JP2023000744A - Radioactive material treatment device and reactor facility - Google Patents

Abstract

To provide a radioactive material treatment device capable of suppressing leakage of a radioactive material to the outside, and a reactor facility.SOLUTION: A radioactive material treatment device for treating gas containing steam and radioactive materials discharged from a reactor containment vessel comprises a containment building that stores the reactor containment vessel in an internal space airtightly isolated from the outside, and a cooling unit that cools the atmosphere of the internal space.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to radioactive material processing equipment and nuclear reactor facilities.

Patent Document 1 discloses a nuclear reactor installation with a filter vent. Filtered vents remove iodine and radioactive particles from gases emitted from the reactor containment. The gas from which these iodine and radioactive particles have been removed is released into the atmosphere.

Japanese Patent No. 5898018

By the way, the gas discharged into the atmosphere from the filter vent contains trace amounts of radioactive substances such as Xe and Kr. However, it is desired that these radioactive substances are not released into the atmosphere.

The present disclosure has been made in view of the above circumstances, and provides a radioactive material processing apparatus and a nuclear reactor facility capable of suppressing leakage of radioactive materials to the outside.

In order to solve the above problems, a radioactive material processing apparatus according to a first aspect of the present disclosure is a radioactive material processing apparatus for processing gas containing steam and radioactive materials discharged from a nuclear reactor containment vessel, A containment building for storing the reactor containment vessel in an airtightly isolated internal space, and a cooling section for cooling the atmosphere of the internal space.

In order to solve the above problems, a radioactive material processing apparatus according to a second aspect of the present disclosure is a radioactive material processing apparatus for processing gas containing steam and radioactive materials discharged from a nuclear reactor containment vessel, A cooling unit is provided for hermetically isolating and cooling the atmosphere of the internal space between the containment building for storing the reactor containment vessel and the reactor containment vessel.

Further, a nuclear reactor installation according to a third aspect of the present disclosure includes the radioactive material processing apparatus and the reactor containment vessel.

Advantageous Effects of Invention According to the present disclosure, it is possible to provide a radioactive material processing apparatus and a nuclear reactor facility capable of suppressing leakage of radioactive materials to the outside.

1 is a cross-sectional view showing an overall schematic configuration of a nuclear reactor facility according to an embodiment of the present disclosure; FIG.

Hereinafter, the nuclear reactor installation according to this embodiment will be described based on the drawings.

(Reactor equipment)
A nuclear reactor facility is provided on the site of a nuclear power plant.
As shown in FIG. 1 , the nuclear reactor installation 1 includes a nuclear reactor 10 , a reactor containment vessel 20 , and a radioactive material processing device 5 .

(Reactor)
The reactor 10 is a pressurized water reactor (PWR) that uses uranium oxide or the like as nuclear fuel. The nuclear reactor 10 heats the primary coolant (light water) by thermal energy of nuclear fission caused by the nuclear fuel in the core.

The heated primary coolant heats and boils the secondary coolant (light water) in a steam generator (not shown) to generate high-temperature, high-pressure steam. The steam generated by a steam generator (not shown) in the nuclear reactor 10 is sent to, for example, a steam turbine (not shown) provided outside the nuclear reactor facility 1 via a steam line (not shown). be done. Steam introduced into the steam turbine rotates the turbine of the steam turbine. Rotation of this turbine drives a generator (not shown) to generate power.

(Reactor containment vessel)
The reactor containment vessel 20 is a pressure vessel that stores the nuclear reactor 10 and retains inside the gas V containing radioactive substances present in the reactor containment vessel 20 in an emergency. The reactor containment vessel 20 is made of a material such as steel or concrete, for example. The gas V inside the containment vessel 20 contains steam as a condensable gas, radioactive substances, and non-condensable gas.

The reactor containment vessel 20 has a containment vessel body 21 and a vent device 22 .
The containment vessel main body 21 houses the reactor 10 and water injection equipment (not shown) for supplying water injection from the outside.

The vent device 22 is designed to prevent the pressure inside the containment vessel main body 21 from reaching the withstand pressure limit due to a rise in the pressure inside the containment vessel main body 21 when the gas V containing radioactive substances is generated inside the containment vessel main body 21 in an emergency. It is a device for discharging the gas V to the outside. The vent device 22 is provided in the containment vessel main body 21 . The vent device 22 has a vent pipe 22a and a vent valve 22b.

The vent pipe 22a is a pipe that communicates the inside and outside of the containment vessel main body 21 with each other. The vent valve 22b is provided on the vent pipe 22a. The vent valve 22b is normally closed. The vent valve 22b is opened, for example, when the pressure inside the containment vessel main body 21 reaches or exceeds a preset threshold value. As a result, a large amount of gas V generated in the containment vessel main body 21 is discharged into the internal space R of the containment building 30 through the vent pipe 22a.

(Radioactive material processing equipment)
The radioactive substance processing device 5 is a device that processes the gas V containing radioactive substances discharged from the nuclear reactor containment vessel 20 . The radioactive material processing apparatus 5 includes a containment building 30, a cooling unit 40, a water source 100, a supply line 60, a drainage device 50, a return line 61, a demineralization tower 70, a cooler 80, and a pump 90. , a bypass line 62 .

(Containment building)
The containment building 30 is a reactor building that houses the reactor containment vessel 20 . The containment building 30 forms an internal space R that is airtightly isolated from the outside, and stores the reactor containment vessel 20 in the internal space R. The containment building 30 retains the gas V discharged from the inside of the containment vessel main body 21 through the vent device 22 in the space.

(cooling part)
The cooling unit 40 is a device that cools the atmosphere of the internal space R. As shown in FIG. The cooling unit 40 is provided above the reactor containment vessel 20 in the internal space R inside the containment building 30 . The cooling unit 40 has a spray device 41 that sprays the cooling water W supplied from the outside of the containment building 30 from above the reactor containment vessel 20 .

The spray device 41 is a spray ring having a ring portion 41a and a spray nozzle 41b. The ring portion 41 a is a pipe through which cooling water W flows, and is provided over the entire ceiling wall portion of the containment building 30 . A plurality of spray nozzles 41b are provided on the ring portion 41a at regular intervals, and spray downward the cooling water W flowing inside the ring portion 41a. The cooling water W sprayed by the spray nozzle 41b spreads in the internal space R and falls. Therefore, the cooling unit 40 can distribute the cooling water W in the internal space R almost evenly. Note that the ring portion 41 a may be provided over the entire side wall portion of the containment building 30 .

Among the components of the gas V discharged from the containment vessel main body 21 into the internal space R through the vent device 22, the condensable gas such as steam exchanges heat with the cooling water W sprayed by the cooling unit 40. is cooled and condensed. Also, the non-condensable gas contracts by exchanging heat with the cooling water W sprayed by the cooling unit 40 . Thereby, the pressure in the internal space R can be maintained at a pressure that can sufficiently reduce the leakage of the gas V from the containment building 30 . The cooling water W, which has been heat-exchanged with the gas V discharged into the internal space R and whose temperature has risen, accumulates at the bottom of the containment building 30 . Part of the condensed radioactive material is dissolved in this cooling water W that accumulates at the bottom of the containment building.

(water source)
The water source 100 is a fuel replacement water tank provided outside the containment building 30 . The water source 100 stores cooling water W inside. The cooling water W stored in the water source 100 in this embodiment is used as emergency water for cooling the internal space R by the cooling unit 40 .

(supply line)
The supply line 60 is a pipe that supplies cooling water W from the water source 100 to the cooling unit 40 . One end of the supply line 60 is connected to the water source 100 . The other end of the supply line 60 is connected to the cooling section 40 . This allows the cooling water W stored in the water source 100 to flow through the inside of the supply line 60 .

(drainage device)
The drainage device 50 is a device that discharges the cooling water W whose temperature has increased by exchanging heat with the gas V discharged into the internal space R to the outside of the containment building 30 as circulating water. The drainage device 50 is a drainage sump pit provided below the reactor containment vessel 20 in the internal space R of the containment building 30 .

(return line)
The return line 61 is a pipe for sending the circulating water discharged from the drainage device 50 to the supply line 60 . One end of the return line 61 is connected to the drainage device 50 . The other end of the return line 61 is connected to the middle of the supply pipe outside the containment building 30 . Thereby, the circulating water discharged from the drainage device 50 is led to the supply line 60 via the return line 61 and joins the cooling water W flowing through the supply line 60 .

That is, the return line 61 returns the circulating water as the cooling water W to the supply line 60 . Therefore, the cooling water W sprayed into the internal space R by the cooling unit 40 is again guided to the cooling unit 40 via the supply line 60 as the cooling water W.

(Demineralization tower)
The demineralization tower 70 is installed in the middle of the supply line 60 outside the containment building 30, and removes the condensed portion of the gas V discharged into the internal space R and the radioactive substances dissolved in the cooling water W. The demineralization tower 70 adsorbs and removes part of the ionized radioactive substances dissolved in the cooling water W. Therefore, cooling water W with reduced radioactive substances is introduced into the cooling unit 40 .

(Cooler)
The cooler 80 is a device that cools the cooling water W, provided in the middle of the supply line 60 outside the containment building 30 . Cooler 80 is provided in supply line 60 between demineralization tower 70 and the connection where return line 61 and supply line 60 are connected.

(pump)
The pump 90 is a device that is provided in the middle of the supply line 60 outside the containment building 30 and pumps the cooling water W flowing through the supply line 60 to the cooling unit 40 . A pump 90 is provided in the supply line 60 between the cooler 80 and the connection where the return line 61 and the supply line 60 are connected.

(bypass line)
The bypass line 62 is a pipe that changes the distribution route of the cooling water W flowing through the supply line 60 in the middle of the supply line 60 outside the containment building 30 . One end of bypass line 62 is connected to supply line 60 between demineralizer 70 and cooler 80 . The other end of the bypass line 62 is connected to the supply line 60 between the demineralization tower 70 and the cooling section 40 . A bypass valve 22 c is provided in the middle of the bypass line 62 .

The bypass valve 22c is a normally closed valve. The bypass valve 22c is in an open state, for example, when clogging or the like occurs in the adsorption device of the demineralization tower 70 and the cooling water W does not sufficiently flow inside the supply line 60 on the downstream side of the demineralization tower 70. It is said that Thereby, the cooling unit 40 can spray a sufficient amount of the cooling water W in the internal space R.

(Effect)
In the radioactive material processing apparatus 5 of the above embodiment, the cooling unit 40 cools the atmosphere of the internal space R that is airtightly isolated from the outside of the containment building 30. Therefore, the gas V discharged from the reactor containment vessel 20 contains Some of the condensable vapors and radioactive materials condense. Also, the non-condensable gas contracts by exchanging heat with the cooling water W sprayed by the cooling unit 40 . Thereby, the pressure in the internal space R can be maintained at a pressure that can sufficiently reduce the leakage of the gas V from the containment building 30 . In other words, it is possible to confine the radioactive material in the containment building 30 and prevent the internal space R from becoming high pressure. Therefore, for example, even if gas V containing a large amount of radioactive substances is generated in the containment vessel main body 21 in an emergency, it is possible to prevent the internal pressure of the reactor containment vessel 20 from rising and to suppress the leakage of radioactive substances to the outside. .

Further, in the radioactive substance processing apparatus 5 of the above embodiment, the cooling water W is supplied from the water source 100 to the cooling unit 40 through the supply line 60 . A spray device 41 included in the cooling unit 40 sprays cooling water W in the internal space R from above the containment vessel 20 . As a result, it is possible to achieve the above effects with a more specific configuration, and at the same time, part of the radioactive substance after condensation is dissolved in the cooling water W. Then, the cooling water W in which the radioactive substance is dissolved drops and accumulates in the lower part of the internal space R. Therefore, the cooling water W in which radioactive substances are dissolved can be efficiently collected.

Further, in the radioactive substance processing apparatus 5 of the above-described embodiment, the cooling water W in which the radioactive substance is dissolved is discharged to the outside of the containment building 30 by the drainage device 50 as circulating water. The discharged circulating water joins the cooling water W flowing in the supply line 60 via the return line 61 , and then part of the radioactive substances are removed in the demineralization tower 70 . As a result, the cooling unit 40 can reuse the circulating water as the cooling water W, and the amount of radioactive substances in the internal space R is reduced. Therefore, an increase in the concentration of radioactive substances in the internal space R can be mitigated.

Further, in the radioactive material processing apparatus 5 of the above embodiment, the cooler 80 lowers the temperature of the cooling water W sprayed by the cooling unit 40 . As a result, the effect of condensing radioactive substances in the containment building 30 can be enhanced.

Further, in the radioactive material processing apparatus 5 of the above embodiment, the demineralization tower 70 , cooler 80 , pump 90 and bypass valve 22 c are provided outside the containment building 30 . As a result, a worker can safely maintain the demineralization tower 70, the cooler 80, the pump 90, and the bypass valve 22c while keeping the containment building 30 airtight. In addition, since the pump 90 and the bypass valve 22c are not exposed to a high-temperature and high-pressure atmosphere, the operating environment of the pump 90 and the bypass valve 22c can be relaxed.

Moreover, in the nuclear reactor installation 1 of the above-described embodiment, leakage of radioactive substances to the outside can be suppressed.

[Other embodiments]
As described above, the embodiment of the present disclosure has been described in detail with reference to the drawings, but the specific configuration is not limited to the configuration of the embodiment. , substitutions, and other modifications are possible. Moreover, this disclosure is not limited by the embodiments, but only by the claims.

Moreover, the cooling unit 40 may further include a package air conditioner or the like that cools the atmosphere of the internal space R. As a result, the atmosphere in the internal space R can be further cooled, and the effect of condensing radioactive substances in the containment building 30 can be further improved.

Further, in the above embodiment, the reactor 10 is a pressurized water reactor (PWR), but is not limited to the pressurized water reactor, and the reactor 10 may be a boiling water reactor (BWR) or the like. may be

[Appendix]
The radioactive material processing apparatus and the nuclear reactor facility described in the embodiments are grasped, for example, as follows.

(1) The radioactive material processing apparatus 5 according to the first aspect is a radioactive material processing apparatus 5 that processes gas V containing radioactive substances and steam discharged from the reactor containment vessel 20, and is airtightly isolated from the outside. A containment building 30 for storing the reactor containment vessel 20 and a cooling unit 40 for cooling the atmosphere of the internal space R are provided in the internal space R.

According to the above configuration, since the cooling unit 40 cools the atmosphere of the internal space R that is airtightly isolated from the outside of the containment building 30, the condensable steam contained in the gas V discharged from the reactor containment vessel 20 and Some of the radioactive material condenses. In addition, the non-condensable gas contracts, and the pressure in the internal space R can be maintained at a pressure at which the leakage of the gas V from the containment building 30 can be sufficiently reduced. As a result, the radioactive material can be confined within the containment building 30, and high pressure in the internal space R can be suppressed.

(2) A radioactive substance processing device 5 according to a second aspect is the radioactive substance processing device 5 of (1), which is provided outside the containment building 30 and includes a water source 100 that stores cooling water W, a supply line 60 for supplying the cooling water W from the water source 100 to the cooling unit 40, and the cooling unit 40 supplies the cooling water W from above the reactor containment vessel 20 in the internal space R. It may have a spray device 41 for distribution.

According to the above configuration, the cooling water W is supplied from the water source 100 to the cooling section 40 through the supply line 60 . A spray device 41 included in the cooling unit 40 sprays cooling water W in the internal space R from above the containment vessel 20 . As a result, it is possible to achieve the above effects with a more specific configuration, and at the same time, part of the radioactive substance after condensation is dissolved in the cooling water W. The cooling water dissolved in the cooling water W drops and accumulates in the lower part of the internal space R.

(3) A radioactive material processing apparatus 5 according to a third aspect is the radioactive material processing apparatus 5 of (2), wherein the gas V condensed by the cooling water W is used as circulating water together with the cooling water W. A drainage device 50 for discharging to the outside of the containment building 30, a return line 61 for returning the circulating water as the cooling water W from the drainage device 50 to the supply line 60, and the supply line 60 outside the containment building 30. and a demineralization tower 70 for removing a part of the radioactive substances contained in the cooling water W may be further provided.

According to the above configuration, the cooling water W in which radioactive substances are dissolved is discharged to the outside of the containment building 30 by the drainage device 50 as circulating water. The discharged circulating water joins the cooling water W flowing in the supply line 60 via the return line 61 , and then part of the radioactive substances are removed in the demineralization tower 70 . As a result, the cooling unit 40 can reuse the circulating water as the cooling water W, and an increase in the concentration of radioactive substances in the internal space R can be mitigated.

(4) A radioactive material processing apparatus 5 according to a fourth aspect is the radioactive material processing apparatus 5 of (2) or (3), and is provided in the middle of the supply line 60 outside the containment building 30. , a cooler 80 for cooling the cooling water W may be further provided.

According to the above configuration, the cooler 80 lowers the temperature of the cooling water W sprayed by the cooling unit 40 . Thereby, the effect of condensing the condensable gas and the effect of contracting the non-condensable gas in the containment building 30 can be enhanced.

(5) A radioactive material processing apparatus 5 according to a fifth aspect is a radioactive material processing apparatus 5 that processes gas V containing radioactive substances and steam discharged from a nuclear reactor containment vessel 20, and is airtightly isolated from the outside. A cooling unit 40 is also provided for cooling the atmosphere of the internal space R between the containment building 30 that houses the reactor containment vessel 20 and the containment vessel 20 .

(6) The nuclear reactor installation 1 according to the sixth aspect may include the radioactive material processing apparatus 5 according to any one of (1) to (5) and the reactor containment vessel 20 .

According to the above configuration, leakage of radioactive substances to the outside can be suppressed.

DESCRIPTION OF SYMBOLS 1... Nuclear reactor equipment 5... Radioactive material processing apparatus 10... Nuclear reactor 20... Reactor containment vessel 21... Containment vessel body 22... Vent device 22a... Vent pipe 22b... Vent valve 22c... Bypass valve 30... Containment building 40... Cooling part DESCRIPTION OF SYMBOLS 41... Spray apparatus 41a... Ring part 41b... Spray nozzle 50... Drainage apparatus 60... Supply line 61... Return line 62... Bypass line 70... Demineralization tower 80... Cooler 90... Pump 100... Water source R... Internal space V... Gas W...Cooling water

Claims (6)

A radioactive substance processing apparatus for processing gas containing steam and radioactive substances discharged from a nuclear reactor containment vessel,
a containment building that stores the reactor containment vessel in an internal space airtightly isolated from the outside;
a cooling unit that cools the atmosphere of the internal space;
A radioactive material processing device. a water source provided outside the containment building and storing cooling water;
a supply line for supplying the cooling water from the water source to the cooling unit;
further comprising
2. The radioactive material processing apparatus according to claim 1, wherein said cooling unit has a spray device for spraying said cooling water from above said reactor containment vessel in said internal space. a drainage device for discharging the gas condensed by the cooling water to the outside of the containment building as circulating water together with the cooling water;
a return line returning the circulating water as the cooling water from the drainage device to the supply line;
a demineralization tower provided in the middle of the supply line outside the containment building for removing the radioactive material contained in the cooling water;
The radioactive material processing apparatus according to claim 2, further comprising: 4. The radioactive material processing apparatus according to claim 2, further comprising a cooler provided in the middle of said supply line outside said containment building for cooling said cooling water. A radioactive substance processing apparatus for processing gas containing steam and radioactive substances discharged from a nuclear reactor containment vessel,
A radioactive material processing apparatus comprising a cooling unit that airtightly isolates it from the outside and cools an atmosphere in an internal space between a containment building that houses the reactor containment vessel and the reactor containment vessel. A radioactive material processing apparatus according to any one of claims 1 to 5;
the reactor containment vessel;
A reactor installation with a

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