JPH0385493A - Accident management system for a plurality of units - Google Patents

Abstract

PURPOSE:To enable treatment of leaking liquid from a plant which fails during an accident, in a containment vessel at a side of a normal plant by connecting, by flow- paths, each gaseous phase part of a dry well and each gaseous part of a wet well of two nuclear reactor containment vessels. CONSTITUTION:Two nuclear power plants 21 and 21' which have the same structure and the same function, are placed at the same nuclear power station 20, and the containment vessels 2 and 2' of the both plants 21 and 21' are connected by a connecting piping 3. When inner pressure of the vessel 2 rises by an accident of a residual heat treatment system 5 of the plant 21, for example, a measured pressure value 15 is transferred to a controller 14. When a difference between the measured pressure values transferred from pressure measurement devices 15 and 15', reaches a value more than a specific one, the controller 14 opens a flow regulating valve 4, make a high temperature and high pressure atmosphere in the vessel 2, flow into the vessel 2' and de-pressurizes the vessel 2. By this procedure, the pressure in the vessel 2' rises, but flowing-in heat is removed by a residual heat treatment system 5'. Even though the treatment system 5' loses its function, a heat capacity of the two containment vessels can treat heat from one vessel and therefore a pressure rising rate can stay at a low level.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a technology for suppressing and concluding accidents in a nuclear power plant having a plurality of nuclear power plants.

[Prior Art] Conventionally, in the event that an accident occurs in a nuclear power plant in which the internal pressure of the reactor containment vessel increases due to a cause such as failure to remove decay heat, response equipment and equipment have been developed. As a corresponding method, Japanese Patent Application Laid-Open No. 63-755
As stated in Publication No. 98, the atmosphere containing nuclear fission products filled in the reactor containment vessel can be released directly from the reactor containment vessel or indirectly through various filters. Equipment and methods called so-called containment vessel vents (filter vents) are being considered.

In addition, as another conventional example, a nuclear power plant having a configuration in which a plurality of containment vessels are connected is
There is a device described in Japanese Patent No. 289488, and this device is intended to interconnect the sections of pressure suppression chambers and increase the free space volume.

[Problem to be solved by the invention]

Among the conventional technologies mentioned above, the containment vessel vent and filter vent adopt a method of dissipating the atmosphere in the reactor containment vessel to the atmosphere, even if it is through a filter, etc., and the final absorption of decay heat It seeks its medium in the atmosphere.

Adopting such a method would release nuclear fission products contained in the atmosphere into the environment, albeit a small amount, and there would be no direct health impact on the residents near the site. Even if the level is negligible, it is not the preferred method.

Furthermore, this type of method was devised on the premise that the accident would be resolved at the plant where the accident occurred, and does not take into account the fact that Japan's nuclear power plants are located in multiple locations. In other words.

Even in the unlikely event that an accident occurs, if a site has multiple bases, even if a particular safety function is lost at the accident plant, there is a possibility that it will not be lost at other plants. Although it is possible to supply this function to the accident plant by some means, this point has not been considered in the past.

Further, among the conventional techniques, the device for interconnecting the pressure suppression chambers of a plurality of atomic couplants does not take into consideration the condensation of steam released from the accident plant.

The purpose of the present invention is to provide a nuclear power plant with a pressure suppression pool inside the reactor containment vessel, so that even in the event of an accident, the atmosphere of the accident plant will not be released into the environment. The purpose of this invention is to provide a means to bring the accident to a conclusion as well as a means to effectively carry out the steam condensation required at this time.

[Means to solve the problem]

The first means is a multi-unit accident management system in which a dry well gas phase part of one reactor containment vessel and a wet well gas phase part of the other reactor containment vessel are connected by a flow path,
A second means is a multi-unit accident management system in which, in the first means, the wet well gas phase part of the one reactor containment vessel and the dry well gas phase part of the other reactor containment vessel are connected by a flow path. and the third means is a multi-unit accident management system in which, in the first means or the second means, the wet well gas phase portions of the one and the other reactor containment vessels are connected by a flow path. , the fourth means is to connect the dry well gas phase part and wet well gas phase part of one reactor containment vessel with the dry well gas phase part and wet well gas phase part of the other reactor containment vessel by a flow path. and a multi-unit accident management system including a valve in the flow path for switching the flow direction of the fluid, and a fifth means is a multi-unit accident management system in which the flow path is provided with a valve that switches the flow direction of the fluid, and a fifth means is configured to connect the space of one reactor containment vessel and the underwater pool in the wet well of the other reactor containment vessel. The sixth means is a multi-unit accident management system in which, in the fifth means, the space in one of the reactor containment vessels is This is a multi-unit accident management system characterized by a gas phase space of a wet well, and the seventh means is a system that connects the gas phase parts in each wet well of one reactor containment vessel and the other reactor containment vessel. a fluid discharge port of the piping provided through a means for blocking the flow in the pipe into the pool water in each wet well in each of the reactor containment vessels; a plurality of unit accident management system comprising: a fluid inlet of said piping disposed in a gas phase portion of each wet well within said piping via a means for blocking fluid flow in an outward direction of said piping; , the seventh means is a multi-unit accident management system comprising a valve in the middle of the piping that communicates the gas phase in each wet well of one reactor containment vessel and the other reactor containment vessel, and the ninth means In the eighth means, the valve is a flow rate regulating valve, and the flow rate regulating valve is connected to each pressure measuring device that measures the pressure of a plurality of reactor containment vessels to which the piping is connected, and from each of the pressure measuring devices. The tenth means is a multi-unit accident management system comprising a controller that controls the opening degree of a flow rate control valve installed in the piping based on the obtained pressure value, and the tenth means is a system for controlling leakage fluid in one reactor containment vessel. This is a multi-unit accident management method that includes a step of introducing the leaked fluid into the other reactor containment vessel and condensing the leaked fluid with pool water in a wet well in the other reactor containment vessel.

[Effect]

The first method is to receive the leaked fluid at the time of the accident through a flow path from the wet well gas phase of the other reactor containment vessel in the failed plant to the dry well gas phase part of one reactor containment vessel in a normal plant. The leaked fluid from the failed plant is treated on the reactor containment vessel side of the normal plant.

In addition to the action of the first means, the second means is such that even if the plant side equipped with the one reactor containment vessel fails, the wet well gas phase part of the one reactor containment vessel is transferred to the other side of the normal plant. The fluid from the malfunctioning plant can be transferred to the dry well gas phase section of the reactor containment vessel through a flow path, and the fluid from the failed plant can be treated in the other reactor containment vessel of the normal plant, so that it can be handled even if either one fails.

In addition to the action of the first means or the second means, the third means is configured to transfer the condensed liquid increased on the failed side to the flow path between the wet wells of the reactor containment vessels of one of the failed plants and the other of the normal plants. The effect of transferring it to the normal side can be achieved through.

The fourth means is to switch the valve so that the fluid in the wet well of the reactor containment vessel on the failed plant side flows from the failed plant side to the normal plant side and into the dry well of the reactor containment vessel on the normal plant side. It is possible to process fluid from the failed plant in the containment vessel of the normal plant.

The fifth means is that the leaked fluid leaked into the space of one reactor containment vessel is directly discharged into the pool water in the wet well of the other reactor containment vessel, receives direct condensation action, and flows toward the former dry well. The flow of the pool water is blocked by the backflow prevention means, so that the backflow accident of the pool water does not occur.

The sixth means, in addition to the action of the fifth means, is a multiplex method in which fluid that has been condensed in the wet well of one reactor containment vessel is led into the other reactor containment vessel and condensed again. A condensing effect is given.

The seventh means is that the leaked fluid from one reactor containment vessel of the failed plant is condensed with pool water in the wet well of that one reactor containment vessel and accumulates in the gas phase in the upper wet well. The fluid in the part is discharged into the pool water in the wet well in the other reactor containment vessel of the normal plant through means for blocking fluid flow outward from the piping and means for blocking fluid flow inward from the piping. The pool water is again subjected to condensation action, and the pool water is prevented from flowing backwards by means of blocking the flow into the pipe.

This type of action is a function that allows for the opposite flow to occur when the faulty plant and the normal plant are reversed, and that even if either plant fails, the fault can be reliably dealt with by using the normal plant as well. is obtained.

In addition to the action of the seventh means, the eighth means controls the amount of fluid transferred between one reactor containment vessel and the other reactor containment vessel by operating a valve in the middle of the piping. The receiving side due to sudden transfer has the effect of mitigating the dynamic shock on the receiving side,
By completely closing the valve, it is possible to isolate both reactor containment vessels from each other so that there is no interference.

In the ninth means, in addition to the action of the eighth means, when the pressure vessel rises due to leakage fluid in the negative reactor containment vessel, the pressure vessel measuring instrument detects the pressure, and according to the detection result. The controller adjusts the opening degree of the flow rate regulating valve to automatically deal with failures.

The tenth means provides the effect that the leaked fluid in one reactor containment vessel of the failed plant can be transferred to the other reactor containment vessel of the normal plant and treated by the normal plant.

〔Example〕

A first embodiment of the present invention will be described below with reference to FIG.

The nuclear power plant 21 includes a nuclear reactor 1 housed in a reactor containment vessel 2 having a dry well 2a and a wet well 2b, and a residual heat removal system 5, etc. installed in the nuclear power plant 20. ing.

Similar to the nuclear power plant 21, the nuclear power plant 21' also includes a reactor 1', a containment vessel 2', and a residual heat removal system 5'.
etc., and is installed in the same nuclear power plant 20 as the nuclear power plant 21.

A connecting pipe 3 is provided between the nuclear power plants 21 and 21', and connects the two containment vessels.

This connecting pipe 3 includes suction parts 3a, 3a', discharge parts 3b, 3b', and check valves 30, 3c'3d, 3d.
' has been installed.

Further, on this connecting pipe 3, a valve 4 is installed to adjust the flow rate of fluid flowing between a plurality of plants, and this valve 4 is controlled by a controller 14.

The input signal to the controller 14 is provided by pressure measuring devices 15,15'4 located in both containments.

Now, if an accident that causes the residual heat removal system 5 of the nuclear power plant 21 installed in this nuclear power plant 20 to be lost for some reason occurs at the same time as reactor isolation, the decay heat inside the reactor 1 1 becomes steam and releases safety valve 13
and flows into the wet well 2b. If such a phenomenon force 1 continues for a long time, the amount of heat exceeding the heat capacity in the containment vessel 2 will flow into the containment vessel, and the internal pressure in the containment vessel 2 corresponds to the water temperature of the pool water 2c in the wet well 2b. rises at the saturation pressure.

A pressure measuring device 15 installed inside the containment vessel 2 measures this pressure rise.
detects and transmits this measured value to the controller 14. The controller 14 compares the pressure measurements transmitted from the measuring devices 15 and 15', and when this pressure difference reaches a certain value or more, the valve 4
A signal to open the valve is transmitted to the valve 4. In response to this signal, the valve 4 is opened, the high temperature and high pressure atmosphere within the containment vessel 2 flows into the containment vessel 2', and the pressure within the containment vessel 2 is reduced.

At this time, since the connecting pipe 3 is configured as described above, the atmosphere of the containment vessel 2 enters the pipe from the suction part 3a in the wet well 2b and passes through the pipe 3.
c', the discharge into the gas phase of the wet well 2b' is suppressed, and the water is ejected from the discharge part 3b' provided in the liquid phase of the wet well 2b', and is released by the pool water 2c' in the wet well 2b'. The ejected water vapor in the atmosphere is condensed.

Even if there is an accident on the plant 21' side, the movement path of this atmosphere can be changed from suction part 3a' to
The pipe 3 becomes the discharge part 3b, and is guided from the gas phase part of the accident plant to the liquid phase part of the healthy plant. That is, even if an accident occurs in any plant, the atmosphere of the accident plant is guided to the liquid phase part of the healthy plant, and the water vapor in the atmosphere is condensed.

In this way, a high-temperature, high-pressure atmosphere flows into the containment vessel 27, so the pressure inside the containment vessel 2'increases;
There is little possibility that the safety function of this plant 21' is lost, and the amount of heat that has flowed in can be removed by the decay heat removal system 5'. Even if the function of the decay heat removal system 5' on the plant 21' side had been lost, the accumulated decay heat would be that of one unit of the accident plant 21, while the heat capacity would be that of both containment vessels 2 and 21. 2', the rate of pressure increase is slow, and if the function of either the decay heat removal system 5 or 5' recovers during this time, the accident will be resolved.

According to the embodiments described above, even if an accident occurs in which the pressure rise inside the containment vessel cannot be suppressed, the accident can be brought under control without releasing the atmosphere containing nuclear fission products inside the containment vessel into the atmosphere. It has the effect of being able to

Further, according to this embodiment, when the above-mentioned accident occurs, there is an effect of providing a means to settle the accident without any operation by the operator.

Furthermore, according to this embodiment, in supplying the above-mentioned accident convergence means, there is also an effect of providing a water vapor condensation effect in pool water.

Furthermore, according to this embodiment, in supplying the above-mentioned steam condensation effect, it is possible to suppress the sudden inflow of steam, and therefore it is possible to reduce the load applied to the pressure suppression chamber.

Next, a second embodiment of the present invention will be described with reference to FIG.

In the nuclear power plant 20 shown in FIG.
2. 31', 32', connect to both the dry well and wet well, and connect each pipe 31, 32, 31
Isolation valves 4a, 4a', 4b, 4 are installed in the middle of ', 32'.
b' is provided.

The other parts other than those related to the piping 3 have the same configuration as the nuclear power plant shown in FIG.

If such a configuration is adopted, even if cooling water is injected from the outside into the accident plant 21 and the wet well 2b becomes full at the time of the accident assumed in the above embodiment, the isolation valves 4a, 4a', 4b will be closed. .

By selecting the opening and closing of 4b' for each valve, the piping 31
- Piping 3 - The strain of the accident plant 21 is absorbed by transferring it to the wet well 2b' via the piping route of the piping 31'.

In addition, by selecting opening and closing of the isolation valves 4a, 4a', 4b, and 4b' for each valve, the piping 32-piping 3-piping 3
When the piping path 2' is opened, the high pressure fluid in the dry well 2a enters the dry well 2a', and is then discharged into the pool water 2c' through the vent flow path 41', and is discharged into the containment vessel of the normal plant 21'. The condensation process is carried out within 2'.

Alternatively, by selecting opening and closing of the isolation valves 4a, 4a', 4b, and 4b' for each valve, the piping route consisting of the piping 31-piping 3-piping 32' can be opened. The condensed fluid enters the dry well 2a' of the healthy plant 21', is then discharged into the pool water 2c' through the vent flow path 41', and is condensed in the containment vessel 2' of the normal plant 21'. It is processed.

In addition, isolation valves 4a, 4a', 4b.

By selecting whether to open or close 4b' for each valve, the movement of the atmosphere in various directions can be switched depending on the purpose.

In other words, according to this embodiment, most of the effects of the first embodiment are common except that automatic operation is not possible, and on top of that, there are various ways to deal with accidents as described above. This has the effect of increasing the number of conditions that can be obtained.

In either embodiment, even if an accident occurs in the nuclear couple in which the pressure increase in the containment vessel cannot be suppressed, the containment vessel of a healthy plant can be used as heat capacity.
In addition, since the safety functions of healthy plants can be shared, there is an effect that the accident can be brought under control without inadvertently dissipating the atmosphere inside the containment vessel of the accidental plant into the atmosphere.

〔Effect of the invention〕

According to the invention of claim 1, even if a failure occurs in the other nuclear coupler, the fluid from the malfunctioning plant is stored in the reactor containment vessel of one healthy plant, and the pressure suppression process is carried out on the healthy plant side to ensure safety. You can take the following steps.

According to the invention of claim 2, in addition to the effect of the invention of claim 1, even if a failure occurs in one plant, safety can be taken in the other healthy plant. However, you can take precautions to ensure safety.

According to the invention of claim 3, in addition to the effects of the invention of claim 1 or 2, it becomes possible to treat the increased pool water in the failed plant in the stored state.

According to the invention of claim 4, even if a failure occurs in one plant, safety can be ensured in the other healthy plant, and the fluid to be treated between multiple plants can be freely moved to any suitable location. , and can freely respond to accidents.

According to the invention of claim 5, the fluid of the failed plant can be stored in the reactor containment vessel of the healthy plant, and the condensation action for safety can be efficiently performed in the healthy plant. Water backflow accidents can also be suppressed.

According to the invention of claim 6, in addition to the effect of the invention of claim 5, the fluid on the accident side that has once condensed in the reactor containment vessel on the accident side can be re-condensed on the healthy side, which improves safety. The treatment will be certain. ! According to the invention of II claim 7, safety is ensured by condensing the fluid of the failed plant in the reactor containment vessel of the failed plant by using the healthy plant when any of the nuclear couplers fails. In addition, backflow of both the gas phase and the liquid phase can be prevented.

According to the invention of claim 8, in addition to the effect of the invention of claim 7, dynamic impact in a healthy plant can be alleviated.

According to the invention of claim 9, the effect of the invention of claim 8 can be automatically obtained.

According to the invention of claim 10, 1. Since the functional loss of the malfunctioning plant can be compensated for within the reactor containment vessel on the normal side by using the normal functions of the healthy plant, pressure rise failures can be resolved without inadvertently releasing the atmosphere inside the reactor containment vessel to the atmosphere. can be done.

[Brief explanation of drawings]

FIG. 1 is a conceptual diagram of an atomic couplant according to a first embodiment of the present invention, and FIG. 2 is a conceptual diagram of an atomic couplant according to a second embodiment of the present invention. 1.1'... Nuclear reactor, 2,2'... Reactor containment vessel. 2a, 2a'...Dry well, 2b, 2b'...
Wet well, 3... Connection piping, 3a, 3a'.
・・Connection pipe suction part, 3b, 3b'...Connection pipe discharge part, 3c, 3c'-suction part check valve, 3d, 3d'・
・・Discharge part check valve, 4...Flow rate control valve, 5.5'...
・Residual heat removal system, 6, 6'...Residual heat removal pump, 7
゜7'...Residual heat removal system suction piping, 8,8'...Residual heat removal system discharge piping, 9,9'...Heat exchanger, 10゜10'...Residual heat removal seawater pump , 11.11'...
・Residual heat removal seawater suction piping, 12.12'... Residual heat removal seawater discharge piping, 13... Relief safety valve, 14...
Valve opening controller, 15, 15'...pressure measuring device, 2o.
...Nuclear power plant, 21.21'...Nuclear power plant.

Claims (1)

[Claims] 1. A multi-unit accident management system in which a dry well gas phase part of one reactor containment vessel and a wet well gas phase part of the other reactor containment vessel are connected by a flow path. 2. The multi-unit accident management system according to claim 1, wherein the wet well gas phase part of the one reactor containment vessel and the dry well gas phase part of the other reactor containment vessel are connected by a flow path. 3. The multi-unit accident management system according to claim 1 or 2, wherein the wet well gas phase portions of the one reactor containment vessel and the other reactor containment vessel are connected by a flow path. 4. Connect the dry well gas phase part and wet well gas phase part of one reactor containment vessel with the dry well gas phase part and wet well gas phase part of the other reactor containment vessel by a flow path, and A multi-unit incident management system with a valve that switches the direction of fluid flow in the channel. 5. Multiple unit accident management in which the space in one reactor containment vessel and the pool water in the wet well of the other reactor containment vessel are communicated via backflow prevention means oriented to prevent flow toward the dry well. system. 6. The multi-unit accident management system according to claim 5, wherein the space in one of the reactor containment vessels is a gas phase space of a wet well. 7. Piping that communicates the gas phase parts in the wet wells of one reactor containment vessel and the other reactor containment vessel, and the pipes extending into the pool water in each wet well in each of the reactor containment vessels. A fluid discharge port of the piping is provided through a means for blocking the flow of the fluid, and a means for blocking the flow of fluid in the outward direction of the piping is provided in the gas phase portion in each wet well in each of the reactor containment vessels. a multi-unit incident management system comprising: a fluid inlet of said piping deployed through the fluid inlet; 8. The multi-unit accident management system according to claim 7, further comprising a valve in the middle of a pipe that communicates the gas phase in each wet well of one reactor containment vessel and the other reactor containment vessel. 9. In claim 8, the valve is a flow rate regulating valve, and the flow rate regulating valve is connected to each pressure measuring device that measures the pressure of a plurality of reactor containment vessels to which the pipes are connected, and from each of the pressure measuring devices. A multi-unit accident management system comprising: a controller that controls the opening degree of a flow rate regulating valve installed in the piping based on the obtained pressure value. 10. A plurality of units having a process of guiding leaked fluid in one reactor containment vessel into the other reactor containment vessel, and then condensing the leaked fluid with pool water in a wet well in the other reactor containment vessel. Accident management methods.