JP6585463B2 - Hydrogen concentration measuring device for nuclear facilities - Google Patents

Description

  Embodiments described herein relate generally to a hydrogen concentration measuring element and a hydrogen concentration measuring apparatus for a nuclear facility.

  Generally, hydrogen concentration measuring devices include devices that employ measuring methods such as a catalytic combustion type and a semiconductor type.

  As the catalytic combustion type, there is a technology that detects the hydrogen concentration by using the resistance value of a resistance meter (thermistor) that arises from the temperature change using combustion heat on the catalyst that promotes the combustion of hydrogen and oxygen. . As a semiconductor type, there is a technique that uses a change in electric resistance value by utilizing a change in carrier density on a semiconductor surface such as tin oxide due to adsorption of a reducing gas.

  In addition, hydrogen concentration measurement technology for nuclear power plants focuses on volume expansion due to hydrogen absorption of palladium, focuses on changes in scattered light when light of a specific wavelength is incident through an optical fiber, and electricity on hydrogen storage materials. There is a technology that focuses on resistance.

JP 2013-76605 A

  At the time of a severe accident at a nuclear power plant, the temperature and gas composition in the reactor containment vessel vary depending on the reactor type and accident mode, and therefore the hydrogen concentration measuring device needs to be able to operate in various environments.

  According to the technique using the electric resistance value of the hydrogen storage material, palladium having high catalytic activity is used as the hydrogen storage material. Therefore, when oxygen, iodine, or the like in the reactor containment vessel is present, the hydrogen storage material is easily affected and it is difficult to stably measure the hydrogen concentration.

  A problem to be solved by the present invention is a technique for measuring a hydrogen concentration using an electric resistance value of a hydrogen storage material, a hydrogen concentration measuring element for a nuclear facility capable of outputting an accurate electric resistance value representing the hydrogen concentration, and It is to provide a hydrogen concentration measuring device.

  The hydrogen concentration measuring element for a nuclear facility according to this embodiment includes a detection unit and a fixing unit. The detection part was covered with a protective coating layer having hydrogen permeability on a metal wire having a hydrogen storage capacity whose electrical resistance value changes due to hydrogen storage. The fixing unit fixes the detection unit.

  According to the hydrogen concentration measuring element and the hydrogen concentration measuring device for a nuclear facility according to the embodiment of the present invention, in the technique of measuring the hydrogen concentration using the electric resistance value of the hydrogen storage material, the electric power with high accuracy representing the hydrogen concentration is obtained. The resistance value can be output.

Schematic which shows the environment where the hydrogen concentration measuring apparatus for nuclear facilities which concerns on 1st Embodiment is installed. The external view which shows the structure of a hydrogen concentration measuring element. (A), (B) is a figure which shows the structure of a detection part. The figure which shows the heater which heats a hydrogen concentration measuring element. Schematic which shows the environment where the hydrogen concentration measuring apparatus for nuclear facilities which concerns on 2nd Embodiment is installed. The external view which shows the structure of a hydrogen concentration measuring element. (A), (B) is a figure which shows the structure of a reference detection part. The graph which shows the example of a behavior of the electrical resistance value at the time of hydrogen and oxygen supply in the metal wire which is not coat | covered with the protective coating layer. The graph which shows the example of a behavior of the electrical resistance value at the time of hydrogen and oxygen supply in the metal wire with which the protective coating layer was coat | covered. (A), (B) is a figure which shows the protective container which can accommodate a hydrogen concentration measuring element. The figure which shows the protective container in which the hydrogen concentration measuring element was accommodated.

  A hydrogen concentration measuring element and a hydrogen concentration measuring apparatus for a nuclear facility according to this embodiment will be described with reference to the accompanying drawings.

(First embodiment)
1. Configuration FIG. 1 is a schematic view showing an environment in which a hydrogen concentration measuring apparatus for a nuclear facility according to a first embodiment is installed.

  FIG. 1 shows a location in a nuclear power plant where hydrogen concentration is measured (monitored), for example, a reactor containment vessel 1 and a hydrogen concentration measuring device 10 that measures the hydrogen concentration in the reactor containment vessel 1. .

  The reactor containment vessel 1 stores all the facilities of a nuclear reactor (not shown) and a primary cooling system (not shown).

  The hydrogen concentration measuring device 10 includes a hydrogen concentration measuring element 11, a resistor (tester) 12, a control unit 13, and a heater 14 (shown in FIG. 4).

  The hydrogen concentration measuring element 11 includes a metal wire having a hydrogen storage capability in which an electrical resistance value changes due to hydrogen storage, and a protective coating layer that covers the metal wire and has hydrogen permeability. A specific structure of the hydrogen concentration measuring element 11 will be described later with reference to FIGS. 2 and 3A and 3B.

  The resistor 12 measures the electric resistance value of the metal wire by causing a current to flow through the metal wire 51 (shown in FIGS. 3A and 3B) of the hydrogen concentration measuring element 11. As the resistor 12, a known one is applied. However, when a resistance measuring method other than the four-terminal method (for example, the two-terminal method, Wheatstone bridge) is adopted as the resistor 12, each measuring method is used. The one suitable for is applied.

  The control unit 13 includes a CPU (central processing unit) and a memory. The control unit 13 calculates the hydrogen concentration based on the electrical resistance value measured by the resistor 12. For example, the control unit 13 calculates the hydrogen concentration corresponding to the electrical resistance value measured by the resistor 12 based on the correlation equation between the hydrogen concentration and the electrical resistance value acquired in advance.

  Further, the control unit 13 controls the temperature of the hydrogen concentration measuring element 11 by controlling the operation of a heater 14 (shown in FIG. 4) for heating the hydrogen concentration measuring element 11. It is known that when a hydrogen storage material, which is a metal having a hydrogen storage capability, is generally used near room temperature, the rate of taking up hydrogen and the rate of releasing hydrogen are not sufficient. Since the detection unit 31 used in the hydrogen concentration measuring element 11 is desirably used at a temperature of 200 [° C.] or higher, the control unit 13 controls the operation of the heater 14 so that the hydrogen concentration measuring element 11 is 200 [ [° C.]

  FIG. 2 is an external view showing the structure of the hydrogen concentration measuring element 11.

  As shown in FIG. 2, the hydrogen concentration measuring element 11 includes a detection unit 31, a fixing unit 32, and a connection unit 33.

  The detection unit 31 is arranged so as to be spirally wound on the outer surface of the fixed unit 32.

  3A and 3B are diagrams showing the structure of the detection unit 31. FIG. FIG. 3A is a longitudinal sectional view of the detection unit 31. FIG. 3B is a transverse sectional view of the detection unit 31.

  As shown in FIGS. 3A and 3B, the detection unit 31 includes a metal wire 51 and a protective coating layer 52.

  The metal wire 51 contains at least one of palladium and niobium and has a hydrogen storage capacity. The diameter of the metal wire 51 having hydrogen storage capacity is not particularly limited, and may be about 1 [μm] or more and 1000 [μm] or less.

  The protective coating layer 52 includes at least one of oxides, nitrides, and carbides of silicon or aluminum, and is made of an inorganic material that can selectively permeate hydrogen. The thickness of the protective coating layer 52 is preferably 5 [nm] or more and 200 [nm] or less. When the thickness of the protective coating layer 52 is 5 [nm] or more, the effect of preventing the progress of side reactions caused by chemical species derived from the external air layer such as oxygen and iodine is remarkably exhibited. Moreover, when the thickness of the protective coating layer 52 is 200 nm or less, the hydrogen permeability is excellent.

  Here, the detection part 31 is produced | generated by apply | coating or vapor-depositing the protective coating layer 52 to the metal wire 51 which has hydrogen storage capability. As a method of applying or vapor-depositing, general methods such as CVD (Chemical Vapor Deposition), PVD (Physical Vapor Deposition), sol-gel method, and impregnation method are used. In addition, it is generally known that the detection unit 31 generated by the above method is used after heat treatment is performed at 350 [° C.] or more and 500 [° C.] or less.

  Returning to the description of FIG. 2, the fixing portion 32 is made of an insulating material such as ceramics and glass, and is used for fixing (supporting) and insulating the detection portion 31. Although FIG. 2 illustrates the case where the fixing portion 32 has a cylindrical shape, the fixing portion 32 does not necessarily have a cylindrical shape. That is, it is not necessary for the entire fixing portion 32 to be made of the same material. When the fixing | fixed part 32 has a cylindrical shape, the fixing | fixed part 32 can take the structure of including a heater in the interior space as an alternative of the heater 14 (illustrated in FIG. 4) or with the heater 14. FIG. Moreover, when the fixing | fixed part 32 has a cylindrical shape, the fixing | fixed part 32 can take the structure which encloses an electrical wiring in the interior space.

  The connection part 33 functions as a terminal for measuring the electrical resistance value of the metal wire 51 (shown in FIGS. 3A and 3B) of the detection part 31 while fixing the detection part 31 to the fixing part 32. To do. 2 shows an example in which the connection portion 33 is installed on the outer surface of the side surface of the fixed portion 32, but the connection portion 33 may be installed on the inner surface of the side surface of the fixed portion 32.

  FIG. 4 is a diagram showing a heater for heating the hydrogen concentration measuring element 11.

  As shown in FIG. 4, the heater 14 for heating the hydrogen concentration measuring element 11 is arranged so as to cover the outer surface of the side surface of the hydrogen concentration measuring element 11.

2. Action In the hydrogen concentration measuring apparatus 10, the temperature of the hydrogen concentration measuring element 11 is controlled to 200 ° C. or more by the heater 14. In this state, the electrical resistance value of the metal wire 51 covered with the protective coating layer 52 is sequentially measured by the resistor 12 connected to the connection portion 33 of the hydrogen concentration measuring element 11. Here, when the metal wire 51 absorbs hydrogen, the phenomenon that the electric resistance value increases is used. Based on the correlation equation between the hydrogen concentration and the electrical resistance value acquired in advance and the electrical resistance value of the metal wire 51, the control unit 13 sequentially calculates the hydrogen concentration.

  Since the metal wire 51 is covered with the protective coating layer 52, it is possible to avoid direct contact between the metal wire 51 and the external gas phase during the measurement of the hydrogen concentration. Therefore, it is possible to prevent the side reaction from proceeding due to the metal wire 51 and the chemical species derived from the external gas phase such as oxygen and iodine.

3. Effect According to the hydrogen concentration measuring element 11 for a nuclear facility according to the first embodiment, in the technique for measuring the hydrogen concentration using the electrical resistance value of the hydrogen storage material, a wide range of gas phase composition corresponding to the case of a severe nuclear accident. Thus, it is possible to output an accurate electric resistance value representing the hydrogen concentration. Moreover, according to the hydrogen concentration measuring apparatus 10 for a nuclear facility according to the first embodiment, the hydrogen concentration can be accurately measured with a wide gas phase composition corresponding to a nuclear accident.

(Second Embodiment)
1. Configuration FIG. 5 is a schematic view showing an environment in which a hydrogen concentration measuring apparatus for a nuclear facility according to the second embodiment is installed.

  FIG. 5 shows a hydrogen concentration measuring apparatus 10 </ b> A that measures the hydrogen concentration in the reactor containment vessel 1. The hydrogen concentration measuring device 10A includes a hydrogen concentration measuring element 11A, resistors 12, 12A, a control unit 13A, and a heater 14 (shown in FIG. 4). In FIG. 5, the same members as those shown in FIG.

  The resistor 12A measures the electric resistance value of the metal wire 51A by passing a current through the metal wire 51A (illustrated in FIGS. 7A and 7B) of the hydrogen concentration measuring element 11A.

  The control unit 13A includes a CPU, a memory, and the like, like the control unit 13 illustrated in FIG. The controller 13A calculates the hydrogen concentration based on the electric resistance values measured by the resistors 12 and 12A, respectively.

  Further, similarly to the control unit 13 shown in FIG. 1, the control unit 13A controls the operation of the heater 14 (shown in FIG. 4) for heating the hydrogen concentration measuring element 11A to control the temperature of the hydrogen concentration measuring element 11A. To control.

  FIG. 6 is an external view showing the structure of the hydrogen concentration measuring element 11A.

  As shown in FIG. 6, the hydrogen concentration measuring element 11 </ b> A includes a detection unit 31, a fixing unit 32, and a connection unit 33. The hydrogen concentration measuring element 11A includes a reference detection unit 31A and a connection unit 33A. In FIG. 6, the same members as those shown in FIG.

  Similar to the detection unit 31, the reference detection unit 31 </ b> A is arranged so as to be spirally wound on the outer surface of the fixed unit 32. 31 A of reference detection parts are arrange | positioned so that the detection part 31 may not be contacted. In FIG. 6, for convenience, the reference detection unit 31 </ b> A is represented by a thinner line than the detection unit 31. However, this does not necessarily mean that the diameter of the reference detection unit 31A is smaller than the diameter of the detection unit 31.

  The connection unit 33A fixes the reference detection unit 31A to the fixed unit 32 and is a terminal for measuring the electrical resistance value of the metal wire 51A (shown in FIGS. 7A and 7B) of the reference detection unit 31A. Function as. 6 shows an example in which the connection portion 33A is installed on the outer surface of the side surface of the fixed portion 32, but the connection portion 33A may be installed on the inner surface of the side surface of the fixed portion 32.

  7A and 7B are diagrams illustrating the structure of the reference detection unit 31A. FIG. 7A is a longitudinal sectional view of the reference detector 31A. FIG. 7B is a cross-sectional view of the reference detection unit 31A.

  As shown in FIGS. 7A and 7B, the reference detection unit 31A includes a metal wire 51A and a protective coating layer 52A.

  The metal wire 51A is a material such as platinum used for a resistance temperature detector and does not have a hydrogen storage capacity. The diameter of the metal wire 51A having no hydrogen storage capacity is about 1 [μm] or more and 1000 [μm] or less, similar to the diameter of the metal wire 51 shown in FIGS. 3 (A) and 3 (B). That's fine.

  Similarly to the protective coating layer 52 shown in FIGS. 3A and 3B, the protective coating layer 52A includes at least one of an oxide, nitride, and carbide of silicon or aluminum, and selectively permeates hydrogen. Made of inorganic material that is possible. Similarly to the protective coating layer 52 shown in FIGS. 3A and 3B, the thickness of the protective coating layer 52A is preferably 5 nm or more and 200 nm or less. In addition, the diameter of the reference detection part 31A which consists of the thickness of the protective coating layer 52A and the diameter of the metal wire 51A is based on the thickness of the protective coating layer 52 and the diameter of the metal wire 51 shown in FIGS. More preferably, it is the same as the diameter of the detection unit 31.

2. Action In the hydrogen concentration measuring apparatus 10A, the temperature of the hydrogen concentration measuring element 11A is controlled to 200 [° C.] or more by the heater 14. In this state, the electrical resistance value of the metal wire 51 covered with the protective coating layer 52 is sequentially measured by the resistor 12 connected to the connection portion 33 of the hydrogen concentration measuring element 11A. Further, the electrical resistance value of the metal wire 51A covered with the protective coating layer 52A is sequentially measured by the resistor 12A connected to the connection portion 33A of the hydrogen concentration measuring element 11A. Based on the electrical resistance value of the metal wire 51 and the electrical resistance value of the metal wire 51A, the hydrogen concentration is sequentially calculated by the control unit 13A.

  Here, the electrical resistance value of the metal wire 51 of the detection unit 31 includes a component due to hydrogen storage and a component due to temperature. On the other hand, the electrical resistance value of the metal wire 51A of the reference detection unit 31A does not include a component due to hydrogen storage, and is an electrical resistance value due to temperature. Therefore, in the second embodiment, by adopting the reference detection unit 31A, a component caused by temperature is separated and excluded from the electrical resistance value of the metal wire 51, so that hydrogen storage is performed from the electrical resistance value of the metal wire 51. The purpose is to extract and measure only the components caused by

  Here, the operation when the reference detection unit 31A is employed will be specifically described.

  It is known that the electric resistance value of a metal changes approximately in proportion to the temperature, and the electric resistance value R (T) at the temperature T is expressed by the following equation (1), for example. Is done.

R (T) = R0 [1 + α (T−T0)] (1)
T0: Reference temperature T: Measurement temperature R0: Electrical resistance value at reference temperature T0 α: Rate of change in electrical resistivity per unit temperature

  Α in the above formula (1) is a numerical value unique to the metal. In addition, the electric resistance value R0 and the reference temperature T0 set in advance in the metal wire 51A having no hydrogen storage ability and the electric resistance value measured in the metal wire 51A are expressed as R (T) in the above equation (1). When substituted, the measured temperature T is calculated. The calculated measurement temperature T can be regarded as the measurement temperature T of the metal wire 51A, that is, the measurement temperature T in the vicinity of the metal wire 51 having hydrogen storage capability.

  Subsequently, the electric resistance value R0 and the reference temperature T0 set in advance in the metal wire 51 having the hydrogen storage ability, and the measurement temperature T calculated from the metal wire 51A having no hydrogen storage ability are expressed by the above formula (1). Is substituted, the electric resistance value R (T) of the metal wire 51 is calculated. The calculated electric resistance value R (T) is an electric resistance value of the metal wire 51 due to temperature.

  As described above, by calculating the temperature in the vicinity of the metal wire 51 from the electrical resistance value of the metal wire 51A, from the electrical resistance value measured in the metal wire 51, the component (calculated electrical resistance value calculated from the temperature). R (T)) can be excluded, and components due to hydrogen storage can be separated. By adopting such a configuration, it becomes possible to obtain a more accurate hydrogen concentration based on a component resulting from hydrogen occlusion in the electrical resistance value measured on the metal wire 51 and a pre-correlation equation. .

  Next, the operation when the protective coating layers 52 and 52A are employed will be specifically described.

  FIG. 8 is a graph showing an example of the behavior of the electrical resistance value when hydrogen and oxygen are supplied in a metal wire not covered with a protective coating layer. FIG. 9 is a graph showing an example of the behavior of the electrical resistance value when hydrogen and oxygen are supplied in a metal wire coated with a protective coating layer.

  The horizontal axis of FIGS. 8 and 9 shows the change over time, the left vertical axis shows the ratio of the electrical resistance value when the electrical resistance value when heated to the operating temperature is 1, and the right vertical axis shows the hydrogen The hydrogen concentration and oxygen concentration in the gas supplied to the concentration measuring element are shown.

  FIG. 8 shows the change in electrical resistance value between palladium as a metal wire having a hydrogen storage capability and platinum as a metal wire having no hydrogen storage capability at a temperature of 200 [° C.] or higher. Indicates.

  As shown in FIG. 8, in the coexistence of hydrogen and oxygen, a change in electrical resistance value greatly exceeds the change in electrical resistance value that occurs when hydrogen alone is supplied. Although not shown in the graph, when the temperature of the hydrogen concentration measuring element 11 was measured, it was confirmed that an event in which a change in temperature occurred when a change in electrical resistance value due to the coexistence of hydrogen and oxygen occurred. . This event can be considered that hydrogen and oxygen react by contacting both metal wires, and the temperature of the metal wire changes due to the heat of reaction.

FIG. 9 shows palladium as a metal wire 51 having a hydrogen storage capacity in which a silicon oxide protective coating layer 52 is deposited by CVD in the same temperature state as FIG. 8, and a silicon oxide protective coating layer by CVD. The result which showed the change of the electrical resistance value with platinum as the metal wire 51A without the hydrogen storage ability in which 52A was vapor-deposited is shown. The thickness of the protective coating layers 52 and 52A was 7 [nm]. As shown in FIG. 9, the electrical resistance of the metal wire 51 A also when the oxygen concentration is increased by the presence of the protective coating layer 52,52A is not changed, the metal wire 51 is the electrical resistance value corresponding to the hydrogen concentration .

The results shown in FIGS. 8 and 9, by depositing a protective coating layer 52,52A each made of silicon oxide on the metal line 51 A without a metal wire 51 and the hydrogen storage capacity having a hydrogen storage capacity, respectively Side reactions occurring on the metal wires 51 and 51A .

  FIG. 9 shows an example of the behavior of the electrical resistance value when the thickness of the protective coating layers 52 and 52A is 7 [nm]. The thickness of the protective coating layers 52 and 52A is 5 [nm] or more. Also under the other conditions of 200 [nm] or less, the same results as in FIG. 9 were obtained.

3. Effect According to the hydrogen concentration measurement element 11A and the hydrogen concentration measurement device 10A for the nuclear facility according to the second embodiment, in addition to the effect of the first embodiment, the change in the electrical resistance value of the detection unit 31 accompanying the temperature change is referred to Since it can correct | amend based on the electrical resistance value of 31 A of detection parts, more highly accurate hydrogen concentration can be obtained.

(Modification)
The hydrogen concentration measuring devices 10 and 10A of the first and second embodiments further include a protective container 60 that can accommodate the hydrogen concentration measuring elements 11 and 11A.

  FIGS. 10A and 10B are diagrams showing a protective container 60 that can accommodate the hydrogen concentration measuring elements 11 and 11A. FIG. 10A is an external view of the entire protective container 60. FIG. 10B is a longitudinal sectional view of the side wall portion of the entire protective container 60 shown in FIG.

  A protective container 60 shown in FIGS. 10A and 10B has an inner space V and has a cylindrical shape in which one of the two bottom surfaces is sealed. 10A and 10B show a case where the protective container 60 has a cylindrical shape according to the shape of the hydrogen concentration measuring elements 11 and 11A, but the present invention is not limited to this case. Further, the side wall of the protective container 60 includes an inorganic porous body 61 and a protective coating layer 62 inside thereof.

  Similar to the protective coating layers 52 and 52A, the protective coating layer 62 includes at least one of oxides, nitrides, and carbides of silicon or aluminum, and is made of an inorganic material that can selectively permeate hydrogen. Similarly to the protective coating layers 52 and 52A, the thickness of the protective coating layer 62 is preferably 5 [nm] or more and 200 [nm] or less. At that time, even if the sum p + q of the thickness p of the protective coating layer 62 and the thickness q of the protective coating layers 52 and 52A to be accommodated is 5 [nm] or more and 200 [nm] or less. Good.

  The protective coating layer 62 is illustrated as being provided inside the inorganic porous body 61, but is not limited to that case. For example, the protective coating layer 62 may be provided only on the outside of the inorganic porous body 61 or on both the inside and the outside of the inorganic porous body 61.

  The protective container 60 can accommodate the hydrogen concentration measuring elements 11 and 11A via the internal space V.

  FIG. 11 is a view showing the protective container 60 in which the hydrogen concentration measuring elements 11 and 11A are accommodated.

  Hydrogen concentration measuring elements 11 and 11A are inserted into the internal space V of the protective container 60 (shown in FIGS. 10A and 10B), and the hydrogen concentration is measured in the protective container 60 with a fixing jig (not shown) such as a bolt. When the elements 11 and 11A are fixed, the state shown in FIG. 11 is obtained. After the hydrogen concentration measuring elements 11 and 11A are fixed to the protective container 60, the unsealed bottom surface of the two bottom surfaces of the protective container 60 is closed with a lid or the like so that the internal space V is airtight. It is.

  According to such a configuration, the hydrogen concentration measuring elements 11 and 11A having the protective coating layers 52 and 52A can be further covered with the protective container 60, and the hydrogen concentration measuring elements 11 and 11A are in contact with the external gas phase. It is possible to avoid.

  Further, the fixing jig is removed, and the hydrogen concentration measuring elements 11, 11 </ b> A are taken out from the internal space V of the protective container 60. That is, the hydrogen concentration measuring elements 11 and 11A can be easily removed from the protective container 60.

  Further, during the maintenance of the protective coating layer, if the gas selective permeability of the protective container 60 having the protective coating layer 62 is evaluated and it can be confirmed that the protective container 60 has the ability to transmit only a specific gas, the hydrogen concentration measurement is performed. The performance check of the protective coating layer of the elements 11 and 11A can be omitted. In addition, when there is a problem in the gas selective permeability of the protective container 60 during maintenance of the protective coating layer, it can be handled only by replacing the protective container 60.

  According to the protective container 60, in addition to the effects of the first and second embodiments, more reliable contact with the external gas phase can be prevented, and maintenance of the protective coating layer can be improved.

  Although several embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 10,10A ... Hydrogen concentration measuring device, 11, 11A ... Hydrogen concentration measuring element, 12, 12A ... Resistor, 13, 13A ... Control part, 31 ... Detection part, 31A ... Reference detection part, 51, 51A ... Metal wire, 52, 52A, 62 ... protective coating layer, 60 ... protective container.

Claims (9)

Metal wire having a hydrogen storage capacity of the electrical resistance value is changed by hydrogen occlusion is a detection portion that is covered by a protective coating layer has hydrogen permeability, hydrogen concentration measuring device comprising a fixing portion for fixing the detecting portion When,
A protective container that can accommodate the hydrogen concentration measuring element and has a structure removable from the hydrogen concentration measuring element, the protective container having a protective coating layer made of the same material as the protective coating layer;
Hydrogen concentration measuring device for nuclear facilities equipped with The hydrogen concentration measuring apparatus for a nuclear facility according to claim 1, wherein the protective coating layer is made of an inorganic substance. The hydrogen concentration measuring device for a nuclear facility according to claim 2, wherein the protective coating layer contains at least one of silicon and aluminum. The hydrogen concentration measuring apparatus for a nuclear facility according to any one of claims 1 to 3, wherein the protective coating layer is deposited on the metal wire by CVD (Chemical Vapor Deposition). Calculating means for calculating the hydrogen concentration from the electrical resistance of the metal wire before Symbol hydrogen concentration measuring device,
The hydrogen concentration measuring device for a nuclear facility according to any one of claims 1 to 4 , further comprising: The hydrogen concentration measuring device, the co-when provided with the detecting portion in which the first metal wire is coated by said protective coating layer as the metal wire, a second metal wire without the hydrogen storage capacity is the It further comprises a reference detector covered with a protective coating layer ,
Calculating means for calculating a hydrogen concentration based on an electric resistance value of the first metal wire and an electric resistance value of the second metal wire;
The hydrogen concentration measuring apparatus for nuclear facilities as described in any one of Claims 1 thru | or 4 provided with these . The temperature is calculated from the electrical resistance value of the second metal wire, and the component caused by the hydrogen occlusion of the first metal wire is separated from the electrical resistance value of the first metal wire based on the temperature. The hydrogen concentration measuring apparatus for nuclear facilities according to claim 6 . A heater capable of heating the hydrogen concentration measuring element;
Control means for controlling the temperature of the hydrogen concentration measuring element to 200 [° C.] or more by controlling the heater;
The hydrogen concentration measuring device for a nuclear facility according to any one of claims 1 to 7 , further comprising: The nuclear power facility according to any one of claims 1 to 8, wherein the protective coating layer has a thickness determined from a relationship between at least prevention of a side reaction caused by oxygen and iodine and hydrogen permeability. Hydrogen concentration measuring device.

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