JP3362599B2 - Sodium leak prevention thermometer - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sodium thermometer installed in a pipe facility for circulating liquid sodium, and particularly to sodium leakage suitable for preventing liquid sodium from flowing through the thermometer and leaking to the outside. It relates to the prevention thermometer.

[0002]

2. Description of the Related Art Generally, in a fast reactor of a nuclear power plant, liquid sodium is circulated in order to cool high heat generated in the core, and a thermometer for measuring the temperature of sodium is provided in the pipe. is set up.

As shown in FIG. 7, such a sodium thermometer has a thermometer main body 21 having a measuring section 26 therein.
And a terminal storing section 27 attached to the main body 21.

The thermometer main body 21 is formed by sequentially connecting a well portion 22, a connecting pipe 23, a socket portion 24 and a nipple portion 25. The well portion 22 has a tubular shape in which the tip is closed and the other end is opened, and the well socket portion 24 is connected to the other end via a connecting pipe 23.
One end of the nipple portion 25 is attached to the socket portion 24 to form the thermometer main body 21. The terminal storage portion 27 is attached to the other end of the nipple portion 25, and the terminal board 2 is provided inside.
8 and the wiring 9 for connecting the terminal plate 28 and the measuring unit 26
And a wiring (not shown) for drawing a signal from the terminal board 28 to the outside.

The well portion 22 of the thermometer main body 21 is attached to a pipe (not shown) in a piercing state, and the heat of liquid sodium flowing through the pipe is applied to the well portion 22.
The measurement signal of the measurement unit 26 is transmitted to the tip of the measurement unit 26 through the terminal plate 28 of the terminal storage unit 27 and is extracted to the outside. In this case, in order to enhance the measurement sensitivity of the measuring section 26, the tip of the measuring section 26 is urged by the spring force of the spring 29 provided in the nipple section 25 so as to abut the tip of the well section 22. .

On the other hand, a heat insulating material is provided around the pipe (not shown). In addition, in case sodium leaks from the pipe, sodium detecting means (not shown) or the like is provided between the pipe and the heat insulating material.

[0007]

However, in the sodium thermometer of the prior art shown above, when the thermometer main body 21 is damaged, the leakage of liquid sodium flowing through the pipe is not taken into consideration. There is.

That is, in the prior art, when the tip portion of the well portion 22 installed in the pipe of the thermometer main body 21 is damaged for some reason, the liquid sodium flowing in the pipe is indicated by the arrow shown in FIG. As described above, from the inside of the thermometer main body 21 and the measuring portion 26, that is, from the inside of the well portion 22 into the terminal storing portion 27 through the connecting pipe 23, the socket portion 24, and the nipple portion 25, the terminal storing portion 27 is inserted. There is a problem that it leaks to the outside. The liquid sodium leaked to the outside is detected by a detection means (not shown) installed in the atmosphere, but if it is detected after it has leaked, a serious accident may occur.

In view of the above-mentioned problems of the prior art, an object of the present invention is to provide a sodium leakage prevention thermometer capable of reliably preventing the sodium from leaking outside even when liquid sodium enters the inside. To provide.

[0010]

In sodium leakage prevention thermometer of the present invention According to an aspect of, the well portion is attached to pierce the pipe for circulating the liquid sodium, the well
A thermometer having a measuring unit for measuring the temperature of liquid sodium in the pipe in the inner space of the section, a detecting means for detecting the liquid sodium that has entered the interior of the thermometer, the invasion <br/> and input And a leak prevention means for preventing liquid sodium from leaking to the outside.

In the present invention, when the thermometer is installed in the pipe and the portion of the thermometer located in the pipe is damaged for some reason, the liquid sodium in the pipe is put inside the thermometer. As it enters, it tries to leak to the outside through the inside of the thermometer. However, as described above, since the detecting means for detecting the liquid sodium that has entered the inside and the leakage preventing means for preventing the liquid sodium that has entered the inside from leaking to the outside are configured, the leakage preventing means prevents never leaks or internal et outer portion of the total. Moreover, when the detecting means detects the presence of liquid sodium that has penetrated inside, it can be seen that sodium has entered the inside of the thermometer.

Therefore, the sodium leakage prevention thermometer can reliably prevent the liquid sodium from leaking to the outside by the leakage preventing means even if the liquid sodium enters the inside due to the damage of the thermometer or the like. Since it can be detected by the detecting means, it is possible to take prompt action.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIGS. FIG. 1 is an explanatory sectional view showing a first embodiment of a sodium leakage prevention thermometer according to the present invention. In this embodiment, as shown in FIG.
And a terminal storage portion 7 attached to the main body 1.

Although the thermometer body 1 is not shown in detail,
A tubular well portion 2 having a closed end and an opening at the other end, and a connecting pipe 3 having one end connected to the well portion 2.
And a socket portion 4 connected to the other end of the connecting pipe 3, and a nipple portion 5 having one end connected to the socket 4. A measuring section 6 for measuring the temperature of liquid sodium is provided inside the well section 2, the connecting tube 3, the socket section 4, and the nipple section 5. The terminal storage 7 is
Attached to the other end of the nipple portion 5, a terminal plate 8, a wiring 9 for connecting the terminal plate 8 and the measuring portion 6 and a wiring 10 for extracting a signal from the terminal plate 8 to the outside are provided inside. ing. This point is similar to the conventional technique.

In the embodiment, a bellows 11 for urging the tip of the measuring section 6 to contact the tip of the well 2 is provided in the nipple section 5. The bellows 11
Is made of a material having resistance to liquid sodium, for example, made of stainless steel in a bellows shape, and the periphery of one end is fixed to the inner wall of the nipple portion 5 by welding or the like while the measurement portion is inserted thereinto. The periphery of the other end is also fixed to the measuring unit 6 by welding or the like. That is, bellows 1
1, the inner peripheral portion of the nipple portion 5 and the outer peripheral portion of the measuring portion 6 are hermetically sealed. In this case, the bellows 11 urges the tip of the measuring section 6 by its own elastic force so as to abut the tip of the well section 2, and when the well section 2 is installed in a pipe (not shown), the bellows 11 flows through the pipe. The heat of the generated liquid sodium is transferred to the measuring unit 6 via the well unit 2. Therefore, the bellows 11 has a sealing function of preventing liquid sodium that has entered from the well portion 2 from flowing out to the terminal storage portion 7 side, and a spring function of bringing the measuring portion 6 into contact with the well portion 2. .

Further, the nipple portion 5 is provided with sodium detecting means capable of detecting the leaked sodium when sodium leaks into the nipple portion 5. The sodium detecting means is a sodium detector 12 mounted from the outside at a position closer to the well portion 2 than the bellows 11 in the nipple portion 5, and when the sodium detector 12 detects the sodium detector 12, the sodium detector 12 judges it and transmits it to the outside. And a circuit 13. In the sodium detector 12, an electrode is arranged at a position of a hole 5a formed in the outer peripheral portion of the nipple portion 5, and when liquid sodium leaks from the well portion 2 side, the sodium comes into contact with the electrodes and a gap between the electrodes is generated. By short-circuiting, sodium is detected and the occurrence of an abnormality in the well portion 2 is detected.

Since the sodium leakage prevention thermometer of the embodiment is constructed as described above, when the well portion 2 is installed in a pipe (not shown), what portion of the well portion 2 is located inside the pipe is determined. If it is damaged due to, the liquid sodium in the pipe will enter the well part 2, so the nipple part 5
And then leaks to the outside.

However, as described above, since the bellows 11 is airtightly attached between the inner peripheral portion of the nipple portion 5 and the outer peripheral portion of the measuring portion 6, liquid sodium is stored in the nipple portion 5 from the bellows 11 to the terminal storage. It does not enter the part 7 side. Moreover, since the sodium detector 12 is provided at a position closer to the well portion 2 than the bellows 11 in the nipple portion 5, when the detector 12 detects the presence of liquid sodium that has entered the nipple portion 5, the circuit 13 is turned on. A detection signal is transmitted via the so that it can be seen that sodium has entered the thermometer.

Therefore, in the sodium leakage prevention thermometer, even if liquid sodium enters the inside due to damage to the well portion 2 or the like, the bellows 11 prevents the liquid sodium from further advancing, so that the liquid sodium is prevented from leaking to the outside. Since it can be surely prevented and can be detected by the sodium detecting means, it is possible to take prompt measures.

Further, the sodium leakage prevention thermometer is provided with the bellows 11 in terms of internal structure, while the sodium detecting means is provided only in terms of external structure.
It is not necessary to change the structure of the sodium leakage prevention thermometer drastically, and it can be easily manufactured by only changing a part of the conventional product.

FIG. 2 shows a second embodiment of the sodium leakage prevention thermometer according to the present invention. In this case, a bellows 11 is provided between the inner peripheral portion of the nipple portion 5 and the outer peripheral portion of the measuring portion 6, and a sodium detector 12 of sodium detecting means is connected to the terminal plate 8 and The detection wiring 14 is connected to the outside from 8.

Therefore, the terminal housing 7 is provided with an introduction hole 7a for introducing the signal line 12a of the sodium detector 12, while the terminal plate 8 is connected with the signal line 12a and the detection wiring 14. The connecting portion 8a is added. It should be noted that it is preferable to provide a seal member (not shown) or the like capable of blocking the inside and outside of the terminal storage portion 7 when the detection wiring 14 is inserted into the introduction hole 7a of the terminal storage portion 7. Further, the detection wiring 14 is led out from the terminal storage portion 7 like the wiring 10 for the measurement portion.

According to this embodiment, the mounting structure of the bellows 11 and the sodium detector 12 with respect to the nipple portion 5 is the same as that of the first embodiment, so basically the same operational effect can be obtained. You can Further, only the wiring form of the sodium detector 12 is different from that of the first embodiment, the signal line 12a from the sodium detector 12 is connected to the terminal plate 8, and the detection wiring 14 is used for the measuring section. Since it is led out to the outside like the wiring 10, the wiring processing can be integrated, and the wiring work can be simplified accordingly.

FIG. 3 shows a third embodiment according to the present invention. Before describing the embodiments, the terminal storage section 7 will be described. The terminal storage section 7 includes a storage main body 7 having a terminal plate 8.
A and a storage head 7B mounted on the storage body 7A. When the thermometer body 1 is attached to the pipe, the storage body 7A is assembled to the nipple portion 5, the storage head 7B is attached to the storage body 7A, and the fastening portion 17 of the flexible hose 16 for wiring is attached. Are assembled. The fastening portion 17 is connected to one end of the flexible hose 16 and is fastened to the cord insertion portion 7b of the main storage main body 7 so that the storage main body 7 is closed.
Both the internal wiring 10 and the detection wiring 14 are introduced into the flexible hose 16.

In the present embodiment, first, the sodium detector 12 is provided on the terminal plate 8 itself in the terminal housing 7. Further, in the terminal storage section 7, between the storage main body 7A and the storage head 7B, and between the storage main body 7A and the nipple section 5.
The seal means 18A to the space between the cord insertion portion 7b of the storage body 7A and the fastening portion 17 of the flexible hose portion 16.
18C is provided.

That is, the sealing means 18A to 18C are both O-rings in this example to shut off the inside and outside. The seal 18A on one side is used for the terminal storage portion 7
When the storage head 7B and the storage main body 7A are assembled, the storage head 7B is embedded in a position where the storage head 7B comes into contact with the storage main body 7A, and an assembled portion between the both is hermetically sealed. The sealing means 18B is the fastening portion 1 of the flexible hose 16.
7 is embedded inside the storage main body 7A for fastening, and when the fastening portion 17 is fastened to the storage main body 7A, the fastening portion between the two is hermetically sealed. The sealing means 18C is embedded in the nipple portion 5 at a position where it is connected to the storage body 7A,
When the nipple portion 5 and the storage main body 7A are connected, the connecting portion between them is hermetically sealed.

According to this embodiment, the sodium detector 12 is provided in the terminal storage portion 7, and the terminal storage portion 7 itself is sealed inside and outside by the sealing means 18A and at the same time as the terminal storage portion 7. Since the sealing means 18B and 18C hermetically seal between the nipple portion 5 attached to this and the fastening portion 17 of the flexible hose 16, the liquid sodium in the pipe passes through the well portion 2 and the nipple portion 5 to store the terminal. When it flows into the portion 7, it can be prevented from leaking to the outside from the terminal storing portion 7. Therefore, even if liquid sodium enters the inside of the thermometer, there is no risk of leaking to the outside of the thermometer, and Since the presence or absence of liquid sodium can be detected by the sodium detector 12, it can be seen that sodium has entered the inside of the thermometer.

4 to 6 show another embodiment of the thermometer according to the present invention. In this example, the sodium detector is constructed as follows. That is, in the measuring section 6, the compensation lead wire 6a in the middle of the nipple section 5
6b is exposed, and the exposed portions of the compensation conductors 6a and 6b are supported by the ceramics portion 19. Compensation lead wire 6
Reference characters a and 6b constitute a measuring unit 6 for measuring the sodium temperature. The ceramics portion 19 is composed of the compensating lead wires 6a, 6
It is formed by cutting out so that b is exposed in the internal space of the nipple portion 5. Then, when the liquid sodium in the pipe enters the nipple portion 5 and touches the compensating conductors 6a and 6b, when the temperature measured by the compensating conductors 6a and 6b decreases from T0 to TL as shown in FIG. By doing so, the inflow of liquid sodium can be determined by sensing it through the wiring 10 by a monitoring means (not shown). This is because when the measuring unit 6 measures the temperature of the liquid sodium in the pipe through the well portion 2 in a normal state, it shows a high temperature indicated value as shown in FIG. 6, but the pressure of the liquid sodium in the pipe is Since the temperature is low, the liquid sodium flows into the well 2 and the nipple portion 5 while being cooled to the surroundings, and also flows after a certain period of time, so that the temperature becomes low.

Therefore, by monitoring the change in the temperature measured by the measuring unit 6, it is possible to determine whether or not the liquid sodium has entered the thermometer main body 1.

Further, in the nipple portion 5, a protrusion 5b also serving as a seal is provided projecting from the ceramic portion 19 of the measuring portion 6 so as to lock the head portion 6c at the upper end portion.
As shown in, the liquid sodium that has entered the nipple portion 5 is prevented from flowing into the terminal storage portion 7 side, and the tip of the measuring portion 6 is positioned at the tip portion of the well portion 2. Therefore, since the tip of the measuring section 6 is located at the tip of the well section 2, the temperature of the liquid sodium flowing in the pipe can be measured with good sensitivity.

Further, in each of the embodiments described above, since the detector for detecting sodium by directly contacting with liquid sodium is used, the leaked and aerosolized sodium is inhaled to a predetermined position and the inhaled. Compared to a non-contact type detector having a structure configured to detect sodium, the structure of the detector itself can be simplified and can be manufactured in a small size and at a low cost.
Moreover, it can be easily installed in either the thermometer main body 1 or the terminal storage portion 7.

[0032]

As described above, the claims 1 to 3 of the present invention are as follows.
According to claim 5 , since it has a detecting means for detecting the liquid sodium that has entered the inside of the thermometer body and a leakage preventing means for preventing the liquid sodium that has entered the internal space from leaking to the outside, (1) the thermometer body The liquid sodium that invades inside due to the damage to the inside of the pipe can be detected early by the detection means as in the case of detecting leaked sodium due to the damage to the normal piping section. Although many are installed, it is possible to identify which thermometer the liquid sodium has invaded by the detection means, and (3) even if liquid sodium invades, it can be leaked to the outside by the leakage prevention means. Absent.

Therefore, according to the present invention, the soundness of the liquid sodium flow equipment can be ensured, and the reliability of preventing leakage of sodium into the atmosphere can be improved.

[Brief description of drawings]

FIG. 1 is a partially broken cross-sectional explanatory view showing a first embodiment of a sodium leakage prevention thermometer according to the present invention.

FIG. 2 is an explanatory view showing a second embodiment of a sodium leakage prevention thermometer according to the present invention.

FIG. 3 is an explanatory view showing a third embodiment of a sodium leakage prevention thermometer according to the present invention.

FIG. 4 is an explanatory view showing another embodiment of the sodium leakage prevention thermometer according to the present invention.

FIG. 5 is a cross-sectional view of essential parts showing the positional relationship between the tip of the thermometer main body and the tip of the measurement unit.

FIG. 6 is an explanatory diagram showing the relationship between the temperature indicated by the thermometer and the time when the well portion is damaged.

FIG. 7 is an explanatory cross-sectional view showing a conventional thermometer.

[Explanation of symbols]

1 ... Thermometer main body, 2 ... Well part, 3 ... Connection pipe, 4 ... Socket part, 5 ... Nipple part, 6 ... Measuring part, 7 ... Terminal storage part, 8 ... Terminal plate, 11 ... Bellows, 12 ... Sodium detection Container, 13 ... Circuit, 18A-18C ... Sealing means, 6
a, 6b ... Compensation lead wire that constitutes the measurement unit.

Front Page Continuation (72) Inventor Sadao Mizuno 1-1-1, Sachimachi, Hitachi City, Ibaraki Hitachi Ltd. Hitachi factory (72) Inventor Yasuo Tate 3-1-1, Sachimachi, Hitachi City, Ibaraki Company Hitachi, Ltd. Hitachi factory (56) Reference JP-A-4-174329 (JP, A) JP-A-5-312656 (JP, A) JP-A-56-79935 (JP, A) Actual development Sho-51-123855 (JP, U) Actual development Sho 61-114338 (JP, U) Actual public Sho 52-45254 (JP, Y2) (58) Fields investigated (Int.Cl. ⁷ , DB name) G01K 1 / 00-13 / 02 G21C 17/02 GDF

Claims (5)

(57) [Claims] 1. A well unit is attached to pierce the pipe for circulating the liquid sodium, a thermometer having a measuring unit for measuring the temperature of liquid sodium in the pipe into the internal space of the well portion, the temperature sodium leakage prevention thermometer, characterized in that it comprises detecting means for detecting the liquid sodium that has entered the interior of the meter, and a leakage preventing means for the invading liquid sodium is prevented from leaking to the outside. Wherein the well portion is attached to pierce the pipe for circulating the liquid sodium, the temperature gauge body having a measuring unit for measuring the temperature of liquid sodium in the pipe within the well portion, the temperature gauge body a thermometer and a terminal storage portion attached to, entering inside the thermometer body
Leakage prevention hand to prevent the leaked liquid sodium from leaking outside
The leakage prevention means has a step, and the leakage prevention means is an inner peripheral portion of the thermometer body.
It is attached airtight between the outer circumference of the measuring unit and the
Energize the tip to the tip located inside the pipe of the thermometer body.
The bellows and the wafer.
Liquid that has penetrated inside the thermometer body between the
A sodium leakage prevention thermometer, which is provided with a detection unit for detecting a sodium. Wherein the well portion is attached to pierce the pipe for circulating the liquid sodium, the temperature gauge body having a measuring unit for measuring the temperature of liquid sodium in the pipe within the well portion, the temperature gauge body A thermometer having a terminal storing part attached to a thermometer main body or a terminal storing part.
Has a detecting means for detecting the liquid sodium that has entered the inside, the liquid sodium that has entered into the interior and leakage means to prevent the leaking out, the sodium detection means mounted externally to the thermometer body A sodium leakage prevention thermometer, comprising a detector and a detector installed inside the terminal housing. 4. A well unit is attached to pierce the pipe for circulating the liquid sodium, the temperature gauge body having a measuring unit for measuring the temperature of liquid sodium in the pipe within the well portion, the temperature gauge body a thermometer and a terminal storage unit attached to the leakage preventing and detecting means for detecting the liquid sodium that has entered the interior of the thermometer body, the liquid sodium that has penetrated to the inside from leaking to the outside The leakage prevention means is provided so as to project from the inner peripheral portion of the thermometer body, and the leakage prevention means of the measurement portion is positioned with the tip of the measurement portion positioned at the tip of the thermometer body. The other end is composed of a seal-cum-protrusion that can be airtightly locked, and the detecting means forms a detector by exposing a compensating lead wire in the middle of the seal-cum-protrusion in the measuring unit to the inside of the thermometer main body, and measuring. The measured temperature of Sodium leakage prevention thermometer, characterized in that it comprises means for determining the penetration of liquid sodium at this point. 5. The sodium leakage prevention according to any one of claims 1 to 4, wherein the detector of the detection means has a contact type structure for detecting liquid sodium by contacting with liquid sodium. thermometer.