JPH0337540A - Apparatus for detecting leaking of sodium - Google Patents

Abstract

PURPOSE:To facilitate the attachment and removal of a heat insulating material at the time of installation and after the occurrence of the leakage of Na by providing inlet ports penetrating a pipe support that is to becomes a boundary wall between a cavity part and a space part which are formed at the flange part of the pipe support and an extracting pipe which is guided from the cavity part. CONSTITUTION:A valve 6 is opened when Na flows in a pipe 1 and the presence or absence of the Na leaking from the pipe 1 is detected. When Na is not leaking, air in a space part 4 reaches a detector 7, and there is no detected output. When Na leaks out of the pipe 1, the Na comes contact with the air in the space part 4 and becomes an aerosol state. The Na is detected with a detector 7 by way of an inlet port 12, a cavity part 14 and an extracting pipe 5. The flow rate of the gas into the detector 7 is regulated with a valve 8, and the proper value is kept with a flowmeter 9. The gas whose detection is finished is sent into an exhausting pipe 11 through a gas blower 10. It is necessary to remove a heat insulating material in order to observe the leaking spot visually. Since both the heat insulating material 3 and an interior plate 13 are of a simple cylindrical type, they can be readily attached and removed.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention provides a sodium leakage detection device for detecting leakage from a liquid sodium flow pipe in a sodium-cooled fast breeder reactor plant, etc. Regarding.

(Prior art) For example, in a sodium-cooled fast breeder reactor plant, in the event that sodium leaks from the piping through which liquid sodium, which is the coolant, leaks, it is necessary to promptly detect this and take appropriate measures. These pipes are equipped with sodium leak detection devices.

As shown in FIG. 3, this type of piping passing through liquid sodium is supported by pipe supports 2 provided at intervals, and the outer periphery of the plumber is covered with heat insulating material 3, and the heat insulating material 3 and pipe 1 Space portions 4 are formed at regular intervals between them. If sodium leaks from the pipe ■, it becomes an aerosol in the space 4, so it is transferred to the extraction pipe 5, which is installed to pass through the heat insulating material 3 and communicate with the space 4.
This is detected by a detector 7 inserted into the extraction pipe 5.

Note that the extraction pipe 5 has a first engineering valve 6 and a second valve 8 installed before and after the detector 7, and a flow meter 9 and a blower 10 further downstream, and then reaches an exhaust pipe 11.

(Problem to be Solved by the Invention) In the above-mentioned device, a plumber is installed and then the heat insulating material 3 is attached around it. In order to prevent the gas in the space 4 from leaking through the gap between the two or to prevent the original heat-insulating effect from being impaired, it was necessary to process the two so that they were in close contact with each other, which made the construction work complicated. Furthermore, if sodium leakage is detected, the leakage location must be visually identified, which requires removal and repair work of the heat insulating material 3, but this work is also extremely complicated.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a sodium leakage detection device which overcomes the above-mentioned drawbacks and allows easy installation and removal of a heat insulating material after a sodium leakage occurs.

[Structure of the invention]

(Means for Solving the Problems) The present invention includes pipes through which liquid sodium flows, and each pipe has a part fixed to the pipe in the form of a brim, and is arranged at intervals to support the pipe. A piping support that is made of aluminum and a heat insulating material that surrounds the outer periphery of the pipe at a fixed interval are installed, and the gas that fills the space formed between the pipe and the heat insulating material is extracted and leaked from the pipe. In the sodium leakage detection bag W that detects the presence or absence of lium,
There is a cavity formed in the brim-shaped part of the piping support, a suction hole that penetrates a part of the piping support that serves as a boundary wall between this cavity and the space, and an extraction piping led out from the cavity. has been established.

(Function) When liquid sodium flowing inside the pipe leaks to the surface of the pipe, this sodium reacts with the gas filling the space and becomes an aerosol. When suctioned through the extraction pipe, this aerosol The sodium reaches the cavity from the space through the suction hole and can be taken out via the extraction pipe, so if it is guided to an appropriate detector, it is possible to detect the occurrence of sodium leakage.

Since the extraction piping is led out from the hollow part of the piping support, there is no need to penetrate the heat insulating material, and the presence of the extraction piping does not pose a problem when attaching or removing the heat insulating material after the fact.

(Example) An example of the present invention will be described below with reference to FIGS. 1 and 2.

In FIG. 1, a pipe 1 constituting a flow path for liquid sodium has pipe supports 2 fixed to the outer periphery of a fixed structure at appropriate intervals (for example, several meters to several tens of meters). It is supported by A portion of the piping support 2 that is fixed to the piping 1 extends around the surface of the piping 1 in the form of a brim. A heat insulating material 3 is wrapped around the outer periphery of the plumber, separated by this brim-like overhanging part. The heat insulating material 3 is wound at a certain distance from the surface of the pipe 1, and a space 4 is formed between them.

The details of the part where the piping support 2 is fixed to the piping 1 are as shown in FIG. 2, which is an enlarged view of part A in FIG. A number of suction holes 12, 12 are perforated in the wall 2A of the piping support 2 at the portion between the pipe support 14 and the space 4, respectively. Further, an extraction pipe 5 is connected to this cavity 14.

Note that an end portion of a cylindrical interior plate 13 surrounding the pipe 1 is fixed to the wall 2A by, for example, bolting, and the heat insulating material 3 is adhered to the interior plate 13.

The extraction pipes 5 connected to the cavities 14 of the respective pipe supports 2 are joined together as shown in FIG. 1, and then connected to the detector 7 with a first valve 6 inserted therein. As the detector 7, for example, a radiation ionization detector or a semiconductor type detector can be used.

A second valve 8, a flow rate side 9, and a blower 10 are further inserted into the extraction pipe 5, and then connected to an exhaust pipe 11.

Next, the effect of this will be explained.

When liquid sodium is flowing through the plumber, the first valve 6 is opened when the presence or absence of sodium leaking from the pipe 1 is to be detected. The space 4 is filled with air. In addition to air, for example, nitrogen, argon gas, etc. can also be used instead.

When there is no sodium flow leakage, for example, air within the space 4 reaches the detector 7 as it is, and no detection output is generated at this time. If sodium leaks from the pipe 1, this sodium comes into contact with gas, such as air, in the space 4 and becomes an aerosol, which is detected by the detector 7 via the suction hole 12, the cavity 14, and the extraction pipe 5. information, allowing you to know that a leak has occurred. The gas flow rate to the detector 7 can be maintained at an appropriate value by adjusting the second valve 8 and monitoring the flow meter 9. The gas after the detection operation is sent to the exhaust pipe 11 via the blower 10.

In order to identify the location where the leak actually occurred due to the sodium flow, it is necessary to remove the insulation material 3 and directly visually inspect the surface of the plumber. It has a cylindrical shape, and even if an extraction pipe 5 is present, it can be attached and detached without any hindrance. In addition, the flange of the piping support 2 and the interior plate 13
The contact surface with the heat insulating material 3 is a part where the gas in the space 4 is likely to leak to the outside, but since the suction hole 12 is located close to this, the gas in the space 4 can be efficiently removed. Can be inhaled.

〔Effect of the invention〕

According to the present invention, the installation of sodium distribution piping is carried out at the appropriate time, and in the unlikely event that sodium leaks from the piping, it is detected.
When it becomes necessary to expose the piping surface in order to visually inspect the leak location, it is possible to provide a sodium leak detection device in which the piping heat insulating material can be easily attached and detached.

[Brief explanation of drawings]

Fig. 2 is a sectional view showing an embodiment of the present invention together with a piping connection diagram, Fig. 2 is an enlarged sectional view showing part A in Fig. 1 in detail, and Fig. 3 is a conventional sodium leak diagram. FIG. 2 is a sectional view showing the detection device together with a piping connection diagram. 1... Piping 2... Piping support 3... Heat insulating material 4... Space extraction piping 12... Suction hole 14... Cavity part

Claims (1)

[Claims] 1. Piping through which liquid sodium flows, piping supports that each have a part fixed to the piping in a brim shape and are arranged at intervals to support the piping, and the outer periphery of the piping is spaced at a constant interval. and a heat insulating material surrounding the pipe, the sodium leak detection device detecting the presence or absence of the sodium leaking from the pipe by extracting gas filling a space formed between the pipe and the heat insulating material. In,
A cavity formed in the brim-shaped portion of the piping support, a suction hole penetrating a part of the piping support that serves as a boundary wall between the cavity and the space, and a suction hole led out from the cavity. A sodium leak detection device characterized by being provided with an extraction pipe.