A liquid metal, alloy, or molten salt nuclear reactor comprising heat transfer fins and capable of consuming nuclear fuel stored as waste.

Abstract

The present invention relates to a liquid metal or molten alloy or salt nuclear reactor in which the heat produced is transferred by heat transfer fins for use in generating electricity and / or heat. This nuclear reactor is designed to meet the safety criteria defined for a fourth-generation nuclear reactor capable of using nuclear fuel stored as waste.

Description

Title of the invention: Nuclear reactor with liquid metal or molten alloys or salts comprising heat-carrying fins and capable of consuming nuclear fuel stored as waste.

[0001] The present invention relates to a liquid metal or molten alloy or salt nuclear reactor in which the heat produced is transferred by heat transfer fins for use in generating electricity and / or heat. This nuclear reactor is designed to meet the safety criteria defined for a fourth-generation nuclear reactor, capable of using nuclear fuel stored as waste, and to ensure a country's energy sovereignty. State of the art:

[0002] The growth of the world's population over the last two centuries is largely due to advances in modern medicine and improved living standards. This has led to a significant reduction in infant, child, and maternal mortality, thereby contributing to increased life expectancy. The current world population is 7.6 billion. It continues to grow, but at a slower pace than in the past. It is projected to increase by 1 billion within 15 years and by another billion within 25 years, reaching 10 billion by 2050. These projections are based on average variations, which assume a decline in the fertility rate and an increase in life expectancy. This population growth is accompanied by a growing need for energy.

[0003] Moreover, approximately 90% of its global production comes from fossil fuels such as coal, gas, and oil. Therefore, the use of energy sources compatible with high and sustainable development is one of the major challenges of the 21st century.

[0004] The development of clean energy technologies that can reduce dependence on fossil fuels is therefore of great interest, particularly as a generator of electricity and / or heat.

[0005] The concept of a liquid metal or molten salt reactor was first proposed in 1946 by the USA to create a nuclear-powered supersonic jet. Corrosion caused by pipes cracked by hot salt and the low radioactivity of thorium made it very difficult to develop fission reactions at sustained levels without the addition of uranium.

[0006] In reactor engineering (see US, JP, UK, FR, CN docs), it is common practice to propose the use of liquid metals because these are alloys with low melting points. This allows for an operating temperature range generally higher than the At ambient temperature, even at ambient pressure, liquid metals or alloys can be used as coolants because they possess excellent heat transfer properties and are suitable for use in low-pressure systems. This is the case in a sodium-cooled reactor (Phoenix, Astrid). Furthermore, liquid metals or alloys absorb very few neutrons, allowing the reactor to operate with a fast neutron spectrum. Consequently, a liquid metal or alloy fast reactor is a high-power-density reactor that does not necessarily require a neutron moderator. The main differences between thermal reactors and fast reactors lie in their neutron cross-sections, which exhibit significant energy dependence. However, it should be noted that the drawback of many alloys lies in their high chemical activity, particularly their interaction with oxygen, water, and other materials.

[0007] In most known reactors, the core is enclosed in a reflective containment structure capable of reflecting the neutrons generated by nuclear fission; the liquid metal or molten salts / fuel is pumped from the core to the heat exchanger by a pump located outside the core containment structure. Furthermore, the use of control rods remains necessary to prevent any risk of core overheating. These control rods are generally mounted to slide along the longitudinal direction of the reactor so that they can be more or less immersed in the reactor core. In combination with a moderator structure and depending on the length of the immersed control rod, they allow control of the fuel temperature and the velocity of the neutrons generated by fission. Controlling the reactor with such control rods is particularly challenging.Furthermore, the presence of such control rods significantly increases the height and overall size of known reactors. Finally, an emergency cooling system is generally included in older reactors, which increases the manufacturing and maintenance costs of the reactors.

[0008] By way of example, US patent 0027536 describes a concept for a portable heat pipe reactor that has a monolithic core made of solid stainless steel. A heat pipe reactor has the advantage of not requiring an active pump. However, the fuel and heat pipe configuration of the solid monolith can cause neutron leakage and absorption by the monolith.

[0009] By way of example, patent JP2014 / 119429 describes, in one of its configurations, a molten salt reactor in which the cooling circuit does not pass through the reactor core but uses fins attached to the vessel and a thermosiphon, both enclosed in a common housing. This configuration presents a common mode, a risk of the thermosiphon losing its prime, and it does not appear to include a corium receptacle to ensure a high level of safety.

[0010] By way of example, patent WO2016 / 197807 describes a molten salt reactor in which the The cooling circuit passes through the reactor core. This configuration presents a safety risk, particularly in the event of a cooling circuit failure.

[0011] By way of example, patent GB2543461 describes a recommendation for a building One example is the future AP1000 reactor, which features metal rods running through the reactor building to dissipate residual heat in the event of an accident. This configuration is used to reinforce the Emergency Injection Network (EIN) but is not designed for use with a reactor operating at full power.

[0012] By way of example, US patent 2018 / 075931 describes a molten salt reactor in which the cooling circuit passes through the reactor core. This configuration presents a safety risk, particularly in the event of a failure of the cooling circuit.

[0013] In the present novel and inventive application, the high-safety liquid metal and / or molten salt nuclear reactor operates at near-ambient pressure. The nuclear reactor transfers heat via heat transfer fins, which are not attached to the reactor containment vessel, the safety vessel, or the protective shell, to the outside of the reactor and / or the containment vessel without thermosiphoning. The nuclear reactor can be operated for heating and / or for electricity generation by a conventional or supercritical device.

[0014] Compared to current operating technologies (PWR, EPR, PWR), the nuclear reactor in the present invention requires fewer components (no primary circuit or circuit passing through the reactor) and allows for increased efficiency and safety. The present invention structurally reduces investment, construction, maintenance, operating, and fuel costs.

[0015] This invention is designed to meet the safety criteria defined for a fourth-generation nuclear reactor, capable of consuming nuclear fuel stored in the form of waste, and to ensure in the long term the energy sovereignty of a country such as France. Summary of the invention

[0016] The present invention relates to the implementation of a liquid metal and / or molten salt nuclear reactor offering certain advantages by eliminating most of the drawbacks of loop and through-circuit systems and allowing for a significant reduction in investment costs compared to current reactors. The present invention mainly consists of a high-safety nuclear reactor which may include a containment vessel, a nuclear reactor core housed inside the containment vessel, a neutron reflector spaced from the containment vessel and positioned between the core and the containment vessel, and a fuel composed of a nuclear fission material dissolved in a liquid metal and / or molten salt as the main constituent. from the core of the nuclear reactor, a plurality of heat transfer fins, a possible heat exchanger external to the reactor to receive the heat transfer, at least one nuclear reactor shutdown system, a safety / retention tank surrounding the containment vessel to collect the corium and thus provide another containment barrier, possibly a protective shell providing another containment barrier. Brief description of the drawings

[0017] The liquid metal or molten alloy or salt nuclear reactor of the present invention will be better understood from the figures:

[0018] [Fig-1] [Fig. 1] is a cross-sectional view of one embodiment of the nuclear reactor in a normal operating state.

[0019] [Fig.2] Fig.2 is a cross-sectional view of another embodiment of the reactor nuclear in a normal operating state.

[0020] [Fig.3] Fig.3 is a top view of one embodiment of the reactor nuclear in a normal operating state.

[0021] [Fig.4] Fig.4 is a schematic view of one mode of reactor use nuclear.

[0022] [Fig. 5] [Fig. 5] is a schematic view of another mode of reactor use nuclear.

[0023] [Fig. 6] Fig. 6 is a top view of a heat transfer device under the reactor. Description of the invention:

[0024] The liquid metal or molten alloy or salt nuclear reactor can generate reliable, safe, and emission-free energy for heat and electricity production at decentralized sites. Decentralized emission-free energy production can complement or even exceed centralized electricity generation capacity, thereby increasing the distribution and availability of clean and reliable energy at significant cost savings. Indeed, the fuel cost is reduced. The fuel is molten, so there is no need for a fuel fabrication plant, which can represent substantial savings, particularly during operation. For example, thorium has a low cost, approximately €0.03 / MWh of electricity. Compared to uranium, at approximately €10 / MWh of electricity, thorium would be about 300 times cheaper.

[0025] The liquid metal or molten alloy or molten salt nuclear reactor has the potential to generate a much smaller quantity of very long-lived radioactive waste.

[0026] The liquid metal or molten alloy or salt nuclear reactor may possibly to help reduce the risk of nuclear weapons proliferation.

[0027] The liquid metal, alloy, or molten salt nuclear reactor can potentially play a vital role in the deployment of a closed fuel cycle and the reduction of long-lived waste. The thorium nuclear cycle produces traces of uranium-232 when fast neutrons eject a neutron by (n, 2n) reaction from thorium-232 nuclei. The uranium-232 undergoes alpha decay and joins the thorium-228 decay chain. It should be noted that during this process, elements such as radium-224 emit significant gamma radiation.

[0028] The liquid metal, alloy, or molten salt nuclear reactor can burn uranium, thorium, or plutonium and transform minor actinides, long-lived nuclear waste, into shorter-lived nuclear waste through transmutation. The ultimate waste is then limited to the fission products of the minor actinides, which are simpler to store. In this case, the radioactivity level is close to 300 years. Furthermore, by using the stocks of depleted uranium and the spent fuel from reactors currently installed in France, this nuclear reactor is capable of autonomously supplying energy to a country like France for 500 years.

[0029] Given the high power density, it is possible to design and construct a very small liquid metal or molten alloy or salt nuclear reactor for decentralised energy production of heat and / or electricity outside the transmission network.

[0030] It is possible to design and construct a very small liquid metal, alloy, or molten salt nuclear reactor for energy production on Earth, the Moon, or Mars. The dimensions and materials used for the design and construction are specified for operation on Earth but can easily be adapted to each specific scenario.

[0031] It is also possible to have a small reactor core without very high enrichment. Furthermore, the neutron behavior of the molten fuel improves the control capability required for autonomous operation.

[0032] By design, the liquid metal, alloy, or molten salt nuclear reactor can produce as much or more fissile material than it consumes. In other words, each time a fast neutron causes the fission of a plutonium-239 atom, other neutrons simultaneously transform uranium-238 into plutonium-239. The necessary condition for the continuous regeneration of plutonium is that the neutrons not be slowed down.

[0033] The liquid metal, alloy, or molten salt nuclear reactor can operate differently depending on the application: • in generator (equality between production and consumption of matter) fissile) • as a sub-reactor (net consumption of fissile materials) to consume plutonium • in a breeder reactor (plutonium production exceeding consumption).

[0034] The fuel is integrated into a liquid metal and / or molten salt and cooled by heat removal to the outside of the containment vessel of the liquid metal or alloy or molten salt nuclear reactor by heat transfer. It therefore incorporates a novelty and an innovation aimed at strengthening the safety of a basic nuclear installation.

[0035] The fuel used is in the form of a mixture of uranium-238 (approximately 80%) and plutonium (approximately 20%) or thorium. The fuel is immersed in a liquid metal or molten salts. The liquid metal or molten salts acts as a coolant. The temperature in the core of the nuclear reactor is between 600°C and 800°C. The fuel transfers the heat generated by fission to an external circuit via heat transfer fins through which a heat transfer fluid can circulate.

[0036] To meet safety requirements, a corium (molten core) safety / recovery vessel is placed under and / or around the containment vessel of the liquid metal or molten alloy or salt nuclear reactor to collect the corium in the event of a core meltdown. The objective is to collect the corium, spread it out, cool it, and contain the radioactivity.

[0037] A protective shell or other enclosure made of steel or concrete can serve as an additional containment barrier to increase the safety of the liquid metal or molten alloy or salt nuclear reactor.

[0038] A deterministic approach complemented by a probabilistic approach makes it possible to consider virtually all types of possible accidents, even if the probability of the event occurring is low. The hypothesis of a severe accident is taken into account. The core geometry is designed to have a negative void ratio, allowing the chain reaction to stop in the event of a loss of liquid metal, even in the hypothetical situation where no protection system is functioning. Malicious acts are taken into account in the design, including the intentional crash of an aircraft.

[0039] The energy conversion system may use a gas (nitrogen) heat exchanger. The overall net efficiency of the reactor may exceed 50%. Residual thermal power may be passively removed, in the event of a loss of electrical sources, by gas / air heat exchangers, through natural convection.

[0040] The liquid metal or molten alloy or salt nuclear reactor does not need to be built near large watercourses.

[0041] The liquid metal or molten alloy or salt nuclear reactor has a confi- geometric figure that allows inspection of internal structures.

[0042] The liquid metal or molten alloy or salt nuclear reactor can be operated for heating use and / or for electricity production by a conventional or supercritical device.

[0043] The high-safety liquid metal or alloy or molten salt nuclear reactor is designed so that the fuel is cooled by liquid metal and / or by molten salts.

[0044] The liquid metal or molten alloy or salt nuclear reactor is designed to operate at near ambient pressure.

[0045] The liquid metal or molten alloy or salt nuclear reactor is designed to transfer heat outside the core of the nuclear reactor by means of heat-carrying fins not attached to the containment vessel of the nuclear reactor and without thermo-siphon.

[0046] The liquid metal or molten alloy or salt nuclear reactor is not limited to the few examples of embodiment described, on the contrary it is susceptible to variants and modifications.

[0047] The liquid metal or molten alloy or salt nuclear reactor (1000) includes a nuclear thermal energy generation device of a few kW to a few MW thermal and can provide reliable, sustainable, flexible, safe energy at a moderate cost.

[0048] The liquid metal or molten metal alloy or molten salt nuclear reactor (1000) has its core housed in a containment vessel. The core of the liquid metal or molten metal alloy or molten salt nuclear reactor is the site of the nuclear fission reactions and therefore the site of heat and radiation release. This design offers several advantages, particularly from a safety perspective, as it ensures excellent containment of radioactive materials, high thermal inertia, and relatively simple operation. Furthermore, it should be noted that with such a configuration, considerable latitude is possible in calculating thermal characteristics and heat exchange, particularly regarding the dimensions of piping and heat transfer fins, as well as associated pressure losses. Under these conditions, the nuclear reactor is much easier to size and optimize to reduce the cost of an installation.

[0049] The liquid metal or molten alloy or salt nuclear reactor (1000) is self-stabilizing. Indeed, during an increase in reactivity, the temperature rises. The strong thermal expansion of the liquid metal / fuel mixture pushes it out of the active region of the core as it heats up, thus decreasing its density in the active region of the core and reducing reactivity in the reactor. The temperature drops immediately. Conversely, when the liquid metal / fuel mixture cools, the density in the core increases, the probability of fission increases, as does the capacity to generating heat. These two effects give the reactor its stability and allow it to meet the power demand (heat extraction by the fins). The reactor core temperature, and therefore the thermal power produced by the reactor, is thus regulated by heat extraction.

[0050] The liquid metal or molten alloy or molten salt nuclear reactor (1000) is designed for a long service life.

[0051] The liquid metal or molten alloy or molten salt nuclear reactor (1000) does not require any planned maintenance.

[0052] The liquid metal or molten alloy or molten salt nuclear reactor (1000) allows autonomous energy production for decentralized needs.

[0053] The liquid metal or alloy or molten salt nuclear reactor (1000) comprises a modular nuclear reactor with a high degree of safety which incorporates fourth generation reactor safety criteria.

[0054] The liquid metal or molten alloy or molten salt nuclear reactor (1000) includes a passive heat transport system.

[0055] The liquid metal or molten alloy or molten salt nuclear reactor (1000) includes at least one shutdown system.

[0056] The liquid metal or molten alloy or molten salt nuclear reactor (1000) includes a safety / retention vessel, to recover the corium in case of meltdown of the containment vessel.

[0057] According to a configuration of the liquid metal or molten alloy or salt nuclear reactor (1000), the reactor includes a neutral gas buffer tank and means for injecting said neutral gas into the gaseous space for the purpose of compensating for variations in fuel volume.

[0058] According to a configuration of the liquid metal or molten alloy or salt nuclear reactor (1000), fission gases, such as helium, xenon, krypton, and radon, are generated by the nuclear fission reaction in the reactor core. Volatile fission gases are toxic to reactors, and to increase reactor life, it is preferable to eliminate them. Therefore, it may be appropriate to install a device that adsorbs the fission gases, such as molecular sieves, to trap and retain these gases in order to reduce the pressure in the reactor vessel. In this case, the cooling of the molecular sieves can be achieved passively by convective or heat-transfer fins.

[0059] According to a configuration of the liquid metal or alloys or molten salts nuclear reactor (1000), the liquid metal / or molten salt is molten halide.

[0060] According to a configuration of the liquid metal or alloys or molten salts nuclear reactor (1000), the fuel such as uranium oxyhalide is dissolved in the molten metal / or salt (1010).

[0061] According to a configuration of the liquid metal or molten alloy or salt nuclear reactor (1000), the fuel such as UO2Cl2 / UO4 / Plutonium / Thorium is dissolved in KC1 (1010).

[0062] According to a configuration of the liquid metal or molten alloy or salt nuclear reactor (1000), the fuel such as UO2Cl2 / UO4 / Plutonium / Thorium is dissolved in MgCi2 (1010).

[0063] According to a configuration of the liquid metal or molten alloy or salt nuclear reactor (1000), the fuel such as UO2Cl2 / UO4 / Plutonium / Thorium is dissolved in NaCl(1010).

[0064] According to a configuration of the liquid metal or molten alloy or salt nuclear reactor (1000), the fuel such as UO2Cl2 / UO4 / Plutonium / Thorium is dissolved in an alkali or alkaline earth metal halide salt such as a mixture of sodium chloride, potassium chloride, magnesium chloride, calcium chloride (1010).

[0065] According to a configuration of the liquid metal or molten alloy or salt nuclear reactor (1000), fluorides can also be used instead of chlorides.

[0066] According to a configuration of the liquid metal or molten alloy or salt nuclear reactor (1000), the fuel can be uranium chloride or uranium fluoride, uranium oxide or uranium oxyhalides, with possible mixtures of thorium halides and transuranic elements.

[0067] According to one configuration of the invention, the liquid metal or alloys or molten salts nuclear reactor (1000) is a liquid metal / molten salts fast reactor in which the liquid fuel is retained and is not pumped.

[0068] According to one configuration of the invention, the liquid metal or molten alloy or molten salt nuclear reactor (1000) is a thermal reactor in which moderators can be introduced into the core of the liquid metal or molten alloy or molten salt nuclear reactor.

[0069] According to one configuration of the invention, the liquid metal or molten alloy or salt nuclear reactor (1000) is functionally coupled to a heat exchanger which is used to heat a fluid, which may be a superheated gas, or to generate steam for use in a steam turbine to drive an alternator, similar to those of conventional water-cooled reactors. These devices are well known in the power generation industry.

[0070] According to one configuration of the invention, the liquid metal or molten alloy or salt nuclear reactor (1000) is used to directly heat a fluid, which may be a superheated gas, to drive a turbine and / or an alternator. These devices are well known in the power generation industry.

[0071] According to a configuration of the liquid metal or alloys or salts nuclear reactor fused (1000), a neutron mirror or reflector (1020) is arranged inside a containment tank (1040).

[0072] According to a configuration of the liquid metal or molten alloy or salt nuclear reactor (1000), a neutron mirror or reflector (1020) may be annular and have walls, a floor and a ceiling.

[0073] According to a configuration of the liquid metal or molten alloy or salt nuclear reactor (1000), a neutron mirror or reflector (1020) can be made of alumina oxide (Al2O3), beryllium oxide (BeO), or beryllium carbide (Be2C).

[0074] According to a configuration of the liquid metal or alloy or molten salt nuclear reactor (1000), a neutron mirror or reflector (1020) makes it possible to reflect neutrons towards the core of the nuclear reactor, in order to improve the fission process, to stabilize the operating point of the liquid metal or alloy or molten salt nuclear reactor, to optimize the proper distribution of neutron flux inside the liquid metal or alloy or molten salt nuclear reactor according to its geometric dimensions and the quantity of fuel desired to obtain the desired thermal power.

[0075] According to one configuration of the invention, the liquid metal or molten alloy or salt nuclear reactor (1000) is a fast reactor having a thick neutron mirror or reflector (1020) spaced from the inside of the walls of the containment vessel (1040).

[0076] According to one configuration of the invention, the liquid metal or molten alloy or salt nuclear reactor (1000) comprises a containment vessel (1040) having side walls, for example, in the form of a cylinder, a floor / bottom of the vessel and a ceiling / lid of the vessel.

[0077] According to one configuration of the invention, the liquid metal or molten alloy or salt nuclear reactor (1000) comprises a containment vessel floor / bottom (1200) and a containment vessel ceiling / lid (1100) which can be bolted together to facilitate assembly and disassembly of the containment vessel and also ensure good sealing.

[0078] According to one configuration of the invention, the liquid metal or molten alloy or salt nuclear reactor (1000) includes a containment vessel ceiling / lid (1100) which includes ports for the rotating rods of the shutdown system and for the fission gas management system.

[0079] According to one configuration of the invention, the liquid metal or molten alloy or salt nuclear reactor (1000) includes a containment vessel floor / bottom (1200) which includes one or more orifices to facilitate the flow of corium into the safety / retention vessel (1060).

[0080] According to one configuration of the invention, the liquid metal nuclear reactor or alloys or molten salts (1000) the / a safety / containment tank ceiling / cover (1060) includes ports for the rotating rods of the shutdown system and for the fission gas management system.

[0081] According to a configuration of the liquid metal or alloys or molten salts nuclear reactor (1000), a containment vessel (1040) contains the core of the liquid metal or alloys or molten salts nuclear reactor and is the site of the nuclear fission reactions and therefore the site of heat and radiation release.

[0082] According to a configuration of the liquid metal or alloys or molten salts nuclear reactor (1000), a containment vessel (1040) contains the fuel dissolved in the liquid metal / or molten salts, the reflector / the mirror, the moderator, the rotating rods.

[0083] Depending on a configuration of the liquid metal or molten salt or alloy nuclear reactor (1000), a containment vessel (1040) may be made of a structural material to fulfill the containment function. The material may also have good conductive properties. Examples of materials include stainless steel and other structural alloys with good conductivity.

[0084] According to a configuration of the liquid metal or alloy or molten salt nuclear reactor (1000), the containment vessel (1040) is dimensioned to facilitate the fission process, stabilize the operating point of the liquid metal or alloy or molten salt nuclear reactor, optimize the proper distribution of neutron flux according to the geometric characteristics and the quantity of fuel desired to obtain the desired thermal power.

[0085] Depending on a configuration of the liquid metal or molten salt or alloy nuclear reactor (1000), the containment vessel (1040) can be housed in a protective shell (1080) which serves as a containment barrier or external protection. The protective shell contributes to achieving a high level of safety.

[0086] According to a configuration of the liquid metal or molten alloy or salt nuclear reactor (1000), the containment vessel (1040) can be housed within a safety / retention vessel (1060) which acts as a containment barrier. The safety / retention vessel contributes to achieving a high level of safety.

[0087] Depending on a configuration of the liquid metal or molten salt or alloy nuclear reactor (1000), the safety / containment vessel (1060) can be housed in a protective shell (1080) which serves as a containment barrier or external protection. The protective shell contributes to achieving a high level of safety.

[0088] According to a configuration of the liquid metal or molten alloy or salt nuclear reactor (1000), a protective shell (1080) can provide another containment function against leaks of fission and radiation materials.

[0089] Depending on a configuration of the liquid metal or molten alloy or salt nuclear reactor (1000), a protective shell (1080) can provide a safe barrier against the external threats to the core of the liquid metal or alloy or molten salt nuclear reactor.

[0090] According to a configuration of the liquid metal or molten alloy or salt nuclear reactor (1000), a protective shell (1080) can be made of concrete of an appropriate thickness or of a refractory material or of an appropriate structural metal which fulfills the desired functions.

[0091] According to one configuration of the invention, the cooling / or heat transfer of the liquid metal or molten alloy or salt nuclear reactor (1000) can be carried out passively by convective or conductive or heat-carrying fins (1050) between the containment vessel (1040) and the safety / retention vessel (1060), then by convective or conductive or heat-carrying fins (1070) between the safety / retention vessel (1060) and the protective shell (1080), then by convective or conductive or heat-carrying fins (1090) outside the protective shell (1080).

[0092] According to one configuration of the invention, the cooling / or heat transfer of the liquid metal or molten alloy or salt nuclear reactor (1000) can be carried out passively by convective or conductive or heat-carrying fins (1050) between the containment vessel (1040) and the protective shell (1080), then by convective or conductive or heat-carrying fins (1070) between the safety / retention vessel (1060) and the protective shell (1080), then by convective or conductive or heat-carrying fins (1090) outside the protective shell (1080).

[0093] According to a configuration of the liquid metal or molten alloy or salt nuclear reactor (1000), the convective or conductive or heat-carrying fins (1050, 1070, 1090) can be made of stainless steel, copper, tungsten or heat pipe plates.

[0094] According to a configuration of the liquid metal or molten alloy or salt nuclear reactor (1000), the heat transfer fins (1090) may include fluid transfer tubes in their interiors and thus be traversed by a heat transfer fluid.

[0095] According to a configuration of the liquid metal or molten alloy or salt nuclear reactor (1000), the heat transfer fins (1090) through which a heat transfer fluid flows can be connected to a heat pipe.

[0096] According to a configuration of the liquid metal or molten alloy or salt nuclear reactor (1000), the heat transfer fins (1090) through which a heat transfer fluid flows contribute to obtaining a high level of safety.

[0097] According to a configuration of the liquid metal or molten alloy or salt nuclear reactor (1000), the convective or conductive or heat-carrying fins are similar to those known in the art and can be constructed in the same way.

[0098] According to a configuration of the liquid metal or alloys or salts nuclear reactor molten (1000), the interior of the containment vessel or retention vessel of the liquid metal or molten alloy or salt nuclear reactor and all other structures may be made from corrosion-resistant materials such as nickel or molybdenum steel alloys, ceramics, such as alumina or coated with a corrosion / erosion-resistant material, such as high nickel steel, other metals or ceramics.

[0099] According to one configuration of the invention, the liquid metal or molten alloy or salt nuclear reactor (1000) is designed to adapt to the liquid state of the already molten fuel so that there is no risk of fuel melting as is the case when solid fuel can potentially melt at high temperatures in certain severe accident scenarios.

[0100] According to a configuration of the liquid metal or molten alloy or salt nuclear reactor (1000), the containment vessel (1040) is preferably made of a neutron reflecting material such as alumina, which has a very high melting point of the order of 2000°C, and has very little chance of failure due to temperature.

[0101] According to a configuration of the liquid metal or molten alloy or salt nuclear reactor (1000), the ceiling of the containment vessel (1100) is preferably made of a material which has a very high melting point of the order of 2000°C.

[0102] According to a configuration of the liquid metal or molten alloy or salt nuclear reactor (1000), the floor of the containment vessel (1200) is preferably made of a material which has a very high melting point of the order of 2000°C. In this case, the floor of the containment vessel (1200) comprises a metal plate(s) (1300) bolted to the floor with a melting point of the order of 1200°C which closes the orifice(s).

[0103] According to a configuration of the liquid metal or molten alloy or salt nuclear reactor (1000), the floor of the containment vessel (1200) is preferably made of a material which has a melting point of the order of 1200°C.

[0104] According to a configuration of the liquid metal or molten alloy or salt nuclear reactor (1000), the safety / containment vessel (1060) is preferably made of a material which has a very high melting point of the order of 2000°C, and has very little chance of failure due to temperature.

[0105] Depending on a configuration of the liquid metal or molten salt or alloy nuclear reactor (1000), the containment vessel roof (1100), the containment vessel floor (1200), the metal plate(s) (1300), and the bolts may be made of a structural material to fulfill the containment function. The material may also have good conductive properties. Examples of such materials include stainless steel and other structural alloys with good conductivity.

[0106] According to one configuration of the invention, the liquid metal or molten alloy or salt nuclear reactor (1000) includes at least one fusible plug / or melting plug which can be positioned to block, under normal operating conditions, a passage in the wall of the neutron reflector and containment vessel (1040) leading to a safety / retention vessel (1060) which is used to recover the corium.

[0107] According to one configuration of the invention, in the event that the heat transfer does not function properly or if there is a cause of increase in the temperature of the core of the liquid metal or molten alloy or salt nuclear reactor, the shutter / plug / floor / plate / bolted plate(s) of the containment vessel melts(ent) in response to the predetermined temperature increase, draining the molten fuel towards the safety / retention vessel (1060).

[0108] According to one configuration of the invention, the liquid metal or molten alloy or salt nuclear reactor (1000) includes a reactor shutdown system.

[0109] According to a configuration of the liquid metal or molten alloy or molten salt nuclear reactor (1000), the liquid metal or molten alloy or molten salt nuclear fission reaction must start with a radioactive source.

[0110] According to a configuration of the liquid metal or molten alloy or salt nuclear reactor (1000), a neutron-absorbing material can be used in the shutdown system in the form of absorbing spheres, such as boron carbide spheres.

[0111] According to a configuration of the liquid metal or alloys or molten salts nuclear reactor (1000), the safety / retention vessel (1060) is located below the containment vessel (1040).

[0112] According to a configuration of the liquid metal or alloys or molten salts nuclear reactor (1000), the safety / retention vessel (1060) is located around the containment vessel (1040).

[0113] According to a configuration of the liquid metal or molten alloy or salt nuclear reactor (1000), the safety / retention vessel (1060) includes heat dissipation elements that dissipate heat to cool the molten fuel. The safety / retention vessel (1060) serves to collect the corium and allows the corium to cool. The safety / retention vessel (1060) contributes to achieving a high level of safety.

[0114] According to a configuration of the liquid metal or alloys or molten salts nuclear reactor (1000), the safety / retention vessel (1060) serves as a containment barrier.

[0115] According to a configuration of the liquid metal or molten alloy or salt nuclear reactor (1000), the safety / retention vessel (1060) may by construction include a neutron-absorbing material.

[0116] According to a configuration of the liquid metal or alloys or salts nuclear reactor molten (1000), the safety / retention vessel (1060) may include heat dissipation fins (not described) inside / under the protective shell to better cool the corium.

[0117] According to a configuration of the liquid metal or molten alloy or salt nuclear reactor (1000), the safety / containment vessel (1060) comprises a containment vessel floor / bottom (not described) and a containment vessel ceiling / lid (not described) which can be bolted together to facilitate assembly and disassembly of the containment vessel and also ensure good sealing.

[0118] Depending on a configuration of the liquid metal or molten salt or alloy nuclear reactor (1000), a safety / containment vessel (1060) may be made of a structural material to fulfill the containment function. The material may also have good conductive properties. Examples of materials include stainless steel and other structural alloys with good conductivity.

[0119] According to one configuration of the invention, the liquid metal or molten alloy or salt nuclear reactor (1000) comprises a shutdown system consisting of several rotating rods, each of which (1030) is made of absorbing materials used to control the fission reaction.

[0120] If the rotating rods of the shutdown system are rotated so that their absorbing materials face the reactor core, the neutrons from the fuel are absorbed into the absorbing material (for example boron carbide), causing the reactor to reach subcritical neutron levels, so that the nuclear reaction stops.

[0121] When the nuclear reactor is activated, the rotating rods (1030) of the shutdown system are progressively rotated to displace the absorbing material. When the reactor reaches the desired power level, the rotation of the rotating rods (1030) is stopped.

[0122] When the fuel is exhausted, the rotating rods (1030) of the shutdown system reflect more neutrons back towards the core of the nuclear reactor. When there is an accumulation of fission products, the fission reaction stops and the nuclear reactor shuts down.

[0123] According to a configuration of the liquid metal or molten alloy or salt nuclear reactor (1000), the rotating rods (1030) of the shutdown system can be actuated by a pneumatic device (2000) that is more efficient than electric motors, particularly in the event of a power outage.

[0124] According to a configuration of the liquid metal or molten alloy or salt nuclear reactor (1000), the rotating rods (1030) of the shutdown system can be actuated by an undetailed device (2000) composed of electric motors.

[0125] According to a configuration of the liquid metal or molten metal alloy or molten salt nuclear reactor (1000), a gamma ray protection screen (not described) can be positioned outside the liquid metal or molten metal alloy or molten salt nuclear reactor to act as a protective shield for people in the vicinity of the liquid metal or alloy or molten salt nuclear reactor.

[0126] According to one configuration of the invention, the liquid metal or molten alloy or salt nuclear reactor (1000) may have a double-walled protective shell (1080).

[0127] According to one configuration of the invention, the liquid metal or molten alloy or salt nuclear reactor (1000) may have a double-walled safety / retention vessel (1060).

[0128] According to one configuration of the invention, in all normal or abnormal transient conditions, the liquid metal or molten alloy or salt nuclear reactor (1000) is designed to self-regulate in order to ensure the safety of property and persons.

[0129] According to one configuration of the invention, the liquid metal or molten alloy or salt nuclear reactor (1000) is equipped with sensors (not described here) in order to optimize its operation and ensure its safety.

[0130] According to one configuration of the invention, the liquid metal or molten alloy or salt nuclear reactor (1000) has a diameter between 0.1 and 2 meters, and a height between 0.2 and 2.5 meters.

[0131] According to a configuration of the liquid metal or molten alloy or salt nuclear reactor (1000), the containment vessel (1040) has a thickness between 0.02 and 0.5 meters and a height between 0.1 and 1 meter (calculated according to the thermal power delivered by the reactor and the safety rules recommended locally for operating a Basic Nuclear Installation).

[0132] According to a configuration of the liquid metal or alloys or molten salts nuclear reactor (1000), the safety / retention vessel (1060) has a thickness between 0.02 and 0.5 meters and a height between 0.1 and 1 meter (calculated according to the thermal power delivered by the reactor and the safety rules recommended locally for operating a Basic Nuclear Installation).

[0133] According to a configuration of the liquid metal or molten alloy or salt nuclear reactor (1000), the protective shell (1080) has a thickness between 0.1 and 0.5 meters and a height between 0.1 and 2.5 meters (calculated according to the thermal power delivered by the reactor and the safety rules recommended locally for operating a Basic Nuclear Installation).

[0134] According to a configuration of the liquid metal or molten alloy or salt nuclear reactor (1000), the operating temperature of the nuclear reactor is between 600 and 800 °C and the operating pressure is close to ambient pressure.

[0135] According to a configuration of the liquid metal or molten alloy or salt nuclear reactor (1000), a plurality of unwelded heat-carrying fins (1050, 1070, 1090) containment and safety / retention tanks, or the protective shell of the liquid metal or alloy or molten salt nuclear reactor transfer heat without thermo-siphon to the outside of the core of the liquid metal or alloy or molten salt nuclear reactor.

[0136] According to a configuration of the liquid metal or molten alloy or salt nuclear reactor (1000), the heat-carrying fins (1050, 1070, 1090) have a thickness between 1 and 10 cm, a width between 5 and 50 cm, and a length that adapts according to the thickness of the protective shell (1080).

[0137] According to a configuration of the liquid metal or molten salt or alloy nuclear reactor (1000), the heat transfer fins (1050, 1070) touch the containment vessel (1040) but are not welded to it. This allows the containment vessel (1040) to be dismantled without difficulty.

[0138] According to a configuration of the liquid metal or molten salt or alloy nuclear reactor (1000), the heat transfer fins (1070, 1090) touch the safety / containment vessel (1060) and the protective shell (1080) but are not welded to it. This allows the containment vessel (1060) to be dismantled without difficulty.

[0139] According to a configuration of the liquid metal or molten alloy or salt nuclear reactor (1000), the plurality of heat-carrying fins touch the containment vessel, the safety / retention vessel, and the protective shell. The containment function is then ensured by contact between metals.

[0140] According to a configuration of the liquid metal or molten alloy or salt nuclear reactor (1000), a ceramic layer (not described) can be partially installed between the safety / containment vessel and the protective shell. The containment function is then ensured by contact between metals.

[0141] According to a configuration of the liquid metal or molten alloy or salt nuclear reactor (1000), the plurality of heat-carrying fins (1070) is in contact with at least one external heat exchanger (not described here).

[0142] According to a configuration of the liquid metal or molten alloy or salt nuclear reactor (1000), the plurality of heat-carrying fins (1090) is in contact with at least one external heat exchanger (not described here) to the protective shell in the case where the latter is implemented to provide another containment barrier.

[0143] According to one possible configuration, the reactor transfers heat to carbon dioxide in supercritical phase; which makes it possible to directly power a carbon dioxide turbine and an electric generator, for example a high-speed generator.

[0144] According to one possible configuration, the reactor can be placed above a heat transfer device in the ground, particularly in the event of an accidental meltdown of the containment vessel. This device makes it easier to cool the corium which is in the safety / retention tank.

[0145] According to one possible configuration, the safety / retention vessel after a temperature rise can be dismantled and cut into chips for example by laser and reused in another liquid metal or alloy or molten salt nuclear reactor.

[0146] According to one possible configuration, the containment vessel as a whole, damaged after a temperature rise, can be dismantled and cut into chips, for example by laser, and reused in another liquid metal or molten alloy or salt nuclear reactor.

[0147] According to one possible configuration, the containment vessel as a whole, undamaged after a temperature rise, can be reused in the liquid metal or molten alloy or salt nuclear reactor.

[0148] The present invention has been described with reference to various embodiments. Where possible, one or more elements, components, constituents, structures, or modules of the described embodiments may be combined, separated, interchanged, or rearranged with one or more other elements, components, constituents, structures, or modules of the embodiments without departing from the scope of the disclosed invention. The present invention is not limited by the description of the various embodiments. Those skilled in the art may derive other implementations from the technical solutions of the present invention.

Claims

1. Claims , Nuclear reactor (1000) operated, for heating use and / or to produce electricity by a conventional or supercritical device, outside the transport network, with a high level of safety, capable of consuming nuclear fuel stored in the form of waste integrated into a liquid metal, operates at near ambient pressure, transfers heat outside the core of the nuclear reactor by heat transfer fins not integral with the containment vessel of the nuclear reactor, with at least one system for shutting down the nuclear reactor, and comprising, - a containment vessel (1040), contains the core of the liquid metal or alloy or molten salt nuclear reactor, the site of nuclear fission reactions and therefore the site of release of heat and radiation housed inside the nuclear reactor, contains the fuel dissolved in the liquid metal / or molten salts, contains a neutron reflector spaced from the containment vessel and positioned between the core and the containment vessel / the mirror, contains the moderator, contains the rotating rods of the shutdown system, and sized to facilitate the fission process, stabilize the operating point of the liquid metal or alloy or molten salt nuclear reactor, optimize the good distribution of neutron fluxes according to the geometric characteristics and the quantity of fuel desired to obtain the desired thermal power, and made of materials chosen from nickel steel alloys to satisfy the containment function; - a fuel in the form of a mixture of uranium, plutonium or Thorium, integrated into a liquid metal and / or molten salt (1010), preserved and not pumped and cooled by evacuation of the heat outside the containment vessel; - a neutron mirror (1020) allows neutrons to be reflected towards the core of the nuclear reactor, in order to improve the fission process, to stabilize the operating point of the liquid metal or alloy or molten salt nuclear reactor, to optimize the good distribution of neutron flux inside the reactor; - rotating rods (1030) of the stopping system actuated by a pneumatic device, particularly in the event of a power cut; - a plurality of non-integral heat-transfer fins (1050, 1070, 1090) of the containment vessel of the liquid metal or alloy or molten salt nuclear reactor, made of stainless steel, copper, tungsten or heat pipe plates, may have fluid transfer tubes inside them and thus be traversed by a heat transfer fluid, contribute to obtaining a high level of safety, the fins (1050) touch the containment vessel (1040) but are not welded to it, the fins (1070) touch the containment vessel (1040) and the retention vessel (1060) but are not welded to it which allows the containment vessel (1040) and the retention vessel (1060) to be dismantled without difficulty; - a double-walled safety / retention vessel (1060) is used to recover the corium, contributes to obtaining a high level of safety, serves as a containment barrier, may include by construction a neutron-absorbing material;- a double-walled protective shell (1080) can provide a secure barrier against external threats.;

2. , Nuclear reactor (1000) according to claim 1, the reactor has a diameter of between 0.1 and 2 meters, and a height of between 0.2 and 2.5 meters.

3. , Nuclear reactor (1000) according to claims 1 to 2, the structures are manufactured from materials chosen from molybdenum steel alloys.

4. , Nuclear reactor (1000) according to claims 1 to 3, the fuel such as UO2C12 (uralyn chloride) / UO4 / Plutonium / Thorium is dissolved in KC1 (potassium chloride) (1010).

5. , Nuclear reactor (1000) according to claims 1 to 3, the fuel such as UO2C12 (uralyn chloride) / UO4 / Plutonium / Thorium is dissolved in MgCl2 (magnesium chloride) (1010).

6. , Nuclear reactor (1000) according to claims 1 to 3, the fuel such as UO2C12 (uralyn chloride) / UO4 / Plutonium / Thorium is dissolved in NaCl (sodium chloride) (1010).

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