JP2002267786A - Radiation monitor for high-temperature water - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the breakage of NaI crystal by the application of a stress to the part fixed to a detector thereof in the occurrence of a sudden temperature change in the detector in a radiation monitor for high-temperature water for measuring radiation in a high-temperature solution which uses the NaI crystal in the detection part of the detector. SOLUTION: This radiation monitor for high-temperature water comprises the detector and a well containing the detector and in contact with the high- temperature solution. A means for thermally insulating the detector from a system to be measured and moderating the time change of the temperature to prevent a sudden temperature change is added to the detector.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a radiation hot water monitor for measuring radiation in a high temperature solution.

[0002]

2. Description of the Related Art In a conventional radiation high-temperature water monitor, a well for accommodating a detector is provided in a container for a high-temperature solution, and the detector is inserted into the well for measurement. A NaI crystal is used for the detection part of the detector, and when the temperature of the detector suddenly changes, stress is applied to the fixed part of the detector and the NaI crystal may be damaged.

On the other hand, in order to control the temperature change of the solution to a certain level or less, a technique that is difficult in plant control is required. Therefore, it is necessary to reduce the temporal temperature change rate on the detector including the detector holding structure. Therefore, it is desired to prevent a rapid temperature change.

[0004]

As described above, the conventional radiation high-temperature water monitor may damage the NaI crystal used in the detector when a rapid temperature change occurs. The measurement could not be performed reliably and reliably.

The present invention eliminates the above drawbacks and reduces the temperature change on the detector side, thereby preventing breakage of the NaI crystal used in the detector and ensuring reliability even under difficult temperature control conditions. An object of the present invention is to provide a radiation high-temperature water monitor capable of performing high, stable and reliable radiation measurement.

[0006]

In order to achieve the above object, in a high-temperature water radiation monitor according to the present invention, a detector according to the first aspect of the present invention, and a detector containing the detector and contacting the high-temperature solution are provided. And a vacuum layer is formed by evacuating the space between the detector and the well. This prevents well temperature changes from being interrupted by the vacuum layer and transmitted to the detector.

According to a second aspect of the present invention, there is provided a detector and a well containing the detector and being in contact with a high-temperature solution. In order to increase the heat capacity of the detector head, radiation is applied between the detector and the well. (Gamma rays) The heat sink is made of a material with low shielding effect and high specific heat. With this configuration, the temperature change time constant of the detector becomes longer due to the magnitude of the specific heat of the heat sink, thereby preventing damage to the detector.

According to a third aspect of the present invention, the detector comprises a detector and a well containing the detector and being in contact with a high-temperature solution. The well and the detector are vacuum-insulated, and refrigerant or the like is contained in the detector container itself. It is characterized by being circulated and cooled. By doing so, it is possible to prevent the temperature of the detector from rising due to the circulation operation of the refrigerant.

According to a fourth aspect of the present invention, a cooling gas outlet nozzle is provided at a tip of the detector, and a well containing the detector and containing the detector and in contact with a high-temperature solution. Is a return passage for the cooling gas. By doing so, the change in temperature of the detector can be reduced by the cooling action of the cooling gas, and damage to the detector can be prevented.

According to a fifth aspect of the present invention, the detector comprises a detector, a well containing the detector, and a well in contact with a high-temperature solution. The well and the detector are vacuum-insulated, and the detector is provided with an electronic cooling device. The detector is provided to cool the detector. By doing so, the heat of the detector can be released to the outside, the temperature change can be reduced, and damage to the detector can be prevented.

According to a sixth aspect of the present invention, there is provided a detector comprising a detector, a well containing the detector, and a well in contact with a high-temperature solution. The well and the detector are vacuum-insulated, and a heat pipe is provided in the detector. , The detector is cooled. By doing so, the heat of the detector can be released to the outside, the temperature change can be reduced, and the detector can be prevented from being damaged.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a radiation high-temperature water monitor according to an embodiment of the present invention.

FIG. 1 shows a configuration of a radiation high-temperature water monitor according to a first embodiment of the present invention. The inside of the well 2 containing the detector 5 using the NaI crystal is evacuated to prevent the temperature change of the well directly in contact with the high-temperature solution 6 from being transmitted to the detector 5 due to the heat conduction of the air. The material of the vessel 5 itself and the fixing material are also made of stainless steel having a low thermal conductivity. Alternatively, the inner surface of the well 2 and the outer surface of the detector 5 are smoothed and subjected to a surface treatment such as chrome plating to reduce the radiation coefficient, and are further fixed via an insulator 4 having high thermal insulation. By doing so, it is difficult to conduct heat.

Next, a radiation hot water monitor according to a second embodiment of the present invention will be described with reference to FIG. Na of detector 5
For a detector head with an I crystal, a material with a low shielding effect against radiation (gamma rays) and a high specific heat (eg, water)
Is used as heat sink 9. With such a structure, the heat capacity of the detector head can be increased, and as a result, the time constant of the temperature change of the detector 5 becomes longer, and damage to the detector 5 can be prevented.

FIG. 3 shows a configuration of a radiation high-temperature water monitor according to a third embodiment of the present invention. In this embodiment, the well 2
And the detector 5 are vacuum-insulated 7 and the refrigerant 1
0 is circulated for cooling. With this method, the detector 5
Can be reduced, and damage to the detector 5 can be prevented.

FIG. 4 shows a configuration of a radiation high-temperature water monitor according to a fourth embodiment of the present invention. A cooling gas outlet nozzle 11 is provided at the tip of the detector 5, and a gap between the detector 5 and the well 2 is used as a return passage of the cooling gas 16. With this structure, the temperature change of the detector 5 can be reduced. Further, a thermocouple thermometer 12 is arranged at the tip of the detector 5,
The temperature is stabilized by controlling the flow rate of the cooling gas 16 and keeping the temperature constant. On the other hand, by using aluminum for the detector container, the heat conduction can be improved, and the shielding effect against radiation (gamma rays) can be reduced.

FIG. 5 shows a configuration of a radiation high-temperature water monitor according to a fifth embodiment of the present invention. Vacuum insulation 7 is provided between the well 2 and the detector 5, an electronic cooling device 13 is provided in the detector, and heat is released to the upper part of the detector by the radiation fins 14. By doing so, the temperature change of the detector is reduced. Further, by using aluminum for the detector container, heat conduction is improved, and the cooling effect can be enhanced by bringing the electronic cooling device into contact with the detector container.

FIG. 6 shows a configuration of a radiation high-temperature water monitor according to a sixth embodiment of the present invention. A vacuum insulation 7 is provided between the well 2 and the detector 5, and a heat pipe 15 is provided in the detector 5 so that heat is released to the upper part of the detector. By doing so, the temperature change of the detector is reduced. Furthermore, by using aluminum for the detector container, heat conduction is improved, and the cooling effect can be enhanced by bringing the detector container into contact with the heat pipe.

[0019]

As described above, according to the present invention, the temperature change on the detector side is reduced to prevent breakage of the NaI crystal used in the detector, and the reliability is improved even under difficult conditions for temperature control. Therefore, it is possible to provide a radiation high-temperature water monitor capable of stably and surely performing radiation measurement.

The present invention is not limited to the above embodiment, but can be implemented in various ways without changing the gist of the present invention.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a radiation high-temperature water monitor according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a radiation high-temperature water monitor according to a second embodiment of the present invention.

FIG. 3 is a configuration diagram of a radiation high-temperature water monitor according to a third embodiment of the present invention.

FIG. 4 is a construction drawing of boiled radiation high-temperature water according to the fourth embodiment of the present invention.

FIG. 5 is a configuration diagram of a radiation high-temperature water monitor according to a fifth embodiment of the present invention.

FIG. 6 is a configuration diagram of a radiation high-temperature water monitor according to a sixth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Solution container 2 ... Well 5 ... Detector 6 ... Solution 7 ... Vacuum insulation 9 ... Heat sink 10 ... Refrigerant 11 ... Cooling gas outlet nozzle 13 ... Electronic cooling device 14 ... Radiation fin 15 ... Heat pipe

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Naotaka Oda 8 Shinsugita-cho, Isogo-ku, Yokohama-shi, Kanagawa Prefecture F-term in Toshiba Yokohama Office 2G075 CA40 DA08 FA18 FC14 GA05 2G088 EE13 JJ09

Claims (6)

[Claims] 1. A radiation high-temperature water monitor comprising a detector and a well containing the detector and being in contact with a high-temperature solution, wherein the space between the detector and the well is evacuated. 2. A detector, comprising a detector and a well in which the detector is housed and which is in contact with a high-temperature solution. In order to increase the heat capacity of the detector head, shielding between the detector and the well against radiation (gamma rays). A radiation hot water monitor characterized by comprising a heat sink made of a material with a small effect and a large specific heat. 3. A detector, comprising a detector and a well in which the detector is housed and in contact with a high-temperature solution. The well and the detector are vacuum-insulated, and the detector container itself is cooled by circulating a refrigerant or the like. Radiation high-temperature water monitor characterized by the point. 4. A cooling gas outlet nozzle is provided at a tip of the detector, the cooling gas outlet nozzle being provided at a tip of the detector, and a return of the cooling gas is provided between the detector and the well. A radiation high-temperature water monitor characterized by minimizing a temperature change of a detector by using a structure as a passage to prevent damage to the detector. 5. A detector comprising: a detector; a well containing the detector; and a well in contact with the high-temperature solution. The well and the detector are vacuum-insulated, and the detector is provided with an electronic cooling device. A radiation high-temperature water monitor characterized by cooling. 6. A detector, comprising a detector and a well in which the detector is housed and which is in contact with a high-temperature solution. A vacuum is insulated between the well and the detector, a heat pipe is provided in the detector, and the detector is cooled. A radiation high-temperature water monitor characterized in that: