JP2021025967A - Vent facility, nuclear reactor installation, and vent method - Google Patents

Abstract

To vent gas without causing the combustion of hydrogen and oxygen in a nuclear reactor installation.SOLUTION: A vent facility 100 comprises: a vent piping system 110 for passing gas in a reactor containment vessel 3 to discharge the gas to the atmosphere; a filter tank 121 provided in the middle of the vent piping system 110, storing liquid 122 therein and discharging the gas passed through the vent piping system 110 into the liquid 122; a dry type filter 130 passing the gas passed through the inside of the liquid 122 to capture a radioactive material in the gas; and a gas treatment unit 140 for reducing the concentration of at least one of hydrogen gas and oxygen gas in the gas. A first state of heating the liquid 122 by the gas flowing through the gas treatment unit 140 at a first flow rate and a second state of passing through the filter tank 121 at a second flow rate larger than the first flow rate can be formed, and a switch from the first state to the second state is allowed.SELECTED DRAWING: Figure 1

Description

Embodiments of the present invention relate to venting equipment, reactor facilities, and venting methods.

In a nuclear power plant, when a large amount of gas containing radioactive substances is generated in the reactor containment vessel due to the occurrence of a serious accident due to the occurrence of significant damage to the core, the pressure in the reactor containment vessel rises. If there is a risk of overpressure damage to the reactor containment due to increased pressure, in order to minimize public exposure, the gas inside the reactor containment vessel should be removed from the reactor containment vessel as vent gas to reduce the amount of radioactive material. After reducing it, it is released into the atmosphere.

At this time, a filter device is provided in order to reduce the amount of radioactive substances in the bent gas.

Japanese Unexamined Patent Publication No. 2017-203743

FIG. 13 is an equipment piping system diagram showing a conventional configuration example of a vent facility in a nuclear reactor facility.

The vent gas contains a large amount of water vapor from the reactor coolant that has flowed out from the reactor pressure vessel 2 or the main steam pipe or the like into the reactor containment vessel 3. Therefore, the bent gas passes through the scrubber solution 122 in the filter tank 121 to condense the water vapor.

However, if the hydrogen / oxygen concentration in the dry condition of the bent gas, that is, the hydrogen / oxygen concentration after removing water vapor from the bent gas exceeds the flammable limit concentration, after the scrubbing treatment, the hydrogen concentration of the bent gas and There is a risk that the oxygen concentration will reach the flammable range and burn.

Therefore, in the event of a serious accident, the hydrogen / oxygen concentration in the reactor containment vessel 3 is measured under dry conditions using a sampling-type atmospheric gas measuring device, and the filter device 120 is operated so as not to exceed the flammable limit concentration. The policy was to prevent hydrogen combustion inside. On the other hand, when sampling from the reactor containment vessel 3 is not possible and the hydrogen / oxygen concentration is measured by the atmospheric gas measuring device installed in the reactor containment vessel 3, the hydrogen concentration and the oxygen concentration can be measured only under wet conditions. .. That is, there is a problem that the hydrogen concentration and the oxygen concentration in the gas to be vented under dry conditions cannot be grasped in advance.

Therefore, it is an object of the present invention to enable gas venting in a nuclear reactor facility without a risk of a combustion reaction between hydrogen and oxygen.

In order to achieve the above object, the vent equipment according to the present embodiment is provided in the middle of the vent piping system and the vent piping system that allows the gas inside the reactor containment vessel to pass through and releases the gas to the atmosphere. , A filter tank that stores a liquid inside the gas and allows the gas that has passed through the vent piping system to flow out into the liquid, and the gas that has passed through the inside of the liquid to pass the radioactive substance in the gas. The liquid is provided with a dry filter for collecting and a gas treatment device for reducing the concentration of at least one of hydrogen gas and oxygen gas in the gas, and the liquid is brought by the gas flowing through the gas treatment device at a first flow rate. A first state of heating and a second state of passing through the filter tank at a second flow rate larger than the first flow rate can be configured, and the first state to the second state can be configured. It is characterized in that it can be switched to a state.

Further, the reactor facility according to the present embodiment includes a core, a reactor pressure vessel accommodating the core, a reactor containment vessel accommodating the reactor pressure vessel, and the above-mentioned filter vent facility. It is characterized by that.

Further, the venting method according to the present embodiment is provided in a vent piping system that allows the gas inside the reactor storage container to pass through and releases the gas to the atmosphere, and a vent piping system that is provided in the middle of the vent piping system and allows a liquid to be introduced therein. A filter tank in which the gas that has been stored and passed through the vent piping system flows out into the liquid, and a dry filter that allows the gas that has passed through the inside of the liquid to pass through and collects radioactive substances in the gas. A venting method using a venting facility comprising, the liquid is heated by the gas at a first flow rate flowing through a gas treatment apparatus that reduces the concentration of at least one of hydrogen gas and oxygen gas in the gas. The first step of operating in the first state and the second state of switching to the second state in which the gas having a second flow rate larger than the first flow rate is passed through the filter tank and released into the atmosphere are operated. It is characterized by having two steps.

According to the embodiment of the present invention, it is possible to perform gas venting in a nuclear reactor facility without fear of a combustion reaction of hydrogen and oxygen.

It is an equipment piping system diagram which shows the structure of the vent equipment in the reactor facility which concerns on 1st Embodiment. It is a vertical sectional view which shows the structure of the hydrogen oxygen processing apparatus of the vent facility which concerns on 1st Embodiment. It is a vertical sectional view which shows the structure of the modification of the hydrogen oxygen processing apparatus of the vent facility which concerns on 1st Embodiment. It is a flow chart which shows the procedure of the filter vent method which concerns on 1st Embodiment. It is an equipment piping system diagram which shows the structure of the vent equipment in the reactor facility which concerns on 2nd Embodiment. It is an equipment piping system diagram which shows the structure of the vent equipment in the reactor facility which concerns on 3rd Embodiment. It is an equipment piping system diagram which shows the structure of the vent equipment in the reactor facility which concerns on 4th Embodiment. It is an equipment piping system diagram which shows the structure of the vent equipment in the reactor facility which concerns on 5th Embodiment. It is an equipment piping system diagram which shows the structure of the vent equipment in the reactor facility which concerns on 6th Embodiment. It is an equipment piping system diagram which shows the structure of the modification of the vent facility in the reactor facility which concerns on 6th Embodiment. It is an equipment piping system diagram which shows the structure of the vent equipment in the reactor facility which concerns on 7th Embodiment. It is an equipment piping system diagram which shows the structure of the vent equipment in the reactor facility which concerns on 8th Embodiment. It is an equipment piping system diagram which shows the conventional configuration example of the vent facility in a nuclear reactor facility.

Hereinafter, the vent facility, the reactor facility, and the vent method according to the embodiment of the present invention will be described with reference to the drawings. Here, parts that are the same as or similar to each other are designated by a common reference numeral, and duplicate description will be omitted.

[First Embodiment]
FIG. 1 is an equipment piping system diagram showing a configuration of a vent facility 100 in the reactor facility 10 according to the first embodiment.

The reactor facility 10 uses the core 1, the reactor pressure vessel 2 that houses the core 1, the reactor containment vessel 3 that houses the reactor pressure vessel 2, and the gas in the reactor containment vessel 3 in the event of an accident. It has a vent facility 100 that guides the reactor to the outside of the containment vessel 3, reduces the concentration of radioactive substances, and releases the reactor to the atmosphere.

The reactor containment vessel 3 has a dry well 3a and a wet well 3b connected to the dry well 3a by a vent pipe 3c.

The dry well 3a is provided with a dry well vent hole 4, and the inside and outside of the reactor containment vessel 3 can be isolated by the dry well vent first isolation valve 4a and the dry well vent second isolation valve 4b. Further, a bypass valve 4c having a capacity smaller than that of the dry well vent second isolation valve 4b is provided in parallel with the dry well vent second isolation valve 4b.

The wet well 3b is provided with a wet well vent hole 5, and the inside and outside of the reactor containment vessel 3 can be isolated by the wet well vent first isolation valve 5a and the wet well vent second isolation valve 5b. Further, a bypass valve 5c having a capacity smaller than that of the wet well vent second isolation valve 5b is provided in parallel with the wet well vent second isolation valve 5b.

The venting equipment 100 is configured to vent the gas in the dry well 3a and the gas in the wet well 3b, respectively.

The vent facility 100 includes a vent piping system 110, a filter device 120, and a hydrogen oxygen treatment device 140 as a gas treatment device for the gas to be vented.

The vent piping system 110 includes a dry well side pipe 111 as a main pipe connected to the dry well vent second isolation valve 4b, and a wet well side pipe 112 as a main pipe connected to the wet well vent second isolation valve 5b. It has a merging pipe 113 from the merging portion of the dry well side pipe 111 and the wet well side pipe 112 to the filter device 120, and an exhaust pipe 119 from the filter device 120 to the discharge port 119a opened to the atmosphere. The exhaust pipe 119 is provided, for example, along the exhaust pipe 8 of the reactor facility 10, and the exhaust port 119a is arranged near the top of the exhaust pipe 8. Further, the vent pipe system 110 has a dry well side branch pipe 111a connected to the bypass valve 4c and a wet well side branch pipe 112a connected to the bypass valve 5c.

The filter device 120 has a filter tank 121 that stores the scrubber solution 122, and an in-container pipe 123 that is connected to the merging pipe 113 and has a nozzle 124 at the tip. Further, a dry filter 130 is provided inside the exhaust port of the filter device 120 to the exhaust pipe 119 of the filter tank 121. The dry filter 130 may be provided at the outlet of the filter device 120, that is, outside the filter tank 121.

The hydrogen oxygen treatment device 140 is provided on the confluence pipe 113.

FIG. 2 is a vertical cross-sectional view showing the configuration of the hydrogen oxygen treatment device 140 of the vent facility 100 according to the first embodiment.

The hydrogen / oxygen treatment apparatus 140 has a cylindrical container 141 and a catalyst mesh cylinder 142 housed in the container 141.

Both ends of the container 141 are connected to the merging pipe 113, and the container 141 is connected to the cylindrical portion by a cone-shaped member.

One end of the catalyst mesh cylinder 142 is connected to an internal pipe 143 connected to the merging pipe 113 by a connecting flange 144. The catalyst mesh cylinder 142 is a mesh assembled in a cylindrical shape, and a closing plate is provided at an end thereof. The mesh of the catalyst mesh cylinder 142 has a double-layered structure, and ceramic particles coated with a catalyst metal that promotes the reaction of hydrogen and oxygen are provided between the meshes. The catalyst metal is, for example, a platinum-rhodium alloy. Although not shown, the catalyst mesh cylinder 142 has a frame for supporting the mesh. A mesh may be provided instead of the closing plate.

The gas flow from the reactor containment vessel 3 is in the direction of the arrow in FIG. 2 (direction from the left side to the right side in FIG. 2). Instead, the gas flow from the reactor containment vessel 3 is completely It may be in the opposite direction (from the right side to the left side in FIG. 2).

FIG. 3 is a vertical sectional view showing a configuration of a modified example of the hydrogen oxygen treatment device 140 of the vent facility according to the first embodiment.

The hydrogen / oxygen treatment apparatus 140 according to the modified example has a container 145, a catalyst layer 146 built in the container 145, and perforated plates 147 and 148 supporting the catalyst layer 146 on both sides along the flow. The catalyst layer 146 is laminated with, for example, a plurality of ceramic particles coated with a catalyst metal for the reaction of hydrogen and oxygen. The catalyst metal is, for example, a platinum-rhodium alloy.

FIG. 4 is a flow chart showing the procedure of the filter vent method according to the first embodiment.

First, the pressure inside the reactor containment vessel 3 after the accident at the reactor facility 10 is monitored (step S01).

While continuing to monitor the pressure of the reactor containment vessel 3, it is determined whether or not the pressure is equal to or higher than the predetermined pressure (step S02). Here, the predetermined pressure is appropriately set to the maximum working pressure Pd of the reactor containment vessel 3, the normal leakage rate test pressure which is 1.1 times the maximum working pressure, or 1.05 times the maximum working pressure, for example, with a margin. Set.

If it is not determined that the pressure is equal to or higher than the predetermined pressure (step S02 NO), step S01 and subsequent steps are repeated.

When it is determined that the pressure is equal to or higher than the predetermined pressure (YES in step S02), the venting equipment 100 is operated in the first state (step S03). Here, the first state means an operating state at the first flow rate. Specifically, in the present embodiment, for example, when venting the gas in the dry well 3a, the dry well vent first isolation valve 4a and the bypass valve 4c are opened, and the dry well vent second isolation valve 4b Is closed. As a result, since the gas passes through the drywell side branch pipe 111a of the drywell side pipe 111, the gas flows at a lower flow rate than the case where the gas flows through the drywell side pipe 111. Here, the flow rate when the dry well vent second isolation valve 4b is opened and flows through the dry well side pipe 111 is referred to as the second flow rate in the present embodiment, and the operating state at the second flow rate is the second state. I will call it.

When this gas flows through the hydrogen-oxygen treatment apparatus 140, hydrogen and oxygen contained in the gas react with each other due to the action of the catalyst metal and are converted into water vapor. This reaction is an exothermic reaction. Therefore, the gas flowing out from the hydrogen oxygen treatment device 140 in a state where the temperature has risen flows out from the nozzle 124 into the scrubber solution 122 through the internal pipe 123 of the filter device 120. As the gas flows out into the scrubber solution 122, radioactive substances (eg, cesium iodine) contained in the gas are trapped in the scrubber solution 122.

On the other hand, due to the high temperature of the gas flowing out into the scrubber solution 122, the scrubber solution 122 is heated and the temperature rises. When the boiling point is finally reached, the water vapor contained in the gas is almost never condensed by the scrubber solution 122. Here, the boiling point is approximately 100 ° C. because the inside of the filter tank 121 is approximately atmospheric pressure. In this situation, the gas contains water vapor similar to that in the stage of flowing into the filter device 120 even after passing through the filter device 120, and does not reach dry conditions, resulting in hydrogen and oxygen concentrations. Can be maintained in almost the original state. As a result, the hydrogen concentration and the oxygen concentration in the gas reach the combustible range, and the risk of combustion is eliminated.

Next, it is determined whether or not switching is possible (step S04). Here, switching means switching from the first state to the second state.

The switchable judgment criteria include, for example, when the temperature of the scrubber solution 122 by a thermometer (not shown) provided in the filter device 120 reaches the boiling point or a value close to the boiling point, or hydrogen or oxygen in the reactor containment vessel 3. Can be used when the concentration of is reduced.

Alternatively, the second state may be switched to after a predetermined time has elapsed from the first state. It is desirable to switch based on the measurement results of the temperature detector of the scrubber solution 122 and the gas concentration detector in the reactor containment vessel 3, but since the situation where venting is performed is at the time of an accident, the detection results of these instruments are used. It is possible that the situation cannot be obtained. In preparation for such a case, when the time for the scrubber solution 122 to reach a predetermined temperature in the operation in the first state is set as a condition for switching, and the detection result of the temperature or gas concentration cannot be obtained. Can also be suitably vented.

For example, if the measurement result of either the temperature detector or the gas concentration detector is obtained, switching is performed based on the detector, and if the measurement result is not obtained, the switching is performed after a predetermined time has elapsed. can do. This may be carried out by an operator or may be incorporated as a function of the control device. It should be noted that it does not exclude the procedure of switching after a lapse of a predetermined time regardless of whether or not the measurement result can be detected.

If it is not determined that switching is possible (step S04 NO), step S03 and subsequent steps are repeated.

When it is determined that the switching is possible (step S04 YES), the operation proceeds to the second state. Specifically, the dry well vent second isolation valve 4b is opened. The bypass valve 4c may be further closed. In this state, the gas in the reactor containment vessel 3 is vented at the second flow rate, so that the concentrations of hydrogen and oxygen are further lowered as compared with the first state.

Next, it is determined whether or not the pressure of the reactor containment vessel 3 has dropped to a predetermined pressure or less (step S06). Here, the predetermined pressure is set to a sufficient pressure for maintaining the soundness of the reactor containment vessel 3.

If it is not determined that the pressure in the reactor containment vessel 3 has dropped to the predetermined pressure or less (step S06 NO), step S05 and subsequent steps are repeated.

When it is determined that the pressure of the reactor containment vessel 3 has dropped to the predetermined pressure or less (step S06 YES), the venting is stopped (step S07). Specifically, the dry well vent first isolation valve 4a, the dry well vent second isolation valve 4b, and the bypass valve 4c are all closed.

When the pressure in the reactor containment vessel 3 rises again, the steps after step S01 are repeated.

The steps for venting the gas in the dry well 3a have been described above as an example, but the same steps can be used for venting the gas in the wet well 3b.

As described above, according to the present embodiment, even when the concentrations of hydrogen and oxygen in the reactor containment vessel 3 under dry conditions are unknown, the radioactivity concentration is increased when the gas is vented to the outside. By passing through the filter device 120 for reduction, it becomes possible to prevent the occurrence of the combustion reaction of hydrogen and oxygen under dry conditions. That is, at the beginning, for example, while venting at a small flow rate of about 1/10 of the rated capacity of the vent facility 100, the hydrogen and oxygen processing device 140 reduces the concentration of hydrogen and oxygen to prevent the occurrence of combustion, and the gas is released. The temperature of the scrubber solution 122 of the filter device 120 is raised by the heat it has (the heat that it had when it flowed out of the reactor storage container 3 and the heat generated by the hydrogen oxygen treatment device 140). As a result, even when the gas is vented with the rated capacity of the venting equipment 100, the water vapor in the gas is prevented from being condensed by the scrubber solution 122 to be in a dry condition, and the hydrogen concentration and oxygen in the gas to be vented are prevented. The concentration can be kept low.

As described above, according to the present embodiment, it is possible to perform gas venting in a nuclear reactor facility without fear of a combustion reaction of hydrogen and oxygen.

Although the hydrogen oxygen treatment device 140 has been described as a device that combines hydrogen and oxygen, the device is not limited to this, and other devices may be used as long as the device reduces the concentration of hydrogen or oxygen. It is sufficient that the concentration of hydrogen or oxygen can be reduced to such an extent that there is no problem even if water vapor is condensed while the scrubber solution 122 is heated at the first flow rate. However, hydrogen oxygen treatment can reduce both the hydrogen concentration and the oxygen concentration, and the period of the first state can be shortened by heating the scrubber solution 122 with the gas heated by the hydrogen oxygen treatment device 140. It is preferable to adopt the device 140.

[Second Embodiment]
FIG. 5 is an equipment piping system diagram showing the configuration of the vent facility 100 in the reactor facility 10 according to the second embodiment.

The second embodiment is a modification of the first embodiment. In the first embodiment, the hydrogen oxygen treatment device 140 is provided on the merging pipe 113, but in the present embodiment, it is provided on the wet well side branch pipe 112a. Further, an orifice 112b is provided on the wet well side branch pipe 112a on the outlet side of the hydrogen oxygen treatment apparatus 140. The orifice 112b does not necessarily have to be provided.

Also in this embodiment, the same effect as that of the first embodiment can be obtained by the same operation as that of the first embodiment. Further, the hydrogen oxygen processing apparatus 140 can be made smaller than that of the first embodiment. More specifically, in the first embodiment, since the total flow rate of the gas (second flow rate) passes through the hydrogen oxygen treatment apparatus 140 even in the second state, it is necessary to react all the gases of the second flow rate. Even if there is no such thing, the hydrogen oxygen treatment device 140 has to be enlarged from the viewpoint of flow path resistance and the like. In the second embodiment, since only the gas flowing through the wet well side branch pipe 112a passes through the hydrogen oxygen treatment device 140, the hydrogen oxygen treatment device 140 may be relatively small.

[Third Embodiment]
FIG. 6 is an equipment piping system diagram showing the configuration of the vent facility 100 in the reactor facility 10 according to the third embodiment.

This embodiment is a modification of the first embodiment. The dry well side pipe 111 and the wet well side pipe 112 are not provided with bypass pipes. In the present embodiment, the hydrogen oxygen treatment device 140 is arranged above the liquid level of the scrubber solution 122 in the filter tank 121. In this embodiment, the gas flow rate is not switched.

In the present embodiment, although the water vapor in the gas is condensed by the scrubber solution 122, it is immediately treated by the hydrogen oxygen treatment apparatus 140 to reduce the hydrogen oxygen concentration and does not reach the combustible region.

Further, the scrubber solution 122 is heated by the heat that it had when the gas flowed out of the reactor containment vessel 3. Here, it is desirable that the arrangement position of the hydrogen oxygen treatment device 140 in the height direction is close to the liquid surface. In particular, the liquid level is disturbed by the outflow of gas into the scrubber solution 122, which may be the position where the scrubber solution 122 is applied to the hydrogen oxygen treatment device 140.

In the present embodiment, since the hydrogen / oxygen treatment device 140 is housed in the filter tank 121, the structure of the filter tank 121 becomes complicated and the size increases, but the hydrogen / oxygen treatment device 140 is separately placed. There is no need to do so, and there are advantages in terms of placement.

[Fourth Embodiment]
FIG. 7 is an equipment piping system diagram showing a configuration of a vent facility in the reactor facility according to the fourth embodiment.

The venting equipment 100 in this embodiment has a make-up water tank 160. The make-up water tank 160 replenishes the scrubber solution 122 in the filter tank 121, and the make-up water tank 160 and the filter tank 121 communicate with each other through a communication pipe 161.

With such a configuration, in the present embodiment, the scrubber solution 122 can be replenished in the filter tank 121, so that the scrubber solution 122 evaporates even when the filter tank 121 has a small capacity. However, the reduction does not affect the venting, and the operation time in the first state can be shortened by reducing the capacity of the filter tank 121.

[Fifth Embodiment]
FIG. 8 is an equipment piping system diagram showing a configuration of a vent facility in the reactor facility according to the fifth embodiment.

This embodiment is a modification of the first embodiment. In the present embodiment, the dry well side pipe 111 and the wet well side pipe 112 are not provided with the branch pipe, and the branch pipe is provided at the inlet portion of the filter device 120 of the merging pipe 113. Further, in the present embodiment, a cooler 150 for cooling the gas treated by the hydrogen oxygen treatment device 140 with the scrubber solution 122 is provided.

The merging pipe 113 as a part of the vent piping system 110 includes a first pipe 115 as a main pipe and a second pipe 116 as a branch pipe, a third pipe 117, and a first pipe arranged in parallel with each other. It has a rejoining pipe 118 in which the pipe 115 and the third pipe 117 are merged. The first pipe 115 is provided with a first stop valve 115a, and the second pipe 116 is provided with a second stop valve 116a.

A cooler 150 is provided on the branch pipe side, and the cooler 150 is specifically a cooling tank 151 for storing the scrubber solution 122. A coolant supply pipe 151a connected to the filter tank 121 is connected to the cooling tank 151, and a check valve 151b is provided in the coolant supply pipe 151a.

Further, a hydrogen oxygen treatment device 140 is provided between the first stop valve 116a of the second pipe 116 on the branch pipe side and the cooling tank 151. The gas that has passed through the hydrogen / oxygen treatment apparatus 140 is configured to be released into the scrubber solution 122 of the cooling tank 151.

One end of the third pipe 117 of the branch side pipe is connected to the top of the cooling tank 151, and the other end is connected to the first pipe 115 which is the main pipe.

In the fifth embodiment configured as described above, when venting the gas in the dry well 3a, the dry well vent first isolation valve 4a and the dry well vent second isolation valve 4b are opened and wet. When venting the gas in the well 3b, the wet well vent first isolation valve 5a and the wet well vent second isolation valve 5b are opened.

In the present embodiment, the first state is a state in which the gas flows on the branch pipe side. That is, the first stop valve 115a is closed and the second stop valve 116a is open. As a result, the gas flows into the cooling tank 151 after passing through the hydrogen oxygen processing device 140, and then passes through the remerging pipe 118.

Also in this embodiment, the scrubber solution 122 in the filter tank 121 is heated by utilizing the heat of reaction due to the reaction of hydrogen and oxygen in the hydrogen oxygen treatment apparatus 140. On the other hand, when the amount of heat of reaction in the hydrogen / oxygen treatment apparatus 140 is large, it is expected that the piping on the downstream side will be affected by thermal stress. Therefore, in the present embodiment, the cooler 150 is provided in order to mitigate the influence of the gas temperature.

After the determination of switchability, the transition to the second state may be performed by opening the first stop valve 115a. Further, the second stop valve 116a may be further closed.

As described above, according to the present embodiment, gas venting without fear of occurrence of a combustion reaction of hydrogen and oxygen is possible while maintaining the structural soundness in the venting equipment 100.

[Sixth Embodiment]
FIG. 9 is an equipment piping system diagram showing a configuration of a vent facility in the reactor facility according to the sixth embodiment.

The sixth embodiment is a modification of the fifth embodiment. The venting equipment 100 in the present embodiment has, as the cooler 150, a spray-type cooler 152 as a mixer that cools the scrubber solution 122 by mixing it with a gas stream instead of the cooling tank 151 in the fifth embodiment. .. Therefore, it has a coolant supply pipe 152a and a pump 152b that supply the coolant to the spray cooler 152. Other than this, it is the same as the fifth embodiment.

The coolant supply pipe 152a is connected from the filter tank 121 to the spray cooler 152, and the pump 152b drives the coolant to the spray cooler 152.

The spray cooler 152 is provided with a nozzle 152c inside the second pipe 116 at the outlet of the hydrogen oxygen treatment device 140, and is pumped to the nozzle 152c by the pump 152b to supply the scrubber solution 122 into the second pipe 116. Spray.

FIG. 10 is an equipment piping system diagram showing a configuration of a modified example of the vent facility in the reactor facility according to the sixth embodiment. In this modification, the Venturi type cooler 153 is provided instead of the spray type cooler 152. Further, the Venturi type cooler 153 has a coolant supply pipe 153a and a check valve 153b for supplying the coolant.

In the case of the Venturi type cooler 153, since the static pressure is reduced by the amount of the increase in the dynamic pressure at the throttle portion in the flow direction, pumping by a pump is unnecessary. Further, a check valve 153b is provided in consideration of the back pressure.

As described above, according to the present embodiment, gas venting without fear of occurrence of a combustion reaction of hydrogen and oxygen is possible while maintaining the structural soundness in the venting equipment 100. Further, the cooler 150 in the present embodiment is not limited to these examples, and may be a mixer that cools the scrubber solution 122 by mixing it with a gas stream.

[7th Embodiment]
FIG. 11 is an equipment piping system diagram showing the configuration of the vent facility 100 in the reactor facility 10 according to the seventh embodiment.

The seventh embodiment is also a modification of the fifth embodiment. The venting equipment 100 in the present embodiment has a heat exchanger 154 as the cooler 150 instead of the cooling tank 151 in the fifth embodiment. Therefore, it has a coolant supply pipe 154a and a pump 154b that form a flow path between the heat exchanger 154 and the cooling source on the cooling side. Other than this, it is the same as the fifth embodiment.

This embodiment also has the same effect as that of the fifth embodiment, and enables gas venting without fear of occurrence of a combustion reaction between hydrogen and oxygen while maintaining the structural soundness in the venting equipment 100. Here, instead of providing the coolant supply pipe 154 and the pump 152b, the second pipe 116 penetrates the filter tank 121, passes through the scrubber solution 122, and then is connected to the remerging pipe 118. There may be.

[8th Embodiment]
FIG. 12 is an equipment piping system diagram showing a configuration of a vent facility in the reactor facility according to the eighth embodiment. The eighth embodiment is a modification of the first embodiment.

In the eighth embodiment, the dry well side pipe 111 and the wet well side pipe 112 are not provided with the branch pipe, and the branch pipe is provided at the inlet portion of the filter device 120 of the confluence pipe 113. There is.

That is, the merging pipe 113 as a part of the vent pipe system 110 has a first pipe 115 as a main pipe and a second pipe 116 as a branch pipe arranged in parallel with each other. The first pipe 115 is provided with a first stop valve 115a, and the second pipe 116 is provided with a second stop valve 116a.

The second pipe 116 penetrates the filter tank 121 and immerses the open end in the scrubber solution 122. The hydrogen / oxygen treatment device 140 is provided in the air portion of the filter tank 121 of the second pipe 116.

In the present embodiment, in the first state, the gas flows out from the second pipe 116 into the scrubber solution 122 at the first flow rate, and in the second state, the scrubber solution 122 is discharged from the first pipe 115 at the second flow rate. Let the gas flow out inside.

With this configuration, the second pipe 116 on the outlet side of the hydrogen oxygen treatment device 140 is cooled by the scrubber solution 122 because the tip thereof is immersed in the scrubber solution 122.

As described above, the eighth embodiment also has the same effect as that of the first embodiment, and there is a risk that a combustion reaction of hydrogen and oxygen may occur while maintaining the structural soundness in the vent facility 100. No gas venting is possible. The hydrogen oxygen treatment device 140 may be provided on the outside of the filter tank 121.

[Other Embodiments]
Although some embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention.

For example, in the embodiment, the case of a Mark I type containment vessel in a boiling water reactor is shown as an example, but the present invention can be applied to a newer type of containment vessel. Further, the present invention is not limited to boiling water reactors, and can be applied to other types of reactors such as pressurized water reactors.

In addition, the features of each of the plurality of embodiments may be combined.

Furthermore, these embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, as well as in the scope of the invention described in the claims and the equivalent scope thereof.

1 ... Core, 2 ... Reactor pressure vessel, 3 ... Reactor containment vessel, 3a ... Dry well, 3b ... Wet well, 3c ... Vent pipe, 4 ... Dry well vent hole, 4a ... Dry well vent first isolation valve, 4b ... Dry well vent second isolation valve, 4c ... Bypass valve, 5 ... Wet well vent hole, 5a ... Wet well vent first isolation valve, 5b ... Wet well vent second isolation valve, 5c ... Bypass valve, 8 ... Exhaust Cylinders, 10 ... Reactor facilities, 100 ... Vent equipment, 110 ... Vent piping system, 110a ... Upstream piping, 111 ... Drywell side piping, 111a ... Drywell side branch piping, 112 ... Wetwell side piping, 112a ... Wet Well side branch pipe, 112b ... orifice, 113 ... confluence pipe, 115 ... first pipe, 115a ... first stop valve, 116 ... second pipe, 116a ... second stop valve, 117 ... third pipe , 118 ... Rejoining piping, 119 ... Exhaust piping, 119a ... Discharge port, 120 ... Filter device, 121 ... Filter tank, 122 ... Scrubber solution, 123 ... In-container piping, 124 ... Nozzle, 130 ... Dry filter, 140 ... Hydrogen Oxygen treatment device (gas treatment device), 141 ... container, 142 ... catalyst mesh cylinder, 143 ... internal piping, 144 ... connection flange, 145 ... container, 146 ... catalyst layer, 147 ... 148 ... perforated plate, 150 ... cooler, 151 ... Cooling tank, 151a ... Coolant supply pipe, 151b ... Check valve, 152 ... Spray cooler (mixer), 152a ... Coolant supply pipe, 152b ... Pump, 152c ... Nozzle, 153 ... Venturi type cooler (Mixer), 153a ... Coolant supply pipe, 153b ... Check valve, 154 ... Heat exchanger, 154a ... Coolant supply pipe, 154b ... Pump, 160 ... Makeup water tank, 161 ... Communication pipe

Claims (14)

A vent piping system that allows the gas inside the reactor containment vessel to pass through and releases the gas to the atmosphere.
A filter tank provided in the middle of the vent piping system, which stores a liquid therein, and the gas that has passed through the vent piping system flows out into the liquid.
A dry filter that collects radioactive substances in the gas by passing the gas that has passed through the inside of the liquid.
A gas treatment device that reduces the concentration of at least one of hydrogen gas and oxygen gas in the gas, and
With
A first state in which the liquid is heated by the gas flowing through the gas treatment device at the first flow rate, and a second state in which the liquid is passed through the filter tank at a second flow rate larger than the first flow rate. Is configurable, and the first state can be switched to the second state.
Vent equipment characterized by that. The gas treatment apparatus allows the entire amount of the gas from the reactor containment vessel to pass through.
A state switching unit for switching the flow rate of the gas from the first flow rate to the second flow rate is further provided.
The vent facility according to claim 1, wherein the vent facility is characterized in that. The vent system piping is
The main pipe provided with the first valve and
A branch pipe provided in parallel with the main pipe and provided with a second valve,
Have,
The gas treatment device is provided in the middle of the branch pipe.
The first state and the second state can be switched by opening and closing the first valve and the second valve.
The vent facility according to claim 1, wherein the vent facility is characterized in that. Cooling provided between the confluence of the branch pipe and the main pipe and the gas treatment facility, to which the liquid of the filter tank is supplied, and the gas that has passed through the gas treatment device is cooled by the liquid. The venting facility according to claim 3, further comprising an apparatus. The cooling device has a cooling tank for storing the liquid.
The cooling tank is characterized in that the gas that has passed through the gas treatment device is discharged into the liquid of the cooling tank, passes through the liquid, and then is guided to the confluence. Item 4. Vent equipment according to item 4. The venting equipment according to claim 4, wherein the cooling device includes a mixer that mixes the liquid and the gas supplied from the filter tank. The venting equipment according to claim 4, wherein the cooling device includes a heat exchanger that exchanges heat between the gas in the branch pipe and the liquid in the filter tank. The vent piping system is located on the reactor containment vessel side of the filter tank.
The main pipe provided with the first valve and
It has a branch pipe that branches from the main pipe and is provided with a second valve to discharge the gas into the liquid in the filter tank separately from the main pipe.
The gas treatment device is provided in the middle of the branch pipe,
The first state and the second state can be switched by opening and closing the first valve and the second valve.
The vent facility according to claim 1, wherein the vent facility is characterized in that. The venting device according to claim 1, further comprising a replenishment tank for supplying the liquid to the filter tank. A vent piping system that allows the gas inside the reactor containment vessel to pass through and releases the gas to the atmosphere.
A filter tank provided in the middle of the vent piping system, which stores a liquid therein, and the gas that has passed through the vent piping system flows out into the liquid.
A dry filter that collects radioactive substances in the gas by passing the gas that has passed through the inside of the liquid.
A gas treatment device provided between the liquid and the dry filter to reduce at least one of the oxygen concentration and the hydrogen concentration in the gas.
Vent equipment characterized by being equipped with. With the core
The reactor pressure vessel that houses the core and
The reactor containment vessel that houses the reactor pressure vessel and
The venting equipment according to any one of claims 1 to 10.
A nuclear reactor facility characterized by being equipped with. A vent piping system that allows the gas inside the reactor containment vessel to pass through and releases the gas to the atmosphere.
A filter tank provided in the middle of the vent piping system, which stores a liquid therein, and the gas that has passed through the vent piping system flows out into the liquid.
A dry filter that collects radioactive substances in the gas by passing the gas that has passed through the inside of the liquid.
It is a venting method using a venting facility equipped with
A first step of operating in a first state in which the liquid is heated by the gas at a first flow rate flowing through a gas treatment apparatus that reduces the concentration of at least one of hydrogen gas and oxygen gas in the gas.
A second step of switching to a second state in which the gas having a second flow rate larger than the first flow rate is passed through the filter tank and released into the atmosphere is operated.
A venting method characterized by having. The venting method according to claim 12, wherein the switching from the first state to the second state is performed when the temperature of the liquid is equal to or higher than a predetermined temperature. 12. The switching from the first state to the second state is performed when the oxygen concentration or the hydrogen concentration in the gas in the reactor containment vessel becomes a predetermined concentration or less. The venting method described in.

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