JPS5848051B2 - Sodium leak detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sodium leak detection device.

With the development of fast breeder reactors, the value of liquid sodium as a heat transfer medium is rapidly increasing.

For this reason, the importance of liquid sodium instrumentation has increased, but because liquid sodium is extremely chemically reactive, there are various technical problems in handling it, and there are currently many unresolved problems. It is.

Although the amount of liquid sodium leaking from piping for transporting IJum and tanks for storing high-temperature liquid sodium in Takagata is small, it is feared that if left unchecked, it could lead to a major accident. Therefore, the problem of liquid sodium leakage needs to be resolved as soon as possible.

However, since the amount of liquid sodium that leaks is very small, it is often difficult to detect the leak, and no satisfactory solution has yet been found.

An object of the present invention is to provide a sodium leakage detection device that can detect sodium microleakage at an early stage.

A feature of the present invention is that a first cylindrical body containing liquid sodium is surrounded by a transparent second cylindrical body, and an annular space between the first cylindrical body and the second cylindrical body is A means for making the sodium leaking from the first cylindrical body emit light is disposed in the annular space, and a means for detecting the luminescence of sodium is disposed outside the second cylindrical body.

The present invention will be explained below with reference to FIG. 1 and FIG. 2, which show one embodiment of the present invention.

FIG. 1 is an explanatory diagram of piping for high-temperature liquid sodium.

In FIG. 1, an outer wall 3 is provided outside an inner wall 1 through which high-temperature liquid sodium 2 flows.

The outer wall 3 is made of glass. Note that the outer wall is not limited to being made of glass as long as it is transparent and has an excellent heat insulating effect.

A gap 4 is provided between the outer wall 3 and the inner wall 1, and a vacuum pump 5 is connected to a pipe having a cock 6.
The desired reduced pressure state is maintained.

A heater 7 is spirally provided in the gap to emit light from the sodium leaking from the inner wall, and is connected to an external power source 9 via a joint 8 provided on the outer wall 3. .

Seven phototubes 11 are provided at equal intervals on the outside of the outer wall 3.

The phototube 11 is not particularly limited, but it is preferable to use one that has excellent sensitivity in the yellow wavelength range.

The light tube 11 is connected to an amplifier 12, and an alarm device 13 is connected to the amplifier 12.

In the above embodiment, for example, a crack 1 is formed at a location marked with an x on the inner wall 1.
0 occurs and the liquid sodium inside the inner wall 1 leaks,
Since the gap between the inner wall 1 and the outer wall 30 is under reduced pressure, the leaked liquid sodium turns into vapor at the location marked with an "X", and due to the heat of the heater 7, yellow fluorescence with a wavelength of approximately 589 OA is emitted at the location marked with the "X".

Then, the fluorescent light is detected by the phototube 11, and the output current of the phototube 11 is amplified by the amplifier 12 and sent to the alarm device 13, which activates the alarm device 13.

FIG. 2 is an explanatory diagram showing an embodiment different from the embodiment shown in FIG. 1.

In FIG. 2, an outer wall 3 is provided on the outer wall of the inner wall 1 through which high-temperature liquid sodium 2 flows.

The outer wall 3 is made of glass.

A gap is provided between the outer wall 3 and the inner wall 1, and is maintained at a desired reduced pressure by a vacuum pump 5 connected to a pipe having a stop 6.

In order to cause the sodium leaking from the inner wall to emit light, electrodes, that is, a positive coil 14 and a negative coil 1 are installed in the gap.
5 are provided in a spiral shape at desired intervals, and are connected to the positive side and the negative side of the power source 9, respectively.

Note that the distance between the positive side coil 14 and the negative side coil 15 is preferably made as short as possible in order to reduce the voltage applied to the sodium vapor.

A phototube 11 is provided on the outside of the outer wall 3 and runs along the surface of the outer wall 30.

The phototube 11 is connected to an amplifier 12, and an alarm device 13 is connected to the amplifier.

In the above embodiment, the liquid that leaked from the inner wall 1
The principle of detecting Jum is the same as that of the embodiment shown in Figure 1, but it has the effect of requiring fewer phototubes and amplifiers, and also has the advantage of reducing the number of phototubes and amplifiers, and since the electric field is applied to the sodium vapor using a coil to cause it to emit light, it is possible to detect fluorescent light. Since the light appears strongly, the detection sensitivity of leaked liquid sodium is high.

According to the present invention, it is possible to detect sodium microleakage at an early stage.

[Brief explanation of the drawing]

FIG. 1 and FIG. 2 are explanatory views for explaining different embodiments of the present invention.

Claims (1)

[Claims] 1. A device for detecting leakage of sodium from a first cylindrical body containing sodium, comprising: a transparent second cylindrical body surrounding the first cylindrical body with a gap therebetween; means for making an annular space existing between the first cylindrical body and the second cylindrical body a negative pressure; a means provided in the annular space for causing the sodium leaked into the annular space to emit light; A sodium leakage detection device comprising: a means for detecting the light emission arranged outside the second cylindrical body.