JP2013088419A - Nuclear power plant with radioactive decontamination facility - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that a utility is provided with a decontamination facility to perform treatment inside a power plant without performing discharge to the outside, since it is too risky to perform discharge without decontaminating radioactivity included in a gas to be discharged when a nuclear reactor falls into an uncontrollable state, the risk of explosion of a pressure container increases and vent execution is needed.SOLUTION: While a system which decontaminates all the radioactivity generated inside a nuclear power plant within the power plant and does not discharge it to the outside is needed, a large-sized decontamination system in a tower structure for decontaminating the gas generated inside the plant and contaminated circulation water is constructed to perform the entire treatment inside without performing discharge to the outside at all.

Description

  The present invention prevents release and diffusion of radioactive gas and contaminated water generated at nuclear power plants to surrounding areas outside the facility, and decontaminates radioactive gas and contaminated water within the facility to an extremely low level. It relates to radioactive decontamination facilities of nuclear power plants to be processed.

  If in Ukraine regional cities by the explosion of the Chernobyl nuclear power plant in 1986 still residents for more than acceptance criteria of radioactivity time can be homecoming remains were evacuated, one end serious in is a nuclear power plant in the state that does not stand prospect If an accident occurs and radioactivity is released and diffused in the surrounding area, it becomes a serious and serious problem of radioactive contamination. In addition, a total power outage due to the tsunami of the Fukushima Daiichi Nuclear Power Station on March 11, 2011 occurred, and due to the cooling water circulation stop, high concentration of radioactivity diffused to the surrounding area due to meltdown of the fuel rod and hydrogen explosion, Residents outside the 30-kilometer zone were evacuated, starting with the suspension of market shipments due to radioactive contamination in agricultural products, livestock industry, and fisheries, enormous security problems occurred. In this way, there are many places where nuclear power plants are currently installed along the coast or in the vicinity of rivers and lakes. When the pressure vessel or containment vessel inside the reactor building is destroyed due to an accident, Are released into the atmosphere, and a wide range of surrounding areas contaminated with radioactivity can have serious consequences.

  If the structure of the nuclear power plant facility should have been constructed with due consideration for accident countermeasures before and during construction, but it is not possible to cope with an accident that occurred based on the word of unexpected, as described above, the disastrous result Will be invited. For this reason, in order for the people to continue to maintain their cultural life, the current energy technology and natural renewable energy alone will not be able to meet the demand for electricity to promote and develop citizens' lives and industries. Until it can not be satisfied and new energy technologies are developed, nuclear power generation must be relied on for the time being.

  Sho 53-110793   Sho 61-84588   Japanese Patent No. 2883938   2-85779   2010-101144

  The standard style of current nuclear power generation facilities is that the reactor building, turbine building, and other incidental facilities are constructed along the coast and on the flat ground where the cooling water source is located. Although nuclear power facilities have taken sufficient measures for accidents, there is a possibility that a radioactive emission accident may occur due to an unexpected factor as in the accident example at the Fukushima Daiichi nuclear power plant. At present nuclear power plants, it is extremely difficult to prevent the containment vessel and pressure vessel from being destroyed due to an explosion or the like, or to prevent the radioactivity from spreading to the surrounding area by venting. Radiation is performed by taking measures to prevent the diffusion of radioactivity outside the power plant facility by completely decontaminating cooling circulating water contaminated by the radioactivity of the reactor and decontaminating radioactivity in the air inside the reactor building. It is a difficult problem to completely release to the outside after removing the ability removal in the facility. However, it was proved again that if a nuclear accident caused an explosion for some reason, contamination of the surrounding area due to radioactive diffusion to the surrounding area or the ocean would have extremely serious consequences. It is necessary to establish a nuclear power plant system that can absolutely prevent the spread of radioactivity in order to prevent a reoccurrence.

  Even if the external power supply is lost and the emergency power supply stops and the temporary cooling water stops circulating, the cooling water supply continues to the reactor and the fuel pool, and the containment pressure increases and venting is performed. However, it is necessary to take safety measures to prevent radioactive gases and vapors from diffusing and flowing out of the nuclear facilities. At the Fukushima Daiichi nuclear power plant, when the circulating water of the reactor was stopped for a long time, the pressure increased, so venting was carried out, but this pressure was released from the exhaust tower through the piping, but this did not cause radioactivity in the surrounding area. It was scattered. This should never be done in future nuclear power plants. It is also important to cancel the construction of nuclear power plants where there are active faults. Even if the situation of total power loss occurs, while implementing multiple safety measures systems, construction of multiple countermeasures until power restoration, temporary storage tank of contaminated water generated in the reactor building, turbine building, and It is necessary to complete a decontamination facility for contaminated water when power is restored, and it is necessary to be based on the basic idea that the radioactivity generated within a nuclear power plant is decontaminated inside the facility and not emitted outside. . Needless to say, the construction of a seawall above the tsunami wave height is also an important factor as a countermeasure against the tsunami caused by the earthquake, like the Fukushima Daiichi nuclear power plant.

  G21C1 / 00 of the IPC patent classification is a method to prevent radioactive materials from being released and diffused from the reactor facility to the surrounding area even if an accident occurs for some reason when building a nuclear power plant and operating it safely. When @D is searched, a lot of methods such as the underground nuclear power plant of Patent Document 2 of the prior art document are searched. Such techniques are already known but do not appear to be very popular. The reason for this seems to be the soaring construction costs. However, it can be expected that adopting such a underground method as much as possible with the highest priority on safety measures and utilizing nuclear power generation will result in an accident, and it will be cheaper to calculate the amount of damage and compensation .

  Like the accident at the Fukushima Daiichi Nuclear Power Station, the loss of all power caused by the tsunami caused the inability to circulate cooling water into the reactor, resulting in a hydrogen explosion and the worst result of radioactivity spreading to the surrounding area. This was a shame, and the contaminated water that had accumulated in the basement of the turbine building was washed away into the open ocean. Never again have such an accident. To that end, a facility equipped with a radioactive decontamination system as in the present invention is installed at an existing nuclear power plant or a newly established power plant, etc., and the nuclear accident of residents living in the surrounding area by taking the greatest safety measures The nuclear power plant must be reassured that there is no need to worry because the safety measures have been taken to eliminate the fear of occurrence. In order to meet the power demands of the modern society, and the current nuclear operation guidelines that threaten the right of survival for the residents in the vicinity of nuclear power plants must be improved.

  In order to solve the above problems, the present invention has a large-sized structure in which a vapor or gas containing radioactivity discharged when a vent is carried out due to an accident that causes a high pressure in the reactor and an explosion is carried out, and a vent is sealed. Without touching the outside air to the closed storage hollow tunnel, air is sent through the pipeline, and after closing, decontamination with a water spray shower from the pipe installed in the upper part of the storage tunnel, and the remaining gas is compressed by accumulating the sprayed water. Then, the gas is decontaminated by being led to the lower water tank, discharged as bubbles from the pipe line at the lower part of the tank, and again brought into contact with water a gas containing radioactivity in the decontamination water, and transferring the radioactivity to water. The low-level gas is further moved to the next upper tank, and the residual radioactivity contained in the gas is passed through each multi-layer filter made of a highly adsorbable chemical to decontaminate the radioactivity. . The gas that passes through each filter is further passed through a filter made of clay soil with good adsorption of clay radioactivity, and decontaminated to reduce the radioactivity to a safe level. At this time, the radioactivity removal filter is a filter for individually decontaminating radioactive substances such as iodine, cesium 134, cesium 137, strontium, and plutonium, and performs decontamination for each. Each filter uses a product of a specialized manufacturer that uses the most suitable adsorbent, so it is always possible to select and use the most advanced and efficient products of the time.

  Although the decontamination work when the containment vessel was vented was explained, when the radiation level of the air inside the reactor building or turbine building rises during the normal time when venting is not conducted, the air is blown into the above-mentioned storage hollow tunnel It is also important to design the structure so that it can be used for decontamination work. Even in the interior of the reactor building and turbine building, air containing radioactivity is not directly discharged to the outside, but is always decontaminated inside, thus ensuring safety.

  Next, once the contaminated water collected in the reactor building and turbine building is temporarily stored in the underground storage tank, and the decontamination work of the decontamination layer is stopped, the remaining water from the basement is removed from the basement by a pump. After sending water to the tank for dyeing and injecting chemicals, decontamination of radioactive material ability, removal of oil components, removal of salt if seawater is included, removal work if organic components are included, etc. It is designed to be used as cooling water or circulating water for the fuel storage pool in the power plant as circulating water again without being discharged to the outside.

  Even if a control rod is inserted into the reactor due to an earthquake or the like and the nuclear reaction stops, the circulation of the cooling water in the ascites and the cooling water to the fuel pool must be continuously poured and cannot be stopped. As a measure for continuing cooling and water injection even if the entire power supply is lost, the storage tank for cooling water is located higher than the storage container in the present invention. Even if the water in the tank evaporates, the shortage will be replenished by the action of gravity from the tank, and the fear of meltdown will be dispelled, so there will be no such thing as the accident at the Fukushima Daiichi nuclear power plant. Even if the power supply is lost, the amount of water stored and the amount of water to be evaporated have a time margin, so that a time for recovering the power supply is secured during that time, and the external power supply and the emergency power supply can be restored.

  For some reason, control rods are inserted into the reactor body, and even if the reactor body stops power generation, the pressure vessel and fuel pool must be continuously cooled. is there. In the present invention, even if the power supply is not recovered from about 1 week to 10 days, the vented gas decontamination work can be continued with only a small amount of power of the emergency storage battery. It can be done. The purpose of this is to recover the power supply at an early stage by the recovery work of the standby power supply or the recovery work of the external power supply, and to achieve a stable cold shutdown of the nuclear power plant. Furthermore, as a countermeasure against accidents at nuclear power plants, even if the nuclear reactor becomes uncontrollable due to an accident, radioactive materials that are contained in the storage tank tunnel without being released into the atmosphere outside the reactor will be contaminated. This is a nuclear power plant with a decontamination facility that uses a decontamination process in the storage tank tunnel.

  As with all nuclear power plants, the main purpose of the nuclear power generation facilities of this system is to ensure stable operation without accidents, and even if accidents occur in the future, human damage and radioactive contamination will occur safely. The purpose is to prevent radiation damage to the surrounding area. In the future, it is still impossible for human beings to continue to live a civilized and comfortable life by technically satisfying the demand for electric power using only natural energy and renewable energy. In order to make up for this, it will be necessary to rely on nuclear power for the time being. If safer energy technology is developed in the future, nuclear power generation may be abolished, but in reality, nuclear power generation must be continued from the CO2 reduction. In addition, since this patent is applicable to both boiling and pressurized water reactors, it is possible to prevent the release of radioactivity outside by adding this system to a reactor that is already under construction. It can be safe as a response, and at the same time be the biggest solution that can eliminate the biggest anxiety factors of nuclear power plants. It seems that the traditional nuclear power generation is aimed at intensively deploying multiple systems based on safety measures for accident countermeasures based on the goal of safe operation. It may be said that a huge damage accident occurred because I often heard that it was unexpected, like the accident at the Fukushima Daiichi nuclear power plant, but did not take measures against the unexpected accident. Therefore, it can be said that it is an absolutely necessary facility for future nuclear power plants with the cane that does not fall even if the construction cost becomes large as in the present invention.

  The present invention relates to a radioactive decontamination facility associated with a nuclear power plant, gas containing radioactivity, released gas in the event of an accident and venting, contaminated reactor building or turbine building. The indoor stagnant water is guided to a dedicated storage tank, and multiple radioactivity decontamination operations corresponding to each are conducted to reduce the level to a level that does not affect the human body and can be reused in the power plant. is there. Therefore, no harmful substances including radioactive materials generated in the nuclear power plant are discharged in the surrounding suburbs outside the nuclear power plant, so that residents in the neighborhood can live without worry.

  In the case of constructing a nuclear power plant of the present invention, an embodiment will be described by classifying a newly constructed nuclear power plant and a case where a nuclear power plant that has already been constructed is remodeled into the present system. When constructing in a mountainous area or when constructing a new pumping dam, it will be as in Example 1. When remodeling to a nuclear power plant application system already constructed and operated, Example 2 Example 3 is obtained.

  In the case of constructing a new nuclear power plant from now on, a pumped-storage power plant is suitable as an optimum place as an embodiment of the present invention. A nuclear power plant is added to the pumped storage power plant. The biggest factor is that it is easy to secure power in the nuclear power plant in the event of an emergency. This is because the electric power generated at the pumped storage power plant can always be used in the nuclear power plant even if the external power supply is stopped in an emergency. Even in the event of repeated accidents, such as an emergency external power supply stop or emergency private power generation stoppage, the pumped-storage power station can generate power by discharging water from the upper dam to the lower dam, so it can easily generate power and supply power. Is possible. Normally, the surplus power at night of the nuclear power plant is used to pump water from the lower dam to the upper dam, and a system that can always generate hydraulic power by accumulating hydraulic power in the upper dam can be established. is there. Furthermore, even if the power generation of the nuclear power plant stops and the cooling function is not activated, the water in the upper dam can be forced to inject the cooling water of the containment vessel or pressure vessel and the fuel storage pool. In this way, it is easy to ensure cooling water, ensure power supply, and the like.

  The pumped storage power plant has a merit that the construction cost can be suppressed because the land cost is low because the location is in a mountainous area. Since the construction site is in a mountainous area, there is a problem that a new work and work approach path must be constructed, but it is not so difficult from the current mechanized civil engineering work. Most of the power plants are underground, eliminating the danger of appearance in terms of scenery. The primary purpose is to discharge radioactive materials from nuclear power plants because they are decontaminated in the ground. There is no such thing, and even a small number of residents in the surrounding area can live with peace of mind.

  As shown in FIG. 1, the containment vessel 9 which is the main body of the nuclear reactor is constructed in the large end 25 of FIG. 2, the turbine 13 and the ascites 12 are connected to the containment vessel, the lower dam 15 and the cooling water conduit for cooling water. 18 is connected to the ascites vessel 12 and further to the underground contaminated water storage tank 19. The water in the upper dam 2 in FIG. 1 is connected to the first-layer decontamination water intake 3 at the top of the decontamination tower and stored in the first layer 33 in FIG. It is stored in the second layer 36 and the third layer 37. Returning to FIG. 1, the reactor containment vessel 9 and the decontamination tower 7 are connected to the sixth layer 46 of the decontamination tower of FIG. 8 by the exhaust duct 5 when vented. In addition, the upper and lower dams are equipped with a water supply channel 4 for generating electricity during the daytime, generating power when needed, and using the surplus power at night to pump the water from the lower dam to the upper dam for use during the daytime. Is done. The leaked water and accumulated water from the reactor, the turbine 13 and the ascites 12 are stored in the underground contaminated water storage tank 19 and then through the contaminated water pumping pipe 54 by a pump of the underground contaminated water storage tank at a normal time other than emergency. The decontamination work is performed by pumping up to the seventh layer 50 and flowing through the oil separation device 65 and the coagulation sedimentation device 66 to the next plurality of decontamination chambers 51. Further, if the air concentration in the reactor building 8 and the turbine building 11 shown in FIG. 1 needs to be measured by measuring the radioactivity concentration, it can be sent to the fourth layer 40 by a blower to perform filter decontamination. is there. Of course, facilities such as power transmission facilities for emergency external power, emergency power generators, emergency storage batteries, etc. are also deployed and multiplexed to ensure a diversified power source.

  The outline of the decontamination equipment tower of the nuclear power plant of this system, the operation method of the decontamination facility, and the rough process of the decontamination work are explained. As shown in the side view of Fig. 1, the middle of the upper dam and lower dam of the pumped storage power plant Drill the required length of the Suido on the hillside of the location, reinforce and reinforce the inner surface of the Suido with reinforced concrete, and arrange each facility as shown in Fig. 1 to use the heat generated by the nuclear reaction to generate electric power. It will be a facility that generates

  FIG. 2 is a front view of each end road excavated on the hillside. Each end road is arranged on the hillside as shown in the figure, and is closed by a hatch and completely cut off from the outside except when necessary. In the side view of FIG. 1, the layout of each facility of the tower structure that is a decontamination facility is designed with a structure of 10 stages, but the structure is freely designed according to the power generation capacity of the power plant, etc. and is specified separately. It is sufficient if necessary facilities are arranged instead of things. As shown in FIG. 8, the outline of the decontamination tower is as follows. Cooling water for decontamination is taken from the upper dam 2 into the decontamination water intake 3 of the uppermost first-layer storage tank, passes through the purification device 34, and passes through the purification device 34. The second layer 36 and the third layer 37 are used as a storage tank. The fifth layer 42 and the sixth layer 48 are introduced into the gas when the gas is vented in an emergency from the nuclear reactor through the discharge duct 5. The vented gas flows naturally because of high temperature and pressure. When the pressure sensor and temperature sensor mounted in the fifth layer and the pressure sensor and temperature sensor in the discharge duct 5 (not shown) are stabilized at a certain value, the discharge duct shielding water discharge valve 39 is opened. Thus, the water inside the discharge duct shielding water storage tank 38 is discharged to the sixth layer through the piping below the valve. When this water reaches the water level of the dotted line shown in the drawing of the water level liquid level 47 for shielding the discharge duct, the discharge duct 5 and the sixth layer are blocked by water and cannot be vented. At this time, the discharge duct shielding float valve 63 shown in FIG. 8 closes the sixth layer inlet and the duct portion to prevent ventilation.

The gas discharged by venting is confined in the sixth layer and the fifth layer, and the radioactivity contained in this gas is subjected to water decontamination work by sprinkling with decontaminated water. In water decontamination, a large number of decontamination water stored in the third layer 37 is suspended by the pipe support 43 on the ceiling of the fifth and sixth layers through the sprinkling pipe 60 by opening the decontamination water discharge valve 56. Sprinkle decontamination of the radioactivity contained in the gas in the bed by sprinkling water in the shower state from the hole in the lower part of the pipe placed in the state where it is placed. The decontamination water discharge valve 56 is opened in conjunction with the closing operation of the discharge valve shielding float valve 63. The decontaminated water that has started to sprinkle the 5th and 6th layers accumulates in the lower part of the 6th layer, but at the start, the water surface position indicated by the dotted line 47 of the 6th layer 48 is sprinkled. As the water level in the layer rises due to water spraying 60, the gas is compressed to the upper part of the layer, and the gas in the sixth layer is pushed up to the fifth layer. When the water is filled up to the top of the sixth layer by continuing the watering operation, the float valve 45 at the top of the sixth layer operates to shut off the sixth layer and the fifth layer. And the sprinkling pipe 44 which is a connection part of the 6th layer and the 5th layer also closes the watering pipe 44, and the 6th layer sprinkling work is completed. The water sprinkling work of the water sprinkling pipe 60 of the fifth layer 42 is continuously performed. In the fifth layer, the water level of the decontamination water continues to rise, whereby the gas pressure increases and the gas discharged from the gas discharge port 58 passes through the decontamination gas discharge pipe 62 and is laid under the water surface of the sixth layer. The radioactivity in the bubbles is further reduced by being released into the decontamination water accumulated in the sixth layer as bubbles from the small hole in the upper part of the gas, and further, the radioactivity in the bubbles is taken into the decontamination water. Even if the amount of gas released as bubbles in the sixth layer rises, the fifth layer is sucked from the gas suction port 46 at the top of the sixth layer without being discharged to the fifth layer by closing the valve 45 described above. , Will be discharged to the fourth layer. The sixth layer gas exhaust pipe 61 is connected to the fourth layer filter chamber. The valve at this connection port opens the sixth layer gas discharge valve 59 by the action of the float valve that is activated when the sixth layer is full of water, and is in a state of ventilation with the fourth layer. Therefore, the gas in the sixth layer automatically flows into the filter chamber. The decontamination process with water twice in the fifth layer and the sixth layer is performed, and the gas whose radioactivity is reduced passes through the radioactivity removal filter in the fourth layer 40 and further decontamination work is performed.

  In FIG. 8, there are five fourth-layer filter chambers, and each chamber has a necessary number of filters made of chemicals that have good adsorption properties such as iodine, cesium 134, cesium 137, strontium, and plutonium. Is installed in each filter chamber, and the gas component that has entered through the sixth-layer gas exhaust pipe 61 is passed through the filter to be decontaminated. For final decontamination of the filter chamber, decontamination is performed by passing through a soil with good radioactivity adsorption as a filter. In this way, the gas exhausted at the vent is passed through two filter decontamination processes and further through the filter layer, and the decontamination work is repeated to reduce the radiation level to a safe level. It is a multiplex system that secures the maximum. After confirming the decrease in radioactivity to a safe level, it is circulated and reused inside the reactor building or the like, but some may also be discharged from the exhaust tower 1. The decontaminated water contaminated with the radioactivity of the fifth layer and the sixth layer opens the contaminated water discharge valve 64 at the lower part of the sixth layer after the decontamination work of the gas component, and the seventh layer 47 is contaminated with the contaminated water. Will be poured.

  The oil separation device 62 and the coagulation sedimentation device 63 are arranged in the seventh layer, and the contaminated water passes through this device and enters the contaminated water decontamination chamber 51. In FIG. 8, the three contaminated water decontamination chambers 51 are arranged side by side, and the contaminated water can be processed in parallel in each decontamination chamber to increase the decontamination efficiency. By adopting many decontamination systems from world-renowned manufacturers in each room, it is possible to compare the capacity and measure the failure stop rate, and use it as a guideline for subsequent countermeasures. It is possible to perform efficient decontamination by always installing the latest high decontamination equipment. The water decontaminated in the seventh layer is stored in the eighth to tenth layers and used as cooling water for fuel storage pools, reactor containment vessels, pressure vessel replenishment water, ascites and the like.

  The degassing of the vented gas is completed in the sixth layer and the fifth layer, and the decontaminated gas passes through the filter chamber of the fourth layer to complete the recontamination. Contaminated water accumulated in the 6th and 5th layers also passes through the oil separation device and coagulation sedimentation device installed in the 7th layer, then passes through the radioactive decontamination facility, and the decontaminated water is finished. The first decontamination process is completed by storing in the lower layer from the eighth layer to the tenth layer. In this initial decontamination process, it is possible to carry out the decontamination work at the initial stage with the electric power operated by the power station instruments even when the entire power supply is lost even when an emergency situation occurs and the power source is operated by a small power source such as an emergency battery. This is a preventive measure for avoiding the worst situation by avoiding the meltdown of the fuel rod in the pressure vessel of the reactor main body. When the decontamination work at the initial stage is completed, the float valves and other valves in the respective layers are returned to the initial state, and the next decontamination process is started. Radioactivity that could not be supplied to the sixth layer in the vent discharge duct 5 for the first time when the discharge duct shielding float valve 61 was opened when the contaminated water of the sixth layer and the fifth layer disappeared to the seventh layer. The residual gas containing gas is again supplied to the sixth layer by the air supply fan, and the decontamination work for residual radioactivity is performed. At this time, if the reason for the emergency shutdown of the reactor is due to the power shutdown, the restart of the power is a condition for entering the second decontamination process. It will be possible. In the case of Example 1, since the pumped storage power plant and the decontamination tower are in the same place, in the case of occurrence of an emergency or loss of all power sources, pre-treatment for stable cooling or power restoration is extremely important. It is advantageous.

  The salt separation desalinator arrangement chamber 35 of FIG. 8 is not necessary in the pumped storage power plant of Example 1 because the upper dam is fresh water. This is arranged in the first layer of the decontamination tower only in the case of Example 2 and Example 3.

  Even if an earthquake occurs or an abnormal situation occurs in various parts of the reactor, the reactor control rod is inserted and the nuclear reaction stops, the surface temperature of the fuel rod is 500 degrees Celsius, the internal temperature is as high as 1800 degrees, the containment vessel, Although it is a well-known fact that meltdown may occur when cooling is stopped even if the pressure vessel is submerged, it is assumed that 100 tons of water evaporates per hour in this state. Even in the event of a loss of all power in the event of an emergency, even if the cooling circulation of the ascites device is stopped, if 100 tons of water is automatically continued, 100 hours per ton × 24 hours × 7 days = 16,800 tons of cooling water is required to continuously circulate water. Since it is necessary to store this amount of water in the worst case, it is necessary to design the decontamination tower in consideration of this amount of water. However, when constructing a nuclear power plant for a pumping dam as in the first embodiment, if a sufficient amount of water is secured in the upper dam, there is little need to secure this amount of cooling water for injection. When constructing a decontamination tower of this method at a nuclear power plant constructed on the coastline as in the second embodiment or the third embodiment, it is necessary to consider sufficient cooling water capacity.

  In this way, the present invention prevents the gas and polluted water contaminated by radioactivity in the nuclear power plant from being guided to the building of the tower structure where the decontamination facility is installed, and prevents leakage and diffusion to the outside. This facility prevents the surrounding area from being contaminated with radioactivity. As can be seen from past accidents at nuclear power plants, once the radioactivity spreads to the surrounding area, the surrounding residents cannot live for a long period of time, causing a great deal of damage. The damage has already been experienced by mankind and will depend on nuclear power generation from the standpoint of global warming countermeasures until the establishment of technology to fully secure safety measures and secure new energy sources in the future. In the current situation, we must carefully consider accident countermeasures.

  If the decontamination is completed in the 6th and 5th tiers of the decontamination tower, the gas discharged first by the venting will be able to be used by the pumped-storage power and the emergency power supply depending on the emergency situation. Residual gas shielded in the vent exhaust duct may be sent to the sixth layer by driving a fan to resume water decontamination and continue decontamination, or accumulated in the underground contaminated water storage tank 19. Contaminated water may be pumped up to the seventh layer to start decontamination. If hydrogen gas is generated in the containment vessel or pressure vessel, nitrogen gas injection is started while the surroundings of the pressure vessel are started. Continued the cooling water injection work, guided the ventilation of air contaminated with radioactivity in the buildings and facilities, and carried out the decontamination process in consideration of the health management of workers, and resumed power generation. Information is centralized and integrated into the central control room, and judgment is made as necessary. Management and operation is required.

  The decontamination tower facility of the second embodiment is shown in FIG. 3 in the case where the nuclear power plant already built along the coast or the like adopts the present invention to add a decontamination tower in order to strengthen safety measures. ing. This is suitable when there are mountains and hills behind the reactor facility. In the case of Example 2, as in Example 1, the decontamination tower itself is excavated in the ground such as a mountain behind, and reinforced concrete is reinforced in each hole. A decontamination tower is installed in the underground to decontaminate the gas and polluted water vented to the decontamination tower so that the radioactivity does not spread to the surrounding area even in the worst case of an accident. The structure of the facility is almost the same as in Example 1, but because it is along the sea in the event of an emergency, take measures such as installing an emergency power source, a breakwater, or securing multiple power sources, assuming damage from an earthquake tsunami It is necessary to prepare a facility for storing fresh water by installing a salt removal device in consideration of the situation of using seawater in addition to securing a water source when the worst situation occurs. FIG. 4 is a plan view of FIG. 3 in which cooling water is taken from the sea through an underground channel and taken into the turbine building and the contaminated water underground storage tank to be used for cooling. When contaminated water is stored in the underground storage tank, it is pumped up to the decontamination tower by a pump (P) and decontaminated when it is not an emergency, and the decontaminated water is reused. In addition, it is buried in the ground in the event of an emergency to prevent the spread of radioactivity in the surrounding area.

  In the case of Example 3, when there is no mountainous hilly area behind the nuclear power plant along the coast as in Example 2, the decontamination tower is installed in a building constructed with steel bars or steel structure concrete as shown in FIG. To carry out decontamination work. Fig. 6 shows a plan view of the layout plan, and Fig. 7 is a front view of the decontamination tower structure. A tower-structure tunnel that houses each decontamination facility is constructed in the center, and work is performed on both sides of the front view. There is a mine shaft. In this case, since construction is performed in the ground as in the first and second embodiments, it is easier to construct a circular structure, but in the case of the third embodiment, a high-rise building structure is constructed on a flat ground. It is easier to construct with a structure like 7 in terms of construction and budget. Although it is a large structure, there are many problems such as rising costs, but it is a problem that must be overcome as a safety measure if an accident occurs. In this case as well, the decontamination tower as shown in FIG. 8 is clawed in the same manner as in Example 2 in consideration of the necessity of using seawater in consideration of the supply of fresh water in an emergency. It is necessary for safety measures that salt separation fresh water is installed in the rear part of the first layer as a countermeasure for accidents by installing the device 35. The special installation location is not specified and any suitable location may be used.

  The continued power supply of nuclear power plants under the current situation that public opinion about denuclearization is increasing globally, it is difficult to expect a decrease in nuclear power plant movement unless the concerns about safe driving are completely eliminated. Even if a radiological accident occurs, the construction operation of the plant prevents radioactive diffusion to the surrounding area of the power plant and contains it in the mountains or in the decontamination facility. Is to be discharged after being decontaminated by a decontamination device installed inside, so that diffusion to the outside is prevented. As it is well known that an accident occurred at a conventional nuclear power plant, in which case radioactive gas was released and diffused into the surrounding area, the damaged area started from residential areas to farmland forests, and pollution spread to the agricultural, marine and livestock industries. This creates enormous compensation problems. In some cases, there may be a risk of being unable to live in the area for a period of several decades.

  The construction of the power plant of Example 1 and Example 2 in this system can be completed early by excavating with a tunnel excavating machine and the inner surface is reinforced with reinforced concrete, and is covered outside the facility Because the part is rock, it can be judged that construction costs can be made at low cost rather than construction on flat ground. Considering the compensation amount generated at the time of the accident as described above, it can be determined that the cost problem of the construction amount is not covered. Various sensors and monitor communication lines in the decontamination tower of each layer are centrally integrated in the central control room to automate as much as possible, and parts and points that are manually operated manually are entered into each layer through work tunnels. Is possible. Even if the power supply is lost due to an emergency, it is possible to continue the decontamination work of the vented gas and contaminated water semi-automatically until the power supply is restored.

  Reactor and decontamination facility layout of this method with pumping dam method   Layout of conventional nuclear power plant facilities   Layout map of existing coastal nuclear power plant and decontamination facility   Plan view of ground layout of power plant decontamination facilities along existing coast   Construction method of decontamination facility on the flat ground of the existing power plant   Arrangement plan view of the method of FIG.   Structure diagram of decontamination facility using the method of FIG.   Detailed view of decontamination tower

DESCRIPTION OF SYMBOLS 1 Exhaust tower 2 Upper dam 3 Decontamination water intake 4 Pumping dam waterway 5 Vent discharge duct 6 Exhaust duct 7 Decontamination tower 8 Reactor building 9 Containment vessel 10 Fuel storage pool 11 Turbine building 12 Astrocharger 13 Turbine 14 Central control room 15 Lower dam 16 Pumped-storage generator 17 Contaminated water discharge line 18 Cooling water line 19 Underground contaminated water storage tank 20 Contaminated water pump 21 Work tunnel 22 1st layer 23 2nd layer 24 10th layer 25 Reactor building final road 26 Underground contaminated water storage tank 27 Construction work tunnel 28 Cooling water conduit 29 Sea 30 Breakwater 31 Fifth layer 32 Decontaminated water pumping conduit 33 First layer 34 Purification device placement chamber 35 Salt separation and desalination device placement chamber 36 Second Layer 37 Third layer 38 Discharge duct shielding water storage tank 39 Discharge duct shielding water discharge valve 40 Fourth layer 41 Decontamination water pipe 42 Fifth layer 43 Decontamination water pipe support 4 4 Decontamination water sprinkling pipe closing valve 45 6th layer, 5th layer connecting pipe closing valve 46 6th layer exhaust gas intake port 47 Exhaust duct closing water upper liquid level 48 6th layer 49 Bubble discharge pipe 50 7th layer 51 Contamination Water decontamination treatment chamber 52 8th layer 53 9th layer 54 Contaminated water pumping pipe 55 10th layer 56 Decontamination water discharge valve 57 Gas decontamination filter chamber 58 5th layer gas discharge port 59 6th layer gas discharge valve 60 Water spray Piping 61 Sixth layer gas discharge pipe 62 Decontamination gas discharge pipe 63 Discharge duct shielding float valve 64 Contaminated water discharge valve 65 Oil content separation device 66 Coagulation sedimentation device 67 Decontamination circulation water discharge valve

In order to solve the above problems, the present invention has a large-sized structure in which a vapor or gas containing radioactivity discharged when a vent is carried out due to an accident that causes a high pressure in the reactor and an explosion is carried out, and a vent is sealed. Without touching the outside air to the closed storage hollow tunnel, air is sent through the pipeline, and after closing, decontamination with a water spray shower from the pipe installed in the upper part of the storage tunnel, and the remaining gas is compressed by accumulating the sprayed water. Then, the gas is decontaminated by being led to the lower water tunnel , discharged as bubbles from the pipeline at the lower part of the tunnel , brought into contact with water again with a gas containing radioactivity in the decontamination water, and transferred to the water. The low-level gas is further moved to the next upper tunnel, and the residual radioactivity contained in the gas is passed through each multi-layer filter made of a highly adsorbable chemical substance to decontaminate the radioactivity. . The gas that passes through each filter is further passed through a filter made of clay soil with good adsorption of clay radioactivity, and decontaminated to reduce the radioactivity to a safe level. At this time, the radioactivity removal filter is a filter for individually decontaminating radioactive substances such as iodine, cesium 134, cesium 137, strontium, and plutonium, and performs decontamination for each. Each filter uses a product of a specialized manufacturer that uses the most suitable adsorbent, so it is always possible to select and use the most advanced and efficient products of the time.

Next, once the contaminated water collected in the reactor building and turbine building is temporarily stored in the underground storage tank, and the decontamination work of the decontamination layer is stopped, the remaining water from the basement is removed from the basement by a pump. After sending water to the tunnel of the dyeing storage tank and injecting chemicals, decontamination of radioactive material ability, removal of oil components, removal of salt when seawater is contained, removal work when organic components are contained, etc. It is designed to be used as cooling water or circulating water for the fuel storage pool in the power plant as circulating water again without being discharged to the outside.

Even if a control rod is inserted into the reactor due to an earthquake or the like and the nuclear reaction stops, the circulation of the cooling water in the ascites and the cooling water to the fuel pool must be continuously poured and cannot be stopped. As a measure for continuing cooling and water injection even if the entire power supply is lost, the storage tunnel for cooling water is located higher than the containment vessel in the present invention. Even if the water in the tank evaporates, the shortage will be replenished by the action of gravity from the tank, and the fear of meltdown will be dispelled, so there will be no such thing as the accident at the Fukushima Daiichi nuclear power plant. Even if the power supply is lost, the amount of water stored and the amount of water to be evaporated have a time margin, so that a time for recovering the power supply is secured during that time, and the external power supply and the emergency power supply can be restored.

In the case of constructing a new nuclear power plant from now on, a pumped-storage power plant is suitable as an optimum place as an embodiment of the present invention. A nuclear power plant is added to the pumped storage power plant. The biggest factor is that it is easy to secure power in the nuclear power plant in the event of an emergency. This is because the electric power generated at the pumped storage power plant can always be used in the nuclear power plant even if the external power supply is stopped in an emergency. Even in the event of repeated accidents, such as an emergency external power supply stop or emergency private power generation stoppage, the pumped-storage power station can generate power by discharging water from the upper dam to the lower dam, so it can easily generate power and supply power. Is possible. Normally, the surplus power at night of the nuclear power plant is used to pump water from the lower dam to the upper dam, and a system that can always generate hydraulic power by accumulating hydraulic power in the upper dam can be established. is there. Furthermore, even if the power generation of the nuclear power plant is stopped and the cooling function is not activated, it is possible to continue to inject cooling water of the containment vessel and pressure vessel and cooling water of the fuel storage pool with the water of the upper dam. In this way, it is easy to ensure cooling water, ensure power supply, and the like.

The gas discharged by venting is confined in the sixth layer and the fifth layer, and the radioactivity contained in this gas is subjected to water decontamination work by sprinkling with decontaminated water. In water decontamination, a large number of decontamination water stored in the third layer 37 is suspended by the pipe support 43 on the ceiling of the fifth and sixth layers through the sprinkling pipe 60 by opening the decontamination water discharge valve 56. Sprinkle decontamination of the radioactivity contained in the gas in the bed by sprinkling water in the shower state from the hole in the lower part of the pipe placed in the state where it is placed. The decontamination water discharge valve 56 is opened in conjunction with the closing operation of the discharge valve shielding float valve 63. The decontaminated water that has started to sprinkle the 5th and 6th layers accumulates in the lower part of the 6th layer, but at the start, the water surface position indicated by the dotted line 47 of the 6th layer 48 is sprinkled. 60 by the gas the gas by the water level in the layer rises had more sixth layer tunnel that is compressed in the upper layer by sprinkling is gradually pushed up to the fifth layer. When the water is filled up to the top of the sixth layer by continuing the watering operation, the float valve 45 at the top of the sixth layer operates to shut off the sixth layer and the fifth layer. And the sprinkling pipe 44 which is a connection part of the 6th layer and the 5th layer also closes the watering pipe 44, and the 6th layer sprinkling work is completed. The water sprinkling work of the water sprinkling pipe 60 of the fifth layer 42 is continuously performed. In the fifth layer, the water level of the decontamination water continues to rise, whereby the gas pressure increases and the gas discharged from the gas discharge port 58 passes through the decontamination gas discharge pipe 62 and is laid under the water surface of the sixth layer. The radioactivity in the bubbles is further reduced by being released into the decontamination water accumulated in the sixth layer as bubbles from the small hole in the upper part of the gas, and further, the radioactivity in the bubbles is taken into the decontamination water. Even if the amount of gas released as bubbles in the sixth layer rises, the fifth layer is sucked from the gas suction port 46 at the top of the sixth layer without being discharged to the fifth layer by closing the valve 45 described above. , Will be discharged to the fourth layer. The sixth layer gas exhaust pipe 61 is connected to the fourth layer filter chamber. The valve at this connection port opens the sixth layer gas discharge valve 59 by the action of the float valve that is activated when the sixth layer is full of water, and is in a state of ventilation with the fourth layer. Therefore, the gas in the sixth layer automatically flows into the filter chamber. The decontamination process with water twice in the fifth layer and the sixth layer is performed, and the gas whose radioactivity is reduced passes through the radioactivity removal filter in the fourth layer 40 and further decontamination work is performed.

In the case of Example 3, when there is no mountainous hilly area behind the nuclear power plant along the coast as in Example 2, the decontamination tower is installed in a building constructed with steel bars or steel structure concrete as shown in FIG. To carry out decontamination work. Fig. 6 shows a plan view of the layout plan, and Fig. 7 is a front view of the decontamination tower structure. A tower-structure tunnel that houses each decontamination facility is constructed in the center, and work is performed on both sides of the front view. There is a mine shaft. In this case, since construction is performed in the ground as in the first and second embodiments, it is easier to construct a circular structure, but in the case of the third embodiment, a high-rise building structure is constructed on a flat ground. It is easier to construct with a structure like 7 in terms of construction and budget. Although it is a large structure, there are many problems such as rising costs, but it is a problem that must be overcome as a safety measure if an accident occurs. In this case as well, the decontamination tower as shown in FIG. 8 is used in the same manner as in Example 2 in consideration of the necessity of using seawater in consideration of the supply of fresh water in an emergency. It is necessary for safety measures that salt separation fresh water is installed in the rear part of the first layer as a countermeasure for accidents by installing the device 35. The special installation location is not specified and any suitable location may be used.

Even if a control rod is inserted into the reactor due to an earthquake or the like and the nuclear reaction stops , the cooling water circulation of the condenser and the cooling water to the fuel pool must be continuously poured and cannot be stopped. As a measure for continuing cooling and water injection even if the entire power supply is lost, the storage tunnel for cooling water is located higher than the containment vessel in the present invention. Even if the water in the tank evaporates, the shortage will be replenished by the action of gravity from the tank, and the fear of meltdown will be dispelled, so there will be no such thing as the accident at the Fukushima Daiichi nuclear power plant. Even if the power supply is lost, the amount of water stored and the amount of water to be evaporated have a time margin, so that a time for recovering the power supply is secured during that time, and the external power supply and the emergency power supply can be restored.

As with all nuclear power plants, the main purpose of the nuclear power generation facilities of this system is to ensure stable operation without accidents, and even if accidents occur in the future, human damage and radioactive contamination will occur safely. The purpose is to prevent radiation damage to the surrounding area. In the future, it is still impossible for human beings to continue to live a civilized and comfortable life by technically satisfying the demand for electric power using only natural energy and renewable energy. In order to make up for this, it will be necessary to rely on nuclear power for the time being. If safer energy technology is developed in the future, nuclear power generation may be abolished, but in reality, nuclear power generation must be continued from the CO2 reduction. In addition, since this patent is applicable to both boiling and pressurized water reactors, it is possible to prevent the release of radioactivity outside by adding this system to a reactor that is already under construction. It can be safe as a response, and at the same time be the biggest solution that can eliminate the biggest anxiety factors of nuclear power plants. It seems that the traditional nuclear power generation is aimed at intensively deploying multiple systems based on safety measures for accident countermeasures based on the goal of safe operation. Fukushima was heard well represented that unexpected as in the first nuclear power plant accident or will not be said that it had not taken measures against the unexpected accident has become enormous damage accident. Therefore, it can be said that it is an absolutely necessary facility for future nuclear power plants with the cane that does not fall even if the construction cost becomes large as in the present invention.

As shown in FIG. 1, the containment vessel 9 which is the main body of the nuclear reactor is constructed in the large end 25 of FIG. 2, the turbine 13 and the condenser 12 are connected to the containment vessel, the lower dam 15 and the cooling water pipe for cooling water. It is also connected to the path 18 and the condenser 12 and further to the underground contaminated water storage tank 19. The water in the upper dam 2 in FIG. 1 is connected to the decontamination water intake 3 of the first layer tunnel at the top of the decontamination tower, and is stored in the first layer tunnel 33 in FIG. After that, it is stored in the second layer tunnel 36 and the third layer tunnel 37. Returning to FIG. 1, the reactor containment vessel 9 and the decontamination tower 7 are connected to the sixth layer tunnel 48 of the decontamination tower of FIG. 8 by the exhaust duct 5 when vented. Further, in FIG. 1, the upper dam and the lower dam are provided with a water channel 4 for irrigation power generation, generating electricity when needed during the daytime, and using the surplus power at night to pump the water from the lower dam to the upper dam. Used for daytime use. The leaked water and accumulated water from the nuclear reactor, turbine 13 and condenser 12 are stored in the underground contaminated water storage tank 19 and then pumped through the contaminated water pumping pipe 54 by a pump of the underground contaminated water storage tank at a normal time other than emergency. The decontamination work is performed by pumping up to the seventh seventh layer tunnel 50 and flowing through the oil separation device 65 and the coagulation sedimentation device 66 to the next plurality of decontamination chambers 51. Further, if the air concentration in the reactor building 8 and the turbine building 11 shown in FIG. 1 needs to be measured by measuring the radioactivity concentration, it can be sent to the fourth-layer tunnel 40 by a blower to perform filter decontamination. is there. Of course, facilities such as power transmission facilities for emergency external power, emergency power generators, emergency storage batteries, etc. are also deployed and multiplexed to ensure a diversified power source.

FIG. 2 is a front view of each end road excavated on the hillside. Each end road is arranged on the hillside as shown in the figure, and is closed by a hatch and completely cut off from the outside except when necessary. In the side view of FIG. 1, the layout of each facility of the tower structure that is a decontamination facility is designed with a structure of 10 stages, but the structure is freely designed according to the power generation capacity of the power plant, etc. and is specified separately. It is sufficient if necessary facilities are arranged instead of things. The outline of the decontamination tower is as shown in FIG. 8. Cooling water for decontamination is taken from the upper dam 2 into the decontamination water intake 3 of the storage tank of the uppermost first layer tunnel , and passes through the purification device 34. The second layer tunnel 36 and the third layer tunnel 37 are used as storage tanks. The fifth-layer tunnel 42 and the sixth-layer tunnel 48 are guided into the gas when vented in an emergency from the nuclear reactor through the discharge duct 5. The vented gas flows naturally because of high temperature and pressure. When the pressure sensor and temperature sensor mounted in the fifth layer and the pressure sensor and temperature sensor in the discharge duct 5 (not shown) are stabilized at a certain value, the discharge duct shielding water discharge valve 39 is opened. Thus, the water inside the discharge duct shielding water storage tank 38 is discharged to the sixth layer through the piping below the valve. When this water reaches the water level of the dotted line portion shown in the drawing of the water level liquid level 47 for shielding the discharge duct, the discharge duct 5 and the sixth layer tunnel are blocked with water and cannot be vented. At this time, the discharge duct shielding float valve 63 shown in FIG. 8 closes the sixth-layer tunnel entrance and the duct portion so as not to allow ventilation.

The gas discharged by venting is confined in the sixth-layer tunnel and the fifth-layer tunnel, and the radioactivity contained in this gas is subjected to water decontamination work by sprinkling with decontaminated water. In the water decontamination, the decontaminated water stored in the third layer tunnel 37 is opened with the decontamination water discharge valve 56 and the sprinkling pipe 60 is connected to the ceiling of the fifth layer tunnel and the sixth layer tunnel by the pipe support 43. Sprinkle decontamination of the radioactivity contained in the gas in the bed by sprinkling water in the shower from the detail holes at the bottom of the pipes arranged in a suspended state. The decontamination water discharge valve 56 is opened in conjunction with the closing operation of the discharge valve shielding float valve 63. The decontaminated water that has started to sprinkle in the 5th and 6th layer tunnels accumulates in the lower part of the 6th layer tunnel. At the start, the decontaminated water is at the water surface position indicated by the dotted line 47 of the 6th layer tunnel 48. there is gas gas by the water level in the layer rises by sprinkling had more sixth layer tunnel that is compressed in the upper layer by sprinkling pipe 60 is gradually pushed fifth layer tunnel. When water is filled up to the top of the sixth layer tunnel by continuing the watering operation, the float valve 45 above the sixth layer tunnel operates to shut off the sixth layer tunnel and the fifth layer tunnel . Then, the sprinkling pipe 44 is also connected to the sixth-layer tunnel and the fifth-layer tunnel , and the sprinkling work of the sixth-layer tunnel is completed. The water sprinkling work of the water sprinkling pipe 60 of the fifth layer tunnel 42 is continuously performed. In the fifth layer tunnel, the water level of the decontamination water continues to rise, so that the gas pressure increases and the gas discharged from the gas outlet 58 is laid under the surface of the sixth layer tunnel through the decontamination gas discharge pipe 62 . From the small hole in the upper part of a certain pipe, it is released into the decontamination water accumulated in the 6th layer tunnel as a bubble, and the radioactivity in the bubble is further taken into the decontamination water. Go. Even if the amount of gas released into the sixth layer tunnel as bubbles rises, the fifth layer tunnel is not discharged into the fifth layer tunnel by closing the valve 45 described above, but the gas suction port located above the sixth layer tunnel. It is sucked in from 46 and discharged to the fourth layer tunnel . The sixth layer gas discharge pipe 61 is connected to the filter chamber of the fourth tunnel . The valve at the connection port opens the sixth layer gas discharge valve 59 by the action of the float valve that is activated when the sixth layer tunnel is full of water, and enters the fourth layer tunnel in a vented state. Therefore, the gas in the sixth layer tunnel automatically flows into the filter chamber. The decontamination process with water is performed twice in the fifth-layer tunnel and the sixth-layer tunnel , and the gas with reduced radioactivity is further decontaminated by passing through the radioactivity removal filter in the fourth-layer tunnel 40.

In FIG. 8, there are five filter chambers in the fourth-layer tunnel , and each chamber requires a filter made of chemicals with good adsorption, such as iodine, cesium 134, cesium 137, strontium, and plutonium. The number of gas is set in each filter chamber, and the gas component that has entered through the sixth layer gas discharge pipe 61 is passed through and contacted with the filter for decontamination. For final decontamination of the filter chamber, decontamination is performed by passing through a soil with good radioactivity adsorption as a filter. In this way, the gas exhausted at the vent is passed through two filter decontamination processes and further through the filter layer, and the decontamination work is repeated to reduce the radiation level to a safe level. It is a multiplex system to ensure the maximum. After confirming the decrease in radioactivity to a safe level, it is circulated and reused inside the reactor building or the like, but some may also be discharged from the exhaust tower 1. The decontaminated water contaminated by the radioactivity of the fifth layer tunnel and the sixth layer tunnel opens the contaminated water discharge valve 64 at the lower part of the sixth layer after the decontamination work of the gas component and opens the seventh layer tunnel 47. Contaminated water will be poured into the water.

The oil separation device 62 and the coagulation sedimentation device 63 are arranged in the seventh layer tunnel 50 , and the contaminated water passes through this device and enters the contaminated water decontamination chamber 51. In FIG. 8, the three contaminated water decontamination chambers 51 are arranged side by side, and the contaminated water can be processed in parallel in each decontamination chamber to increase the decontamination efficiency.
By adopting many decontamination systems from world-renowned manufacturers in each room, it is possible to compare the capacity and measure the failure stop rate, and use it as a guideline for subsequent countermeasures. It is possible to perform efficient decontamination by always installing the latest high decontamination equipment. Water decontaminated in the 7th layer tunnel is stored in the 8th layer tunnel to the 10th layer tunnel and used as cooling water for fuel storage pools, reactor containment vessels, pressure vessel refill water, condensers, etc. .

DESCRIPTION OF SYMBOLS 1 Exhaust tower 2 Upper dam 3 Decontamination water intake 4 Pumping dam channel 5 Vent discharge duct 6 Exhaust duct 7 Decontamination tower 8 Reactor building 9 Containment vessel 10 Fuel storage pool 11 Turbine building 12 Condenser 13 Turbine 14 Central control Chamber 15 Lower dam 16 Pumped-storage generator 17 Contaminated water discharge pipe 18 Cooling water pipe 19 Underground contaminated water storage tank 20 Contaminated water pumping pump 21 Working tunnel 22 First layer 23 Second layer 24 Tenth layer 25 Reactor building Road 26 Underground contaminated water storage tank 27 Construction tunnel 28 Cooling water pipe 29 Sea 30 Breakwater 31 Fifth layer tunnel 32 Decontaminated water pumping pipe 33 First layer tunnel 34 Purification device arrangement room 35 Salt separation and desalination equipment arrangement room 36 second layer tunnel 37 third layer tunnel 38 exhaust duct shielding water storage tank 39 the discharge duct shielding water discharge valve 40 fourth layer ton Le 41 decontaminated water pipe 42 fifth layer tunnel 43 decontaminated water pipe support 44 decontaminated water sprinkler pipe closing valve 45 the sixth layer, the fifth layer communication pipe closing valve 46 the sixth layer exhaust gas inlet port 47 exhaust duct closed Water upper liquid level 48 6th layer tunnel 49 Bubble discharge pipe 50 7th layer tunnel 51 Contaminated water decontamination processing chamber 52 8th layer tunnel 53 9th layer tunnel 54 Contaminated water pumping pipe 55 10th layer tunnel 56 Decontaminated water discharge Valve 57 Gas decontamination filter chamber 58 Fifth layer gas discharge port 59 Sixth layer gas discharge valve 60 Sprinkling pipe 61 Sixth layer gas discharge pipe 62 Decontamination gas discharge pipe 63 Discharge duct shielding float valve 64 Contaminated water discharge valve 65 Oil content Separation device 66 Coagulation sedimentation device 67 Decontamination circulation water discharge valve

Claims (1)

  In the structure of a vented exhaust gas decontamination system in a nuclear power plant, the tunnel storing the exhaust gas has an inclination angle alternately so that water flows down from the upper stage to the lower stage by the action of gravity in two upper and lower stages. A storage tank is arranged, two stages of tunnels having a capacity satisfying the inside of the two-stage tunnel are arranged on one stage of the two-stage tunnel, and the inside is filled with fresh water that decontaminates radioactivity. After the gas discharged from the reactor containment vessel is stored in the two-stage tunnel on the lower stage side of the two-stage tunnel, the fresh water stored in the upper tunnel of the two-stage tunnel is laid on the ceiling in the two-stage tunnel The decontaminated water sprayed in the shower shape is accumulated in the bottom of the lower tunnel of the two-stage tunnel, and the lower tank gas is compressed and stored in the upper tank, and then the lower tank and upper tank are connected. The gas that has been compressed and accumulated in the lower tank is circulated and discharged again from the bottom of the lower tank, which is filled with bubbles through the piping, and the radioactivity in the gas is reduced to the lower Provided with a plurality of filter decontamination chambers for the tank above the two-stage tank that transfers the radioactivity to the decontamination water of the tunnel and sprinkles water until the two-stage tank becomes full and discharges it to the lower tank. At the same time that the residual radioactivity in the gas is decontaminated by discharging into the tank, the contaminated water accumulated in the full water in the two-stage tank opens a valve in the tunnel tank located in the lower part of the two-stage. After flowing out, passing through the oil separator and passing through the coagulation sedimentation device, the contaminated water is decontaminated to a low concentration through multiple decontamination systems, and further reused as reactor circulation water in the tank below it. Decontamination systems each tunnel has a structure for storing to internal processing radioactivity generated in the nuclear power plant of the tower structure, characterized in that naturally drops outflow by gravity to have a tilt angle alternately.

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