UNUSED NUCLEAR FUEL MeV NUCLEAR REACTOR AND SHALLOW COMBUSTION NUCLEAR FUEL MeV NUCLEAR REACTOR AND SUPPORTED SUBCRITICAL MeV NUCLEAR REACTOR

Abstract

To perform nuclear combustion of accumulated light-water reactor spent nuclear fuel and depleted uranium.SOLUTION: A nuclear fuel is taken out from an unused nuclear fuel rod assembly, metallized, and cooled with heavy rare gas.EFFECT: Energy for a long period can be secured from accumulated light-water reactor spent nuclear fuel.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to the combustion of spent nuclear fuel for light water reactors and depleted uranium.

Background Art

[0002] A new nuclear fuel rod assembly is prepared. However, if the reactor scheduled for loading is forced to stop operating for a long time due to some reason, there is no place for the nuclear fuel rod assembly, and it has to be stored in a storage facility. Nuclear fuel for which procurement for a new nuclear fuel rod assembly has been completed also has to be stored in a storage facility. In addition, nuclear fuel rod assemblies for which procurement has been completed, the loading destination is specific, or the design has been completed are also referred to as used nuclear fuel rod assemblies here. Nuclear fuel for which procurement for a new nuclear fuel rod assembly has been completed and nuclear fuel at the design stage with a specific loading destination are referred to as used nuclear fuel. For example, used nuclear fuel rod assemblies and used nuclear fuel are generated from light water reactors and sodium-cooled fast reactors. Highly enriched plutonium oxide (MOX) may be used. When MOX is used in a used nuclear fuel rod assembly, it is referred to as a used MOX nuclear fuel rod assembly. Depleted uranium is uranium in which the enrichment of uranium-235 (U235) is lower than the enrichment of U235 in natural uranium. It is generated during the production of enriched uranium. Since depleted uranium contains U235, due to spontaneous neutrons emitted from uranium-238 (U238), depleted uranium always maintains nuclear fission. U235 always undergoes nuclear fission reactions. The fission neutrons from U235 and the spontaneous neutrons from U238 are absorbed by U238, and U238 becomes plutonium-239 (Pu239). Pu239 always maintains nuclear fission. Depleted uranium undergoes nuclear fission reactions constantly by spontaneous neutrons even without reaching criticality. It generates heat monotonically. It also emits radiation, which collides with objects and is converted into heat. U238 undergoes intense nuclear fission by neutrons with an energy of 0.8 MeV or more. It also undergoes some nuclear fission even at an energy of 0.1 eV or less. The fission spectrum is said to have a peak at 0.7 MeV and an average of 2 MeV (presumably the neutron flux spectrum). Looking at the nuclear data library of the general public, it is up to about 14 MeV. However, the nuclear fission cross-sections of actinides such as uranium (U), neptunium (Np), plutonium (Pu), and americium (Am) do not decrease even above 14 MeV. On the other hand, the neutron absorption cross-section seems to continue to decrease even above 14 MeV. The number of neutrons ν generated per nuclear fission increases as the neutron velocity increases. The nuclear fission effects of actinides such as U238 can be incorporated. Proton accelerators have seen significant technological development in the medical field. 100 MeV proton accelerators are common. A large number of neutrons (the velocity is mostly thought to be below 1 MeV) are generated by nuclear fragmentation, causing a large amount of U235 to undergo nuclear fission. The excess neutrons convert U238 to Pu239. If there is little neutron moderator around U238 and Pu239, plutonium with a low Pu240 ratio is produced, resulting in plutonium with fewer fizzles. Proton accelerators in the tens of MeV range seem to be inexpensive and commercially available.

Disclosure of the Invention

Problems to be Solved by the Invention

[0003] The timing of using old nuclear fuel rod assemblies and old nuclear fuel is uncertain, and it is troublesome and costly to store them until actual use. The nuclear fuel from deteriorated nuclear weapons and the spent nuclear fuel from ship reactors have a concentration of 20 wt% or more. There is a large amount of deteriorated uranium. It is only used for deteriorated uranium warheads. It seems that a large amount was scattered in the desert during the desert war. It will probably sink underground in the desert under its own weight. The troublesome deteriorated uranium is stored around the world as deteriorated uranium warheads. In Japan, it seems that the warheads of cannons are made of expensive tungsten by the Diet. Only a small number can be used even for training. However, in modern Japan, there is no use for cannons. Even if war is declared, one cannot respond with cannons or tanks. One responds with rockets and drones. The core burnup calculation code set of the conventional design is up to about 14 MeV. However, the nuclear fission cross section of actinides does not decrease even above 14 MeV. The neutron absorption cross section seems to continue to decrease even above 14 MeV. It is necessary to consider nuclear reactions above 14 MeV in reactor design and incorporate the nuclear reactions of actinides.

Means for Solving the Problems

[0004] Means 1 is a new and old nuclear fuel MeV reactor. The new and old MeV reactor incorporates a large number of flat nuclear fuel bodies (100) arranged in a square lattice and a heavy noble gas coolant (220) in a reactor vessel (1000) which is a stainless-steel sealed container. An upper lid (1010) is laid on the upper surface of the reactor vessel (1000). A control plate (300) is laid between the upper surface of the reactor vessel (1000) and the upper lid (1010), and the control plate (300) can move in the gap between the reactor vessel (1000) and the upper lid (1010) by a driving device. The flat nuclear fuel body (100) incorporates a new and old Pu-U mixed metal (111) manufactured from a new and old MOX nuclear fuel rod assembly or a Pu-U mixed metal (2011) obtained by metallizing and mixing the nuclear fuel of the new and old Pu-U mixed metal (111) and the spent nuclear fuel rod assembly of a boiling water reactor in a stainless-steel flat rectangular parallelepiped container (101) or a flat cylindrical container (2101). In the case of the flat cylindrical container (2101), the upper surface radius is the same as the minimum critical sphere radius r of the new and old Pu-U mixed metal (111) or the Pu-U mixed metal (2011), and the cylinder height is 4 / 3 times r or less. In the case of the flat rectangular parallelepiped container (101), one side of the square bottom surface of the rectangular parallelepiped is the cube root of (πx4 / 3) times the minimum critical sphere radius r of the new and old Pu-U mixed metal (111) or the Pu-U mixed metal (2011), and the height is equal to or less than the said side. The above minimum critical sphere radius r is the radius of the sphere when the new and old Pu-U mixed metal (111) or the Pu-U mixed metal (2011) becomes critical without a reflector. The heavy noble gas (220) is a noble gas heavier than helium. An old-new nuclear fuel MeV reactor characterized by operating at an inlet temperature of the reactor vessel (1000) of 185 °C or higher and an outlet temperature of 315 °C or lower.

[0005] Heavy noble gas is a noble gas excluding helium. There are xenon, argon, krypton, and xenon. It has a lower neutron moderation effect compared to helium (Patent Document 1). Since noble gases hardly become radioactive, there is no problem even if they leak to the outside. The radiation emission lifetime of the gaseous fission products released is relatively short. If filtered by a filter at all times and released to the outside, a large amount of gaseous fission products will not be released to the outside during an accident. Enhance safety by volume rather than strength. For example, lay the dome of a domed stadium in a sealed manner. The operation is continuously controlled by replacing the flattened nuclear fuel body (100) in which combustion has progressed and the plutonium enrichment has increased with a new flattened nuclear fuel body.

Patent Document 1

[0006] Means 2 is a shallow-burn used nuclear fuel MeV reactor. In claim 1, a shallow-burn used Pu-U-MA metal nuclear fuel (2211) containing MA is mixed with an old-new Pu-U mixed metal (111) to form a Pu-U-MA mixed metal (2212). A shallow-burn used nuclear fuel MeV reactor characterized by this.

[0007] Means 3 is a subcritical MeV reactor with support. The subcritical MeV subcritical reactor with support is formed by arranging a large number of flattened deteriorated uranium bodies (1100) in a square lattice in a reactor vessel (1000) containing a heavy noble gas coolant (220). The flattened deteriorated uranium body (1100) is formed by incorporating a deteriorated uranium metal nuclear fuel (3211) into a stainless steel flattened rectangular parallelepiped container (101) or a flattened cylindrical container (2101). A leakage neutron acceleration tube (1300) is laid on the surface of the flattened deteriorated uranium body (1100). The leakage neutron acceleration tube (1300) is connected to a mixed proton beam tube (400) penetrating the reactor vessel (1000). The mixed proton beam tube (400) is a tube for introducing a beam composed of protons, deuterons, and tritons having a speed of 1 MeV or more by an accelerator laid outside the reactor vessel (1000). A subcritical MeV reactor with support, characterized in that it converts deteriorated uranium into nuclear fission and Pu238 with the support of an accelerator laid outside.

[0008] The means 4 is an MeV reactor and a subcritical MeV reactor with support, characterized in that it takes into account the nuclear reaction of actinides by fast neutrons of 20 MeV or more. The improved nuclear combustion calculation code set for calculating the combustion behavior of the reactors of claims 1 to 3 consists of an improved nuclear combustion calculation code for calculating the combustion behavior and an improved nuclear data library. The improved nuclear combustion calculation code sets the upper limit of neutron energy to 100 MeV. The improved nuclear data library replaces the neutron incident reaction data from 1 MeV to the upper limit energy in the conventional nuclear data library with a minimum rational approximation formula or a least squares approximation formula. An MeV reactor and a subcritical MeV reactor with support, characterized in that the nuclear reaction of actinides by fast neutrons of 20 MeV or more is considered by the improved nuclear combustion calculation code set.

[0009] So far, the critical mass and critical radius of nuclear materials have been made public. However, it is not clear whether it is BE (Best Estimate) or EM (Evaluation Model). Political intentions may be involved. If substances with a neutron decelerating effect such as light water, heavy water, sodium, helium, or oxygen exist in the reactor, it would be reasonable to set the upper limit of neutron speed to 14 MeV. In Japan, it is necessary to reconfirm the improved nuclear combustion calculation code set of the present invention and the experimental values. In particular, it is possible to conduct experiments on depleted uranium mainly composed of U238 and natural uranium. If there are experimental values at 60 MeV for natural uranium metal and depleted uranium metal, it will be an interpolation formula of the minimum rational approximation formula or the least squares formula. Just by removing oxygen from the nuclear fuel in the upper quarter of the BWR's shallow burn used nuclear fuel rod assembly and metallizing it, it will approach criticality. As the combustion progresses, it will reach criticality. Further progress of combustion will result in supercriticality. Just by adding nuclear fuel obtained by removing oxygen from the average nuclear fuel of the BWR's shallow burn used nuclear fuel rod assembly and metallizing it to the supercritical nuclear fuel, it will reach criticality. This can be repeated any number of times.

Advantages of the Invention

[0010] If the spent nuclear fuel metal of the present invention is metallized with the BWR spent nuclear fuel from six villages and burned after mixing, the BWR spent nuclear fuel can be disposed of. Therefore, a permanent disposal site becomes unnecessary. Candidate sites for the permanent disposal site for PWR spent nuclear fuel will emerge. Autonomous bodies in depopulated areas will be unable to see their own feet. In principle, the reactor of the present invention has little accumulation of Pu240. Pu240 is difficult to be generated if there is little Pu239. Even if it is generated, Pu240 will undergo nuclear fission. Since the spent nuclear fuel of the present invention has little Pu240, the spontaneous neutrons are few. The neutrons during storage are few. The reactor of the present invention can reuse Pu any number of times, so a final disposal site is not required, and it can be reduced while effectively utilizing the LWR spent nuclear fuel. A large amount of U238 in the LWR spent nuclear fuel can be made into metal and effectively disposed of by annihilation. Even if the metal LWR spent nuclear fuel obtained by reprocessing and metallizing the oxide LWR spent nuclear fuel contains heavy elements such as iron group and platinum group, there is no significant obstacle to criticality and combustion. A simple reprocessing to remove light metals is sufficient. If a final disposal site is not required, autonomous bodies that raise their hands in the selection of candidate sites for interim storage will continue to emerge. This will stop the expansion of depopulated areas. In the reactor of the present invention, it is difficult to consider that the enrichment of plutonium exceeds 50%. Therefore, it is difficult to become an efficient nuclear weapon as in the past.

BEST MODE FOR CARRYING OUT THE INVENTION

[0011] A nuclear reactor capable of burning spent nuclear fuel of a light water reactor has been provided. Disposal of the spent nuclear fuel can be expected.

Example 1

[0012] Example 1 is an old and new MeV nuclear reactor. FIG. 1 is a general view of the old and new nuclear fuel MeV nuclear reactor (in the case of a flat rectangular parallelepiped container). The old and new MeV nuclear reactor incorporates a large number of flat nuclear fuel bodies (100) arranged in a square lattice and a heavy rare gas coolant (220) in a reactor vessel (1000) which is a stainless steel sealed container. A detachable upper lid (1010) made of a neutron reflector is laid on the upper surface of the reactor vessel (1000). A control plate (300) is laid between the upper surface of the reactor vessel (1000) and the upper lid (1010), and the gap between the reactor vessel (1000) and the upper lid (1010) can be moved by a control plate (300) driving device. The flat nuclear fuel body (100) incorporates an old and new Pu-U mixed metal (111) manufactured from an old and new MOX nuclear fuel rod assembly or a Pu-U mixed metal (2011) obtained by metallizing and mixing the nuclear fuel of the old and new Pu-U mixed metal (111) and a boiling water reactor spent nuclear fuel rod assembly in a stainless steel flat rectangular parallelepiped container (101). In the case of the flat rectangular parallelepiped container (101), one side of the square bottom surface of the rectangular parallelepiped is (π×4 / 3)^(1 / 3) times the minimum critical sphere radius r of the old and new Pu-U mixed metal (111) or Pu-U mixed metal (2011), and the height is equal to or less than the one side. The above minimum critical sphere radius r is the radius of the sphere when the old and new Pu-U mixed metal (111) or Pu-U mixed metal (2011) becomes critical without a reflector. FIG. 2 shows the case where the flat nuclear fuel body (100) in FIG. 1 consists of a flat cylindrical container (2101). In claim 1 of the present invention, it is assumed that the fresh and used Pu-U mixed metal (111) does not contain minor actinides (MA) such as Np and Am. In claim 2, MA is actively contained. When extracting Pu from spent nuclear fuel, it always contains MA, and MA is generated by nuclear reactions due to spontaneous neutrons from actinides during nuclear fuel storage. However, in current reactors, in principle, they do not actively try to contain MA (Non-Patent Document 1). In high-power operations of 50 kW / l or more, MA affects heat and temperature. At low power densities, even if MA affects heat and temperature, it is not a major issue. A bottom neutron reflector (221) is fixed to the bottom surface of the sealed container (1000), and a side neutron reflector (222) is fixed to the outer side surface of the sealed container (1000) to be arranged on the outer periphery, reducing neutron leakage to the outside. A heavy noble gas coolant (220) with a low neutron moderation effect flows through the reactor vessel (1000). The reactor vessel (1000) and the control board (300) are stored in a radiation shielding container (200). Since neutrons leaking in the plane direction of the flat nuclear fuel body (100) can move back and forth between adjacent flat nuclear fuel bodies (100), there is approximately no neutron leakage in the plane direction. A sealed cylinder (1100) with a closed upper end and an open lower end is laid on top of the flat nuclear fuel body (100) to store the expansion of the fresh and used Pu-U metal nuclear fuel (111) or the spent Pu-U metal (2011). A coolant insertion pipe is connected to the reactor vessel (1000), and the heavy noble gas coolant (220) flows into the reactor vessel (1000). Operate at an inlet temperature of the reactor vessel (1000) of 185 °C or higher and an outlet temperature of 315 °C or lower. As shown in Fig. 4, the density of plutonium changes significantly with temperature. Above 185°C and below 315°C, the density change is not extreme, and it can achieve a thermal efficiency similar to that of surface-derived power generation. As in the present invention, if the plutonium enrichment is about 10%, the remaining 90% of uranium alleviates the density fluctuation. Alloys with about 10% zirconium or aluminum or with 4% gallium added to plutonium have increased stability. In Japan, plutonium close to 100% is not politically acceptable. If the plutonium temperature rises due to a decrease in coolant flow rate, the plutonium density decreases, the nuclear reaction decreases, and the temperature decreases. Since it has negative feedback, stable operation can be achieved. Even if the coolant is lost or the outside air is used, cooling can be achieved. Cooling can also be done with nitrogen gas or carbon dioxide gas. Even if the plutonium temperature rises rapidly, the sealed cylinder (1020) covers the expansion of the nuclear fuel.

Non-Patent Document 1

[0013] The heavy noble gas coolant (220) flowing through the bottom surface of the upper and bottom neutron reflectors (221) of the flat nuclear fuel body (100) receives heat from the flat nuclear fuel body (100). The coolant heated to a high temperature passes through the radiation shielding container (200) from the coolant discharge pipe connected to the reactor vessel (1000) and reaches a power generation device installed outside. The coolant that has completed work in the power generation device and has become low temperature enters the reactor vessel (1000) from the coolant insertion pipe through the radiation shielding container (200).

[0014] In case of emergency, boric acid or an aqueous solution of sodium pentaborate is scattered inside and outside the reactor vessel (1000) to absorb neutrons. If the roof of the radiation shielding container (200) is made of boron - added stainless steel, it can absorb the leaked neutrons. The side surface of the radiation shielding container (200) is made of boron - added concrete to absorb the leaked neutrons (it is made brittle and in case of emergency, an aqueous solution of sodium pentaborate is injected). The bottom of the radiation shielding container (200) incorporates steel bars into the boron - added concrete to absorb the leaked neutrons. If the flat nuclear fuel body (100) is supported by a seismic isolation base, its seismic resistance performance will increase.

[0015] Once combustion starts, since there is no moderator, more Pu239 is generated from U238 compared to the Pu239 burned out by combustion, and thus Pu239 increases. Therefore, even if it starts burning in a sub - critical state, it will exceed criticality. If the output is low and the neutron flux is small, it will gradually exceed criticality. When combustion progresses to a certain extent and the degree of exceeding criticality becomes high, the burned - out flat nuclear fuel body (100) is replaced with an unburned flat nuclear fuel body (100). As the flat nuclear fuel body (100) burns, the plutonium enrichment increases. Since U238 is overwhelmingly abundant, compared to the consumption of Pu, more Pu is generated by U238 absorbing neutrons. Furthermore, since U238 also undergoes nuclear fission by fast neutrons, less Pu is consumed to obtain a certain output. Therefore, plutonium enrichment increases. When the plutonium enrichment increases, the nuclear fission reaction rate becomes too high, so fuel replacement becomes necessary. By replacing the nuclear fuel of the burned - out flat nuclear fuel body (100) with increased plutonium enrichment with a flat nuclear fuel body mixed with a Pu - U metal nuclear fuel obtained by metallizing the nuclear fuel of the nuclear fuel rods (upper part or average) of a boiling - water - type spent nuclear fuel rod assembly, it is made sub - critical or slightly critical for continuous operation control. The breeding performance will decrease, but it is also possible with MOX which is an oxide.

[0016] Figure 5 shows an example of the minimum critical sphere radius without a reflector (the density is the theoretical density). The new and used Pu - U mixed metal (111) is the case where the nuclear fuel with plutonium enrichment in the MOX planned to be loaded in the Takahama No. 3 reactor is made into metal. Or it is the case of Pu metal prepared for the said MOX or MOX made into metal. It is an available nuclear fuel. Since the plutonium enrichment is low, the influence of the density change of U238-Pu due to the plutonium density change is considered to be small. For safety, the plutonium enrichment is expressed in at%. In the case of a metal nuclear fuel example of a sodium-cooled FBR, U-Pu 13 wt%-Zr has been considered. Although it is a digression, the minimum critical sphere radius due to the plutonium density change is shown as density-dependent. An alloy of Pu and 4 at% Ga melted and cooled together with solidified Ga becomes a constant δ-phase Pu. Since a plutonium enrichment of about 90% is not considered, the alloy with Ga has no meaning in Japan. It seems to be stable when alloyed with aluminum or zirconium. The flat nuclear fuel body (100) is preferably subcritical when loaded into a reactor. Since it does not contain a moderator, the nuclear reaction mainly proceeds by fast neutrons. As the burning progresses, the plutonium enrichment increases. There is a possibility of exceeding the criticality excessively. One side of the square bottom surface of the rectangular parallelepiped of the flat nuclear fuel body (100) is (πx4 / 3)^(1 / 3) times the minimum critical sphere radius r, and the height is less than or equal to the said side. The nuclear fuel rods with a shallow burnup in the boiling water type spent nuclear fuel rod assembly contain about 2% plutonium oxide enrichment and about 2% uranium oxide concentration. Oxygen is removed from this to obtain a burned used Pu-U-MA metal nuclear fuel (2211) as a metal nuclear fuel.

[0017] Example 2 is a shallow burnup spent nuclear fuel MeV reactor. In claim 1, a shallow burnup spent Pu-U-MA metal nuclear fuel (2211) containing MA is mixed with a new and used Pu-U mixed metal (111) to obtain a Pu-U-MA mixed metal (2212) nuclear fuel. Fig. 5 shows the minimum critical sphere radius, which is the minimum sphere radius of the sphere when it becomes critical in the case of no reflector, for the Pu-U-MA mixed metal (2212) of Example 2. The addition of americium 241 (Am241) reduces the minimum critical sphere radius. The nuclear fission cross-section is about 6 barns for neutrons near 1 eV and above 1 MeV. Some isotopes of americium have an extremely large nuclear fission cross-section. Note that the Np237 nuclear fission cross-section is larger than that of U238. The slightly burned spent Pu-U-MA metallic nuclear fuel (2211) manufactured from the nuclear fuel of a slightly burned spent BWR nuclear fuel rod assembly is rich in the unburned U235 and MA, and has a small minimum critical sphere radius. If a slightly burned spent nuclear fuel MeV reactor is burned, since U238 is overwhelmingly abundant, compared to the consumption of Pu, more Pu is generated by U238 absorbing neutrons. Furthermore, since U238 also undergoes nuclear fission by fast neutrons, less Pu is consumed to obtain a certain output. Therefore, the plutonium enrichment increases as the burning progresses. When the plutonium enrichment increases, the nuclear fission reaction rate becomes too high, so fuel replacement becomes necessary. By mixing and replacing the Pu-U-MA metallic nuclear fuel manufactured from the nuclear fuel of a boiling water type spent nuclear fuel rod assembly with the burned nuclear fuel with increased plutonium enrichment, the reactor is made subcritical or slightly subcritical so as to continue operation control. This helps to reduce the cumulative amount of spent BWR nuclear fuel rod assemblies.

[0018] Example 3 is a subcritical MeV reactor with support. Figure 3 is a general view of a subcritical MeV reactor with support. A reactor vessel (1000) containing a heavy noble gas coolant (220) has a large number of flat deteriorated uranium bodies (1100) arranged in a square lattice. The flat deteriorated uranium body (1100) is formed by incorporating deteriorated uranium metallic nuclear fuel (3211) into a flat rectangular parallelepiped container (101) made of stainless steel. Leakage neutron acceleration tubes (1300) are laid on the surface of the flat deteriorated uranium body (1100). The leakage neutron acceleration tubes (1300) are connected to a mixed proton beam tube (400) penetrating the reactor vessel (1000).

[0019] Since the neutrons flying around in the reactor vessel (1000) can also fly around in the leakage neutron acceleration tubes (1300), the neutrons in the leakage neutron acceleration tubes (1300) become fast neutrons when they collide with the mixed proton beam. The fast neutrons collide with U238 in the metallic deteriorated uranium and U238 undergoes nuclear fission. The protons (1, 2) of the mixed proton beam damaged by collision with neutrons collide with U238 (92, 238), release two neutrons, and convert U238 into Np238. Np238 (93, 238) has a half-life of about two days and undergoes β decay to become Pu238 (94, 238). Since Pu238 has a relatively long half-life, it can accumulate. As shown in Figure 5, when about 8% of Pu238 accumulates in U238, it becomes critical. The released neutrons either convert U238 into Pu239 or cause U238 to fission. Since Pu238 emits a large amount of spontaneous neutrons, even if the criticality is close to critical but not yet critical with about 6% of Pu238, a large output can be expected. Note that Np238 has a very large fission cross-section and undergoes intense fission before decaying, so caution is required.

[0020] Even in the future, if reprocessing of spent nuclear fuel is prohibited, recycled nuclear fuel power generation is possible if there is depleted uranium or natural uranium. That is, even if the accelerator is stopped when the Pu238 reaches about 6%, the fission reaction continues. As combustion progresses, Pu238 will exceed 8%, and Pu239 will also be generated, so the criticality will be greatly exceeded. Therefore, by replacing a part of the burned flattened depleted uranium body (1100) with a new flattened depleted uranium body (1100) of depleted uranium, roughly discarding the fission products from the fuel of the removed burned flattened depleted uranium body (1100) and adding depleted uranium, a 1 MeV reactor without an accelerator can be constructed. U238 (92, 238) may react with a proton (1, 1) to become Np239 (93, 239). The fission cross-section of Np239 is large. In the nuclear fragmentation of U238 by proton acceleration using an accelerator, the number of neutrons released is large, but the energy per neutron is small. Therefore, U235 and Pu239 undergo intense fission, while U238 is difficult to fission but produces a large amount of Pu239 (if the burnup progresses, a fission reaction by Pu239 can be expected. If sufficient burnup progresses, it becomes critical). The fission cross-section of Am is large. Attention needs to be paid to Pu242 that produces Am.

[0021] Example 4 is an MeV reactor and a subcritical MeV reactor with support, characterized by considering the nuclear reaction of actinides by fast neutrons of 20 MeV or more. Considering the nuclear reaction of actinides by fast neutrons of 20 MeV or more, the minimum critical sphere radius becomes smaller. For U238, the nuclear fission reaction rapidly intensifies from 1 MeV. At an incident neutron energy of 1 MeV or more, the value of ν increases by about 1.0 for every 6 MeV increase. For heavier nuclides such as Pu2238, Pu239, Pu240, Pu241, Pu242, Np, and Am, it becomes larger. It has a significant impact on the multiplication factor. At an incident neutron energy of 1 MeV or more, the value of ν increases by about 1.0 for every 6 MeV increase. The heavier the nuclide, the larger it becomes. It has a significant impact on the multiplication factor. ν for each actinide T (i) It is desirable to have a neutron energy distribution. ν(i,j), where j is the neutron energy from the lowest energy to 60 MeV (100 MeV if possible). Enable handling of nuclear fission and nuclear combustion mixed with Pu238 converted from U238 by heavy protons. SLAROM can select an upper limit energy of 20 MeV or more by input. It is necessary to make it possible to automatically install and calculate NJOY, which was calculated separately. To analyze the behavior of short-lived nuclides, it is useful to be able to perform combustion calculations using a code such as the ORIGEN code (the United States may have usage restrictions). Among the nuclear combustion calculation code sets, those that are publicly available and frequently used include SRAC and MVP-BURN developed by the Japan Atomic Energy Research Institute. MCNOX developed in the United States is paid and recently seems to have usage restrictions. It is not desirable to conduct nuclear power development under foreign restrictions. It is desirable for Japanese companies to receive government funds from the Japanese government and for independent administrative agencies and private companies to improve SRAC and MVP-BURN, commercialize them, and distribute them in executable file format. MCNP is popular among users because it is distributed as an executable file. If there are many users, it can be distributed at a low cost and for a fee. The manual of the Japanese nuclear code comes with an English version, but translation should become easier with generative AI. If it is in Japanese, it can be used by both men and women in all fields of science and engineering without bias towards nuclear reactors, as well as by retired nuclear power civil engineers.

Industrial Applicability

[0022] With the nuclear reactor of the present invention, spent nuclear fuel from newly developed nuclear reactors in the future can also be combusted and disposed of. Long-term energy can be secured from the accumulated spent nuclear fuel of light water reactors. There is a vast area of land in Shikoku + Kyushu or more that no one wants to buy even for free. If foreigners buy all of it with only the registration fee, it will become impossible for the Japanese government to administer infrastructure such as roads, railways, and water supply. In the worst case, if refugees from all over the world are transported here by cargo, the Japanese government will have no choice but to provide life support. To prevent this, Japanese foundations should acquire land and build several nuclear reactors of the present invention, just in case of an emergency. The reactor of the present invention should be considered as something different from a reactor with a moderator. It would be better for those who have nothing to do with conventional nuclear fuel and reactor designers to design a reactor without a moderator. If there are conflicts of opinion with experienced conventional designers, it will hinder the work of both parties. The construction of the reactor of the present invention will be decades away. By then, due to the declining population, it will be impossible to ensure the number of examiners. The examination will be carried out by the above-mentioned foundation itself by recruiting experts and conducting the examination on its own. If an accident occurs, the situation will be resolved by the above-mentioned experts and another expert from outside. It can be handled by a private nuclear power inspection company like a private vehicle inspection company. The national examination regulations are insufficient due to a shortage of personnel and are reaching a dead end. If it is necessary to undergo the examination, conduct research and development in Pakistan, Israel, Iran, and other newly nuclear-armed countries. The accelerator used in the present invention may be an existing inexpensive so-called generic accelerator. The Ministry of Economy, Trade and Industry promotes the purchase of rotating machines, establishes a number of fund institutions, and promotes the construction and research of generic accelerators at national independent administrative agencies universities. The cooperation between Sumitomo and Fuji Electric with Sweden and Germany in detail is also helpful for activating nuclear power. Regarding the large accelerator in Iwate Prefecture, the Ministry of Economy, Trade and Industry can buy rotating machines and establish a fund institution, and it will be solved by issuing Iwate Prefecture bonds and net financing. However, exchanges with foreign countries will conflict with the Ministry of Education, Culture, Sports, Science and Technology (which likes overseas business trips), so it is probably not advisable to engage in overseas joint research. It is still much slower compared to the former Ministry of Economy, Trade and Industry. It is hoped that the Ministry of Economy, Trade and Industry bureaucrats will be given about 10 funds per person. If the bureaucrats of the Ministry of Economy, Trade and Industry are in charge of the actual work, Japan will fall behind in the world. It is necessary for each bureaucrat of the Ministry of Economy, Trade and Industry who has been in the ministry for more than two years to concurrently serve as the vice president of the fund. In the future, monitors who can immediately withdraw from funds that seem unlikely to move forward are needed. It is important to improve metabolism. Without the active participation of women, it will stagnate. During the recent oil crisis, there was a news story about women going on business trips to the Middle East. (To interact with foreign magicians who can do a thousand tricks on the sea and a thousand tricks on the mountains, it is better to be a little more neatly dressed.) Not only the nuclear reactor of the present invention, but also all nuclear reactors cannot be exported. Exorbitant compensation will be claimed in case of an accident. A country with force can refuse if exorbitant compensation is demanded by saying "come and take it by brute force". In the previous Fukushima accident, there was a small newspaper article saying that the CEO of GE of the United States, which boasts of strong force, came to TEPCO the next day and returned on the same day. What will happen if a particularly severe accident occurs to a Mitsubishi Group nuclear reactor abroad? On the other hand, foreign countries demand Japanese nuclear reactors (Japanese nuclear reactors are excellent in seismic resistance. In countries with few earthquakes, expensive Japanese-made nuclear reactors have no attraction.) because it is threatening with a certain connection. The claim amount will go through the roof. If the Japanese government bears it with government compensation, it will not be enough to the extent that the regime will collapse. Chubu Electric Power and Tohoku Electric Power, which have not restarted their nuclear reactors, achieved good results. They have been able to avoid being criticized by the president due to the accident. They don't have to worry about being exhausted physically and mentally in dealing with regulations. If they leave the regulation response to other power companies, the regulatory side can also conduct centralized regulation. They can restart after the form of regulation is completed. If the regulatory commissioners are allowed to freely come and go inside the premises and carry out terrorist attacks, it will be understood that it is a waste of time. The control of bazookas and TNT explosives is the job of the police. If it is damaged by a bazooka, it means that the police's control has failed. The perpetrator of the Ikebukuro runaway car accident at the former Institute of Industrial Science and Technology (the predecessor of the Nuclear Regulation Authority) made statements that would shake Japan's automobile industry. It won't pay off to comply with regulations that are inexplicable like anti-terrorism measures. Pay a lot of taxes to reward the people and use hospitality expenses to reward the local area. Among the managers, there are those who repay the debts incurred for internal reserves for anti-terrorism measures, implementation of anti-terrorism measures, and restart. It is almost impossible technically to take anti-terrorism measures for wind power generation. There is no technical way to deal with terrorist attacks where a large number of drones are collided by remote control. It is the job of the public security, the Ministry of Defense, and the police. Even for solar power, it is enough to let pachinko balls fall like sleet or hail from a large number of drones. Incidentally, there may be some groups that have gradually withdrawn from Japan's wind power development (the amount of accident compensation is impossible to estimate, and it is difficult to secure maintenance personnel). Japanese buckwheat farmers have started to make a profit. The excessive weakening of the yen has become prominent. Exports to the United States will be stagnant. Even the United States alone is wary of the excessive strengthening of the dollar. The soaring oil prices will also subside. If subsidies are provided for gasoline, it will remain high forever. It only fattens the majors. Just provide gasoline subsidies only for the export industry and the distribution industry. At the same time, use the subsidies to increase the amount of surface origin energy (SOE) (equipment, spare parts, and enterprises are made in Japan). Even if the electricity is in surplus and the price is high, keep operating the SOE and suppress LNG. Scatter the houses in the mountain village and convert each household into a single-house large-scale construction by a carpenter with SOE attached, and gather and relocate them around the village office (general complex, nursing facility, convenience store, post office). If we provide pick-up and drop-off services to the original houses once a month, we can make up for the high gasoline prices and the shortage of taxis. The power shortage can be compensated for by this invention. There is plenty of land without buyers. SOE and this invention are complementary to each other. It is suitable for the Self-Defense Forces which emphasize self-sufficiency. The ministries and agencies exist to protect the vested interests of bureaucrats and the public and to make the current situation comfortable. They have not been able to improve efficiency. We may need a prime minister's direct jurisdiction ministry and agency to implement a tilt production method like what the Nazis did. If dragged down by a backward newspaper that believes the public is receptive to safety and security, the economy will deteriorate and survival will be at risk. Probably so. After that, we will build the reactor of this invention. If the Great Kanto Earthquake (epicenter in Chigasaki, Kawasaki, Tsuru) occurs again, the impact will be greater than before. Especially in the areas near Yokohama and Kawasaki, the damage was small at that time because the population and infrastructure were sparse, but now the population has increased rapidly. There is a risk of a tsunami. The economic damage will be huge. The yen will plummet and we won't be able to buy oil. We should secretly prepare the reactor of this invention. The Tokai Nankai Earthquake will stimulate economic growth because the population in the epicenter area is small and there is only old and outdated infrastructure.

Brief Description of Drawings

[0023]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Explanation of Reference Signs

[0024] 100 is the flat nuclear fuel body 101 is the flat rectangular parallelepiped container 111 is a new and used Pu-U mixed metal 200 is a radiation shielding container 220 is a heavy noble gas coolant 221 is a bottom neutron reflector 222 is a side neutron reflector 300 is a control rod 400 is a mixed proton beam tube 1000 is a reactor vessel 1010 is an upper lid 1020 is a sealed cylinder 1100 is a flat deteriorated uranium body 1300 is a leakage neutron acceleration tube 2011 is a Pu-U mixed metal 2101 is a flat cylindrical container 2211 is a shallow burn used Pu-U-MA metal nuclear fuel 2212 is a Pu-U-MA mixed metal 3211 is a deteriorated uranium metal nuclear fuel

Claims

1. The new MeV reactor is composed of a stainless steel sealed reactor vessel (1000) containing a number of flat nuclear fuel bodies (100) arranged in a square lattice pattern and a heavy rare gas coolant (220). A top cover (1010) is laid on the top surface of the reactor vessel (1000), A control plate (300) is laid between the upper surface of the reactor vessel (1000) and the top cover (1010), and the control plate (300) can be moved in the gap between the reactor vessel (1000) and the top cover (1010) by a drive device; The flat nuclear fuel body (100) is a stainless steel flat rectangular container (101) or flat cylindrical container (2101) containing a new used Pu-U mixed metal (111) produced from a new used MOX nuclear fuel rod assembly, or a Pu-U mixed metal (2011) produced by metallizing and mixing the new used Pu-U mixed metal (111) and a nuclear fuel from a boiling water reactor spent nuclear fuel rod assembly; In the case of the flat cylindrical container (2101), the upper radius is equal to the minimum critical spherical radius r of the new used Pu-U mixed metal (111) or the Pu-U mixed metal (2011), and the cylinder height is 4 / 3 times or less of r; In the case of the flat rectangular container (101), one side of the square bottom of the rectangular container is 1 / 3 times the minimum critical sphere radius r of the new used Pu-U mixed metal (111) or the Pu-U mixed metal (2011) to the power of (πx4 / 3), and the height is less than or equal to the one side; The minimum critical sphere radius r is the radius of a sphere when the new used Pu-U mixed metal (111) or Pu-U mixed metal (2011) becomes critical when there is no reflector, Heavy noble gas (220) is a noble gas heavier than helium, A new used nuclear fuel MeV reactor, characterized in that it operates with a reactor vessel (1000) inlet temperature of 185°C or more and an outlet temperature of 315°C or less.

2. A lightly burned spent nuclear fuel MeV reactor, as claimed in claim 1, characterized in that a new used Pu-U mixed metal (111) is mixed with lightly burned spent Pu-U-MA metallic nuclear fuel (2211) containing MA to produce a Pu-U-MA mixed metal (2212).

3. The assisted subcritical MeV subcritical reactor is composed of a reactor vessel (1000) containing a heavy rare gas coolant (220) and a number of flat depleted uranium bodies (1100) arranged in a square lattice pattern; The flat depleted uranium body (1100) is made by incorporating depleted uranium metal nuclear fuel (3211) in a stainless steel flat rectangular container (101) or flat cylindrical container (2101), A leaky neutron accelerating tube (1300) is laid on the surface of the flat depleted uranium body (1100), The leaky neutron accelerating tube (1300) is connected to a mixed proton beam tube (400) that penetrates the reactor vessel (1000); The mixed proton beam tube (400) is a tube that introduces a beam consisting of protons, deuterons, and tritons with a velocity of 1 MeV or more by an accelerator installed outside the reactor vessel (1000). An assisted subcritical MeV reactor characterized by the fission and transmutation of depleted uranium into Pu238 with the assistance of an external accelerator.

4. The improved nuclear burnup calculation code set for calculating the burnup behavior of a nuclear reactor according to claims 1 to 3 comprises an improved nuclear burnup calculation code for calculating the burnup behavior and an improved nuclear data library; The improved nuclear burnup calculation code has an upper limit of neutron energy of 100 MeV, The improved nuclear data library replaces the neutron-induced reaction data from 1 MeV to the upper energy limit in the conventional nuclear data library with least rational approximation formulas or least squares approximation formulas. An MeV reactor and an assisted subcritical MeV reactor, characterized by taking into account nuclear reactions of actinides induced by fast neutrons of 20 MeV or more using an improved nuclear burnup calculation code set.

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