JP2013096928A - Reactor facilities and reactor containment vessel cooling system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To supply cooling water without using an external power source when sprinkling water from an upper side to an outer surface of a reactor containment vessel in the case of coolant leakage.SOLUTION: In nuclear facilities including a reactor vessel 2 which contains a reactor core and a reactor coolant, a reactor containment vessel 4 which accommodates the reactor vessel 2 and a leakage cooling system for cooling the reactor containment vessel 4 from the outside when the reactor coolant is leaked from the reactor vessel 2. The leakage cooling system comprises a cooling water supply pump 141 which transfers cooling water for cooling an external wall surface of the reactor containment vessel 4 to the upper side of the reactor containment vessel 4, and a cooling pump motive force supply section which supplies a motive force to the cooling water supply pump 141 by utilizing heat from the leaked reactor coolant.

Description

  The present invention relates to a nuclear reactor facility and a reactor containment vessel cooling system.

  When the coolant is discharged into the reactor containment vessel due to pipe breakage or the like in the nuclear power plant, the coolant becomes high-temperature steam due to the reduced pressure, and thus the pressure in the reactor containment vessel rises.

  In such a case, in order to suppress the rise in pressure in the containment vessel and ensure soundness, the generated steam is guided to the pressure restraint pool in the containment vessel and condensed, or sprayed by the containment vessel spray system. A method is known in which water is sprinkled from the upper part of the reactor containment vessel with water to condense the steam (Non-Patent Document 1).

  In these methods, heat accumulated in the pressure suppression pool and spray water needs to be finally released to the outside through a heat exchanger by a dynamic device such as a pump.

  On the other hand, reactor cooling system piping is connected to the reactor vessel, and these are stored in the reactor containment vessel. Between the reactor containment vessel and the reactor building, an annulus-shaped annular flow path is provided so as to surround the reactor containment vessel, and an upper cooling water tank is installed above the reactor containment vessel.

  Water is sprinkled from the upper water pipe connected to the upper cooling water tank to the upper surface of the reactor containment vessel. Water evaporates by heat transfer from the wall in the process of flowing down the side of the containment vessel as it is due to gravity. At this time, heat corresponding to the latent heat of vaporization is taken from the surface of the reactor containment vessel, and the evaporated vapor rises with the air flowing in from the lower part of the annular flow path and is discharged from the chimney.

  Due to these effects, there has been proposed a structure that enables the inside of a reactor containment vessel to be cooled and decompressed without using a power source (Patent Document 1).

Japanese Patent No. 2813412

Japan Nuclear Safety Research Association, Summary of light water reactor power plants, 1992

  The above-described reactor containment cooling structure has a relatively large heat transfer area for cooling the outer surface of the reactor containment vessel, and does not require a power source for operation because water is sprayed by gravity. There are advantages.

  On the other hand, since the evaporated water is discharged from the chimney as it is, it is necessary to store in advance the cooling water necessary for the cooling period in the upper part of the reactor containment vessel.

  If an attempt is made to enlarge the upper cooling water tank, the height of the reactor building will increase and the center of gravity of the reactor building will also increase, and measures will be required in terms of construction and earthquake resistance.

  On the other hand, when the accident occurs, the decay heat from the core is relatively large for about one week, so it is necessary to spray the cooling water to the outer surface of the reactor containment vessel and ensure the heat removal performance by the latent heat of evaporation.

  However, as described above, from the viewpoint of earthquake resistance, the capacity that can be secured in the upper cooling water tank is about three days. Subsequent cooling water must be procured from the outside by some method and sent to the upper cooling water tank.

  Accordingly, an object of the present invention is to replenish cooling water without using an external power source when water is sprinkled from the top onto the outer surface of a reactor containment vessel when a coolant leaks.

  In order to achieve the above-mentioned object, the present invention provides a reactor vessel containing a core and a reactor coolant, a reactor containment vessel for storing the reactor vessel, and the reactor coolant from the reactor vessel. In a nuclear facility comprising a leakage cooling system that cools the reactor containment vessel from the outside at the time of leakage, the leakage cooling system supplies cooling water for cooling the outer wall surface of the reactor containment vessel from an external water source. A cooling water supply pump that transports the reactor containment up to the upper part of the reactor containment vessel; and a cooling water pump power supply unit that supplies power to the cooling water supply pump using heat from the leaked reactor coolant. It is characterized by that.

  Further, the present invention provides a containment vessel cooling system for cooling a reactor containment vessel from the outside when a reactor coolant leaks from the reactor vessel, wherein cooling water for cooling the outer wall surface of the reactor containment vessel is A cooling water supply pump that transports the reactor containment vessel up to the upper part of the reactor containment vessel, and a cooling water pump power supply unit that supplies power to the cooling water supply pump using heat from the leaked reactor coolant, The cooling water pump power supply unit is driven by an evaporator in the reactor containment vessel that contains a working medium that evaporates by receiving heat from the reactor coolant, and a working medium from the evaporator. A cooling water pump driving turbine for supplying power to the cooling water supply pump, and a condenser for condensing the working medium outside the reactor containment vessel by heat radiation to the outside , Is driven by the working medium from said evaporator, characterized by having a a working medium transfer pump for sending the working medium condensed from said condenser to said evaporator.

  According to the present invention, when water is leaked from the upper part of the reactor containment vessel when coolant leaks, the cooling water can be replenished without using an external power source.

It is a conceptual diagram which shows the structure of 1st Embodiment of the cooling device of the reactor containment vessel which concerns on this invention. It is a conceptual diagram which shows the structure of 2nd Embodiment of the cooling device of the reactor containment vessel which concerns on this invention. It is a conceptual diagram which shows the structure of 3rd Embodiment of the cooling device of the reactor containment vessel which concerns on this invention. It is a conceptual diagram which shows the structure of 4th Embodiment of the cooling device of the reactor containment vessel which concerns on this invention. It is a conceptual diagram which shows the structure of 5th Embodiment of the cooling device of the reactor containment vessel which concerns on this invention. It is a conceptual diagram which shows the structure of 6th Embodiment of the cooling device of the reactor containment vessel which concerns on this invention. It is a conceptual diagram which shows the structure of 7th Embodiment of the cooling device of the reactor containment vessel which concerns on this invention.

  Hereinafter, an embodiment of a reactor containment vessel cooling system according to the present invention will be described with reference to the drawings. Here, the same or similar parts are denoted by common reference numerals, and redundant description is omitted.

[First Embodiment]
FIG. 1 is a conceptual diagram showing a configuration of a first embodiment of a reactor containment vessel cooling apparatus according to the present invention.

  A reactor core 1 is installed in a reactor vessel 2, and a reactor coolant is contained in the reactor vessel 2 and a reactor cooling system pipe 3 connected to the reactor vessel 2. The reactor containment vessel 4 stores the reactor vessel 2 and the reactor cooling system piping 3, and the reactor containment vessel 4 constitutes a sealed space during normal operation of the reactor.

  A reactor building 5 is provided on the outer periphery of the reactor containment vessel 4, and an air inlet 7 is formed at a lower end portion of the reactor building 5 between, for example, the ground. The reactor building 5 has a reduced radius at the top and forms an exhaust port 8. An annular channel 6 is formed between the reactor containment vessel 4 and the reactor building 5, and an air channel is formed through the intake port 7, the annular channel 6 and the exhaust port 8.

  An upper cooling water tank 143 and an upper watering pipe 144 for spraying cooling water to the outer surface of the reactor containment vessel 4 are provided on the upper portion of the reactor containment vessel 4. The upper watering pipe 144 is provided with a watering valve 145 that is closed during normal operation of the nuclear reactor and opened when the coolant leaks.

  Although the cooling water is stored in the upper cooling water tank 143 during the normal operation of the reactor, the cooling water is supplied from the external water source 150 to replenish the cooling water in the upper cooling water tank 143 when the coolant leaks. A cooling water supply pump 141 and a water supply pipe 142 for transferring to the cooling water tank 143 are provided.

  Here, the external water source 150 is not limited to a dedicated tank as shown in the figure, and if a measure such as using a filter for preventing clogging is used at the inlet of the cooling water supply pump 141, It may be a river or pond.

  The cooling water supply pump 141 is driven by a cooling water pump drive turbine 122. The cycle of the working medium includes an evaporator 101 provided in the stored water of the reactor containment sump 9 that collects the condensed water in the reactor containment vessel 4, and a condenser 111 provided outside the reactor containment vessel 4. And a working medium transfer pump 121 for circulating the working medium and a working medium drive turbine 123 for driving the working medium transfer pump 121.

  A reactor containment sump 9 is connected to the reactor vessel 2, and a return pipe 10 having a drain gradient is provided from the reactor containment sump 9 to the reactor vessel 2 side. Further, the return pipe 10 is provided with a return valve 11 that is closed during normal operation of the nuclear reactor and opened when leaked. The return path of the condensed water from the reactor containment sump 9 to the reactor vessel 2 is a low pressure core injection system in which the reactor containment sump 9 injects water into the reactor vessel 2 for flooding of the core. It is also possible to return to the reactor vessel 2 by the action of another system, as in the case where it is a water intake source of the other system.

  The condenser 111 is provided in the external water source 150. In the present embodiment, the condenser 111 is provided in the same water source as the external water source 150 that is a water intake source of the cooling water supply pump 141, but another water source may be used.

  Here, the working medium is a low boiling point medium having a boiling point of 100 ° C. or less at atmospheric pressure such as alternative chlorofluorocarbons and ammonia.

(Function)
When the reactor coolant leaks from the reactor cooling system piping 3 or the like, the reactor coolant leaked into the reactor containment vessel 4 becomes ruptured steam due to decompression, and enters the reactor containment vessel 4. And is contained in the reactor containment vessel 4.

  When the temperature inside the reactor containment vessel 4 rises, the air in the annular flow path 6 is heated, and by natural convection, air flows into the annular flow path 6 from the intake port 7 and rises in the annular flow path 6. Then, it is discharged from the exhaust port 8 to the outside.

  When the internal pressure of the reactor containment vessel 4 rises, cooling water is sprinkled from the upper cooling water tank 143 to the outer surface of the reactor containment vessel 4, so that the internal ruptured steam is condensed on the inner wall of the reactor containment vessel 4, The condensed water falls as it passes through the inner wall and accumulates in the reactor containment sump 9. Since the return valve 11 installed in the return pipe 10 connecting the reactor vessel sump 9 and the reactor vessel 2 is opened when the reactor coolant leaks, the condensation accumulated in the reactor containment sump 9 is accumulated. Water returns to the reactor vessel 2 by gravity. The reactor coolant in the reactor vessel 2 is heated for a long time due to the decay heat from the core 1.

  The condensed water accumulated in the reactor containment sump 9 heats the low boiling point medium inside the evaporator 101 installed in the reactor containment sump 9, so that the low boiling point in the evaporator 101 is reduced. The medium evaporates. The generated low-boiling-point medium vapor is guided from the outlet of the evaporator 101 to the cooling water pump drive turbine 122 and the working medium pump drive turbine 123 to drive the cooling water pump drive turbine 122 and the working medium pump drive turbine 123.

  The low boiling point medium that has worked in the cooling water pump drive turbine 122 and the working medium pump drive turbine 123 is cooled and condensed by the condenser 111 in the external water source 150, and sent to the evaporator 101 by the working medium transfer pump 121.

  The cooling water supply pump 141 driven by the cooling water pump drive turbine 122 supplies the cooling water taken from the external water source 150 to the upper cooling water tank 143 through the water supply pipe 142.

  With the above configuration, the cooling water necessary for cooling the outer surface of the reactor containment vessel 4 can be sent to the upper portion of the containment vessel using heat derived from the decay heat of the inner core 1. As a result, the capacity of the upper cooling water tank 143 is used for cooling from immediately after the leakage of the reactor coolant until the condensed water accumulates in the reactor containment sump 9 and the low boiling point medium in the evaporator 101 can be heated. It can be reduced to the required capacity.

  According to this embodiment, when water is sprayed from the upper part to the outer surface of the reactor containment vessel 4 when the coolant leaks, the cooling water can be replenished without using an external power source.

  Further, since the upper cooling water tank 143 is provided, the water for cooling stored in the upper cooling water tank 143 is opened by the natural fall by opening the water spray valve 145 immediately after leakage of the coolant. Water can be sprinkled from the top to the outer surface.

  As described above, in the present embodiment, water can be sprayed from the upper part to the outer surface of the reactor containment vessel 4 by the gravity drop of the cooling water from the upper cooling water tank 143 immediately after the occurrence of the coolant leakage. Further, when the leaked reactor coolant accumulates in the reactor containment sump 9, the heat is recovered and the cooling water pump drive turbine 122 drives the cooling water supply pump 141, thereby the upper cooling water tank. Cooling can be performed over a capacity of 143.

[Second Embodiment]
FIG. 2 is a conceptual diagram showing the configuration of the second embodiment of the reactor containment vessel cooling apparatus according to the present invention.

  This embodiment is a modification of the first embodiment. As shown in the drawing, the upper water tank 143 provided in the first embodiment is not provided, and the cooling water supply pump 141 is replaced with the external water source 150. Is used to supply the cooling water from the top of the reactor containment vessel 4.

  Even in this case, in the present embodiment, after the leakage of the coolant, the reactor coolant recovers from the stage where the leaked reactor coolant accumulates in the reactor containment sump 9, and the cooling water pump drive turbine 122 is recovered. By driving the cooling water supply pump 141, a long-term cooling effect similar to that of the first embodiment can be obtained.

[Third Embodiment]
FIG. 3 is a conceptual diagram showing the configuration of the third embodiment of the reactor containment vessel cooling apparatus according to the present invention.

  This embodiment is a modification of the first embodiment, and the driving method of the working medium transfer pump 121 is different. That is, the working medium transfer pump 121 is directly connected to the shaft of the cooling water pump drive turbine 122 that drives the cooling water supply pump 141, or is mechanically connected via a gear or the like. Since the capacity of the turbine driven by the working medium is larger than that in the case of the first embodiment, the turbine efficiency is improved accordingly.

  As described above, according to the present embodiment, when water is sprinkled from the top onto the outer surface of the reactor containment vessel 4 when coolant leaks, the cooling water can be replenished without using an external power source.

[Fourth Embodiment]
FIG. 4 is a conceptual diagram showing the configuration of the fourth embodiment of the reactor containment vessel cooling apparatus according to the present invention.

  This embodiment is a modification of the third embodiment, and the cooling water supply pump 141 and the working medium transfer pump 121 are supplied with electric power from the generator 124 driven by the cooling water pump drive turbine 122. That is, the thermal energy received by the working medium from the reactor coolant heated by the decay heat is converted into electrical energy.

  Since the power sources of the cooling water supply pump 141 and the working medium transfer pump 121 are electric power, the electric power can be supplied by routing the cable, so that the arrangement restrictions are reduced and the control is advantageous. Furthermore, when the decay heat is large, it can be used as a power supply source or an instrumentation power source for other electric drives in the plant.

  As described above, according to the present embodiment, when water is sprinkled from the top onto the outer surface of the reactor containment vessel 4 when coolant leaks, the cooling water can be replenished without using an external power source.

[Fifth Embodiment]
FIG. 5 is a conceptual diagram showing the configuration of the fifth embodiment of the reactor containment vessel cooling apparatus according to the present invention.

  This embodiment is a modification of the first embodiment, and a condenser 111 is provided in an annular flow path 6 formed between the reactor containment vessel 4 and the reactor building 5.

  As the temperature inside the reactor containment vessel 4 rises, an upward flow of air is formed in the annular flow path 6, so the heat of the working medium in the condenser 111 and the upward flow of air in the annular flow path 6 By the replacement, the working medium in the condenser 111 is cooled, and the same effect as that of the first embodiment is brought about.

  Further, the external water source 150 may be any water source that can be taken in by the cooling water supply pump 141, and water sources that are difficult to install the condenser 111, such as river water and groundwater, can be applied.

  As described above, according to the present embodiment, when water is sprinkled from the top onto the outer surface of the reactor containment vessel 4 when coolant leaks, the cooling water can be replenished without using an external power source.

[Sixth Embodiment]
FIG. 6 is a conceptual diagram showing the configuration of the sixth embodiment of the reactor containment vessel cooling apparatus according to the present invention.

  The present embodiment is a modification of the fifth embodiment. In the fifth embodiment, the condenser 111 is provided in the annular flow path 6, whereas in the present embodiment, the condenser 111 is provided in the cooling tower 112. ing. The cooling tower 112 is disposed outside the reactor building 5 and performs cooling by natural convection of air.

  In this case, since there is a cooling effect regardless of the temperature in the reactor containment vessel 4, a flexible design can be achieved.

  As described above, according to the present embodiment, when water is sprinkled from the top onto the outer surface of the reactor containment vessel 4 when coolant leaks, the cooling water can be replenished without using an external power source.

[Seventh Embodiment]
FIG. 7 is a conceptual diagram showing the configuration of the seventh embodiment of the reactor containment vessel cooling apparatus according to the present invention.

  The evaporator / condenser 102 is installed at a position higher than the reactor vessel 2. The evaporator / condenser 102 and the reactor vessel 2 are connected by an inlet pipe 132 and an outlet pipe 133. The inlet pipe 132 is provided with an inlet valve 134, and the outlet pipe 133 is provided with an outlet valve 135. The inlet valve 134 and the outlet valve 135 can be operated from the outside of the reactor containment vessel 4.

  The tube side of the evaporator / condenser 102 which is a heat exchanger is connected to the inlet pipe 132 and the outlet pipe 133 so that the steam reactor coolant is condensed, and the working medium flows on the trunk side and the heat received from the reactor coolant. The region through which the reactor coolant flows is used as a tube because it is a structure that evaporates due to the structure and is advantageous in terms of structure.

  When the coolant leaks, the inlet valve 134 and the outlet valve 135 are opened to induce the reactor coolant in the reactor vessel 2 into the evaporator / condenser 102 through the inlet pipe 132, and the evaporator / condenser 102. The internal working medium is evaporated and guided to the cooling water pump drive turbine 122 and the working medium pump drive turbine 123.

  The reactor coolant that has exchanged heat in the evaporator / condenser 102 returns to the reactor vessel 2 from the evaporator / condenser 102 through the outlet pipe 133 due to a temperature drop or a density difference accompanying condensation.

  In this configuration, not only the working medium is used for driving the cooling water supply pump 141 but also the working medium is evaporated / evaporated even when the reactor coolant does not leak into the reactor containment vessel 4. By evaporating in the condenser 102, it can be used for removing decay heat generated in the core 1 in the reactor vessel 2.

  As described above, according to the present embodiment, when water leaks from the upper part to the outer surface of the reactor containment vessel 4 at the time of leakage, cooling water can be supplied without using an external power source.

[Other Embodiments]
As mentioned above, although some embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of invention. For example, in each embodiment, although the nuclear reactor which uses water for a coolant was demonstrated, it can apply also to the nuclear reactor which uses a molten metal and gas as a coolant.

  Moreover, you may combine the characteristic of each embodiment. For example, the cooling method of the condenser 111 and the heating method of the evaporator 101 may be combined with those of the respective embodiments, or a plurality of methods may be used in combination.

  Furthermore, these embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. For example, although the pump driving system using the working medium has been described for the turbine, an equivalent system may be used.

  These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1 ... Core 2 ... Reactor vessel 3 ... Reactor cooling system piping 4 ... Reactor containment vessel 5 ... Reactor building 6 ... Annular flow path 7 ... Inlet 8 ... Exhaust port 9 ... Sump in reactor containment vessel 10 ... Return pipe 11 ... Return valve 101 ... Evaporator 102 ... Evaporator / condenser 111 ... Condenser 112 ... -Cooling tower 121 ... Working medium transfer pump 122 ... Cooling water pump drive turbine 123 ... Working medium pump drive turbine 124 ... Generator 131 ... Heat transfer tube 132 ... Inlet piping 133 ... -Outlet piping 134 ... Inlet valve 135 ... Outlet valve 141 ... Cooling water supply pump 142 ... Water supply pipe 143 ... Upper cooling water tank 144 ... Upper watering pipe 145 ... Watering valve 150 ... External water source

Claims (11)

A reactor vessel containing a core and a reactor coolant, a reactor containment vessel containing the reactor vessel, and cooling the reactor containment vessel from the outside when the reactor coolant leaks from the reactor vessel In an atomic facility with a leakage cooling system that
The leakage cooling system is:
A cooling water supply pump for transferring cooling water for cooling the outer wall surface of the reactor containment vessel from an external water source to above the reactor containment vessel;
A cooling water pump power supply unit for supplying power to the cooling water supply pump using heat from the leaked reactor coolant;
A nuclear reactor facility characterized by comprising: The cooling water pump power supply unit is
An evaporator containing a working medium in the reactor containment vessel that evaporates by receiving heat from the reactor coolant;
A cooling water pump drive turbine driven by a working medium from the evaporator to supply power to the cooling water supply pump;
A condenser that is outside the reactor containment vessel and the working medium is condensed by heat radiation to the outside;
A working medium transfer pump driven by the working medium from the evaporator and sending the working medium condensed from the condenser to the evaporator;
The nuclear reactor facility according to claim 1, wherein:   The nuclear reactor facility according to claim 2, wherein the working medium transfer pump is mechanically connected to the cooling water pump drive turbine.   The nuclear reactor facility according to claim 2, wherein the working medium transfer pump is driven by a working medium pump drive turbine driven by the working medium.   3. The nuclear reactor facility according to claim 2, wherein the working medium transfer pump is driven by receiving electric power from a generator driven by the cooling water pump drive turbine.   The nuclear reactor facility according to claim 2, wherein the condenser radiates heat to the external water source.   The reactor facility according to any one of claims 2 to 5, wherein the condenser is disposed in an air flow path between the outer surface of the containment vessel and the reactor building. .   The reactor facility according to any one of claims 2 to 5, wherein the condenser is disposed in a cooling tower of a building air conditioning system provided in an outdoor portion of the reactor building.   The said evaporator is arrange | positioned in the sump tank which collect | recovers the condensed water in the reactor containment vessel provided in the said reactor containment vessel, The any one of Claim 2 thru | or 8 characterized by the above-mentioned. Reactor facilities as described in the section. An evaporator inlet pipe and an evaporator outlet pipe connecting the reactor vessel and the evaporator;
An inlet valve and an outlet valve that can be operated from the outside of the storage container disposed in each of the evaporator inlet pipe and the evaporator outlet pipe;
Further comprising
The evaporator is disposed at a position higher than the reactor vessel;
The nuclear reactor facility according to any one of claims 2 to 9, wherein In the containment vessel cooling system that cools the reactor containment vessel from the outside when the reactor coolant leaks from the reactor vessel,
A cooling water supply pump for transferring cooling water for cooling the outer wall surface of the reactor containment vessel to above the reactor containment vessel;
A cooling water pump power supply unit for supplying power to the cooling water supply pump using heat from the leaked reactor coolant;
With
The cooling water pump power supply unit is
An evaporator containing a working medium in the reactor containment vessel that evaporates by receiving heat from the reactor coolant;
A cooling water pump drive turbine that is driven by a working medium from the evaporator and supplies power to the cooling water supply pump;
A condenser outside the reactor containment vessel and condensing the working medium by heat radiation to the outside;
A working medium transfer pump driven by the working medium from the evaporator and sending the working medium condensed from the condenser to the evaporator;
A reactor containment cooling system characterized by comprising:

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