JPS586433A - Leakage detector of lining tank - Google Patents

Abstract

PURPOSE:To detect assuredly the leakage area, by providing a saucer filled with the leakage detecting object at an opening of the downstream side of plural collecting pipes that collect the leaked liquid. CONSTITUTION:In case when the leakage is caused at a welded line part of a liner plate, the leaked liquid passes through a leakage channel formed to a floor base material and flows into a connected leakage liquid collecting pipe 21 to drop to a saucer 24. The saucer 24 filled with a leakage detecting object 33 which is connected to the leaked liquid and varies its state through a chemical reaction or a physical change. As the saucer containing the object 33 that had a state change can be visually checked, the leakage position can be assuredly confirmed with the lined tanks 1 and 2. Then the leaked water collected in the saucer 24 up to a certain level is flowed into a drain pot 36 through a drain pipe 34. When the leaked water reaches a certain level, an alarm 39 attached to a liquid gauge 38 gives an alarm.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a leakage detection device for a lined storage tank, and in particular to a device that can quickly detect leakage of stored liquid when the inner surface of a concrete container is lined with a metal plate and stored liquid is stored therein. This invention relates to a leak detection device for a lined storage tank.

So-called lined storage tanks, in which the container is made of concrete and lined with metal plates such as stainless steel or synthetic resin plates, are widely used in nuclear power-related facilities, general chemical plants, and the like.

Incidentally, as a storage tank for storing radioactive waste liquid in a nuclear power generation facility, a lined storage tank in which the inner surface of a concrete container is lined with stainless steel is used.

However, if a crack or pinhole occurs in the stainless steel weld and the liquid stored in the storage tank leaks, it will cause environmental pollution, so the leak needs to be detected promptly.

Figure 1 shows an example of a conventionally used leak detection device for lining storage, in which reference numeral 1 diagrammatically indicates a spent fuel storage tank 4, and reference numeral 2 diagrammatically indicates a waste liquid storage tank. However, for convenience of explanation, it is hereinafter referred to as a lining storage tank.

These lining reservoirs 1.2 are not shown.

However, the inner surface of the concrete container is lined with stainless steel plates.

The lining storage tanks 1.2 arranged in parallel each contain stored water 6. , this lined storage tank 1.2
Although not shown in the figure, it has a rectangular parallelepiped shape, but the bottom, side walls, and ceiling are made of concrete, and the interior is lined with stainless steel plates that press against the concrete walls. Piping, such as an overflow pipe, and a discharge pipe are provided on the bottom surface, penetrating the walls.

The bottom of the lining storage tank 1 is formed into an inclined bottom so that the contents that have been stored can be completely and easily transferred out of the tank.

A plurality of leakage liquid collection pipes 4 are connected to the bottom of each lining storage tank 1, 2 at approximately equal intervals, and a block area leak gate valve 5 is connected to each collection pipe 4, respectively.

The downstream side of the plurality of collection pipes 4 is connected to a communication pipe 6,
The downstream side of this communication pipe 6 is connected to a drain bot 8 via a sight glass 7. An overflow pipe 9 is led out from the upper side of the drain bot 8, and the lower fi 111+1 of the overflow pipe 9 is connected to the sump tank 10.

Nao, on the side of Trembot 8 is the liquid level gauge 11 Kabalp 1
2.13 and is also connected via Drainbot 8
A drain pipe 14 is connected to the bottom of the drain pipe 14.
is connected to the overflow pipe 9 via a valve 15, and is also connected to the liquid level gauge 11 and the valve 15.

When a leak occurs from the lining tanks 1 and 2 in the above device, the leaked liquid is collected in the collection pipe 4, passes through the block area leak gate valve 5 and the sight glass 7, and is guided to the drain bot 8. It will be destroyed.

Therefore, leakage liquid from the lining storage tanks 1 and 2 can be detected by using the sight glass 7V*4M. Furthermore, the leaked liquid collected in the Trenbot 8 is measured by the liquid level gauge 1.
1 can be constantly monitored, so a double safety measure has been taken.

The leaked water thus collected in the drainbot 8 is connected to the valve 1 which is connected to the sump tank 1° before overflowing.
It can be drained by opening 5.

The second cause shows another conventional example, which has almost the same structure as in Fig. 1, except that the block area leak gate valve 5 is replaced with a sight glass 7, and the other details are the same as in Fig. 1. The structure is similar, and the means for detecting leaked liquid is also the same as the apparatus shown in FIG.

However, in the case of the example shown in Fig. 1, it is possible to immediately detect the occurrence of a leak, but in order to determine from which block in the storage tank the leak is coming from, it is necessary to separate the leak partitions in each block area each time. The opening and closing operations of the valve 5 have to be performed, and there is a drawback that quick response is extremely lacking.

In addition, in the example shown in Figure 2, if the amount of leakage is extremely small, for example, about one drop per hour, it would be extremely difficult for an operator to visually monitor the sight glass, and detection would be extremely difficult. This method has the disadvantage of being difficult and causing false confirmation.

The present invention was made to eliminate the above-mentioned drawbacks, and it is possible to promptly detect a small amount of liquid leaking from a lined storage tank, and also to reliably detect which part of the storage tank is leaking from. , it is an object of the present invention to provide a leak detection device for a lined storage tank with a simple structure.

That is, the present invention provides a lined storage tank having a lining on the inner surface of the container, a plurality of leakage liquid collection pipes arranged around this storage tank to collect leakage liquid leaking from the lining, and a downstream side of these leakage liquid collection pipes. ip# indicates that the receivers arranged in each opening are equipped with a dish, a leak detection object loaded in each of these receivers, and a drain pipe for discharging the leaked liquid stored in the dish. This is a leak detection device for lined storage tanks.

Hereinafter, one embodiment of the present invention will be explained with reference to FIGS. 3 and 4. FIG. 3 is a system diagram showing one embodiment of the present invention, and FIG. 4 is a system diagram showing the storage tank in FIG. It is a longitudinal cross-sectional view which expands and shows a bottom part partially. Reference numerals 1 and 2 in FIG. 3 indicate a spent fuel storage facility and a radioactive waste liquid storage pool, respectively. (Hereinafter, these will be referred to as pool-lined storage tanks.)
The bottom, side, and ceiling surfaces of the containers constituting the main bodies of the lining storage tanks 1 and 2 are made of concrete, and the stainless steel liner plate lining the concrete surfaces is When pouring the outer concrete wall, it is fixed by welding to the embedded base material after the concrete has hardened.The liner plate is usually a thin stainless steel plate of 3 to 6 mm, and is attached to the lining storage tank. It is pressed against the concrete wall surface by the pressure of the stored liquid 6 in 1 and 2.

The lining storage tanks 1 and 2 are provided with piping such as an inflow pipe and an overflow pipe (not shown) on the side surfaces of the lining storage tanks 1 and 2, and discharge pipes are provided on the bottom surfaces thereof penetrating the walls.

FIG. 4 shows the bottom of such a lining storage tank 1, and 20 is an inclined surface so that the stored liquid 6 that has completed its storage purpose can be completely and easily transferred to the outside of the lining storage tank 1. It shows the flooring material that is said to be The upper surface of the flooring material 20 is covered with a liner plate 21 made of stainless steel, for example, and a drain pipe 22 is provided at the lowest part of the lining storage tank 1. In addition, since the stored liquid 6 is radioactive, a plurality of leaked liquid collection pipes 21 are buried in the flooring material 20 in order to detect the leakage of the stored liquid 6 more strictly. A leak groove 26 is provided to guide the liquid to the leak liquid collection tube 21.

Therefore, if leakage occurs from the welded line portion of the liner plate 21, the leaked liquid passes through the leakage groove 26 provided in the subfloor material 20, and flows into the leakage liquid collecting pipe 21 connected to the leakage groove 26, as shown in FIG. As shown, the receiver provided at the downstream opening of the collection tube 21 falls into the pan 24.

In FIG. 3, a leak detection object 33, such as silica gel or quicklime, which changes its state due to a chemical reaction or physical change when it comes into contact with the leaked liquid, is loaded in the tray 24.

Further, a drain pipe 34 for draining leaked liquid accumulated in the tray 24 is connected to the side of each tray 24. Each drain pipe 64 is connected to a communication pipe 65, and the downstream side of the communication pipe 35 penetrates the lid 37 of the drain bot 66 and opens into the drain bot 66. The drain bot 66 is provided with a liquid level gt38, and a liquid level gauge 68
is connected to the hard alarm device 69.

Further, an oat (-flow pipe 40) is connected to the upper side of the drain bot 66, and an oat (-flow pipe 40) is connected to the upper side of the drain bot 66.
The downstream side of is connected to a sump tank 41.

Further, an outlet pipe 42 is connected to the bottom of the drain bot 66, and a loop 43 is inserted downstream of the outlet pipe 42 and connected to the side surface of the oat flow pipe 40.

In the leak detection device for a lined storage tank configured as described above, when a leak occurs due to a crack in the liner plate 21 of the lining tank 1, 2σ), the leaked liquid is detected in the leakage groove 23.
The leaked liquid is collected, passes through the leakage collection pipe 21, and is sent to the tray 2.
When the leaked liquid falls onto the tray 24, it comes into contact with the leakage detection object 33, and the state of the leakage detection object 33 changes due to a chemical reaction or physical change. Since it is possible to visually see whether the state has changed, it is possible to reliably confirm from which position in the lining storage tank 1.2 the leak is occurring. For example, if silica gel colored blue is used as the leakage detection material 36, the silica gel will react with water and turn red, making it possible to quickly detect leakage.

In this receiver, the pan 24 becomes the first leak detection location.

Next, when a certain amount of leaked water accumulates in the tray 24, the leaked water flows into the drain bot 66 through a drain pipe 64 on the side. This drainbot filter 6 also collects leakage water from other blocks or other lining tanks (not shown), and when the leakage water accumulates to a certain level, an alarm 39 attached to the Eri liquid level gauge 39 Therefore, this alarm 39 becomes the second leak detection location, and even if the receiver misses a leak in the pan 24, it can be detected here. In this state, when IF@ is issued, a portion of the water overflows from the over 7° pipe 40, and the state of the leaked water in the drain bot 66 and the state of the tray 24 are checked, and the valve 46 is opened and the leaked water passes through 42 outlet pipes and reaches the overflow pipe 4o.
The water is drained to the sump tank 41 through the

As explained above, according to the present invention, since a leak detection object is loaded for each leak detection section at the first leak detection location, it is easy to immediately determine which block the leak is coming from. Recognize.

In addition, since even a very small amount of leaked liquid causes a chemical reaction or physical change, leakage can be reliably detected using all five senses, that is, visual inspection, and the reliability of leakage detection can be increased.

Furthermore, even if a leak is missed at the first leak detection location, the leak can be detected at the second leak detection location, so there is a double safety measure in place, and its reliability should be greatly improved.

Note that the present invention is not limited to the above embodiments,
There are no limitations on the shape or quantity of the storage tank.

Furthermore, barium oxide (Bad), strontium oxide (SrO), or the like can be used as the leak detection material, and commonly used liquid level needles and alarms provided on the drainbot can be used.

[Brief explanation of the drawing]

1 and 2 are system diagrams showing a conventional lined storage tank leakage detection device i1, FIG. 3 is a system diagram showing an embodiment of the lining storage tank leakage detection device according to the present invention, and FIG. FIG. 4 is an enlarged vertical cross-sectional view of the bottom of the lining reservoir in FIG. 3; 1.2... Lining storage tank 21... Leakage liquid collection pipe 66... Drain pot 68... Liquid level gauge 42... Outlet pipe 40... Overflow piping 41... Sump tank 33...・Leak detected object 24...Plate 43...Valve (731)) Representative Patent Attorney Noriyoshi Chika (and 1 other person) Figure 1 Figure 2

Claims (1)

[Scope of Claims] 1. A lined storage tank having a lining on the inner surface of the container, a plurality of leak source collection pipes arranged around this storage tank to collect leaked liquid leaking from the lining, and a plurality of leak source collection pipes for collecting leakage liquid leaking from the lining. Each of the receivers arranged at the downstream opening is comprised of a dish, each of these receivers has a leakage detection object loaded in each of the dishes, and each of the receivers has a drain pipe for discharging the leaked liquid stored in the dish. - Leakage detection device for filter-lined storage tank. 2. The leak detection object is characterized by being composed of a substance that undergoes a chemical reaction or a physical change in state when it comes into contact with the leaked liquid.
A leak detection device for a lining storage tank according to claim 1. A drain bot having a liquid level gauge with an alarm is provided on the downstream side of the drain piping, an overflow pipe is connected to the top of the drain bot, an outlet pipe is led out from the bottom of the drain bot, and the drain bot has an overflow pipe connected to the top of the drain bot. A leak detection device for a lining storage tank according to claim 1, wherein the overflow pipe is connected to the overflow pipe via a valve, and the downstream side of the overflow pipe is connected to a sump tank.