JPH08146192A - Radioactive gas waste disposal apparatus - Google Patents

Abstract

PURPOSE: To reduce the size of a system, to decrease the gas disposal amount in an off-gas system, to reduce exposure and to improve the reliability. CONSTITUTION: A vacuum pump 4, a filter 14, a hydrogen separator 5, an oxygen and hydrogen separator 10 and an activated carbon hold up tower 12 are put in the connecting state between a main condenser 3 and an exhaust cylinder 13. Hydrogen and water separated by the hydrogen separator 5 are divided to flow to a gas flow regulator 8 and to a pressure reducing valve 7, they flow from a hydrogen discharge piping 6 to the exhaust cylinder 13 on the pressure reducing valve 7 side, and they flow into the inflow side of the vacuum pump 4 through a hydrogen injection piping 9 on the gas flow regulator valve 8 side. Oxygen separated by the oxygen and hydrogen separator 10 flows into the exhaust cylinder 13. Gas inflow from the main condenser 3 to the off-gas system is performed by the vacuum pump 4 to extract and discharge hydrogen, oxygen and vapor, respectively by a selective permeant membrane. Thus, it is possible to eliminate the need of installing the conventional air extractor, pre-heater, recombiner, exhaust gas condenser and dehumidifying and cooling device so as to reduce the size of a system.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radioactive gas waste treatment device in a gas waste treatment system of a nuclear power plant.

[0002]

2. Description of the Related Art Generally, in boiling water reactors, exhaust gases derived from the reactor, that is, N-16 and 0-19 short-lived nuclides produced by activation of reactor water, and Kr, Xe produced by nuclear fission are generally used. Noble radioactive gas such as hydrogen and oxygen generated by radiolysis of reactor water are generated.

In order to reduce the volume of these exhaust gases and attenuate the radioactivity, a shielded gas waste treatment system (hereinafter referred to as an off gas system) is installed in the turbine building of a nuclear power plant. In this process, exhaust gas from the reactor, air leaking into the main condenser, and off-gas system driven main steam are processed.

However, the quantitative breakdown of offgas of a typical 1.1 million kW class boiling water reactor is a design value, and the radiolysis gas of water is 330 m ³ / h (220 m ³ of hydrogen in the standard state. /
h, oxygen 110m ³ / h), air leaking into the main condenser 40m ³ /
The main steam for driving the off-gas system is 6200 m ³ / h. Radioactive noble gas produced by nuclear fission is small in quantity, and its contribution to the treatment flow rate is small.

The structure and function of the conventional off-gas system will be described with reference to FIG. That is, in FIG. 4, reference numeral 1 indicates a boiling water reactor, and the reactor 1 is connected to the turbine 2 and the main condenser 3 by a main steam pipe and a water supply pipe. The reactor 1 and the main condenser 3 are air extractors 16
Connected to the off-gas preheater 1 downstream of the air extractor 16
7, hydrogen / oxygen recombiner 18, off-gas condenser 19, dehumidifying cooler 20, dehumidifying tower 21, activated carbon type hold-up tower 12, vacuum pump 4 and exhaust stack 13 are sequentially connected.

However, since the above-mentioned off gas is generally non-condensable, it accumulates in the main condenser 3 from the reactor 1 through the turbine 2. The off-gas accumulated in the main condenser 3 is extracted from the main condenser 3 by an air extractor 16 (hereinafter abbreviated as SJAE) using a part of the main steam generated in the reactor 1 as a drive source, and is discharged into the off-gas system. Exhausted.

At this time, the hydrogen concentration in the exhausted off-gas is diluted by the main steam of the SJAE drive source, and becomes a concentration outside the detonation range, that is, 4 vol% or less. The exhausted off-gas is first heated by the off-gas preheater 17 to a temperature suitable for recombination of hydrogen and oxygen. Thereafter, in the hydrogen-oxygen recombiner 18, hydrogen and oxygen are recombined by a catalytic reaction.

Water vapor produced by recombination, and SJAE
The main steam used for driving and diluting the hydrogen concentration is
The off-gas condenser 19 receives cooling by the external cooling water and is condensed into water. The condensed water is sent to the main condenser 3 and returned to the reactor 1 which is a generation source. Through this stage, water in the off gas is separated and removed.

Subsequently, the off gas is removed from the dehumidifying cooler 20 and the dehumidifying tower.
After being cooled and dehumidified by 21, it passes through an activated carbon type hold-up tower 12 (hereinafter abbreviated as H / U tower). Radioactive noble gas is adsorbed on the activated carbon due to the adsorption characteristics of the activated carbon, whereby the radioactivity of the noble gas is attenuated. Through the steps described above, the volume of off-gas is reduced and the radioactivity is attenuated, and finally the vacuum pump 4 evacuates and the air is discharged from the exhaust pipe 13 to the atmosphere.

[0010]

In the off-gas system described above, the off-gas from the reactor 1 and the main condenser 3 is extracted by SJAE, and the hydrogen concentration in the latter stage of the main condenser 3 is diluted. Therefore, a large amount of main steam containing radioactivity is required in order to bring the concentration outside the range of detonation to 4 Vol% or less. For this reason, each device, equipment, and the like become large, and as a result, the system of the off-gas system becomes large, and the turbine building of the nuclear power plant occupies a considerable volume.

Further, since each device of the off-gas system is a dynamic device, maintenance is required at the time of regular inspection, which increases running cost. Furthermore, when CFCs are used as the refrigerant for the dehumidifying cooler 20 and the dehumidifying tower 21, there is a global policy of abolishing CFCs,
We must think about measures immediately. When an adsorbent is used in the dehumidification tower 21, a regenerator is required and the equipment becomes large.

A method for selectively separating a gaseous waste treated in an off-gas system by using a hydrogen permeable membrane is disclosed in, for example, JP-A-63-73221. Generally, in a hydrogen permeable membrane, water vapor is permeated more quickly than hydrogen, so that hydrogen is removed and water vapor is removed at the same time.

Therefore, it is considered that the hydrogen treatment performance is relatively lowered and the hydrogen concentration in the system falls within the detonation range. However, in this conventional example, the hydrogen concentration is kept outside the detonation range. There is a problem that there is a risk of hydrogen explosion without studying the method. Moreover, a treatment method for oxygen generated by radiolysis of water has not been studied.

The present invention has been made to solve the above problems, and includes an air extractor, a preheater, a recombiner, an exhaust gas condenser. The installation of a dehumidifying cooler is unnecessary and the system is downsized, and the amount of gas processed in the off-gas system that does not need to drive the air extractor using main steam is reduced, further reducing exposure. Therefore, it is necessary to provide a radioactive gas treatment device with improved reliability, which does not need to take into consideration the problems of the preheater, the deterioration of the recombiner over time, and the problem of the CFC substitute used in the dehumidifying cooler. is there.

[0015]

A first aspect of the present invention is characterized in that a hydrogen separator is provided in the latter stage of a main condenser, and a pipe leading from the hydrogen separator to the exhaust stack is connected. It consists in extracting and removing hydrogen generated by radiolysis.

A second aspect of the present invention is characterized in that a hydrogen and oxygen separator is provided in the latter stage of the main condenser, and a pipe leading from the hydrogen and oxygen separator to the exhaust stack is connected. It consists in extracting and removing the resulting hydrogen and oxygen.

In a third aspect of the invention, a vacuum pump for extracting the exhaust gas generated in the reactor and a hydrogen separator are provided in the latter stage of the main condenser, and a pipe leading from the hydrogen separator to the exhaust stack is connected. The feature is to extract and remove hydrogen generated by radiolysis of reactor water.

In a fourth aspect of the present invention, a vacuum pump for extracting the exhaust gas generated in the reactor is connected to the latter stage of the main condenser, and a hydrogen and oxygen separator is connected to the pipe, and a pipe leading from the hydrogen and oxygen separator to the exhaust stack is connected. The present invention is to extract and remove hydrogen and oxygen generated by radiolysis of reactor water.

A fifth aspect of the present invention is to connect a vacuum pump for extracting exhaust gas generated in a nuclear reactor to a latter stage of a main condenser, a hydrogen separator, a hydrogen and oxygen separator, and connect each separator to an exhaust stack. It is characterized by connecting piping that communicates with it, and is for extracting and removing hydrogen and oxygen generated by radiolysis of reactor water.

A sixth aspect of the present invention is characterized in that a hydrogen separator is provided in the latter stage of the main condenser, and the hydrogen separator is connected to a pipe communicating with the main condenser via a flow control valve. When the hydrogen concentration in the condenser falls below the specified concentration, a portion of the hydrogen extracted by the hydrogen separator at the latter stage of the main condenser is injected into the main condenser to bring the hydrogen concentration out of the detonation range. To keep.

A seventh aspect of the present invention is provided with a vacuum pump for extracting the exhaust gas generated in the reactor, a hydrogen separator and a hydrogen and oxygen separator after the main condenser, and an exhaust stack from each of these separators. It is characterized in that a flow control valve is provided by branching from a pipe leading from the hydrogen separator to the exhaust stack, and a pipe leading from the flow control valve to the main condenser is connected. It is characterized by extracting and removing hydrogen and oxygen generated by radiolysis of nuclear reactor water, and injecting part of the hydrogen into the main condenser to keep the hydrogen concentration outside the detonation range.

In the eighth aspect of the invention, a vacuum pump for extracting the exhaust gas generated in the reactor, a hydrogen / oxygen separator, and a hydrogen / oxygen separator are provided after the main condenser.
Connect the pipes from each of these separation devices to the exhaust stack,
A hydrogen separation device for separating hydrogen from hydrogen and oxygen extracted by the hydrogen and oxygen separation device is provided, a pipe leading from the hydrogen separation device to the exhaust pipe is connected, and a pipe leading from the hydrogen separation device to the exhaust pipe is provided, It is characterized in that a flow control valve is provided branching from this pipe, and a pipe leading from this flow control valve to the main condenser is connected. This is to extract and remove hydrogen and oxygen generated by radiolysis of reactor water, and to inject a part of hydrogen into the main condenser to keep the hydrogen concentration outside the detonation range.

A hydrogen permeable membrane is used as the hydrogen separator, a hollow fiber membrane is used as the hydrogen permeable membrane, and a hydrogen and oxygen permeable membrane is used as the hydrogen and oxygen separator. A membrane having a hollow fiber structure is used as the permeable membrane.

[0024]

In the reactor off-gas system according to the present invention, since the off-gas is first extracted by the vacuum pump, the off-gas system can be driven without inflowing a large amount of main steam.
As a result, first, the total amount of gas processing in the off-gas system is significantly reduced. Therefore, the reactor off-gas system itself can be miniaturized, the space can be effectively used, and the exposure of workers can be reduced accordingly.

Further, hydrogen generated by radiolysis of water,
Oxygen and water vapor in the air that leaks into the main condenser,
Since the gas is extracted by the separator and discharged, the hydrogen-oxygen recombiner is not required to be installed, and accordingly, the off-gas preheater and the off-gas condenser are unnecessary.
Furthermore, since moisture is removed at the same time as the treatment of hydrogen and oxygen, it is not necessary to install a dehumidifying cooler and a dehumidifying tower. By combining these, the equipment can be rationalized.

Further, by using the membrane having the hollow fiber structure, the labor of maintenance can be greatly saved and the economical efficiency is improved, and the reliability is improved by making the processing equipment a static device. Since there is no need for dehumidification or dehumidification methods that use CFCs as a refrigerant, it is not necessary to consider CFC substitutes. By installing the hydrogen injection pipe, the hydrogen concentration can be kept outside the detonation range, and the danger of hydrogen explosion disappears.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the radioactive gas waste treatment apparatus according to the present invention will be described with reference to FIG. In FIG. 1, the reactor 1, the turbine 2, and the main condenser 3 are connected by a main steam pipe and a water supply pipe. Main condenser 3
The off gas extraction side of is connected to the suction side of the vacuum pump 4. The filter 1 is provided on the discharge side of the vacuum pump 4, that is, on the subsequent stage.
4, hydrogen separator 5, oxygen and hydrogen separator 10, activated carbon type hold-up column 12 and exhaust stack 13 are connected in sequence.

A pressure reducing valve 7 and a gas flow rate control valve 8 are connected in parallel on the outflow side of the hydrogen and water separated by the hydrogen separator 5. A hydrogen discharge pipe 6 is connected to the outlet side of the pressure reducing valve 7, and the hydrogen discharge pipe 6 is connected to an exhaust pipe 13. On the other hand, a hydrogen injection pipe 9 is connected to the outlet side of the gas flow rate control valve 8, and this hydrogen injection pipe 9 is connected to the suction side of the vacuum pump 4. An oxygen / hydrogen discharge pipe 11 is connected to the outflow side of the oxygen separated by the oxygen / hydrogen separator 10, and the oxygen / hydrogen discharge pipe 11 is connected to an exhaust pipe 13.

N-16, O- generated by activation of nuclear reactor water
19 (short-lived nuclides), radioactive noble gases such as Kr and Xe produced by fission, hydrogen and oxygen produced by radiolysis of reactor water, and air leaking into the main condenser 3 from the reactor 1. The non-condensable exhaust gas and the accompanying steam from the main condenser 3 which is the condensable gas are extracted by the vacuum pump 4,
It flows into the off-gas system.

[0030] At this time, quantitative breakdown of inflow gas, radiolysis gas water 330 m ³ / h (hydrogen 220 m ³ / h, oxygen 110m ³ /
h), air leaking into the main condenser 3 40m ³ / h, associated steam 15
It is 00m ³ / h. Condensation of the associated steam occurs under the pressure condition (1 to ² kgf / cm ² a) after the vacuum pump 4, and the condensation is about 20 m.
³ / h.

In the above embodiment, however, hydrogen and oxygen in the offgas flowing in from the main condenser 3 are separated and removed by passing them through the two types of separators 5 and 10. That is, first, hydrogen is extracted by the hydrogen separator 5. At this time, at the same time, water vapor in the air that has leaked into the main condenser 3 is also separated and extracted. The extracted hydrogen treatment line is divided into two systems as shown in FIG.

That is, a system for discharging hydrogen from the exhaust pipe 13 via the pressure reducing valve 7 and the hydrogen discharge pipe 6 leading to the exhaust pipe 13, and hydrogen flowing to the gas flow control valve 8 and pipes before and after the vacuum pump 4. It is a system for injecting hydrogen before and after the vacuum pump 4 via an injection pipe 9.

Calculating from the above-mentioned quantitative breakdown of off-gas, the hydrogen concentration in the off-gas before and after the vacuum pump 4 is about 56% within the range of detonation, and there is a danger of hydrogen explosion. In order to avoid hydrogen explosion in the off-gas system, a part of hydrogen extracted by the hydrogen separator 5 is injected through the hydrogen injection pipe 9 before and after the vacuum pump 4. The flow rate of hydrogen to be injected is adjusted by the gas flow rate adjusting valve 8 so that the hydrogen concentration before and after the vacuum pump 4 is outside the detonation range and is about 80% or more.

Subsequently, oxygen and hydrogen which cannot be completely extracted by the hydrogen separator 5 in the preceding stage are separated into hydrogen and oxygen separators.
Extract by 10. The extracted hydrogen and oxygen are discharged from the exhaust pipe 13 through the oxygen and hydrogen discharge pipes 11 leading to the exhaust pipe 13.

In this way, in this embodiment, after separating and extracting hydrogen and oxygen using the two types of separation devices 5 and 10,
An off gas containing a radioactive noble gas is ventilated to the activated carbon holdup tower 12. The radioactive rare gas is adsorbed on the activated carbon due to the adsorption characteristic of the activated carbon, waits for the radioactivity to be sufficiently attenuated there, and finally is discharged from the exhaust stack 13 to the atmosphere.

In the exhaust stack 13, gas waste from a ventilation air conditioning system (hereinafter abbreviated as HVAC) of a nuclear power plant (not shown) is also treated at the same time. HVAC processing flow rate is 10,000 m
It is a unit of ³ / h, and the hydrogen concentration in the exhaust stack 13 is outside the range of detonation, that is, 4 Vol% or less.

The hydrogen separator 5 and the hydrogen / oxygen separator 10 used in this embodiment use, for example, a gas permeable membrane, especially a hollow fiber membrane formed of a polyimide resin. The hollow fiber-shaped membrane is characterized by a large membrane surface area with respect to the treatment flow rate and high pressure resistance.

In the conventional off-gas system, the activated carbon type hold-up tower 12 is operated at a gas treatment flow rate of 40 m ³ / h. Considering that the hydrogen concentration must be 4 Vol% or less in order to prevent hydrogen explosion in the hold-up tower 12, the hydrogen removal efficiency in the hydrogen separation device 5 and the oxygen removal efficiency in the hydrogen and oxygen separation device 10 are shown as an example. Assuming 99.5% and 90% respectively, a gas treatment flow rate of 40 m ³ / h in the conventional activated carbon type hold-up tower 12 can be applied.

The separation device required to satisfy the above-mentioned hydrogen and oxygen removal efficiency is large enough to be installed in a space (about one room) required for installation of a conventional single unit of off-gas system. It becomes Further, if necessary, a filter 14 is provided in front of each permeable membrane to remove dust, dust, and the like in the exhaust gas, so that the gas permeability of each permeable membrane can be prevented from decreasing.

Next, a second embodiment of the radioactive gas waste treatment apparatus according to the present invention will be described with reference to FIG. In FIG. 2, the reactor 1, the turbine 2, and the main condenser 3 are connected by a main steam pipe and a water supply pipe. The off-gas extraction side of the main condenser 3 is connected to the suction side of the vacuum pump 4. A filter is provided on the discharge side of the vacuum pump 4, that is, on the subsequent stage.
14, an oxygen / hydrogen separator 10, an activated carbon holdup tower 12, and an exhaust stack 13 are sequentially connected.

A hydrogen separation device 5 is connected to the outflow side of the oxygen separated by the oxygen and hydrogen separation device 10, and the oxygen outflow side of this hydrogen separation device 5 is connected to an exhaust pipe 13 by an oxygen discharge pipe 15. .

A pressure reducing valve 7 and a gas flow rate control valve 8 are connected in parallel on the outflow side of hydrogen and water of the hydrogen separator 5. Pressure reducing valve 7
A hydrogen discharge pipe 6 is connected to the outlet side of the hydrogen discharge pipe 6, and the hydrogen discharge pipe 6 is connected to the exhaust pipe 13. A hydrogen injection pipe 9 is connected to the outlet side of the gas flow rate control valve 8.
Is connected to the suction side of the vacuum pump 4.

The non-condensable gas and associated steam generated in the reactor 1 are extracted from the main condenser 3 by the vacuum pump 4 and flow into the off-gas system. Hydrogen and oxygen in the inflowing off-gas are extracted by aerating the hydrogen and oxygen separator 10.

Generally, the permeability of hydrogen gas and water vapor in the hollow fiber membrane is higher than that of oxygen. For this reason, a hydrogen and oxygen separator using a hollow fiber membrane is used.
At 10, hydrogen and water vapor are extracted along with oxygen in the offgas.

The extracted hydrogen / oxygen mixed gas is passed through the hydrogen separator 5 to separate and extract hydrogen in the mixed gas.
The off-gas containing oxygen, which has been ventilated through the hydrogen separation device 5, is released into the atmosphere through the oxygen discharge pipe 15 communicating with the exhaust stack 13. The processing line for hydrogen extracted by the hydrogen separator 5 is divided into two systems as shown in FIG.

That is, hydrogen is discharged from the exhaust pipe 13 via the pressure reducing valve 7 and the pipe 6 leading to the exhaust pipe 13. Hydrogen is injected into the front and rear of the vacuum pump 4 through the gas flow rate control valve 8 and the hydrogen injection pipe 9 leading to the pipes before and after the vacuum pump 4.

The off gas containing the radioactive noble gas after ventilating the hydrogen and oxygen separation device 10 is ventilated to the hold-up tower 12 to wait for the decay of the radioactivity of the noble gas, and finally to the atmosphere from the exhaust stack 13.

Next, a third embodiment of the radioactive gas waste treatment apparatus according to the present invention will be described with reference to FIG. In FIG. 3, the reactor 1, the turbine 2, and the main condenser 3 are connected by a main steam pipe and a water supply pipe. Main condenser 3
The off gas extraction side of is connected to the suction side of the vacuum pump 4. The filter 1 is provided on the discharge side of the vacuum pump 4, that is, on the subsequent stage.
4, hydrogen separator 5, activated carbon type hold-up tower 12 and exhaust stack 13 are sequentially connected.

A pressure reducing valve 7 and a gas flow rate control valve 8 are connected in parallel on the outflow side of the hydrogen and water separated by the hydrogen separator 5. A hydrogen discharge pipe 6 is connected to the outlet side of the pressure reducing valve 7, and the hydrogen discharge pipe 6 is connected to the exhaust pipe 13. A hydrogen injection pipe 9 is connected to the outlet side of the gas flow rate control valve 8, and this hydrogen injection pipe 9 is connected to the suction side of the vacuum pump 4.

The non-condensable gas and associated steam generated in the nuclear reactor 1 are extracted from the main condenser 3 by the vacuum pump 4 and flow into the off-gas system. Hydrogen and water vapor in the inflowing off-gas are extracted by ventilating the hydrogen separation device 5. The extracted hydrogen treatment line is 2
It is branched into the system.

That is, hydrogen is discharged from the exhaust pipe 13 through the pressure reducing valve 7 and the hydrogen discharge pipe 6 leading to the exhaust pipe 13. Hydrogen is injected into the front and rear of the vacuum pump 4 through the gas flow rate control valve 8 and the pipe 9 leading to the pipes before and after the vacuum pump 4. The off gas containing the radioactive noble gas after ventilating the hydrogen separation device 5 is ventilated to the hold-up column 12 to wait for the decay of the radioactivity of the noble gas, and finally to the atmosphere from the exhaust stack 13.

[0052]

EFFECTS OF THE INVENTION According to the present invention, a vacuum pump is installed in the latter stage of the main condenser, and exhaust gas from the reactor is introduced by using this as a drive source. The off-gas system is driven without inflow. Therefore, the processing flow rate of the off-gas system can be reduced by 90% or more in terms of volume ratio.

In order to separate and extract hydrogen and oxygen,
Since a hydrogen separator using a hollow fiber structure membrane and a hydrogen and oxygen separator will be installed, the size of the off-gas system can be set sufficiently in the space required to install a conventional off-gas single device. It is possible to reduce the size of equipment and effectively use the space.

Further, since it is unnecessary to install the conventional equipment, the equipment can be rationalized and the space can be effectively used. Since the number of dynamic devices to be installed is reduced, the time and effort required for maintenance at the time of regular inspection are greatly reduced, and the economic efficiency is improved. In addition, since a hydrogen injection pipe is provided to keep the hydrogen concentration in the system outside the range of detonation, it is possible to provide a highly reliable system.

[Brief description of drawings]

FIG. 1 is a first radioactive-gas waste treatment device according to the present invention.
FIG.

FIG. 2 is a second view of the radioactive gas waste treatment device according to the present invention.
FIG.

FIG. 3 is a third view of the radioactive gas waste treatment device according to the present invention.
FIG.

FIG. 4 is a system diagram showing a conventional radioactive gas waste treatment device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Reactor, 2 ... Turbine, 3 ... Main condenser, 4 ... Vacuum pump, 5 ... Hydrogen separator, 6 ... Hydrogen discharge piping, 7 ... Pressure reducing valve, 8 ... Gas flow control valve, 9 ... Hydrogen injection piping , 10 ... Oxygen and hydrogen separator, 11 ... Oxygen and hydrogen discharge pipe, 12
… Activated carbon hold-up tower, 13… Exhaust stack, 14… Filter, 15… Oxygen exhaust pipe, 16… Air extractor, 17… Off-gas preheater, 18… Hydrogen-oxygen recombiner, 19… Off-gas condenser,
20 ... Dehumidifying cooler, 21 ... Dehumidifying tower.

Claims (12)

[Claims] 1. Steam generated in a nuclear reactor flows into a turbine, steam flowing out of this turbine is condensed in a main condenser, and radioactive noble gas in off-gas extracted from the main condenser is held up by activated carbon. In a radioactive gas waste treatment device that removes the off gas from which the noble gas has been removed in the tower and releases it into the atmosphere from the exhaust stack, a hydrogen separation device is provided in the latter stage of the main condenser, and the hydrogen separation device A method and apparatus for treating radioactive gas waste, characterized by connecting a hydrogen discharge pipe leading to an exhaust stack. 2. The steam generated in a nuclear reactor flows into a turbine, the steam flowing out from this turbine is condensed in a main condenser, and a radioactive rare gas in off-gas extracted from the main condenser is held up by activated carbon. In the radioactive gas waste treatment device that removes the off-gas from which the noble gas has been removed in the tower and releases it into the atmosphere from the exhaust stack, a hydrogen and oxygen separation device is provided after the main condenser, and this hydrogen and oxygen separation device is installed. A radioactive gas waste treatment device, characterized in that an oxygen and hydrogen discharge pipe leading from the device to the exhaust stack is connected. 3. Steam generated in a nuclear reactor flows into a turbine, steam flowing out of this turbine is condensed in a main condenser, and radioactive rare gas in off-gas extracted from the main condenser is held up by activated carbon. In the radioactive gas waste treatment device that removes the off gas from which the noble gas has been removed in the tower and discharges it into the atmosphere from the exhaust stack, a vacuum for extracting the exhaust gas generated in the reactor at the latter stage of the main condenser. A radioactive gas waste treatment device comprising a pump and a hydrogen separator, and connecting a hydrogen discharge pipe leading from the hydrogen separator to the exhaust stack. 4. Steam generated in a nuclear reactor flows into a turbine, steam flowing out from this turbine is condensed in a main condenser, and radioactive rare gas in off-gas extracted from the main condenser is held up by activated carbon. In the radioactive gas waste treatment device that removes the off gas from which the noble gas has been removed in the tower and discharges it into the atmosphere from the exhaust stack, a vacuum for extracting the exhaust gas generated in the reactor at the latter stage of the main condenser. A radioactive gas waste treatment device comprising a pump, a hydrogen / oxygen separator, and an oxygen / hydrogen discharge pipe connected from the hydrogen / oxygen separator to an exhaust stack. 5. The steam generated in a nuclear reactor flows into a turbine, the steam flowing out of this turbine is condensed in a main condenser, and a radioactive rare gas in off-gas extracted from the main condenser is held up by activated carbon. In the radioactive gas waste treatment device that removes the off gas from which the noble gas has been removed in the tower and discharges it into the atmosphere from the exhaust stack, a vacuum for extracting the exhaust gas generated in the reactor at the latter stage of the main condenser. A pump, a hydrogen separator, a hydrogen and oxygen separator,
A radioactive gas waste treatment device, characterized in that a hydrogen discharge pipe and hydrogen and oxygen discharge pipes connected from the respective separation devices to the exhaust stack are connected. 6. The steam generated in a nuclear reactor flows into a turbine, the steam flowing out from this turbine is condensed in a main condenser, and a radioactive rare gas in off-gas extracted from the main condenser is held up by activated carbon. In a radioactive gas waste treatment device for removing off-gas from which a noble gas has been removed in a tower and releasing it into the atmosphere from an exhaust stack, a hydrogen separation device is provided after the main condenser, and the hydrogen separation device An apparatus for treating radioactive gas waste, characterized in that a hydrogen injection pipe communicating with a condenser via a flow control valve is connected. 7. The steam generated in a nuclear reactor flows into a turbine, the steam flowing out from the turbine is condensed in a main condenser, and a radioactive rare gas in off-gas extracted from the main condenser is held up by activated carbon. In the radioactive gas waste treatment device that removes the off gas from which the noble gas has been removed in the tower and discharges it into the atmosphere from the exhaust stack, a vacuum for extracting the exhaust gas generated in the reactor at the latter stage of the main condenser. A pump, a hydrogen separator and a hydrogen and oxygen separator are provided,
A hydrogen discharge pipe and hydrogen and oxygen discharge pipes that connect from each of the separation devices to the exhaust pipe are connected, and a flow rate control valve is provided by branching from the pipe that connects the hydrogen separation device to the exhaust pipe.
A device for treating radioactive gas waste, characterized in that a hydrogen injection pipe leading from the flow control valve to the main condenser is connected. 8. The steam generated in a nuclear reactor flows into a turbine, the steam flowing out from this turbine is condensed in a main condenser, and a radioactive rare gas in off-gas extracted from the main condenser is held up by activated carbon. In a radioactive gas waste treatment device that removes the off gas from which the noble gas has been removed in the tower and releases it into the atmosphere from the exhaust stack, a vacuum for extracting the exhaust gas generated in the reactor after the main condenser. A pump and a hydrogen and oxygen separator are provided, and a hydrogen and oxygen discharge pipe leading from the hydrogen and oxygen separator to the exhaust stack is connected to separate hydrogen from the hydrogen and oxygen extracted by the hydrogen and oxygen separator. A hydrogen separator is provided, and a hydrogen discharge pipe that leads from this hydrogen separator to the exhaust pipe is connected, and the flow rate is branched from the pipe that leads from the hydrogen separator to the exhaust pipe. An apparatus for treating radioactive gas waste, characterized in that a control valve is provided, and a hydrogen injection pipe leading from the flow control valve to the main condenser is connected. 9. The radioactive gas waste treatment device according to claim 1, wherein a hydrogen permeable membrane is used in the hydrogen separation device. 10. The radioactive gas waste treatment device according to claim 9, wherein a hollow fiber membrane is used as the hydrogen permeable membrane. 11. The radioactive gas waste treatment device according to claim 2, wherein a hydrogen and oxygen permeable membrane is used in the hydrogen and oxygen separation device. 12. The radioactive gas waste treatment device according to claim 11, wherein a hollow fiber membrane is used as the hydrogen and oxygen permeable membrane.