the seawater heat exchanger. The buffer water in the inner tank region is closer to the discharge tank, so it is at a higher temperature and, advantageously, is cooled within the seawater heat exchanger, thereby allowing the buffer water to enter the buffer water tank through the outlet in the outer tank region.

[0064] In one embodiment, the inner wall of the buffer tank is connected to the inner bottom plate, and as a result, the inner wall and the inner bottom plate have a bowl shape.

[0065] The bowl completely encloses one or more discharge tanks, and the buffer water completely encloses the bowl. The bowl may have substantial rotational symmetry about an axis extending from the upper compartment to the discharge tank compartment, for example, having a substantially circular bowl shape that encloses a discharge tank compartment having a circular outer perimeter. The bowl may also have an open box shape, in which case the open box encloses the discharge tank compartment with a rectangular perimeter.

[0066] The buffer water is located outside the inner wall and inside the outer wall, and therefore between the inner and outer walls. The buffer water is located between the inner bottom plate and the bottom plate of the buffer water tank.

[0067] In the event of a serious accident condition conventionally known as a fuel salt spill incident, the bowl functions as a "fuel salt catcher." This incident can be caused by minor or extensive damage to a container, tank, or piping containing fuel salt. The inner bottom plate protects the integrity of the containment while simultaneously acting as a thermal barrier that facilitates the heat transfer path to the buffer water in the buffer water tank. Preferably, the inner bottom plate is constructed with a greater thickness than the inner wall, for example, three times thicker, or even twice as thick. This means that the "fuel salt catcher" has two main safety functions: namely, protecting the integrity of the containment vessel under serious accident conditions and ensuring the ability to remove decay heat under serious accident conditions. In one embodiment, the inner bottom plate is a multilayer structure, such as a double-layer structure, where the layer facing the discharge tank has a greater thickness than the inner wall, for example, twice as thick, or even 1.5 times thicker.

[0068] In one embodiment, the inner wall of the buffer water tank is a double-wall structure, where the double-wall structure is closed and gas is contained between the two walls, or the double-wall structure is open and the air between the two walls is in communication with the ambient air.

[0069] By providing a double-wall structure on the inner wall of the buffer tank, an additional containment barrier is ensured in case of damage to the inner wall. If damage occurs, water may enter the discharge tank compartment, potentially damaging the discharge tank containing molten fuel salt. When the double-wall structure is closed and gas is contained between the two walls, a gas leak detection system can be used to measure the pressure between the two walls and warn of sudden pressure fluctuations indicating wall failure. The double-wall structure may also provide some form of thermal stress relief, such as thermal stress relief, in the event of contact with molten salt during a fuel salt spill accident.

[0070] In one embodiment, the molten salt discharge system is a molten fuel salt discharge system and comprises a salt piping system having at least one salt plug.

[0071] The salt plug is a salt plug in a salt piping system and may be a freeze valve ("freeze plug") that remains solid while being cooled. When cooling stops, the molten fuel salt in contact with the plug in the salt piping system becomes hot, so the salt piping system in which the salt melts is part of the discharge system, and therefore the molten fuel salt is discharged when the salt plug melts.

[0072] A unique safety feature of this type of design is that its operation in the event of power supply loss is entirely passive (requiring neither operator action nor power supply). In this type of event, active cooling of the freeze valve is lost and the freeze plug melts, enabling passive salt discharge. The salt piping system is connected to other piping, such as carrier gas piping. Depending on the operating mode, for example, depending on the discharge mode or normal power generation mode, the piping system and parts of the salt piping system may contain gases such as molten fuel salt or carrier gas.

[0073] In other types of events without power loss, active cooling must be shut off by the reactor protection system using equipment and signals classified as safe, in a more conventional manner. In all cases, operation and systems can be made fully passive upon request.

[0074] In one embodiment, the furnace structure further comprises a gas supply system, the gas supply system is • Carrier gas storage tank, A carrier gas piping comprising at least one valve, wherein the carrier gas piping connects the carrier gas storage tank to one or more discharge tanks, It is equipped with.

[0075] In one embodiment, the gas supply system further comprises an off-gas system, and the off-gas system is • Off-gas storage tank, A carrier gas piping comprising at least one valve, connecting a chemical control system and a reactor vessel, It is equipped with.

[0076] In most cases, during normal powered operation when the reactor is generating heat from the nuclear fission process, the gas supply system supplies gas to the reactor.

[0077] The supplied gas can function as a carrier gas, continuously transporting gaseous fission products from the reactor to the off-gas system, thereby further processing the gaseous fission products. The supplied gas can also be used alone or in conjunction with gaseous reactants such as H2 to adjust the oxidation-reduction potential of the molten fuel salt, for example. This is intended to reduce the corrosiveness of the molten fuel salt. The valve is open during the normal operation described above.

[0078] If molten fuel salt is discharged, for example during maintenance work, and it is necessary to refill the furnace with molten fuel salt, a gas supply system can be used to push the molten fuel salt back into the furnace from one or more discharge tanks through a piping system.

[0079] This provides a procedure for transferring molten fuel salt that uses an existing gas supply system for the operation of refilling the molten fuel salt, without using a molten fuel salt pump.

[0080] In one embodiment, the molten fuel salt is Sodium fluoride + potassium fluoride + uranium fluoride, Lithium fluoride + thorium fluoride + plutonium fluoride, Lithium fluoride + thorium fluoride + uranium fluoride, Lithium fluoride + Beryllium fluoride + Uranium fluoride Lithium fluoride + Beryllium fluoride + Uranium fluoride + Thorium fluoride, Lithium fluoride + Beryllium fluoride + Uranium fluoride + Thorium fluoride + Zirconium fluoride, Sodium fluoride + rubidium fluoride + uranium fluoride, Sodium fluoride + Beryllium fluoride + Uranium fluoride + Thorium fluoride + Zirconium fluoride Potassium chloride + plutonium chloride + uranium chloride, Sodium chloride + plutonium chloride, Sodium chloride + Plutonium chloride + Uranium chloride The composition is selected from the group consisting of compositions containing the following:

[0081] When using molten fuel salts, the fissile material is dissolved in a molten salt containing a carrier salt, which is preferably a fluoride-based or chloride-based salt. Fluoride salts contain F-19, the only natural isotope of fluorine, which has a low neutron capture probability. Therefore, fluoride salts are particularly suitable for neutron (thermal MSR) applications where economic considerations are critical. The fissile material may also be a fluoride salt or chloride salt containing fissile isotopes such as U-235, U-233, or Pu-239.

[0082] In one embodiment, the molten fuel salt is a fluoride fuel salt or chloride fuel salt based on one or more fluoride compounds or chloride compounds that each form a fuel salt composition.

[0083] The fuel salt containing U-235 may be at various enrichment levels, such as SEU (<2% U-235), LEU (typically 3-5% U-235), HALEU (5-20% U-235), or it may be a naturally occurring grade of uranium.

[0084] In one embodiment, the MSR further comprises a moderator based on a material selected from the group consisting of graphite material, Be compound-containing material, and molten salt of a metal hydroxide, and if the moderator is a molten salt of a metal hydroxide, the furnace structure further comprises a molten salt of a metal hydroxide discharge system, including the molten salt of a metal hydroxide discharge tank.

[0085] In one embodiment, the MSR comprises a molten salt of a metal hydroxide or heavy metal oxide.

[0086] In one embodiment, a molten salt furnace (MSR) comprises a furnace vessel containing molten fuel salt and a moderator which is a molten salt of a metal hydroxide or heavy metal oxide. Such a furnace is known from Patent Document 5, in which the molten fuel salt is located in an inner tube within the furnace vessel, and the molten salt of the metal hydroxide or heavy metal oxide is located in the furnace vessel surrounding the inner tube.

[0087] When a molten moderating salt such as a molten metal hydroxide or heavy metal oxide is used, the upper compartment further comprises a molten moderating salt discharge system connected to the furnace vessel and one or more molten moderating salt discharge tanks.

[0088] Other moderators used may include water, deuterated water (D2O), Be compounds, or hydrides such as zirconium hydride.

[0089] In one embodiment, the furnace structure includes a compartment separator, and the compartment separator is A grid structure that forms a substantially horizontal surface separation between an upper compartment and a discharge tank compartment, comprising a metal grid and an insulating layer, and one or more funnels penetrating the grid structure, each funnel comprising a plug made of sacrificial material, It is equipped with.

[0090] The upper compartment containing the furnace and the discharge tank compartment containing the discharge tank for the molten salt may generally be located within the same volume space within the furnace structure. The upper compartment and the discharge tank compartment may be separated by a physical barrier. Such a compartment separator has the advantage that the furnace instrumentation maintains a relatively low temperature in the upper compartment, which requires protection from the high temperatures of the discharge tank compartment, where the discharge tank may be preheated to a certain high temperature. The desire to preheat the discharge tank is because the rapid discharge of molten salt in an emergency can cause thermal shock to the discharge tank material, and if the discharge tank is not hot enough, there is a risk of rupture, which could cause a salt spill incident. Furthermore, the compartment separator should preferably provide a walkable surface for MTSI (Maintenance, Testing, Monitoring, and Inspection) within the upper compartment.

[0091] However, in the case of a salt spill in the upper compartment related to reactor piping, for example, damage must be mitigated by ensuring that the spilled salt reaches a fuel salt catcher installed at the bottom of the drain tank compartment. The compartment separator solves this problem by providing a grid structure including a funnel. The metal grid provides load-bearing properties when the compartment separator needs to provide a walkable surface.

[0092] In one embodiment, a solid metal sheet is applied to the grid structure to increase the structural strength of the compartment separator, and the solid metal sheet, the heat insulating layer, and the metal grid form a sandwich structure.

[0093] In one embodiment, the plug comprises a disc, preferably having one or more insulating discs beneath the disc, the one or more insulating discs facing the discharge tank compartment.

[0094] The disk is made of sacrificial material, meaning that the material decomposes by melting under thermal influence at a temperature lower than the dominant temperature of the molten salt, for example.

[0095] The disc material may be a low-melting-point metal alloy or a polymer such as a carbon and fluoride-containing polymer. The polymer may be made from polytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP), or ethylene tetrafluoroethylene (EFTE).

[0096] The insulation disc may include an insulation material selected from the list of glass wool, aerogel, and polymer foam.

[0097] The insulation layer may include an insulating material selected from the list of glass wool, stone wool, ceramic wool, aerogel, and silicate composite materials.

[0098] In one embodiment, the number of funnels penetrating the grid structure is such that the grid structure surface area is 5 m². 2 At least one funnel per unit, for example, 5m 2 Two funnels per unit, 5m 2 There are three funnels per unit. Having multiple funnels in a compartment separator results in a lower vertical structure for collecting and discharging molten salt compared to having one or a few large funnels for collecting and discharging molten salt. This is because covering most of the compartment separator's surface area with a few funnels requires a higher structure with a greater inclination angle of the funnels necessary for the molten salt to flow freely at a sufficient speed.

[0099] In one embodiment, the reactor structure is located on an offshore structure, preferably a barge.

[0100] The offshore structure may be a barge comprising a power generation structure equipped with one or more MSRs and steam turbines capable of generating electricity.

[0101] According to one aspect of the present invention, a furnace structure is provided comprising an upper compartment above a discharge tank compartment, wherein the upper compartment is A molten salt reactor (MSR) having a furnace vessel containing molten fuel salt, • Molten salt discharge system connected to the furnace vessel, Equipped with, The aforementioned discharge tank compartment is • One or more discharge tanks connected to the molten salt discharge system, A tube system comprising an inner tube and an outer tube, wherein the inner tube and the outer tube are joined together, and buffer water is located within the tubes of the joined inner and outer tubes of the tube system, surrounding one or more discharge tanks, Equipped with, The first piping structure defines a circuit for at least a portion of the buffer water and includes a heat exchanger that is in thermal contact with a storage water tank, the storage water tank being at a level above the tubing system, and the storage water being in thermal contact with the environment. and / or The second piping structure defines a circuit for at least a portion of the buffer water and includes a heat exchanger that is in thermal contact with the environment, the heat exchanger being located at an upper level of the tubing system. and / or The seawater heat exchanger is in thermal contact with buffer water and seawater, and the seawater heat exchanger is located below the seawater surface outside the outer wall of the tube system.

[0102] According to one aspect of the present invention, a furnace structure is provided comprising an upper compartment above a discharge tank compartment, wherein the upper compartment is A molten salt reactor (MSR) having a furnace vessel containing molten fuel salt, • Molten salt discharge system connected to the furnace vessel, Equipped with, The aforementioned discharge tank compartment is • One or more discharge tanks connected to the molten salt discharge system, A tube system comprising an inner tube and an outer tube, wherein the inner tube and the outer tube are joined together, and buffer water is located within the tubes of the joined inner and outer tubes of the tube system, the tube system surrounds one or more discharge tanks, and the joined inner and outer tubes of the tube system comprise a section where the buffer water evaporates, a section where the buffer water is insulated, and a section where the buffer water condenses. Equipped with, The first piping structure defines a circuit for at least a portion of the buffer water and includes a heat exchanger that is in thermal contact with a storage water tank, the storage water tank being at a level above the tubing system, and the storage water being in thermal contact with the environment. and / or The second piping structure defines a circuit for at least a portion of the buffer water and includes a heat exchanger that is in thermal contact with the environment, the heat exchanger being located at an upper level of the tubing system. and / or The seawater heat exchanger is in thermal contact with buffer water and seawater, and the seawater heat exchanger is located below the seawater surface outside the outer wall of the tube system.

[0103] According to one aspect of the present invention, a furnace structure is provided comprising an upper compartment above a discharge tank compartment, wherein the upper compartment is A molten salt reactor (MSR) having a furnace vessel containing molten fuel salt, • Molten salt discharge system connected to the furnace vessel, Equipped with, The aforementioned discharge tank compartment is • One or more discharge tanks connected to the molten salt discharge system, A tube system comprising an inner tube and an outer tube, wherein the inner tube and the outer tube are joined together, and buffer water is located within the tubes of the joined inner and outer tubes of the tube system, the tube system surrounds one or more discharge tanks, and the joined inner and outer tubes of the tube system comprise a section where the buffer water evaporates, a section where the buffer water is insulated, and a section where the buffer water condenses. Equipped with, The seawater heat exchanger is in thermal contact with buffer water and seawater, and is located in a rectangular or cylindrical recess, preferably a sea chest, below the seawater surface outside the outer wall of the tube system.

[0104] According to one aspect of the present invention, a method for transferring heat from a molten salt is provided, and the method is The steps include supplying molten fuel salt to one or more discharge tanks for molten fuel salt, The steps include: surrounding one or more discharge tanks for molten fuel salt with a buffer water tank, wherein the buffer water tank contains buffer water in the gap between the inner and outer walls of the buffer water tank, and the molten fuel salt transfers heat through at least one of thermal radiation, thermal conduction, or thermal convection with the inner wall, heating the buffer water to vapor; The step of providing a first piping structure, wherein the first piping structure is At least one riser pipe above at least a portion of the buffer water, which collects steam and directs the steam to a heat exchanger in the storage water in the storage water tank above the buffer water tank, where the steam is condensed into water, A descending pipe for guiding water from a heat exchanger in the water storage tank to a buffer water tank, It has steps, and / or The step of providing a second piping structure, wherein the second piping structure is At least one riser above at least a portion of the buffer water, the riser collects steam and leads the steam to a gas heat exchanger which is in thermal contact with a gas-containing environment, the gas heat exchanger is located above the buffer water tank and condenses the steam into water, At least one downpipe for guiding water from the gas heat exchanger to the buffer water tank, It has steps, and / or The step of providing a seawater heat exchanger that comes into thermal contact with buffer water, wherein the seawater heat exchanger is positioned below the seawater level outside the outer wall of the buffer water tank, and the buffer water circulates through the seawater heat exchanger. Includes.

[0105] In one embodiment, the method for transferring heat from the molten salt is: The steps include supplying molten fuel salt to one or more discharge tanks for molten fuel salt, The steps include: surrounding one or more discharge tanks for molten fuel salt with a buffer water tank, wherein the buffer water tank contains buffer water in the gap between the inner and outer walls of the buffer water tank, and the molten fuel salt transfers heat through at least one of thermal radiation, thermal conduction, or thermal convection with the inner wall, heating the buffer water to vapor; The step of providing a first piping structure, wherein the first piping structure is At least one riser pipe above at least a portion of the buffer water, which collects steam and directs the steam to a heat exchanger in the storage water in the storage water tank above the buffer water tank, where the steam is condensed into water, A descending pipe for guiding water from a heat exchanger in the water storage tank to a buffer water tank, It has steps, and / or The step of providing a second piping structure, wherein the second piping structure is At least one riser above at least a portion of the buffer water, the riser collects steam and leads the steam to a gas heat exchanger which is in thermal contact with a gas-containing environment, the gas heat exchanger is located above the buffer water tank and condenses the steam into water, At least one downpipe for guiding water from the gas heat exchanger to the buffer water tank, It has steps, and / or The step of providing a seawater heat exchanger that comes into thermal contact with buffer water, wherein the seawater heat exchanger is positioned below the seawater level outside the outer wall of the buffer water tank, and the buffer water circulates through the seawater heat exchanger. Includes.

[0106] In one embodiment, the method for transferring heat from the molten salt is: The steps include supplying molten fuel salt to one or more discharge tanks for molten fuel salt, The steps include: surrounding one or more discharge tanks for molten fuel salt with a buffer water tank, wherein the buffer water tank contains buffer water in the gap between the inner and outer walls of the buffer water tank, and the molten fuel salt transfers heat through at least one of thermal radiation, thermal conduction, or thermal convection with the inner wall, heating the buffer water to vapor; The step of providing a first piping structure, wherein the first piping structure is At least one riser pipe above at least a portion of the buffer water, which collects steam and directs the steam to a heat exchanger in the storage water in the storage water tank above the buffer water tank, where the steam is condensed into water, A descending pipe for guiding water from a heat exchanger in the water storage tank to a buffer water tank, It has steps, and / or The step of providing a second piping structure, wherein the second piping structure is At least one riser above at least a portion of the buffer water, the riser collects steam and leads the steam to a gas heat exchanger which is in thermal contact with a gas-containing environment, the gas heat exchanger is located above the buffer water tank and condenses the steam into water, A step comprising, at least one downpipe for leading water from a gas heat exchanger to a buffer water tank, and optionally, The step of providing a seawater heat exchanger that comes into thermal contact with buffer water, wherein the seawater heat exchanger is positioned below the seawater level outside the outer wall of the buffer water tank, and the buffer water circulates through the seawater heat exchanger. Includes.

[0107] The method of transferring heat from molten salt is applicable to molten salt regardless of the container in which it is housed.

[0108] In one embodiment, the molten salt is a molten fuel salt.

[0109] This method may involve transferring heat generated from the decay of fission products in the molten fuel salt. This heat may be transferred from the discharge tank for the molten fuel salt to the inner wall via at least one of thermal radiation, thermal conduction, or thermal convection, heating the buffer water and generating buffer steam.

[0110] The riser pipe collects or captures buffer water vapor evaporated from the buffer water tank through its first end, and the buffer water vapor rises upward and forward through the riser pipe by natural circulation. The buffer water vapor may partially condense inside the riser pipe, and generally, some of the buffer water in the riser pipe may be in a liquid state, some in a gaseous state, and therefore may be buffer water vapor. In one embodiment, the riser pipe is at least partially insulated with pipe section insulation or the like. This may mitigate problems related to condensation inside the riser pipe. Finally, the condensed water from inside the riser pipe re-evaporates, and the formed buffer water vapor rises upward. Similarly, some of the buffer water in the descender pipe may be in a liquid state, some in a gaseous state, and therefore may be buffer water vapor. Finally, the buffer water vapor in the descender pipe condenses and is guided downward within the descender pipe.

[0111] As mentioned above, this method is very suitable for transferring heat from molten fuel salt contained in one or more discharge tanks.

[0112] In one embodiment, the method for transferring heat from the molten salt is: The steps include supplying molten fuel salt to the reactor vessel, The step of surrounding the furnace vessel with a buffer water tank containing buffer water in the gap between the inner and outer walls of the buffer water tank, wherein the molten fuel salt transfers heat through at least one of thermal radiation, thermal conduction, or thermal convection with the inner wall, heating the buffer water and turning it into steam, The step of providing a first piping structure, wherein the first piping structure is At least one riser pipe above at least a portion of the buffer water, which collects steam and directs the steam to a heat exchanger in the storage water in the storage water tank above the buffer water tank, where the steam is condensed into water, A descending pipe for guiding water from a heat exchanger in the water storage tank to a buffer water tank, It has steps, and / or The step of providing a second piping structure, wherein the second piping structure is At least one riser above at least a portion of the buffer water, the riser collects steam and leads the steam to a gas heat exchanger which is in thermal contact with a gas-containing environment, the gas heat exchanger is located above the buffer water tank and condenses the steam into water, A step comprising, at least one downpipe for leading water from a gas heat exchanger to a buffer water tank, and optionally, The step of providing a seawater heat exchanger that comes into thermal contact with buffer water, wherein the seawater heat exchanger is positioned below the seawater level outside the outer wall of the buffer water tank, and the buffer water circulates through the seawater heat exchanger. Includes.

[0113] The method of transferring heat from molten fuel salt may, as an alternative, be used in MSRs including a reactor vessel containing molten fuel salt in an operating state, which is an operating state that generates heat from the fission process or an expected operating state. The method of transferring heat from molten fuel salt may also be used for MSRs that are temporarily or permanently shut down. The method of transferring heat from molten fuel salt may also be used for accident conditions.

[0114] When an MSR is operating, there is a trade-off: a certain degree of parasitic heat loss is tolerated in exchange for a passive heat removal system that offers improved safety compared to an active heat removal system.

[0115] In one embodiment, the method for transferring heat from a molten salt further includes the step of transferring heat from a molten salt of a metal hydroxide or heavy metal oxide used as a moderator, and the furnace compartment further comprises a furnace vessel and a molten moderator discharge system connected to one or more molten moderator discharge tanks.

[0116] When one or more discharge tanks for molten fuel salt are located close to the sea, it may be advantageous to use a seawater heat exchanger to transfer heat to the final seawater sink. This is particularly advantageous when one or more discharge tanks for molten fuel salt are located below sea level. Other water-based final heat sinks may be lakes, fjords, rivers, or ponds, and a water-immersed heat exchanger may function equivalently to a seawater heat exchanger. Such a heat exchanger is located below the water level outside the outer wall of the buffer water tank and transfers heat from the buffer water.

[0117] In one embodiment, heat is transferred from the water storage tank to the external environment or other environment that is in thermal contact with the water storage tank.

[0118] In one embodiment, heat transfer from the water storage tank occurs, at least partially, through the evaporation of the water storage tank into the external environment.

[0119] A heat exchanger within a water storage tank transfers heat from buffer water to the water stored in the tank. This heat is then transferred to the external environment, such as air. The water storage tank may be a closed volume, in which case the heated water within the closed volume transfers heat to the external environment, which is in thermal contact with the closed volume. This thermal contact may occur, for example, between the casing of the closed volume and the external environment.

[0120] The water storage tank may also be at least partially open, in which case the heated water transfers heat to the external environment by evaporation. Evaporation of water provides a very efficient method of heat transfer. The water storage comes into thermal contact with but does not directly contact the buffer water in the heat exchanger, and the buffer water may be activated by radiation from the molten salt in the discharge tank, while the water storage is not activated and can therefore evaporate to the external environment without creating safety issues.

[0121] In one embodiment, heat transfer is performed by a passive heat transfer method.

[0122] The method of transferring heat from the molten salt may be carried out without a pump or other active mechanism, which may also require human intervention to activate. Heat transfer from the heated buffer water to the steam relies on the steam carrying heat and naturally evaporating upward through a permanently installed riser pipe, transferring it to a heat exchanger where it comes into thermal contact with cooler storage water, where the steam condenses. The condensed water then flows naturally downward through a permanently installed descender pipe by gravity and returns to the water buffer tank. Water molecules, being lighter than the surrounding air molecules N2 and O2, gain a higher velocity at a given temperature and preferentially flow upward faster than the air molecules in the riser pipe.

[0123] In one embodiment, a natural convection enhancer having a tank wall in the gap between the inner wall and the outer wall divides the buffer water tank into an inner tank region and an outer tank region. • Boil the buffer water in the inner tank area. • Provides an upward flow path for steam.

[0124] The tank walls of a natural convection enhancer separate the water near the heated inner wall from the rest of the water in the buffer water tank, heating the water near the inner wall to a localized boil. The natural convection enhancer also acts as a thermal barrier to the water closer to the outer wall. The difference in temperature and density promotes a flow driven by buoyancy. In addition, the natural convection enhancer provides an upward flow path for steam.

[0125] In one embodiment, the tank wall extends beyond the buffer water level into a dry wall section that contacts the outer wall at the wall contact point, and the dry wall section and / or inner wall are provided with perforations that allow air circulation between the inner and outer tank regions, the first end of the riser pipe is located above the wall contact point, and the second end of the descender pipe is located below the wall contact point.

[0126] The outer tank region has a gas volume above the buffer water surface, and this gas volume is surrounded by the dry wall section, the outer wall, and the surface of the buffer water. Perforations in the dry wall section allow gases such as steam and air to circulate and prevent pressure from accumulating on both sides of the dry wall separating the inner and outer tank regions. This prevents pressure from rising within the outer tank region, thereby preventing water from flowing freely into the outer tank region through the downpipe.

[0127] In one embodiment, the buffer water in the inner tank region has a higher temperature than the buffer water in the outer tank region, and the buffer water in the outer tank region enters the inlet of the seawater heat exchanger through a perforation in the tank wall, where it is then cooled within the seawater heat exchanger and enters the buffer water outlet into the buffer water tank, which is located at a lower position than the inlet.

[0128] In one embodiment, no perforations are provided in the drying wall section and the tank wall. In this embodiment, steam generation increases the pressure in the internal gas space, promoting the circulation of steam and condensate. [Brief explanation of the drawing]

[0129] The present invention will be described in more detail below with reference to the schematic diagrams and using examples.

[0130] [Figure 1] This shows an embodiment of a reactor structure in which the MSR is in operation. [Figure 2] The MSR shows an embodiment of a reactor structure in an accident state. [Figure 3] This shows the reactor structure mounted on the barge. [Figure 4] This shows a reactor structure in which the buffer water tank is implemented as a tubular system. [Figure 5] The reactor structure is shown in which the buffer water tank is implemented as a tube system, the tube system comprising a section where the buffer water evaporates, a section where the buffer water is insulated, and a section where the buffer water condenses. [Figure 6]The reactor structure is shown in which the buffer water tank is implemented as a tube system, comprising a section where the buffer water evaporates, a section where the buffer water is insulated, and a section where the buffer water condenses, with the buffer water and seawater in thermal contact below the sea surface. [Modes for carrying out the invention]

[0131] The present invention is not limited to the embodiments shown in the drawings. Therefore, where reference numerals follow features mentioned in the appended claims, such numerals are included solely for the purpose of enhancing the understanding of the claims and are not intended to limit the claims in any way.

[0132] As used herein and in the claims, the term “comprising” means “consisting of a part thereof.” When interpreting any description in this specification and in the claims that includes the term “comprising,” other features may exist in each description besides those preceded by this term. Related terms such as “comprise” and “comprised” should be interpreted similarly.

[0133] (Detailed explanation) The present invention will now be described in the following non-limiting embodiments with reference to the accompanying drawings.

[0134] The furnace structure 1 of the present invention is shown in Figure 1 and has an upper compartment 2 above the discharge tank compartment 3. Figure 1 shows an embodiment of the furnace structure 1 when the MSR 4 is in operation.

[0135] The entire reactor structure 1, including the upper compartment 2 and the discharge tank compartment 3, is enclosed by a wall structure. The molten salt reactor (MSR) 4 is shown as having a reactor vessel 5 located within the upper compartment 2 and supported by a hearth (not shown). The fission process occurring in the molten fuel salt 6 within the core generates heat within the core, and the resulting heated fuel salt is circulated from the core to a primary heat exchanger 8 by a fuel salt pump 7. The primary heat exchanger 8 may be directly connected to a steam generator (not shown) for generating electricity, or connected via other heat exchangers (not shown). Gaseous fission products are collected and processed in an off-gas system to separate and store the gaseous fission products. A gas supply system can supply a carrier gas such as He to the off-gas system to carry away the gaseous fission products from the core. The gas supply system can also supply gas to a chemical control unit to which reactants are supplied to the molten salt 6 in order to maintain the target chemical composition of the molten salt. The gas supply system includes gas piping 12 for leading carrier gas to the various facilities described herein, but also includes a piping system to a discharge tank in a discharge tank compartment. The piping system to the discharge tank can be opened and closed by valves 11, 110 on the carrier gas piping system.

[0136] The reactor 4 is shown in an operating mode in which the reactor vessel 5 contains molten fuel salt 6 and the discharge tank 10 is empty. The salt piping system is shown with a salt plug 13 that is actively cooled by a salt cooling system 14. The portion of the salt piping system below the salt plug 13 that leads to the discharge tank 10, located below the upper compartment 2, does not contain fuel salt 6 and is shown as a void in the molten salt 6, but contains He gas. The discharge tank compartment 3 is shown with the entire discharge tank 10 surrounded by a rectangular buffer water tank 15 shown in cross-section. The buffer water tank 15 contains buffer water 21 between its inner wall 16 and outer wall 17, both of which are shown in cross-section. The buffer water tank 15 also surrounds the discharge tank 10 from below with buffer water 21, with an inner bottom plate 18 facing the discharge tank 10 on one side and buffer water 21 facing the other side of the inner bottom plate 18. The inner bottom plate 18 is shown as a two-layer plate having a shallow bowl shape, and the plate of the two-layer plate facing the discharge tank 10 can function as a fuel salt catcher. The tank bottom plate 19 is shown at the very bottom of the buffer water tank 15. A natural convection enhancer with a tank wall 34 is shown in cross-section. The lower part of the tank wall 34 is supported by a tank wall support (not shown), allowing circulation and convection of the buffer water 21 below the lowest end of the tank wall 34. The tank wall 34 divides the buffer water tank 15 into an inner tank region 35 facing the discharge tank 10 and an outer tank region 36. A dry wall section 37 connects the tank wall 34 to the outer wall 17, and the dry wall section 37 is a rectangular ring-shaped plate having a ring width approximately corresponding to the width of the outer tank region 36. By assembling the outer wall 17 and the rectangular ring-shaped plate connected thereto, a closed barrier is formed between the inner tank region 35 and the outer tank region 36, except for the aforementioned gap below the lowest end of the tank wall 34 and the perforations 39 in the dry wall section 37 of the natural convection enhancer and / or the tank wall 34. The perforations 39 are located in the tank wall 34 above the water level of the buffer water 21 in the buffer water tank 15.

[0137] The first piping structure 22 is illustrated and described below. The riser pipe 27 is shown with its first end 28 located inside the inner tank area 35 above the dry wall section 37. The first end 28 of the riser pipe is higher than the water level of the buffer water 21, and steam (not shown) in the inner tank area 35 can enter the first end 28 of the riser pipe, thus serving as an inlet for buffer water steam. During normal operation, evaporation of the buffer water 21 is very limited. The riser pipe 27 extends upward from its first end 28 and is shown to enter the storage water tank 30 around the height level of the MSR 4 above the discharge tank compartment 3. The second end 29 of the riser pipe is surrounded by the storage water in the storage water tank 30 and is connected to a heat exchanger 23 that is in thermal contact with the storage water. The buffer steam condenses at least partially within the heat exchanger 23, and the buffer water 21 exits the heat exchanger 23 at its outlet end and enters the first end 32 of the downpipe. As described above, the amount of buffer water 21 evaporated and condensed is very limited during normal operation. The downpipe 31 extends downward from its first end 32 and enters the outer tank area 36 of the buffer water tank 15, where the buffer water 21 can be guided through the second end 33 of the downpipe into the buffer water 21 in the outer tank area 36. The second end 33 of the downpipe is below the ring-shaped dry wall section 37 and above the buffer water level.

[0138] The second piping structure 24 is illustrated and explained below.

[0139] The riser pipe 27 is shown with its first end 28 located inside the inner tank area 35 above the rectangular ring-shaped dry wall section 37. The first end 28 of the riser pipe is above the water level of the buffer water 21, and any steam (not shown) in the inner tank area 35 enters the first end 27 of the riser pipe, thus serving as an inlet for buffer water steam. As described above for the first piping, under normal operation, evaporation of the buffer water 21 is very limited. The riser pipe 27 extends upward from its first end 28 and is shown to connect to the gas heat exchanger 25 around the height level of the MSR 4 above the discharge tank compartment 3. The second end 29 of the riser pipe is surrounded by the external environment and connects to the gas heat exchanger 25, which is in thermal contact with the external environment. Any buffer steam condenses at least partially within the heat exchanger 25, and the buffer water 21 exits the gas heat exchanger 25 at its outlet end and enters the first end 32 of the downpipe. The downpipe 31 extends downward from its first end 32 and enters the outer tank area 36 of the buffer water tank 15, and the buffer water 21 is guided through the second end 33 of the downpipe into the buffer water 21 in the outer tank area 36. The second end 33 of the downpipe is below the ring-shaped dry wall section 37 and above the buffer water level.

[0140] The seawater heat exchanger 26 is located outside the buffer water tank 15 and is submerged in seawater below the sea surface. The seawater heat exchanger 26 has an inlet and an outlet for the buffer water 21, with the inlet being higher than the outlet. The inlet of the buffer water 21 into the seawater heat exchanger 26 terminates at its open end in the inner tank region 35, where the temperature of the buffer water 21 is higher than in the outer tank region 36. During normal operation, the temperature difference between the buffer water 21 in the inner tank region 35 and the buffer water 21 in the outer tank region 36 is very limited. The buffer water 21 flowing into the inlet is cooled by the seawater in the inner tank region 35, which is cooler than the buffer water 21, and the buffer water 21 circulates back to the bottom of the buffer water tank 15. This circulation of buffer water 21 through the seawater heat exchanger 26 occurs as a natural circulation from a high-temperature region to a low-temperature region and is a passive circulation that does not require actively pressurizing the water through the seawater heat exchanger 26.

[0141] Figure 2 shows an embodiment of reactor structure 1 in an accident state with MSR4.

[0142] Figure 1 shows the entire reactor structure 1, including the upper compartment 2 and the discharge tank compartment 3. Molten fuel salt 6 is being discharged from the core, and no fission process is occurring in the molten fuel salt 6 within the core. This discharge was initiated by the loss of external power. This power loss caused the cooling system 14 to shut down, cutting off active cooling to the salt plug 13, which then melted, thus creating a path for the molten fuel salt 6 to flow freely from the MSR 4 through the piping system to the discharge tank 10. The discharge tank 10, located below the upper compartment 2, is shown to contain the fuel salt 6 releasing heat from the decay of fission products. The discharge tank compartment 3 shows the discharge tank 10 completely surrounded by a rectangular buffer water tank 15, as shown in Figure 1. The tank wall 34 divides the buffer water tank 15 into an inner tank region 35 facing the discharge tank 10 and an outer tank region 36. The buffer water 21 in the inner tank region 35 comes into contact with the inner wall 16 facing the discharge tank 10, thus removing heat. The drying wall section 37 connects the tank wall 34 to the outer wall 17, as shown in Figure 1.

[0143] The first piping structure 22 is as described in Figure 1. The first end 28 of the riser pipe is above the water level of the buffer water 21, and steam (not shown) in the inner tank region 35 enters the first end 28 of the riser pipe, which is therefore the inlet for the buffer water steam. Extensive evaporation of the buffer water 21, particularly in the inner tank region 35, may occur immediately after the discharge of the molten fuel salt 6. The steam pressure may be controlled to be below a certain value by steam escaping through perforations 39 in the tank wall 34. The riser pipe 27 extends upward from its first end 28, and the riser pipe 27 is shown to contain evaporated steam as it enters the storage water tank 30 around the height level of the MSR 4 above the discharge tank compartment 3. The second end 29 of the riser pipe is surrounded by the storage water in the storage water tank 30 and is connected to a heat exchanger 23 that is in thermal contact with the storage water. The buffer steam condenses at least partially within the heat exchanger 23, and the buffer water 21 exits the heat exchanger 23 at its outlet end and enters the first end 32 of the downpipe. The downpipe 31 extends downward from its first end 32 and enters the outer tank region 36 of the buffer water tank 15, and the buffer water 21 is guided into the buffer water 21 in the outer tank region 36 through the second end 33 of the downpipe. The second end 33 of the downpipe is below the ring-shaped dry wall section 37 and above the buffer water level. The above circulation of buffer steam and buffer water 21 in the first piping structure 22 is supplemented by the circulation of buffer water 21 by natural convection below the tank wall 34 from the outer tank region 36 to the inner tank region 35.

[0144] The second piping structure 24 is as described in Figure 1. The first end 28 of the riser pipe is above the water level of the buffer water 21, and steam (not shown) in the inner tank area 35 enters the first end 28 of the riser pipe, which is therefore the inlet for the buffer water vapor. The riser pipe 27 extends upward from its first end 28 and is shown to connect to the gas heat exchanger 25 around the height level of the MSR 4 above the discharge tank compartment 3. The second end 29 of the riser pipe is surrounded by the external environment and connects to the gas heat exchanger 25, which is in thermal contact with the external environment. The buffer water vapor condenses at least partially within the heat exchanger 25, and the buffer water 21 exits the gas heat exchanger 25 at the outlet end of the gas heat exchanger 25 and enters the first end 32 of the descender pipe. The descending pipe 31 extends downward from its first end 32 and enters the outer tank area 36 of the buffer water tank 15, and the buffer water 21 is guided into the buffer water 21 in the outer tank area 36 through the second end 33 of the descending pipe. The second end 33 of the descending pipe is below the ring-shaped dry wall section 37 and above the buffer water level.

[0145] The seawater heat exchanger 26 is located outside the buffer water tank 15 and is submerged in seawater below the sea surface. The seawater heat exchanger 26 has an inlet and an outlet for the buffer water, with the inlet being higher than the outlet. The inlet of the buffer water 21 into the seawater heat exchanger 26 has its open end terminated in the inner tank region 35 and, as described above, has a higher temperature due to the decay heat on the other side of the inner tank wall 16. The temperature difference between the buffer water 21 in the inner tank region 35 and the buffer water 21 in the outer tank region 36 causes natural circulation of the buffer water 21. The buffer water 21 enters the buffer water 21 inlet to the seawater heat exchanger 26, is cooled by the seawater which is cooler than the buffer water 21 in the inner tank region 35, and circulates back to the bottom of the buffer water tank 15. The circulation of buffer water 21 through this seawater heat exchanger 26 occurs as a natural circulation from a high-temperature region to a low-temperature region, and is a passive circulation that does not require actively pressurizing the water through the seawater heat exchanger 26.

[0146] In Figure 3, the reactor structure 1 is shown mounted on the barge 40. The reactor structure 1 is shown with the MSR 4 in operation and the molten fuel salt 6 in the core, refer to the description of Figure 1 above. The upper compartment 2 and the discharge tank compartment 3 are surrounded by a double-wall enclosure 41 which may constitute the structure required for the integrity of the hull or biological shielding for the reactor structure.

[0147] A first piping structure 22 and a second piping structure 24 are shown. The first piping structure 22 is shown with an outlet for storage steam passing through the upper deck 42 of the barge 40. The second piping structure 24 is shown with the riser pipe 27 ending and the descender pipe 31 beginning outside the upper deck 42 of the barge 40. The gas heat exchanger 25 is located outside the upper deck 42 of the barge 40 and is surrounded by a heat exchanger 44 structure having openings 45 for the hot air generated from the heat exchanger 44. The hot air is directed into the atmosphere through these openings 45.

[0148] The seawater heat exchanger 26 is located in seawater outside the first wall 46 of the hull structure. The second wall 47 of the hull structure is shown with an opening 48 for the hot seawater resulting from heat exchange with buffer water 21.

[0149] Figure 4 shows a reactor structure in which the buffer water tank is implemented as a tubular system. The reactor structure is similar to that shown in Figure 1. However, the buffer water tank 15 is implemented as a tubular system comprising an inner tube having a hot wall 52 and an outer tube having a cold wall 51, the inner and outer tubes being joined together, and the buffer water from the storage water tank 49 is located in the joined inner and outer tubes of the tubular system, which is also connected to the backup tank 53. The storage water tank 49 houses a condenser 50 that promotes the condensation of evaporated cooling water. The storage water tank 49 is located above the sea level 54.

[0150] Figure 5 shows a furnace structure in which the buffer water tank is implemented as a tube system, comprising a section where the buffer water evaporates, a section where the buffer water is insulated, and a section where the buffer water condenses. The furnace structure is similar to that shown in Figure 4. However, the tube system, which comprises an inner tube with a high-temperature wall 52 and an outer tube with a low-temperature wall 51, comprises a lower evaporation section 57, an intermediate insulated section 56, and an upper condensation section 55, respectively. In the evaporation section 57, the buffer water evaporates. In the insulated section 56, no heat exchange occurs between the buffer water and the environment. In the condensation section 55, the buffer water condenses.

[0151] Figure 6 shows a furnace structure in which the buffer water tank is implemented as a tube system, comprising a section where the buffer water evaporates, a section where the buffer water is insulated, and a section where the buffer water condenses, with the buffer water and seawater in thermal contact below the sea surface. The furnace structure is similar to that shown in Figure 4. However, instead of the tube system being in contact with a storage water tank 49 containing a condenser 50, the tube system is in contact with seawater below the sea surface via a sea chest 58. [Explanation of Symbols]

[0152] 1 Furnace structure 2 Upper compartment 3. Discharge tank compartment 4. Molten Salt Reactor (MSR) 5 Furnace vessel 6. Molten fuel salt 7. Fuel salt pump 8 Primary heat exchanger 9 Emission system 10 Discharge Tanks 11, 110, 111, 112 valves 12 Carrier gas piping 13 Salt Plugs 14 Salt cooling pump 15 Buffer water tank 16 Inner wall 17 Exterior Wall 18 Inner bottom plate 19 Tank bottom plate 20 Fuel Salt Catcher 21 Buffer water 22. First Piping Structure 23 Heat exchanger that comes into thermal contact with the water in the storage tank 24 Second Piping Structure 25. Gas heat exchangers that come into thermal contact with the environment. 26 Seawater heat exchanger 27. Rise-pipe 28 The first end of the ascending pipe 29 The second end of the ascending tube 30 Water storage tanks 31 fall-pipe 32 First end of the descending pipe 33 The second end of the descending pipe 34 Tank wall 35 Inner tank area 36 Outer tank area 37 Dry wall section 38 Wall contact position 39 Dry wall section drilling 40 Barge 41 Double-walled enclosure 42 Upper Deck 43. Outlet for steam from the storage tank 44 Heat exchanger structure 45 Hot air opening 46 The First Wall 47 The second wall 48 Opening for warm seawater 49 Water storage tank 50 Condenser 51 Cold and hot outer wall tube 52 High-temperature wall-inside tube 53 Backup Tank 54 Sea surface 55 Condensing section of the tube system 56 Insulation section of the tube system 57 Evaporator section of the tube system 58 Sea Chest

Claims

1. A furnace structure (1) comprising an upper compartment (2) above a discharge tank compartment (3), The upper compartment (2) is, A molten salt reactor (MSR) (4) comprising a reactor vessel (5) containing molten fuel salt (6), - A molten salt discharge system connected to the furnace vessel (5), Equipped with, The aforementioned discharge tank compartment (3) is - One or more discharge tanks (10) that communicate with the molten salt discharge system, - A buffer water tank (15) comprising an inner wall (16) and an outer wall (17), and buffer water (21) in the gap between the inner wall (16) and the outer wall (17) of the buffer water tank (15), surrounding one or more discharge tanks (10), Equipped with, The first piping structure (22) defines a circuit for at least a portion of the buffer water (21) and includes a heat exchanger (23) that is in thermal contact with the storage water tank (30), the storage water tank (30) being at a level above the buffer water tank (15), and the storage water being in thermal contact with the environment. and / or The second piping structure (24) defines a circuit for at least a portion of the buffer water (21) and includes a heat exchanger (25) that is in thermal contact with the environment, the heat exchanger (25) being at a level above the buffer water tank (15), and / or The furnace structure (1) includes a seawater heat exchanger (26) that is in thermal contact with the buffer water (21) and seawater, and the seawater heat exchanger (26) is located below the seawater surface outside the outer wall (17) of the buffer water tank (15).

2. The furnace structure (1) comprises the upper compartment (2) above the discharge tank compartment (3), The upper compartment (2) is, A molten salt reactor (MSR) (4) comprising a reactor vessel (5) containing molten fuel salt (6), - A molten salt discharge system connected to the furnace vessel (5), Equipped with, The aforementioned discharge tank compartment (3) is - One or more discharge tanks (10) that communicate with the molten salt discharge system, - A buffer water tank (15) that is implemented as a tube system comprising an inner tube (52) and an outer tube (51), wherein the inner tube and the outer tube are joined together, and the buffer water is located within the tubes of the joined inner tube and outer tube of the tube system, and surrounds one or more discharge tanks (10), Equipped with, The first piping structure (22) defines a circuit for at least a portion of the buffer water (21) and includes a heat exchanger (23) that is in thermal contact with the storage water tank (30), the storage water tank (30) being at a level above the buffer water tank (15), and the storage water being in thermal contact with the environment. and / or The second piping structure (24) defines a circuit for at least a portion of the buffer water (21) and includes a heat exchanger (25) that is in thermal contact with the environment, the heat exchanger (25) being at a level above the buffer water tank (15), and / or The furnace structure (1) according to claim 1, wherein the seawater heat exchanger (26) is in thermal contact with the buffer water (21) and seawater, and the seawater heat exchanger (26) is located below the seawater surface outside the outer wall (17) of the buffer water tank (15).

3. The furnace structure (1) comprises the upper compartment (2) above the discharge tank compartment (3), The upper compartment (2) is, A molten salt reactor (MSR) (4) comprising a reactor vessel (5) containing molten fuel salt (6), - A molten salt discharge system connected to the furnace vessel (5), Equipped with, The aforementioned discharge tank compartment (3) is - One or more discharge tanks (10) that communicate with the molten salt discharge system, - A buffer water tank (15) that is implemented as a tube system comprising an inner tube (52) and an outer tube (51), wherein the inner tube (52) and the outer tube (51) are joined together, the buffer water is located within the joined inner and outer tubes of the tube system, the buffer water tank (15) surrounds one or more discharge tanks (10), and the joined inner and outer tubes of the tube system comprise a section (57) where the buffer water evaporates, a section (56) where the buffer water is insulated, and a section (55) where the buffer water condenses. Equipped with, The first piping structure (22) defines a circuit for at least a portion of the buffer water (21) and includes a heat exchanger (23) that is in thermal contact with the storage water tank (30), the storage water tank (30) being at a level above the buffer water tank (15), and the storage water being in thermal contact with the environment. and / or The second piping structure (24) defines a circuit for at least a portion of the buffer water (21) and includes a heat exchanger (25) that is in thermal contact with the environment, the heat exchanger (25) being at a level above the buffer water tank (15), and / or The furnace structure (1) according to claim 1 or 2, wherein the seawater heat exchanger (26) is in thermal contact with the buffer water (21) and seawater, and the seawater heat exchanger (26) is located below the seawater surface outside the outer wall (17) of the buffer water tank (15).

4. The furnace structure (1) comprises the upper compartment (2) above the discharge tank compartment (3), The upper compartment (2) is, A molten salt reactor (MSR) (4) comprising a reactor vessel (5) containing molten fuel salt (6), - A molten salt discharge system connected to the furnace vessel (5), Equipped with, The aforementioned discharge tank compartment (3) is - One or more discharge tanks (10) that communicate with the molten salt discharge system, - A buffer water tank (15) that is implemented as a tube system comprising an inner tube (52) and an outer tube (51), wherein the inner tube (52) and the outer tube (51) are joined together, the buffer water is located within the joined inner and outer tubes of the tube system, the buffer water tank (15) surrounds one or more discharge tanks (10), and the joined inner and outer tubes of the tube system comprise a section (57) where the buffer water evaporates, a section (56) where the buffer water is insulated, and a section (55) where the buffer water condenses. Equipped with, The furnace structure (1) according to any one of claims 1 to 3, wherein the seawater heat exchanger (26) is in thermal contact with the buffer water (21) and seawater, and the seawater heat exchanger (26) is located in a rectangular or cylindrical recess, preferably a sea chest (58), below the seawater surface outside the outer wall (17) of the buffer water tank (15).

5. The furnace structure (1) comprises the upper compartment (2) above the discharge tank compartment (3), The upper compartment (2) is, A molten salt reactor (MSR) (4) comprising a reactor vessel (5) containing molten fuel salt (6), - A molten salt discharge system connected to the furnace vessel (5), Equipped with, The aforementioned discharge tank compartment (3) is - One or more discharge tanks (10) that communicate with the molten salt discharge system, - A buffer water tank (15) comprising an inner wall (16) and an outer wall (17), and buffer water (21) in the gap between the inner wall (16) and the outer wall (17) of the buffer water tank (15), surrounding one or more discharge tanks (10), Equipped with, The first piping structure (22) defines a circuit for at least a portion of the buffer water (21) and includes a heat exchanger (23) that is in thermal contact with a storage water tank (30), the storage water tank (30) being at a level above the buffer water tank (15), and the storage water being in thermal contact with the environment, optionally The second piping structure (24) defines a circuit for at least a portion of the buffer water (21) and includes a heat exchanger (25) that is in thermal contact with the environment, the heat exchanger (25) is located at a level above the buffer water tank (15) and optionally The furnace structure (1) according to any one of claims 1 to 4, wherein the seawater heat exchanger (26) is in thermal contact with the buffer water (21) and seawater, and the seawater heat exchanger (26) is located below the seawater surface outside the outer wall (17) of the buffer water tank (15).

6. The first piping structure (22) is, - At least one riser pipe (27) having a first end (28) that serves as an inlet for at least a portion of the buffer water (21) and a second end (29) that is in contact with the inlet of the heat exchanger (23) in the storage water tank (30), - A furnace structure (1) according to any one of claims 1 to 5, comprising: a first end (32) in contact with the outlet of the heat exchanger (23) in the storage water tank (30) and a second end (33) which serves as an outlet for at least a portion of the buffer water (21).

7. The furnace structure (1) according to claim 6, wherein the minimum cross-section of the first end (28) of the riser pipe is larger than the minimum cross-section of the second end (33) of the descender pipe.

8. The natural convection enhancer is contained in the buffer water (21) in the buffer water tank (15), and the natural convection enhancer includes a tank wall (34) in the gap between the inner wall (16) and the outer wall (17) that divides the buffer water tank (15) into an inner tank region (35) and an outer tank region (35), and the tank wall (34) extends beyond the buffer water level into a dry wall section (37) that contacts the outer wall (17) at a wall contact position (38). - The dry wall section (37) and / or the inner wall (16) are provided with perforations (39) that allow air circulation between the inner tank area (35) and the outer tank area (36), - The furnace structure (1) according to any one of claims 1 to 7, wherein the first end (28) of the riser pipe is positioned above the wall contact position (38), and the second end (33) of the descender pipe is positioned below the wall contact position (38).

9. The inner wall (16) of the buffer tank is connected to an inner bottom plate (18), and as a result, the inner wall (16) and the inner bottom plate (18) have a bowl shape, according to any one of claims 1 to 8, furnace structure (1).

10. The molten salt discharge system is a molten fuel salt discharge system and comprises a salt piping system having at least one salt plug (13), according to any one of claims 1 to 9, the furnace structure (1).

11. The gas supply system further comprises, ・Carrier gas storage tank and - A carrier gas piping (12) having at least one valve (11, 110, 111, 112), the carrier gas piping (12) connecting from the carrier gas storage tank to one or more discharge tanks (10), A furnace structure (1) according to any one of claims 1 to 10, comprising:

12. The molten fuel salt (6) is Sodium fluoride + potassium fluoride + uranium fluoride, Lithium fluoride + thorium fluoride + plutonium fluoride, Lithium fluoride + thorium fluoride + uranium fluoride, Lithium fluoride + Beryllium fluoride + Uranium fluoride Lithium fluoride + beryllium fluoride + uranium fluoride + thorium fluoride, Lithium fluoride + beryllium fluoride + uranium fluoride + thorium fluoride + zirconium fluoride, Sodium fluoride + rubidium fluoride + uranium fluoride, Sodium fluoride + Beryllium fluoride + Uranium fluoride + Thorium fluoride + Zirconium fluoride, Potassium chloride + plutonium chloride + uranium chloride, Sodium chloride + plutonium chloride, Sodium chloride + Plutonium chloride + Uranium chloride A furnace structure (1) according to any one of claims 1 to 11, comprising a composition selected from the group consisting of compositions comprising the above.

13. The furnace structure according to any one of claims 1 to 12, wherein the MSR further comprises a moderator based on a material selected from the group consisting of graphite material, Be compound-containing material, and molten salt of a metal hydroxide, and if the moderator is a molten salt of a metal hydroxide, the furnace structure further comprises a molten salt of a metal hydroxide discharge system including a molten salt of a metal hydroxide discharge tank.

14. The aforementioned furnace structure is equipped with a compartment separator, and the compartment separator is, A grid structure that forms a substantially horizontal surface separation between the upper compartment and the discharge tank compartment, comprising a metal grid and a heat insulating layer, One or more funnels penetrating the grid structure, each funnel having a plug made of sacrificial material, A furnace structure according to any one of claims 1 to 13, comprising:

15. The reactor structure according to any one of claims 1 to 14, wherein the MSR (4) is located on an offshore structure, preferably a barge (40).

16. A method of transferring heat from a molten salt, - A step of supplying molten fuel salt (6) to one or more discharge tanks (10) for molten fuel salt (6), - A step of surrounding one or more discharge tanks (10) for the molten fuel salt (6) with a buffer water tank (15), wherein the buffer water tank (15) contains buffer water (21) in the gap between the inner wall (16) and the outer wall (17) of the buffer water tank, and the molten fuel salt (6) transfers heat through at least one of thermal radiation, thermal conduction, or thermal convection with the inner wall (16), heating the buffer water (21) to vapor, - A step of providing a first piping structure (22), wherein the first piping structure (22) is At least one riser pipe (27) above at least a portion of the buffer water (21) collects steam and guides the steam to a heat exchanger (23) in the stored water in the storage water tank (30) above the buffer water tank (15), and condenses the steam into water, At least one descending pipe (31) for guiding water from the heat exchanger (23) in the water storage tank (30) to the buffer water tank (15), It has steps, and / or - A step of providing a second piping structure (24), wherein the second piping structure (24) is At least one riser pipe (27) above at least a portion of the buffer water (21), the riser pipe (27) collects steam and leads the steam to a gas heat exchanger (25) which is in thermal contact with a gas-containing environment, the gas heat exchanger (25) is located above the buffer water tank (15), and the riser pipe (27) condenses the steam into water. At least one down pipe (31) for guiding water from the gas heat exchanger (25) to the buffer water tank (15), It has steps, and / or A step of providing a seawater heat exchanger (26) that comes into thermal contact with the buffer water (21), wherein the seawater heat exchanger (26) is positioned below the seawater level outside the outer wall (17) of the buffer water tank (15), and the buffer water (21) circulates through the seawater heat exchanger (26), A method of heat transfer from a molten salt, including the method described above.

17. The method for transferring heat from a molten salt according to claim 16, further comprising heat transfer from the storage water tank (30) to an environment such as the external environment that is in thermal contact with the storage water tank (30).

18. The heat transfer method from a molten salt according to claim 17, wherein the heat transfer from the storage water tank (30) is carried out at least partially through the evaporation of the storage water to the external environment.

19. The heat transfer method from a molten salt according to any one of claims 16 to 18, wherein the heat transfer is a passive heat transfer method.

20. A natural convection enhancer, which has a tank wall (34) in the gap between the inner wall (16) and the outer wall (17), divides the buffer water tank (15) into an inner tank region (35) and an outer tank region (36), - The buffer water (21) in the inner tank region (35) is brought to a boil. A method for transferring heat from a molten salt according to any one of claims 16 to 19, comprising providing an upward flow path for steam.

Images