JPS61180198A - Emergency gas treater - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to the amount of radioactive material released outdoors while maintaining negative pressure inside the reactor building in the event of an accident in a nuclear facility having a nuclear reactor such as a nuclear power plant. This invention relates to an emergency gas treatment device for reducing the amount of gas.

[Technical background of the invention]

In general, in nuclear power facilities such as nuclear power plants, radioactive materials in the air are removed by passing the air that may contain radioactive materials inside the reactor building through a filter device in the event of an accident. At the same time, it is necessary to maintain negative pressure inside the reactor building and prevent radioactive materials from leaking outside.

For this reason, existing nuclear power plants are equipped with an emergency gas treatment system (SGTS).
rreatn+ent System> is installed.

FIG. 2 shows a schematic configuration of a conventional emergency gas treatment system. In the figure, 1 indicates a nuclear reactor building, in which a nuclear reactor (not shown) is installed. Also, 2 in the diagram
is an air suction pipe that sucks air inside the reactor building 1 by a suction fan 4, and the air sucked from this air suction pipe 2 is introduced into a filter train 5 through an isolation valve 3 and an exhaust fan 4. It has become. Inside this filter train 5, in order from the suction side, a moisture removal device 6, an electric heater 7, a pre-filter 8. Front high performance particle filter9. A charcoal filter 10 for iodine and a post-installation high-performance particle filter 11 are built in, and space heaters 12 are provided in spaces upstream and downstream of the charcoal filter 10 for iodine.

The moisture removal device 6 and the electric heater 7 are used to prevent the efficiency of the front high-performance particle filter 9 and the iodine charcoal filter 10 from decreasing due to moisture. It removes moisture such as steam. In addition, the electric heater 7 heats the air that exits the moisture removal device 6, and since the air that has passed through the moisture removal device 6 is saturated air with a maximum relative humidity of 100%, the relative humidity is reduced to 7o%. Provided to reduce below.

The pre-filter 8 removes coarse particles in the air, and is provided to protect the front high-performance particle filter 9 and the rear high-performance particle filter 11 from decreasing efficiency due to clogging. The front high-performance particle filter 9 and the rear high-performance particle filter 11 are provided upstream and downstream of the iodine charcoal filter 10, respectively, and the front high-performance particle filter 9 removes fine particles in the air. The post-installed high-performance particle filter 11 removes activated carbon particles and the like from the iodine charcoal filter 10.

In addition, the iodine charcoal filter 1o adsorbs and removes radioactive substances such as radioactive iodine contained in the air using activated carbon, and the space heater 12 is used to control the humidity of the iodine charcoal filter 10 during standby operation. It is set in.

The air inside the reactor building 1 introduced into the filter train 5 containing such filters is first removed from moisture such as steam by the moisture removal device 6, then heated and dried by the electric heater 7, and then After the dust in the air is removed by the pre-filter 8 and the pre-high performance particle filter 9,
The iodine charcoal filter 10 adsorbs and removes radioactive substances such as radioactive iodine. The air that has been processed by the filter train 5 passes through the isolation valve 13 and is discharged to the atmosphere from the exhaust pipe 14.

[Problems with background technology]

By the way, in such a conventional emergency gas processing device, the above-mentioned isolation valve 3. Suction fan 4. Filter train 5.
Two isolation valves 13 and the like are provided, forming a two-series configuration. This system has two systems, one of which is used as a backup, in case the fan or heater breaks down for some reason. In this way, for dynamic equipment such as fans, it is necessary to consider redundancy against single failures, but for static equipment such as filter trains, the possibility of loss of functionality due to failure is low, so redundancy is not necessarily considered. There is no need to consider this. For this reason, it is desirable to have a single filter train in order to reduce costs and installation space.
An electric heater 7 and a space heater 12 are built into the filter train 5, and considering a single failure due to disconnection of these heaters, the filter train can be simply
It was difficult to organize them into series.

[Purpose of the invention]

The present invention was developed in view of the above circumstances, and its purpose is to reduce costs and installation space by integrating filter trains into one series, and to reduce costs and installation space.
An object of the present invention is to provide a highly reliable emergency gas treatment device that can reliably prevent leakage of radioactive materials to the outside in the event of a nuclear reactor accident.

[Summary of the Invention] In order to achieve the above object, the present invention provides at least three electric heaters downstream of the moisture removal device, and space heaters are installed in the spaces upstream and downstream of the iodine charcoal filter. The feature is that three or more units are installed in each.

(Embodiments of the invention) Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic configuration diagram of an emergency gas processing apparatus showing an embodiment of the present invention, in which the same parts as in FIG. 2 are given the same reference numerals. The emergency gas processing device according to the present invention includes air suction piping 2. Isolation valve 3. Suction fan 4. Filter train 5. It is composed of an isolation valve 13 and an exhaust pipe 14, and the isolation valve 3. Suction fan 4. The isolation valve 13 is the same as before.
However, the filter train 5 has one base. Inside this filter train 5, a moisture removal device 6. Electric heater 7, pre-filter 8.
Front high performance particle filter9. Iodine layer charcoal filter 10. A rear high-performance particle filter 11 is built-in, and three electric heaters 7 are provided downstream of the moisture removal device 6. Two of the three electric heaters 7a, 7b, and 7G
The electric heaters 7a and 7b are connected to separate power supply systems (A system, B system).
The remaining electric heater 7C is normally not connected to the N source and can be connected to either system. That is, when one of the electric heaters 7a to 7C breaks down, one of the remaining two electric heaters 7b becomes the operating device, and the last electric heater 7C becomes a standby device. It is.

In addition, a total of six space heaters 12, three each, are arranged in the spaces upstream and downstream of the iodine charcoal filter 10.

These space heaters 12a, 12b, 12c.

12a=, 12b-, 12cm are the electric heaters 7a~
Similarly to 7C, two of the three space heaters 12a
, 12b (12a-, 12b-) are connected to separate power supply systems (A
system), and the remaining space heater 12c (
The 12ci is not normally connected to a power source, but can be connected to either system. Therefore, in this case as well, one space heater 12a (when 12ai fails, one of the remaining two space heaters 12t) (12
b') becomes the driving machine, and the latter one space heater 12
c (12cl is a spare machine.

Note that a temperature and pressure detection device (not shown) is provided inside the filter train 5, so that excessive temperature inside the train, clogging of the filter, etc. can be monitored from the outside.

Next, the operation of this embodiment will be explained.

According to the above configuration, the air inside the reactor building 1 is supplied to the air suction pipe 2 by the suction fan 4. Isolation valve 3. The air is introduced into one series of filter trains 5 through a suction fan 4, where radioactive substances and the like in the air are removed, and then passed through an isolation valve 13 and released into the atmosphere from an exhaust pipe 14. In this embodiment, if the electric heater or space heater in the filter train 5 breaks down during operation, there is one spare m7c in addition to the driving machines 7b, 12b, 12b' that replaces the failed machines 7a, 12a, 12a''. , 12c, 12c= remain, so
It becomes possible to operate the nuclear power plant in accordance with the safety regulations and maintain its function as an emergency gas processing device. Note that malfunctioning equipment can be repaired during regular plant inspections.

In this way, in this embodiment, three electric heaters 7a, 7b, and 7c are provided downstream of the moisture removal device @6, and
Three space heaters 12a, 12b are installed in the upstream and downstream spaces of the iodine charcoal filter 10, respectively.
12c, 12a-.

By arranging 12b= and 12C-, it is possible to form the filter train 5 into one series while maintaining the same function as the conventional one. Therefore, according to the present embodiment, only one filter train is required, whereas conventionally two filter trains are required, thereby reducing cost and installation space, and halving the time and effort required for testing and inspecting filters.

In addition, although three electric heaters were provided downstream of the moisture removal device in this embodiment, four or more electric heaters may be provided.

Further, the same effect can be obtained even if four or more space heaters are arranged in the spaces upstream and downstream of the iodine charcoal filter, respectively.

(Effects of the Invention) As is clear from the above description, according to the present invention, at least three electric heaters are provided downstream of the moisture removal device, and space heaters are installed upstream and downstream of the charcoal filter for iodine. By arranging three or more units in each space, it is possible to combine the filter train, which is static equipment, into one series while maintaining high reliability for heaters, which are dynamic equipment. It is possible to obtain an emergency gas treatment device with excellent reliability and safety that can reliably prevent leakage of radioactive materials to the outside in the event of a reactor accident.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of an emergency gas processing device showing an embodiment of the present invention, and FIG. 2 is a schematic diagram of a conventional emergency gas processing device. 1... Reactor building, 2... Air intake piping, 3...
Isolation valve, 4... Suction fan, 5... Filter train, 6... Moisture removal device, 7a-7C... Electric heater, 8... Pre-filter, 9... Pre-high performance Particle filter, 1o...Charcoal filter for iodine, 11
... Post-mounted high-performance particle filter, 12a to 12c, 12
a-~12C'...Space heater, 13...Isolation valve, 14...Exhaust pipe.

Claims (1)

[Claims] Built-in moisture removal device, electric heater, pre-filter, front high performance particle filter, iodine charcoal filter, and rear high performance particle filter in order from the suction side, and upstream and downstream of the iodine charcoal filter. It has a filter train consisting of a space heater arranged in the space of
In an emergency gas treatment system that removes radioactive substances from the air by discharging the air inside the reactor building through the filter train in the event of an accident, the filter train includes at least three electric heaters downstream of the moisture removal system. What is claimed is: 1. An emergency gas processing device having a built-in iodine charcoal filter, and three or more space heaters disposed in spaces upstream and downstream of the iodine charcoal filter.