JP4828963B2 - Core melt cooling device, reactor containment vessel, and method of installing core melt cooling device - Google Patents

Description

  The present invention relates to a core melt cooling device, a reactor containment vessel, and a method for installing a core melt cooling device.

  In a water-cooled nuclear reactor, the reactor water level falls and the core is exposed and cooled due to the loss of cooling water due to the stoppage of water supply to the reactor pressure vessel or the breakage of the piping connected to the reactor pressure vessel. It may become insufficient. Assuming such a case, the reactor is automatically shut down in response to a water level lowering signal, and the core is submerged and cooled by injecting coolant using an emergency core cooling system (ECCS), and a core melting accident is performed. It is designed to prevent it.

  However, although the probability is very low, it can be assumed that the emergency core cooling device does not operate and water injection devices for other cores cannot be used. In such a case, the core is exposed due to a decrease in the reactor water level, and sufficient cooling is not performed, and the fuel rod temperature rises due to decay heat that continues to occur after the reactor shuts down, eventually leading to core melting. There is a fear.

  When this happens, the high-temperature core melt (corium) melts down into the lower part of the reactor pressure vessel, melts and penetrates the lower head of the reactor pressure vessel, and corium is placed on the floor in the reactor containment vessel. Fall. Corium heats the concrete stretched on the containment floor, reacts with the concrete when the contact surface becomes hot, generates a large amount of noncondensable gases such as carbon dioxide and hydrogen, and melts and erodes the concrete.

  The generated non-condensable gas increases the pressure inside the containment vessel and may damage the reactor containment vessel. Also, the containment vessel boundary may be damaged by concrete melt erosion, and the containment vessel structural strength may be reduced. There is sex. As a result, if the reaction between corium and concrete continues, the containment vessel is damaged, and there is a possibility that radioactive materials in the containment vessel are released to the external environment.

In order to suppress such a reaction between corium and concrete, the corium is cooled and the temperature of the contact surface with the concrete at the bottom of the corium is cooled to below the erosion temperature (1500 K or less for general concrete), or It is necessary to prevent the concrete from coming into direct contact. Conventionally, by cooling by pouring water from above the dropped corium, the corium temperature has been lowered to suppress the concrete erosion reaction (see, for example, Patent Document 1 and Patent Document 2).
JP 2004-333357 A JP 2005-195595 A TGTheofanous, 1 other, "The Coolability Limits of A Reactor Pressure Vessel Lowerhead", 1997, Nuclear Engineering and Design, Volume 169, p.59-p.76

  Only water injection from the top of the corium is only cooling by boiling the water on the top surface of the corium, and if the corium deposition thickness is thick, there is a possibility that the corium bottom cannot be sufficiently cooled. Therefore, it is necessary to increase the floor area and to reduce the corium deposition thickness to a thickness that can be cooled. However, securing a sufficiently large floor area has been difficult in designing the containment structure.

For example, the decay heat of typical corium is about 1% of the rated heat output, and in the case of a furnace with a rated heat output of 4000 MW, the calorific value is about 40 MW. Although the boiling heat transfer amount on the upper surface varies depending on the state of the upper surface of the corium, a heat flux of at least about 0.4 MW / m ² is assumed. In this case, if the amount of heat generated by corium is taken only by heat transfer from the upper surface, a floor area of about 100 m ² (circular diameter of 11.3 m) is required. Considering the structure of the conventional containment vessel, it has been difficult to secure this area.

  Accordingly, an object of the present invention is to improve the efficiency of cooling the core melt generated when the core in the reactor vessel melts and penetrates the reactor vessel without increasing the floor area.

In order to achieve the above object, the present invention provides a core melt cooling apparatus for receiving and cooling a core melt generated when a core in a reactor vessel is melted and penetrates the reactor vessel. A water supply chamber installed below the container; a lower inlet portion that is an opening connected to the water supply chamber; and an upper outlet portion that is an upper opening that is higher than the lower inlet portion. Chi lifting the ring-like projected shape that a direction toward the upper outlet from the inlet portion and the radial direction, a water channel assembly cooling water of the water supply chamber flows to the upper outlet from the lower inlet, the water , the heat-resistant material, which is attached to the upper surface of the channel assembly is provided on the outside of the water channel assembly, the water supply provided with an opening which cooling water upwardly open from the upper outlet Has a circulation pipe for supplying the Enba, wherein the water channel assembly, a plurality of fan-shaped water channels that are separated from each other to rise while spreading radially toward the upper outlet from said lower inlet It is characterized by being arranged radially.

Further, the present invention relates to a reactor containment vessel, a reactor vessel, a pedestal floor located below the reactor vessel, and a cylindrical pedestal surrounding the pedestal floor that supports the reactor vessel. A side wall, a water supply chamber installed on the pedestal floor, a lower inlet part which is an opening connected to the water supply chamber, and an upper outlet part which is an opening opened upward at a position higher than the lower inlet part provided by the upper outlet direction radial to the ring shaped the water channel assembly flowing in the upper outlet cooling water of the water supply chamber Chi lifting the projected shape from the lower inlet portion towards from the lower inlet portion, resistant material attached to the upper surface of the water channel assembly, and, provided on the outside of the water channel assemblies open cooling water from the upper outlet upward Reactor core with an opening provided in the circulation pipe, which is connected to the water supply chamber, the core of the reactor vessel is cooled receiving molten core generated when penetrating the reactor vessel and melted A melt cooling device, wherein the water channel assembly radially radiates a plurality of fan-shaped water channels separated from each other and rising while spreading radially from the lower inlet portion toward the upper outlet portion. It is characterized by being arranged.

Further, the present invention provides a method for installing a core melt cooling device that receives and cools a core melt generated when a core in a reactor vessel melts and penetrates the reactor vessel. A step of disposing a water supply chamber on a pedestal floor located below, a lower inlet part that is an opening connected to the water supply chamber, and an upper part that is an upper opening that is higher than the lower inlet part A water channel assembly having an outlet portion and having a ring-shaped projection shape with a radial direction from the lower inlet portion toward the upper outlet portion is installed, and a heat-resistant material is attached to the upper surface of the water channel assembly. A channel assembly installation step, and a step of installing a circulation pipe provided with an opening outside the water channel assembly and connected to the water supply chamber. Le aggregate, said has a lower inlet portion is formed by radially arranged plurality of fan-shaped water channels that are separated from each other to rise while spreading radially toward the upper outlet portion, and characterized in that To do.

  According to the present invention, the efficiency of cooling the core melt generated when the core in the reactor vessel is melted and penetrates the reactor vessel can be improved without increasing the floor area.

  An embodiment of a core melt cooling apparatus according to the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the same or similar structure, and the overlapping description is abbreviate | omitted.

[First Embodiment]
FIG. 2 is an elevational sectional view of the reactor containment vessel according to the first embodiment of the present invention.

  In the reactor containment vessel 2, a pedestal 15 is formed by a pedestal floor 7 positioned at a lower portion and a cylindrical pedestal side wall 24 surrounding the pedestal floor 7. The reactor pressure vessel 1 containing the core 23 is supported by pedestal side walls 24.

  In addition, a suppression pool 4 is formed in the lower part of the reactor containment vessel 2 so as to surround the pedestal side wall 24. The suppression pool 4 stores water.

  On the pedestal floor 7, a molten core cooling device 30 is disposed. A water injection pipe 8 is connected to the melting core cooling device 30. In addition, the water injection pipe 8 is connected to a water tank 5 located above the reactor containment vessel 2 through an injection valve 14.

  A cooler 6 is disposed on the reactor containment vessel 2. The cooler 6, for example, condenses the steam in the reactor containment vessel 2 with a heat exchanger 6 a submerged in water and returns the condensed water to the water tank 5. As such a cooler 6, a static containment vessel cooling facility, a dry well cooler, or the like can be used.

  FIG. 1 is an elevational sectional view in the vicinity of the pedestal floor 7 in the first embodiment. In FIG. 1, the flow of the cooling water is schematically shown by broken-line arrows. Further, the deposition state of the corium 13 when the corium 13 falls on the molten core cooling device 30 is also shown.

  The reactor cooling device 30 is installed on the pedestal floor 7. The reactor cooling device 30 includes a water supply chamber 10, a water channel assembly 31, a heat resistant material 12, and a circulation pipe 9.

  The water supply chamber 10 is formed in a hollow disk shape and is disposed on the upper surface of the pedestal floor 7. A water injection pipe 8 is connected to the water supply chamber 10.

  The water channel aggregate 31 rises with an inclination from the water supply chamber 10 toward the pedestal side wall 24, rises vertically in the vicinity of the pedestal side wall 24, and its upper end is open. The inner side of the outer peripheral part of the water channel assembly 31 rising vertically is a conical shape opened upward.

  One end of the circulation pipe 9 is opened between the water channel aggregate 31 and the pedestal side wall 24. The other end of the circulation pipe 9 is connected to the water supply chamber 10. In FIG. 1, the circulation pipe 9 and the water injection pipe 8 are illustrated one by one with the water channel aggregate 31 interposed therebetween, but may be increased or decreased as appropriate. Between the water channel assembly 31 and the pedestal side wall 24, the portions other than the circulation pipe 9 and the water injection pipe 8 are covered with a ring-shaped lid so that the cooling water does not flow into the space 29 below the water channel 11. Also good.

  A heat-resistant material 12 is disposed inside the portion of the water channel aggregate 31 that rises vertically along the upper surface and the pedestal side wall 24 so as to cover the entire surface.

As the heat-resistant material 12, for example, metal oxides such as ZrO ₂ and MgO and basalt concrete can be used, and a two-layer structure of metal oxide and concrete may be used. Moreover, you may arrange | position as the heat-resistant material 12 as a rectangular parallelepiped block of such a material. In this case, the shape of the block is not limited to a rectangular parallelepiped.

  FIG. 3 is a plan view of the water supply chamber 10 and the water channel assembly 31 in the first embodiment.

  The water channel aggregate 31 is a combination of a plurality of water channels 11 extending radially around the water supply chamber 10. The projected shape of each water channel 11 has a fan shape, and the water channels 11 are in contact with each other without any gap. In the present embodiment, for example, 16 water channels 11 are combined to form the water channel aggregate 31, but the number of water channels 11 may be increased or decreased as appropriate.

  The cooling water flow path 25 formed inside the water channel 11 extends in the circumferential direction from the lower inlet portion 21 connected to the water supply chamber 10 toward the outer periphery, and is connected to the upper outlet portion 22.

  In the present embodiment, the water channel aggregate 31 is formed by combining a plurality of water channels 11, but any shape can be used as long as it has the cooling water flow passage 25 that rises while spreading from the water supply chamber. Good. For example, two conical plates may be held so as to maintain a predetermined interval.

  When a core melting accident occurs and corium 13 passes through the reactor pressure vessel lower head 3 and falls to the pedestal, it is received by the heat-resistant material 12 of the melting core cooling device 30. When the corium 13 falls, cooling water is supplied to the water supply chamber 10, and the cooling water is distributed from the lower inlet portion 21 to each water channel 11.

  The heat of the hot corium 13 is transferred to the heat-resistant material 12 and further transferred to the cooling water through the wall of the water channel 11. As the heat of the corium 13 is transmitted, the cooling water flowing through the cooling water passage 25 inside the water channel 11 will eventually boil.

  FIG. 4 is a graph showing experimental results of the boiling limit heat flux with respect to the angle of the downward heat transfer surface shown in Non-Patent Document 1.

  FIG. 4 shows that, for example, in the case of a downward heat transfer surface having an inclination of 20 °, the boiling limit heat flux is improved by about 60% compared to the downward horizontal surface (angle 0 °). In the present embodiment, since the cooling water flow path 25 has an inclination, vapor bubbles generated by boiling are easily separated from the inner surface of the water channel 11 which is a heat transfer surface by buoyancy, and a good heat transfer coefficient is obtained. It is done.

  The cooling water that has entered the water channel 11 from the lower inlet portion 21 rises through the cooling water passage 25 and overflows from the upper outlet portion 22 located on the outer periphery. Most of the cooling water overflowing from the upper outlet portion 22 flows into the conical portion of the water channel assembly 30. The cooling water exiting the water channel 11 overflows on the heat-resistant material 12 and forms a water pool on the corium 12. The cooling water that forms this water pool boils on the surface of the corium 13 and cools the corium 13.

  Thus, the corium 13 is cooled by both the boiling inside the water channel 11 and the boiling of the surface of the corium 13.

  The initial water supply to the water supply chamber is performed through the water injection pipe 8 by, for example, dropping the pool water installed above the melting core cooling device by gravity. After the initial water injection is finished, the cooling water overflowing to the upper part of the water channel assembly 30 inside the pedestal 15 is supplied to the water supply chamber 10 from the circulation pipe 9 by natural circulation caused by boiling in the cooling water passage 25. The

  The steam generated by cooling the melting core is condensed by the cooler 6 at the upper part of the containment vessel and returned to the water tank 5. The cooling water obtained by condensing the steam returned to the water tank 5 is used again for cooling the corium 13, and the cooling of the corium 13 is continued by the natural circulation of the water.

The melting point of the heat-resistant material 12 is, for example, about 2200 ° C. when ZrO ₂ is used as the heat-resistant material 12, and thus is higher than the temperature of the corium 13 (on the average, about 2200 ° C.), and is less likely to melt. Further, by arranging the heat-resistant material 12, the corium 13 does not directly contact the water channel 11, and the heat flux is suppressed by the heat resistance of the heat-resistant material 12, so that the wall of the water channel 11 may be damaged. Is also small.

  Thus, the temperature of corium can be effectively lowered by the core melt cooling device 30 of the present embodiment, and the corium 13 is stably held inside the melting core cooling device 30.

  Moreover, since the corium 13 does not come into direct contact with the concrete of the pedestal floor 7, no concrete erosion reaction occurs. Therefore, the risk of pressurization due to the generation of non-condensable gases such as carbon dioxide and hydrogen and damage to the reactor containment vessel are reduced.

As for the heat transfer of the wall surface of the water channel 11, if the angle is 20 ° from the horizontal, the critical heat flux is 0.5 MW / m ² or more. For example, even in the case of a pedestal having a diameter of 10 m, which is about the same as that of an existing furnace, the total heat transfer area of the water channel wall is about 82 m ^2, so that heat removal of about 41 MW at the maximum is possible only with the water channel.

Furthermore, as heat removal by which the overflowed water cools the corium 13 from the surface of the corium 13, a heat flux of about 0.4 MW / m ² can be expected, and the heat transfer area is 75 m ² (equivalent diameter is 9.8 m). ), Heat removal of about 30 MW at maximum is possible by cooling on the heat-resistant material 12.

  In the case of a furnace with a rated heat output of 4000 MW, the amount of heat generated by the corium 13 is about 40 MW, so that the decay heat of the corium can be sufficiently removed by cooling the inside of the water channel 11 and the upper surface of the heat-resistant material 12. Corium can be cooled stably. Furthermore, since there is a thermal margin, it can be applied to a nuclear reactor having a larger thermal output.

  Moreover, in this Embodiment, since it comprises the combination of piping, such as the water channel 11, the heat-resistant material 12, the water supply chamber 10, and the water supply piping 8, it is not necessary to manufacture a large sized container. For this reason, even when it is difficult to carry a large object into the pedestal 15 such as when a core melt cooling device is newly installed in an existing containment vessel, each separately manufactured component is placed inside the pedestal 15. It can be assembled and installed on site and has excellent workability.

[Second Embodiment]
FIG. 5 is a perspective view of the water channel 11 in the second embodiment according to the present invention.

  The water channel 11 of this embodiment is formed by attaching a heat-resistant material 12 to the upper surface of the water channel of the first embodiment. If such a water channel 11 is manufactured in advance in a factory outside the nuclear power plant and the water channel 11 is carried into the pedestal 15 and assembled, the time required for installing the core melt cooling device 30 is shortened. Become.

  The wall surface forming the coolant channel 25 inside the water channel 11 is provided with a number of irregularities. Due to the unevenness, heat transfer on the inner surface of the water channel 11 is promoted, and the corium can be cooled more quickly.

[Third Embodiment]
In the third embodiment of the present invention, the water channel assembly 30 is not conical, but has a bowl shape convex downward.

  FIG. 6 is an elevational sectional view of the vicinity of the pedestal floor 7 in the third embodiment.

  The water channel aggregate 30 of the present embodiment is configured such that the inclination of the cooling water flow path 25 increases stepwise as it moves away from the water supply chamber 10 and approaches the pedestal side wall 25. The water channel aggregate 30 is a combination of fan-shaped water channels as in the first embodiment.

  As shown in FIG. 5, the greater the inclination of the cooling surface from the horizontal, the greater the boiling limit heat flux, and thus the cooling performance increases. For this reason, even if the area of the upper surface of the heat channel 12 that receives corium and the water channel assembly 30 that cools the corium through the heat resisting material 12 is made smaller, the corium 13 can be cooled and stably held.

[Fourth Embodiment]
The fourth embodiment according to the present invention relates to a method for controlling the injection valve 14 attached to the injection pipe 8 for supplying cooling water to the molten core cooling device 30.

  FIG. 7 is an explanatory view showing the core melt cooling device in the fourth embodiment together with the vertical cross section of the reactor containment vessel.

  An injection valve controller 36 is connected to the injection valve 14, and a sensor 37 is connected to the injection valve controller 36 for detecting a sign that the molten core falls.

  The injection valve 14 may be automatically opened by the internal pressure of the pedestal 15 or the like, but in the present embodiment, the injection valve controller 36 opens the injection valve 14. When the injection valve controller 36 receives the signal from the sensor 37 and determines that there is an indication that the molten core will fall, the injection valve controller 36 opens the injection valve 14 and supplies cooling water to the molten core cooling device 30.

  As the sensor 37, for example, a thermometer that measures the pedestal ambient temperature is used, and when the pedestal ambient temperature exceeds a predetermined temperature, the injection valve 14 is opened by the control device 36. Instead of the pedestal atmosphere temperature, a thermometer that measures the temperature of the reactor pressure vessel lower head 3 may be used so that the injection valve 14 opens when the temperature exceeds a predetermined temperature.

  In addition, using a detector for detecting the reactor water level as the sensor 37, when the low reactor water level signal continues for a predetermined time, the control device 36 determines that there is an indication that the molten core falls. The injection valve 14 may be opened.

  Further, these sensors 37 may be used in combination.

  In the present embodiment, the sign that the molten core falls can be detected by an appropriate sensor, and the cooling water can be supplied to the molten core cooling device 30, so that the corium can be cooled immediately even if the molten core falls.

[Fifth Embodiment]
FIG. 8 is an explanatory view showing a core melt cooling device together with a vertical section of a reactor containment vessel in a fifth embodiment according to the present invention.

  In the present embodiment, an external cooling water supply pipe 40 connected to the external cooling water reservoir 38 is connected to the water injection pipe 8. A pump 37 is inserted in the external cooling water supply pipe 40. A pump controller 39 is connected to the pump 37.

  When the pump controller 39 detects a sign that the molten core falls, the pump controller 39 starts the pump 37 and supplies cooling water from the external cooling water storage tank 38 to the core melt cooling device 30. Accordingly, when an external power source for driving the pump 37 is available, not only the cooling water stored in the water tank 5 but also the cooling water stored in the external cooling water storage tank 38 should be used for cooling the corium. Can do. Therefore, corium can be cooled more quickly.

  The above description is merely an example, and the present invention is not limited to the above-described embodiments, and can be implemented in various forms. Moreover, it can also implement combining the characteristic of each above-mentioned embodiment.

It is an elevation sectional view near the pedestal floor in a 1st embodiment concerning the present invention. It is an elevation sectional view of a nuclear reactor containment vessel in a 1st embodiment concerning the present invention. It is a top view of a water supply chamber and a water channel aggregate in a 1st embodiment concerning the present invention. It is a graph which shows the experimental result of the boiling limit heat flux with respect to the angle of a downward heat-transfer surface. It is a perspective view of a water channel in a 2nd embodiment concerning the present invention. It is an elevation sectional view near the pedestal floor in a 3rd embodiment concerning the present invention. It is explanatory drawing which shows the core melt cooling device in 4th Embodiment which concerns on this invention with the standing cross section of a nuclear reactor containment vessel. It is explanatory drawing which shows the core melt cooling device in 5th Embodiment based on this invention with the standing cross section of a nuclear reactor containment vessel.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Reactor pressure vessel, 2 ... Reactor containment vessel, 3 ... Reactor pressure vessel lower head, 4 ... Suppression pool, 5 ... Water tank, 6 ... Containment vessel cooler, 7 ... Pedestal floor, 8 ... Injection pipe, 9 DESCRIPTION OF SYMBOLS ... Circulation piping, 10 ... Water supply chamber, 11 ... Water channel, 12 ... Heat-resistant material, 13 ... Corium (core melt), 14 ... Injection valve, 15 ... Pedestal, 21 ... Lower inlet part, 22 ... Upper outlet part, 24 Pedestal side wall, 25 ... cooling water flow path, 30 ... core melt cooling device, 31 ... water channel assembly, 36 ... control device, 37 ... sensor, 38 ... external cooling water reservoir, 39 ... pump, 40 ... external cooling Water supply piping

Claims (16)

In the core melt cooling device that receives and cools the core melt generated when the core in the reactor vessel melts and penetrates the reactor vessel,
A water supply chamber installed below the reactor vessel;
A lower inlet part that is an opening connected to the water supply chamber and an upper outlet part that is an upper opening that is higher than the lower inlet part, and a direction from the lower inlet part toward the upper outlet part. Chi lifting the ring-like projected shape whose radius direction, and the water channel assembly cooling water of the water supply chamber flows to the upper outlet from the lower inlet portion,
A heat-resistant material attached to the upper surface of the water channel assembly;
A circulation pipe that is provided outside the water channel assembly and that supplies cooling water from the upper outlet portion to the water supply chamber with an opening that opens upward;
Have
The water channel aggregate is formed by radially arranging a plurality of fan-shaped water channels separated from each other and rising while spreading radially from the lower inlet portion toward the upper outlet portion .
A core melt cooling device.   The core melt cooling device according to claim 1, wherein an inclination of the water channel aggregate with respect to a horizontal direction increases from the lower inlet portion toward the upper outlet portion.   The core melt cooling device according to claim 1, wherein a plurality of irregularities are formed on an inner wall of the water channel aggregate.   The core melt cooling device according to any one of claims 1 to 3, wherein the heat-resistant material is any one of a metal oxide and a basalt concrete.   4. The core melt cooling device according to claim 1, wherein the heat-resistant material includes at least a metal oxide layer and a concrete layer. A water injection pipe connected to the water supply chamber;
Detection means for detecting signs of melting core fall;
Cooling water supply means for supplying cooling water to the water supply chamber via the water injection pipe when the detection means detects the indication;
The core melt cooling device according to any one of claims 1 to 5, characterized by comprising: The cooling water supply means is
A first water tank for storing cooling water located above the upper outlet part;
An injection valve inserted in the middle of the water injection pipe;
An injection valve controller connected to the detection means for opening the injection valve when the detection means detects the indication;
The core melt cooling device according to claim 6, wherein The detection means detects the temperature of the atmosphere below the reactor pressure vessel,
The core melt cooling system according to claim 7, wherein the injection valve controller opens the injection valve when the temperature of the atmosphere below the reactor pressure vessel exceeds a predetermined temperature. apparatus. The detection means detects the temperature of the lower head of the reactor pressure vessel,
The core melt cooling device according to claim 7, wherein the injection valve controller opens the injection valve when the temperature of the lower head exceeds a predetermined temperature. The detection means detects the water level inside the reactor pressure vessel,
8. The core melt cooling apparatus according to claim 7, wherein the injection valve controller opens the injection valve when a predetermined time elapses while the water level is below a predetermined water level. The cooling water supply means is
A second water tank for storing cooling water;
A pump for sending cooling water from the second water tank to the water supply chamber;
A pump controller connected to the detection means for activating the pump when the detection means detects the indication;
The core melt cooling device according to claim 6, wherein A reactor vessel;
A pedestal floor located below the reactor vessel;
Cylindrical pedestal side walls surrounding the pedestal floor that support the reactor vessel;
A water supply chamber installed on the pedestal floor, a lower inlet part that is an opening connected to the water supply chamber, and an upper outlet part that is an opening opened upward at a position higher than the lower inlet part. the upper outlet direction radial to the ring shaped the water channel assembly flowing in the upper outlet cooling water of the water supply chamber Chi lifting the projected shape from the lower inlet portion toward the from the lower inlet, the water channel A heat-resistant material attached to the upper surface of the aggregate, and a circulation pipe provided on the outside of the water channel aggregate and provided with an opening that opens upwardly from the upper outlet portion and is connected to the water supply chamber; A core melt cooling device that receives and cools the core melt generated when the core in the reactor vessel melts and penetrates the reactor vessel ,
Have
The water channel aggregate is formed by radially arranging a plurality of fan-shaped water channels separated from each other and rising while spreading radially from the lower inlet portion toward the upper outlet portion .
A reactor containment vessel characterized by that. In the installation method of the core melt cooling device for receiving and cooling the core melt generated when the core in the reactor vessel melts and penetrates the reactor vessel,
Disposing a water supply chamber on a pedestal floor located below the reactor vessel;
A lower inlet part that is an opening connected to the water supply chamber and an upper outlet part that is an upper opening that is higher than the lower inlet part, and a direction from the lower inlet part toward the upper outlet part. A water channel assembly installation step of installing a water channel assembly having a ring-shaped projection shape in the radial direction and attaching a heat-resistant material to the upper surface of the water channel assembly;
Providing an opening outside the water channel assembly and installing a circulation pipe connected to the water supply chamber;
Have
The water channel aggregate is formed by radially arranging a plurality of fan-shaped water channels separated from each other and rising while spreading radially from the lower inlet portion toward the upper outlet portion .
An installation method of a core melt cooling device characterized by the above. The water channel assembly installation process includes:
Manufacturing a block-shaped heat-resistant material piece;
Attaching the heat-resistant material piece to the upper surface of the water channel assembly;
The method for installing a core melt cooling device according to claim 13, wherein: The water channel aggregate is a combination of a plurality of water channels having a fan-shaped projection shape having a radial direction from the lower inlet portion toward the upper outlet portion so as to have a ring-shaped projection shape. ,
The water channel assembly installation process includes:
Attaching the heat-resistant material to the upper surface of each of the water channels;
Assembling a water channel assembly by combining the water channels to which the heat-resistant material is attached;
The method for installing a core melt cooling device according to claim 13, wherein: A water injection pipe connected to the water supply chamber;
A first water tank for storing cooling water located above the upper outlet part;
An injection valve that is inserted in the middle of the water injection pipe and opens when the pressure in the space below the reactor pressure vessel exceeds a predetermined value;
The core melt cooling device according to any one of claims 1 to 5, characterized by comprising:

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