JPS58102199A - Radioactive gaseous waste processing device - 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 invention The present invention relates to radioactive gaseous waste treatment equipment (2).

Technical background of the invention and its problems In a boiling watercolor nuclear power plant, the five gases generated in the reactor core are led together with steam directly through the turbine and into the main condenser. This gas is exhausted to the outside, and a gaseous waste treatment device is provided for the purpose of reducing the radiation level of this exhaust gas.

FIG. 1 is a schematic diagram of a conventional radioactive gas waste treatment apparatus, and first, this radioactive gas waste treatment apparatus will be explained.

The exhaust gas extracted by the air extractor I from the fresh water storage MC is heated in the preheater 2, and the hydrogen and oxygen in the exhaust gas are reacted in the recombiner 3C, and the resulting water is reused within the plant. The temperature of the remaining exhaust gas discharged from the outlet of the recombiner 3 is about 440°C, and most of it is superheated steam. This exhaust gas exchanges heat with the cooling water in the condenser 4C, and at the outlet of the condenser 4 it appears as a non-condensable gas at a relative temperature of about 50° C. and 100%. It is necessary to remove moisture before introducing this exhaust gas into the activated carbon hold-up device 7 In, and for this purpose, a dehumidifier 5. A dehumidifier 6 is provided. removeflil
It 5 dehumidifies the exhaust gas from θ°C to 10°C from the low-temperature refrigerant 42 sent from the cooler IO, and the dehumidifier 6 dehumidifies the exhaust gas from the low-temperature refrigerant from the refrigerator 11 to 1°C to 10°C. It is cooled to -30°C and dehumidified by freezing, but since the water freezes in the dehumidifier b6 and accumulates inside the container, high-temperature refrigerant is introduced into the dehumidifier 6 from the refrigerator 11 to remove dehydration. There are facilities to do so. In this way, the dehumidified exhaust gas is passed through the activated carbon hold-up device 7 to attenuate the radioactive gas that leaks from the fuel, and the treated exhaust gas is discharged through the stack. Two vacuum pumps 8 are provided in order to suck and blow exhaust gas downstream.

By the way, the amount of waste gas flowing in the system downstream of the condenser 4 changes from 4'/l to 40♂/l in a 1.1 million KW class boiling Mito plant depending on the operating condition of the reactor, so the dehumidifier 5 The heat load on the dehumidifier 6C also varies from 1 to 100% of the rating.

In order to cover all of this load range, the cooler 1O and the refrigerator 11 are equipped with a dehumidifier 5 and a dehumidifier I61, and a complicated control mechanism and troublesome adjustment work to control the refrigerant to be sent together with the heat load C2. I was demanded to.

However, compared to the dehumidifying 16Fi dehumidifier 5, the amount of heat exchange is small, about 1, and since the dehumidifying process is performed by freezing, there is no problem even if the exhaust gas is cooled a little too much, and adjustment is relatively easy. On the other hand, if the dehumidifier 5 is cooled too much, moisture will settle inside the container and cause a decline in functionality, so highly accurate temperature control is required, and the amount of heat exchange is large, so vI
The disadvantage of the older sister was that the 4 adjustment was steep and disturbances such as hunting were likely to occur in the cooling cycle under small negative loads (%≦Y).

OBJECTS OF THE INVENTION The present invention solves the above-mentioned drawbacks, and an object thereof is to provide a radioactive gas waste treatment apparatus in which the heat load condition can be stably adjusted and easily adjusted.

Structure of the Invention In order to achieve the above object, the present invention provides a preheater as pretreatment equipment for treating exhaust gas extracted from the main condenser of a boiling water nuclear power plant using an activated carbon hold-up device C. , recombination, condenser.

In a radioactive gas waste processing apparatus equipped with a dehumidifier, a bypass pipe is provided to bypass the exhaust gas from the condenser inlet pipe to the dehumidifier inlet pipe, and the flow rate of the exhaust gas in the bypass pipe is adjusted to the dehumidifier. It is equipped with a control mechanism that controls according to the heat load of the dehumidifier, and this control mechanism receives a signal from a flow rate detector installed in the dehumidifier inlet piping to control the valve installed in the bypass piping. This is a radioactive gas waste treatment equipment.

Examples of the invention An embodiment of the present invention will be explained with reference to FIG. 2.

As shown in FIG. 2C, a bypass pipe 12 is provided so that the condenser inlet pipe 13 and the dehumidifier inlet pipe 14 communicate with each other. This bypass pipe 12 is provided with a valve 15 for adjusting the flow rate of exhaust gas flowing through the bypass pipe 12. Controlled by a controller 171 that controls opening and closing of the valve in response to a signal from a flow rate sensor 16 provided on the dehumidifier inlet pipe 14 upstream from the confluence of the valve 15Fi bypass pipe 12 and the dehumidifier inlet pipe 14. . moreover,
The confluence point of the bypass piping 12 to the dehumidifier inlet piping 14 is where the condensed water condensed in the piping near the dehumidifier 5 is connected to the dehumidifier 5 (
It is placed in a position where it can be guided. In addition, J11!2
Since the configuration other than the above explained with reference to the figure is completely the same as the conventional radioactive gas waste treatment apparatus shown in FIG. 1, the explanation thereof will be omitted.

Operation of the Invention Next, the operation of the radioactive gas waste treatment apparatus configured as described above will be explained.

Now, when the exhaust gas flow rate at the outlet of the condenser 4 decreases, the controller 17 receives a signal from the flow rate detector 16 and the valve 15
Open the condenser 4 and allow the high temperature exhaust gas from flowing into the dehumidifier inlet pipe 14I via the bypass pipe 12 to increase the heat load of the exhaust gas flowing into the dehumidifier 5. , when the exhaust gas flow rate at the outlet of the condenser 4 increases,
The valve 15 closes, and the still hot exhaust gas at the inlet of the condenser 4 no longer flows into the dehumidifier inlet pipe 14. On the other hand, the cooling cycle of the cooler 10 is easily stabilized when the load is +100*. The valve 15 is operated only in a range C2 where the outlet flow rate of the condenser 4 is less than half of the rated flow rate, and is fully closed in the range from medium flow to large flow. Set 12. Even if the valve 15 is fully open at t/i when the flow rate is at the outlet of the condenser 4 within the operating range of the valve 15, the dehumidifier 5
The size of the bypass piping 12 and the condenser input piping 131 is sufficiently smaller than the 131 m of condenser entry piping so that the heat load of the plowed waste in the pipe is smaller than the rated load. In this way, 1: By limiting the operating range of the valve 15, the cooling cycle of the cooler 10 can be easily controlled by controlling the heat load fluctuation range of the dehumidifier 5 without having to control the opening degree of the valve 15 with such high precision. Bistable range C
;The controller 17 can also have a simple structure. Furthermore, the heat load in the condenser 4 is more than 1000 times the heat load in the dehumidifier j+=, and the bypass flow rate is smaller than that in the condenser 4I: the inflowing exhaust gas. Fluctuations in the load on the water dispenser 4 do not pose any problems and do not cause instability of the entire system.

In the embodiment shown in FIG. 2 1 above, the controller 170 control input is the exhaust gas flow rate at the outlet of the condenser 4, but the heat load of the exhaust gas in the system is measured using a heat load measuring device such as an entertameter. In this case, the detection position is set to the dehumidifier 6-input pipe 14 downstream from the confluence of the bypass pipe 12 and the dehumidifier inlet pipe 14, and the heat load at the detection position is kept constant. To control the opening degree of the valve 15 as follows:
The heat load of the exhaust gas flowing into the dehumidifier 5 is controlled to be constant.

As a result, the refrigerant control of the cooler 10 becomes simpler, and the operating state of the cooler 10 can also be kept constant.

Detailed description of the invention 1; Invention I: Therefore, 1 The heat load fluctuation of the exhaust gas flowing through the radioactive gaseous waste treatment equipment can be reduced within a range, so the refrigerant for cooling the exhaust gas in the dehumidifier is used. This makes it easier to adjust the cooling cycle of the cooler that supplies
2, the control mechanism of the chiller can be simplified, and the radioactive gas waste treatment equipment can be made cheaper and more compact.

[Brief explanation of the drawing]

Fig. m1 is a schematic system diagram showing a conventional radioactive gas waste treatment rI & system, and Fig. 2 is a schematic system diagram of a radioactive gas-vehicle processing apparatus showing an embodiment of the present invention.

Claims (1)

[Claims] (1) A preheater and a recombiner are used as pre-treatment equipment to treat waste gas extracted from the main condenser of a boiling water nuclear power plant by covering it with an active vertical hold up device. In a radioactive gas waste treatment equipment C in which two pipes are connected in this order, a dehumidifier, a dehumidifier, and a dehumidifier, bypass piping is used to divert exhaust gas from the condenser entry pipe to the dehumidifier inlet pipe. and a control mechanism for controlling the flow rate of exhaust gas during the Innox distribution according to the heat load of the dehumidifier. The mechanism is characterized in that it receives a signal from the #L lid detector installed in the dehumidifier inlet pipe and controls the valve installed in the inox pipe. A radioactive gaseous waste treatment apparatus according to claim H, item g, and 2.