JP2014206519A - Reactor water level measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reactor water level measuring device which is capable of accurately measuring a water level inside a reactor pressure vessel in an emergency.SOLUTION: A reactor water level measuring device for measuring a water level inside a reactor pressure vessel 1 comprises: a reference pressure pipe 2 connected to a gas phase portion of the reactor pressure vessel 1; a water level pressure pipe 3 connected to a liquid phase portion of the reactor pressure vessel 1; a differential pressure gauge 4 which measures the differential pressure between a reference pressure introduced from the reference pressure pipe 2 and a water level pressure introduced from the water level pressure pipe 3, as a state quantity corresponding to the water level inside the reactor pressure vessel 1; and a balance pipe 8 which is connected to the reference pressure pipe 2 in such a manner that it branches off from a branching part 6 located outside the reactor pressure vessel 5. The balance pipe 8 is configured to let the water in an upper end side portion of the reference pressure pipe 2 above the branching part 6 flow out during emergency so as to obtain a predetermined reference water head of which a water level height is at the branching part 6 of the reference pressure pipe 2. The differential pressure gauge 4 is previously set so as to match the predetermined reference water head.

Description

  The present invention relates to a reactor water level measuring device that measures the water level in a reactor pressure vessel, and more particularly to a differential pressure type reactor water level measuring device.

  Conventionally, a reactor water level measuring device that measures the water level in a reactor pressure vessel has been disclosed (see, for example, Patent Document 1). The reactor water level measuring device described in Patent Document 1 is connected to a gas phase part of a reactor pressure vessel via a condensing tank, and passes through the reactor containment vessel and extends to the outside of the reactor containment vessel. A conduit, a water level pressure conduit connected to the liquid phase part of the reactor pressure vessel, extending through the reactor containment vessel and extending to the outside of the reactor containment vessel, and disposed outside the reactor containment vessel, As a state quantity corresponding to the water level in the pressure vessel, a differential pressure gauge for measuring a differential pressure between the reference pressure introduced from the reference pressure conduit and the water level pressure introduced from the water level pressure conduit is provided.

  The condensing tank is disposed inside the reactor containment vessel. And the vapor | steam which flowed into the condensation tank from the gaseous-phase part of the reactor pressure vessel thermally radiates and condenses, and the condensed water is stored in a condensation tank and a reference | standard pressure conduit. Moreover, in order to keep the water surface height in the condensing tank constant, excess water is returned to the reactor pressure vessel.

  The reference pressure introduced into the differential pressure gauge from the reference pressure conduit is the liquid phase pressure (reference head) due to the water surface height in the condensing tank and the gas phase pressure in the condensing tank (in other words, approximately in the reactor pressure vessel). Gas phase pressure). On the other hand, the water level pressure introduced into the differential pressure gauge from the water level pressure conduit is the difference between the liquid phase pressure (water level head) that fluctuates according to the water level in the reactor pressure vessel and the gas phase pressure in the reactor pressure vessel. It is sum. The differential pressure gauge measures the differential pressure between the reference pressure and the water level pressure described above (that is, approximately the differential pressure between the reference water head and the water head), and outputs a water level signal based on this to a display device or the like.

JP-A-8-220282

  In the above prior art, during normal operation, it is possible to keep the reference head due to the water surface height in the condensing tank constant, and it is possible to accurately measure the water level in the reactor pressure vessel. However, in an emergency where the temperature in the reactor containment vessel rises from the normal operation and the water level in the reactor pressure vessel falls from the normal operation, for example, the water in the condensing tank evaporates and the water surface height increases. It fluctuates and the standard head fluctuates. Therefore, a water level measurement error occurs.

  An object of the present invention is to provide a reactor water level measuring device capable of accurately measuring the water level in a reactor pressure vessel in an emergency.

  In order to achieve the above object, the present invention provides a differential pressure type reactor water level measuring device for measuring a water level in a reactor pressure vessel, wherein the reactor containment vessel is connected to a gas phase part of the reactor pressure vessel. A reference pressure conduit that penetrates and extends outside the reactor containment vessel, and is connected to a liquid phase portion of the reactor pressure vessel, and extends through the reactor containment vessel to the outside of the reactor containment vessel. Existing water level pressure conduits, and disposed outside the reactor containment vessel and introduced from the reference pressure conduits and the water level pressure conduits as state quantities corresponding to the water levels in the reactor pressure vessels. A differential pressure gauge for measuring a differential pressure with respect to the water level pressure, and a branch pipe connected to branch from a branch section located outside the reactor containment vessel in the reference pressure conduit, In the reactor containment vessel In the event of an emergency in which the temperature rises from the normal operation and the water level in the reactor pressure vessel falls from the normal operation, a predetermined reference head having the branch surface of the reference pressure conduit as the water surface height can be obtained. Further, it is configured to allow water on the upper end side to flow out from the branch portion of the reference pressure conduit, and the differential pressure gauge is set in advance so as to correspond to the predetermined reference head.

  In the present invention, in an emergency, water on the upper end side is caused to flow out from the branch portion of the reference pressure conduit using a branch pipe. As a result, a predetermined reference head having a branch surface of the reference pressure conduit as the water surface height can be obtained. The portion from the branch portion to the lower end portion (in other words, the differential pressure gauge) of the reference pressure conduit is located outside the reactor containment vessel and is hardly affected by the high temperature in the reactor containment vessel. Therefore, a predetermined reference head can be maintained even in an emergency. And by setting the differential pressure gauge in advance so as to correspond to this reference head, the water level in the reactor pressure vessel can be accurately measured in an emergency.

  According to the present invention, the water level in the reactor pressure vessel can be accurately measured in an emergency.

It is the schematic showing the structure of the reactor water level measuring apparatus in the 1st Embodiment of this invention, and has shown the water level in the reactor pressure vessel at the time of normal operation, and the water surface height in reference | standard pressure piping. It is the schematic showing the structure of the reactor water level measuring apparatus in the 1st Embodiment of this invention, and has shown the water level in the reactor pressure vessel in the emergency, and the water surface height in a reference | standard pressure piping. It is the schematic showing the structure of the reactor water level measuring apparatus in the 2nd Embodiment of this invention, and has shown the water level in the reactor pressure vessel in the emergency, and the water surface height in reference | standard pressure piping. It is the schematic showing the structure of the reactor water level measuring apparatus in the 3rd Embodiment of this invention, and has shown the water level in the reactor pressure vessel in the emergency, and the water surface height in reference | standard pressure piping. It is the schematic showing the structure of the reactor water level measuring apparatus in the 4th Embodiment of this invention, and has shown the water level in the reactor pressure vessel in the emergency, and the water surface height in reference | standard pressure piping. It is the schematic showing the structure of the reactor water level measuring apparatus in the 5th Embodiment of this invention, and has shown the water level in the reactor pressure vessel in the emergency, and the water surface height in reference | standard pressure piping. It is the schematic showing the structure of the reactor water level measuring apparatus in the 6th Embodiment of this invention, and has shown the water level in the reactor pressure vessel at the time of normal operation, and the water surface height in a condensing tank. It is the schematic showing the structure of the reactor water level measuring apparatus in the 6th Embodiment of this invention, and has shown the water level in the reactor pressure vessel in the emergency, and the water surface height in reference | standard pressure piping. It is the schematic showing the structure of the reactor water level measuring apparatus in the 7th Embodiment of this invention, and has shown the water level in the reactor pressure vessel at the time of normal operation, and the water surface height in a condensing tank. It is the schematic showing the structure of the reactor water level measuring apparatus in the 7th Embodiment of this invention, and has shown the water level in the reactor pressure vessel in the emergency, and the water surface height in reference | standard pressure piping. It is a figure showing the structure of the reactor water level measuring apparatus in one modification of this invention.

  A first embodiment of the present invention will be described with reference to FIGS. FIG.1 and FIG.2 is the schematic showing the structure of the reactor water level measuring apparatus in this embodiment. FIG. 1 shows the water level in the reactor pressure vessel and the water surface height in the reference pressure pipe during normal operation, and FIG. 2 shows the water level in the reactor pressure vessel and the water surface in the reference pressure pipe at the time of emergency. Shows the height.

  The reactor water level measurement device of the present embodiment includes a reference pressure conduit 2 whose upper end is connected to a gas phase part of the reactor pressure vessel 1 (specifically, a part above the top of the active fuel (TAF)), and an upper end. Is connected to the liquid phase part of the reactor pressure vessel 1 (specifically, the part below the effective fuel bottom (BAF)), the lower end of the reference pressure conduit 2 and the lower end of the water level pressure conduit 3 And a differential pressure gauge 4 connected to the section. The differential pressure gauge 4 corresponds to an emergency (details will be described later).

  The reactor pressure vessel 1 is arranged inside the reactor containment vessel 5, and the differential pressure gauge 4 is arranged outside the reactor containment vessel 5. The reference pressure conduit 2 and the water level pressure conduit 3 pass through the reactor containment vessel 5 and extend to the outside of the reactor containment vessel 5. In the present embodiment, the reference pressure conduit 2 and the water level pressure conduit 3 are each composed of an inclined tube and a vertical tube. A balance pipe (branch pipe) 8 extending in the vertical direction is connected between the branch portion 6 of the reference pressure conduit 2 and the junction portion 7 of the water level pressure conduit 3 which are respectively located outside the reactor containment vessel 5. ing. In the present embodiment, the height h1 of the branch portion 6 of the reference pressure conduit 2 is the same as the height of the effective fuel top (TAF).

  As shown in FIG. 1, during normal operation, the water level in the reactor pressure vessel 1 is above the effective fuel top (TAF). At this time, the water surface height in the reference pressure conduit 2 is the same as the water level in the reactor pressure vessel 1. On the other hand, as shown in FIG. 2, in an emergency where the temperature in the reactor containment vessel 5 rises from the normal operation and the water level in the reactor pressure vessel 1 falls from the normal operation, the reactor pressure vessel 1 The water level inside may be below the effective fuel top (TAF). In such a case, the water on the upper end side of the branch portion 6 of the reference pressure conduit 2 flows out to the reactor pressure vessel 1 through the balance pipe 8 and the water level pressure conduit 3. Thereby, the predetermined reference head by the water surface height h1 in the branch part 6 of the reference pressure conduit 2 can be obtained. Since the portion from the branching portion 6 to the lower end portion (in other words, the differential pressure gauge 4) of the reference pressure conduit 2 is located outside the reactor containment vessel 5, it is hardly affected by the high temperature in the reactor containment vessel 5. . Therefore, a predetermined reference head can be maintained even in an emergency.

  The differential pressure gauge 4 measures the differential pressure between the reference pressure introduced from the reference pressure conduit 2 and the water level pressure introduced from the water level pressure conduit 3 as a state quantity corresponding to the water level in the reactor pressure vessel 1. It has become. In an emergency, the reference pressure introduced into the differential pressure gauge 4 from the reference pressure conduit 2 is a predetermined reference head due to the water surface height h1 at the branch portion 6 of the reference pressure conduit 2 and the gas phase in the reference pressure conduit 2. (In other words, substantially the pressure in the gas phase in the reactor pressure vessel 1). On the other hand, the water level pressure introduced into the differential pressure gauge 4 from the water level pressure conduit 3 includes the liquid phase pressure (water level head) that fluctuates according to the water level in the reactor pressure vessel 1 and the gas phase in the reactor pressure vessel 1. It is the sum of the pressure. The differential pressure gauge 4 measures the differential pressure between the reference pressure and the water level pressure (that is, the differential pressure between the reference water head and the water level head) and outputs a water level signal based on this to a display device (not shown) or the like. It has become.

  Further, the differential pressure gauge 4 is set in advance so as to correspond to the aforementioned predetermined reference head. Specifically, the zero point is calibrated at the above-described predetermined reference head, and a water level signal corresponding to the predetermined reference head is output. Therefore, the display device can accurately display the water level in the reactor pressure vessel 1 based on the water level signal from the differential pressure gauge 4 in an emergency.

  As described above, in the present embodiment, the water level in the reactor pressure vessel 1 can be accurately measured in an emergency.

  In the first embodiment, the case where the branch portion 6 of the reference pressure conduit 2 is located at the same height as the effective fuel top (TAF) has been described as an example. However, the present invention is not limited to this. Modifications can be made without departing from the technical idea and spirit. That is, as long as it is located outside the reactor containment vessel 5, it may be located above or below the effective fuel top (TAF). In such a case, the same effect as described above can be obtained. The same applies to the embodiments described later.

  A second embodiment of the present invention will be described with reference to FIG. Note that in this embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  FIG. 3 is a schematic diagram showing the configuration of the reactor water level measuring device in the present embodiment. FIG. 3 shows the water level in the reactor pressure vessel 1 and the water surface height in the reference pressure pipe 2 in an emergency.

  The reactor water level measuring device of the present embodiment includes a reference pressure conduit 2, a water level pressure conduit 3, a differential pressure gauge 4, and a balance tube 8 as in the first embodiment. In the present embodiment, the height h1 of the branch portion 6 of the reference pressure conduit 2 is intermediate between the height of the effective fuel top (TAF) and the height of the effective fuel bottom (BAF).

  The balance pipe 8 is provided with a balance valve (open / close valve) 9. Further, a differential pressure switch (water level detector) 10 for detecting the water level in the balance tube 8 is provided. The balance valve 9 is controlled in accordance with a signal from the differential pressure switch 10. The balance valve 9 is, for example, an electric valve, an electromagnetic valve, or an air operated valve.

  The differential pressure switch 10 will be described in detail. A pressure conduit 12 is connected so as to branch from the branch portion 11 of the reference pressure conduit 2. In addition, a pressure conduit 14 is connected so as to branch from a branch portion 13 located above the on-off valve 9 in the balance pipe 8. A differential pressure switch 10 is connected to these pressure conduits 12 and 14. The differential pressure switch 10 detects a differential pressure between the pressure introduced from the pressure conduit 12 and the pressure introduced from the pressure conduit 14 as a state quantity corresponding to the water level in the balance pipe 8. In the present embodiment, the branch portion 11 of the reference pressure conduit 2 is located on the upper end side of the branch portion 6, and its height h2 is the same as the height of the effective fuel top (TAF).

  Then, the differential pressure switch 10 determines whether or not the detected differential pressure is equal to or higher than a predetermined threshold value set in advance, whereby the water level in the balance pipe 8 is determined by the predetermined value Δh ( However, it is determined whether or not the predetermined value Δh has been lowered by a value that is smaller than the length between the branch portion 6 and the branch portion 13 in the height direction. A signal is output to the balance valve 9 according to the determination result.

  For example, when the water level in the balance pipe 8 is not lower than the branching part 6 of the reference pressure conduit 2 by a predetermined value Δh or more, no signal is output from the differential pressure switch 10 to the balance valve 9 and the balance valve 9 is opened. . Thus, in an emergency, if the water level in the reactor pressure vessel 1 falls below the middle between the effective fuel top (TAF) and the effective fuel bottom (BAF), the upper end side of the branch portion 6 of the reference pressure conduit 2 Is discharged to the reactor pressure vessel 1 through the balance pipe 8 and the water level pressure conduit 2. Thereafter, when the water level in the balance pipe 8 is lowered by a predetermined value Δh or more from the branch portion 6 of the reference pressure conduit 2, a signal is output from the differential pressure switch 10 to the balance valve 9, and the balance valve 9 is switched to the closed state. At this time, a predetermined reference head can be obtained based on the water surface height h1 at the branch portion 6 of the reference pressure conduit 2, and the differential pressure gauge 4 can be measured in this state.

  The differential pressure switch 10 may output a signal to the display device simultaneously with outputting a signal to the balance valve 9. Then, the display device may start displaying the water level in the reactor pressure vessel 1 in response to a signal from the differential pressure switch 10.

  In the present embodiment configured as described above, the measurement accuracy of the differential pressure gauge 4, that is, the measurement accuracy of the water level in the reactor pressure vessel 1 can be increased as compared with the first embodiment. More specifically, for example, when the balance valve 9 is not provided as in the first embodiment (or when the balance valve 9 is provided and the balance valve 9 is opened and the differential pressure gauge 4 is measured), the differential pressure gauge 4, if the water level in the reactor pressure vessel 1 fluctuates, the water level in the balance tube 8 fluctuates. That is, a flow is generated between the reactor pressure vessel 1 and the balance pipe 8 via the water level pressure conduit 2, and dynamic pressure is generated. Therefore, a measurement error of the differential pressure gauge 4 may occur due to this dynamic pressure. On the other hand, in the present embodiment, the balance valve 9 of the balance pipe 8 is closed and no dynamic pressure is generated in the water level pressure conduit 2, so that the measurement accuracy of the differential pressure gauge 4 can be increased.

  Moreover, in this embodiment, the balance valve 9 is arrange | positioned so that it may become lower than the upper end part of the water level pressure conduit 3. FIG. Therefore, even when the water level in the reactor pressure vessel 1 falls to the upper end of the water level pressure conduit 3 (in other words, the lower limit of measurement), the balance in the balance pipe 8 is closed compared to the liquid phase pressure corresponding to the water level. The liquid phase pressure up to the balance valve 9 in the state is small and does not affect the water level pressure introduced into the differential pressure gauge 4. Therefore, the measurement accuracy of the differential pressure gauge 4 can be increased.

  In the second embodiment, the case where the branch portion 11 of the reference pressure conduit 2 is located on the upper end side of the branch portion 6 and is located at the same height as the effective fuel top (TAF) will be described as an example. However, the present invention is not limited to this, and modifications can be made without departing from the technical idea and spirit of the present invention. That is, as long as it is located outside the reactor containment vessel 5, it may be located above or below the effective fuel top (TAF). Further, for example, the branch portion 6 of the reference pressure conduit 2 may be located at the same height as the effective fuel top (TAF), and the branch portion 11 may be located on the lower end side of the branch portion 6. In such a case, the same effect as described above can be obtained.

  In the second embodiment described above, the differential pressure switch 10 that detects the water level in the balance pipe 8 is provided and the balance valve 9 is controlled according to the signal from the differential pressure switch 10 as an example. However, instead of this, for example, an electrode type or float type water level detector for detecting the water level in the balance pipe 8 is provided, and the balance valve 9 is controlled in accordance with a signal from the water level detector. Also good. In such a case, the same effect as described above can be obtained.

  A third embodiment of the present invention will be described with reference to FIG. In the present embodiment, the same parts as those in the first and second embodiments are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  FIG. 4 is a schematic diagram showing the configuration of the reactor water level measuring device in the present embodiment. FIG. 4 shows the water level in the reactor pressure vessel 1 and the water surface height in the reference pressure pipe 2 in an emergency.

  The reactor water level measuring device of the present embodiment includes a reference pressure conduit 2, a water level pressure conduit 3, a differential pressure gauge 4, and a balance tube 8 as in the first and second embodiments. In addition, as in the second embodiment, the balance pipe 8 is provided with a balance valve 9. As in the first embodiment, the height h1 of the branch portion 6 of the reference pressure conduit 2 is the same as the height of the effective fuel top (TAF).

  In the present embodiment, there is a correlation between the temperature in the reactor containment vessel 5 and the water level in the reactor pressure vessel 1 in an emergency, and the temperature in the reactor containment vessel 5 and the water level in the balance tube 8 in an emergency. Is also focused on the correlation. Therefore, instead of the differential pressure switch 10 (water level detector) of the second embodiment, a temperature switch (temperature detector) 15 for detecting the temperature in the reactor containment vessel 1 is provided. The temperature switch 15 determines whether or not the water level in the balance pipe 8 has dropped by a predetermined value Δh or more from the branch portion 6 of the reference pressure conduit 2 by determining whether or not the detected temperature is equal to or higher than a predetermined threshold value set in advance. Determine. A signal is output to the balance valve 9 according to the determination result.

  For example, when the water level in the balance pipe 8 is not lower than the branching part 6 of the reference pressure conduit 2 by a predetermined value Δh or more, no signal is output from the temperature switch 15 to the balance valve 9 and the balance valve 9 is opened. Thus, in an emergency, if the water level in the reactor pressure vessel 1 falls below the top of the active fuel (TAF), the water on the upper end side of the branch portion 6 of the reference pressure conduit 2 is supplied to the balance pipe 8 and the water level. It flows out to the reactor pressure vessel 1 through the pressure conduit 2. Thereafter, when the water level in the balance pipe 8 is lowered by a predetermined value Δh or more from the branch portion 6 of the reference pressure conduit 2, a signal is output from the temperature switch 15 to the balance valve 9, and the balance valve 9 is switched to the closed state. At this time, a predetermined reference head can be obtained based on the water surface height h1 at the branch portion 6 of the reference pressure conduit 2, and the differential pressure gauge 4 can be measured in this state.

  The temperature switch 15 may output a signal to the display device simultaneously with outputting a signal to the balance valve 9. Then, the display device may start displaying the water level in the reactor pressure vessel 1 in response to a signal from the temperature switch 15.

  Also in the present embodiment configured as described above, the measurement accuracy of the differential pressure gauge 4, that is, the measurement accuracy of the water level in the reactor pressure vessel 1 can be increased as in the second embodiment.

  Although not specifically described in the second and third embodiments, the temperature in the reactor containment vessel 5 is detected, and it is determined whether or not the detected temperature is within the normal operation range. A temperature switch that outputs a signal to the balance valve 9 according to the determination result may be provided. Thereby, during normal operation, the balance valve 9 is closed, and when the temperature in the reactor containment vessel 5 starts to rise from that during normal operation, the balance valve 9 is automatically controlled to be switched to the open state. Also good. In such a case, the same effect as described above can be obtained.

  In the second and third embodiments, the configuration in which the balance valve 9 is automatically controlled according to the signal from the differential pressure switch 10 or the temperature switch 15 has been described as an example. However, the present invention is not limited to this. Modifications can be made without departing from the technical idea and spirit of the present invention. That is, the balance valve 9 may be controlled, for example, according to a signal from a manual operation unit, or may be manually operated directly or via a link mechanism. In such a case, the same effect as described above can be obtained.

  A fourth embodiment of the present invention will be described with reference to FIG. Note that in this embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  FIG. 5 is a schematic diagram showing the configuration of the reactor water level measuring device in the present embodiment. FIG. 5 shows the water level in the reactor pressure vessel 1 and the water surface height in the reference pressure pipe 2 in an emergency.

  The reactor water level measuring device of this embodiment includes a reference pressure conduit 2, a water level pressure conduit 3, and a differential pressure gauge 4 as in the first embodiment.

  A drain recovery unit 16 (specifically, for example, a drain pod or a drain line) is provided outside the reactor containment vessel 5. In addition, a drain pipe (branch pipe) 17 connected to the drain recovery part 16 is connected to the reference pressure pipe 2 so as to branch from the branch part 6 located outside the reactor containment vessel 5. . The drain pipe 17 is provided with a drain valve (open / close valve) 18. Although not shown in detail, the drain valve 18 is controlled according to a signal from a manual operation unit, or is manually operated directly or via a link mechanism. In the present embodiment, the height h1 of the branch portion 6 of the reference pressure conduit 2 is intermediate between the height of the effective fuel top (TAF) and the height of the effective fuel bottom (BAF).

  Then, as shown in FIG. 5, in an emergency where the temperature in the reactor containment vessel 5 rises from the normal operation and the water level in the reactor pressure vessel 1 falls from the normal operation, the reactor pressure vessel 1 In some cases, the water level inside is lower than the middle between the effective fuel top (TAF) and the effective fuel bottom (BAF). In such a case, the drain valve 17 is opened, and the water on the upper end side of the branch portion 6 of the reference pressure conduit 2 is allowed to flow out to the drain recovery portion 16 via the drain pipe 17. Thereby, the predetermined reference head by the water surface height h1 in the branch part 6 of the reference pressure conduit 2 can be obtained. Since the portion from the branching portion 6 to the lower end portion (in other words, the differential pressure gauge 4) of the reference pressure conduit 2 is located outside the reactor containment vessel 5, it is hardly affected by the high temperature in the reactor containment vessel 5. . Therefore, a predetermined reference head can be maintained even in an emergency.

  The differential pressure gauge 4 is set in advance so as to correspond to the aforementioned predetermined reference head. Specifically, the zero point is calibrated with the above-mentioned predetermined reference head, and a water level signal corresponding to the reference head is output to a display device or the like. Therefore, the display device can accurately display the water level in the reactor pressure vessel 1 based on the water level signal from the differential pressure gauge 4 in an emergency.

  As described above, in the present embodiment, the water level in the reactor pressure vessel 1 can be accurately measured in an emergency.

  In the fourth embodiment, the drain valve 18 is controlled according to a signal from the manual operation unit, or is manually or directly operated via a link mechanism. The present invention is not limited to this, and modifications can be made without departing from the technical idea and spirit of the present invention. That is, for example, a temperature switch that detects the temperature in the reactor containment vessel 5 and determines whether or not the detected temperature is within a range during normal operation, and outputs a signal to the drain valve 18 according to the determination result. It may be provided. Thus, during normal operation, the drain valve 18 is closed, and when the temperature in the reactor containment vessel 5 starts to rise from that during normal operation, the drain valve 18 is automatically controlled to be switched to the open state. Also good. In such a case, the same effect as described above can be obtained.

  A fifth embodiment of the present invention will be described with reference to FIG. Note that in this embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  FIG. 6 is a schematic diagram showing the configuration of the reactor water level measuring device in the present embodiment. FIG. 6 shows the water level in the reactor pressure vessel 1 and the water surface height in the reference pressure pipe 2 in an emergency.

  The reactor water level measuring device of this embodiment includes a reference pressure conduit 2, a water level pressure conduit 3, and a differential pressure gauge 4 as in the first embodiment.

  A pressurized gas supply unit 19 (specifically, for example, a pressurized gas line, a pressurized gas tank, or a blower) is provided outside the nuclear reactor containment vessel 5. In addition, a blow pipe (branch pipe) 20 connected to the pressurized gas supply unit 19 is connected to the reference pressure conduit 2 so as to branch from the branch part 6 located outside the reactor containment vessel 5. ing. The blow pipe 20 is provided with a blow valve (open / close valve) 21. Although not shown in detail, the blow valve 21 is controlled according to a signal from a manual operation unit, or is manually operated directly or via a link mechanism. In the present embodiment, the height h1 of the branch portion 6 of the reference pressure conduit 2 is the same as the height of the effective fuel top (TAF).

  Then, as shown in FIG. 6, in an emergency where the temperature in the reactor containment vessel 5 rises from the normal operation and the water level in the reactor pressure vessel 1 falls from the normal operation, the reactor pressure vessel 1 The water level inside may be below the effective fuel top (TAF). In such a case, the blow valve 21 is opened, the pressurized gas is supplied from the pressurized gas supply unit 19 to the reference pressure conduit 2 through the blow pipe 20, and the upper end portion of the reference pressure conduit 2 from the branch portion 6. Side water is allowed to flow into the reactor pressure vessel 1. Thereby, the predetermined reference head by the water surface height h1 in the branch part 6 of the reference pressure conduit 2 can be obtained. Since the portion from the branching portion 6 to the lower end portion (in other words, the differential pressure gauge 4) of the reference pressure conduit 2 is located outside the reactor containment vessel 5, it is hardly affected by the high temperature in the reactor containment vessel 5. . Therefore, a predetermined reference head can be maintained even in an emergency.

  The differential pressure gauge 4 is set in advance so as to correspond to the aforementioned predetermined reference head. Specifically, the zero point is calibrated with the above-mentioned predetermined reference head, and a water level signal corresponding to the reference head is output to a display device or the like. Therefore, the display device can accurately display the water level in the reactor pressure vessel 1 based on the water level signal from the differential pressure gauge 4 in an emergency.

  As described above, in the present embodiment, the water level in the reactor pressure vessel 1 can be accurately measured in an emergency.

  In the fifth embodiment, the blow valve 21 is controlled according to a signal from the manual operation unit or is manually operated directly or via a link mechanism. The present invention is not limited to this, and modifications can be made without departing from the technical idea and spirit of the present invention. That is, for example, a temperature switch that detects the temperature in the reactor containment vessel 5 and determines whether or not the detected temperature is within a range during normal operation, and outputs a signal to the blow valve 21 according to the determination result. It may be provided. Thus, during normal operation, the blow valve 21 is closed, and when the temperature in the reactor containment vessel 5 starts to rise from that during normal operation, the blow valve 21 is automatically controlled to be switched to the open state. Also good. In such a case, the same effect as described above can be obtained.

  A sixth embodiment of the present invention will be described with reference to FIGS. Note that in this embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  7 and 8 are schematic views showing the configuration of the reactor water level measuring device in the present embodiment. FIG. 7 shows the water level in the reactor pressure vessel and the water surface height in the condensing tank during normal operation, and FIG. 8 shows the water level in the reactor pressure vessel and the water surface height in the reference pressure conduit at the time of emergency. It shows.

  The reactor water level measuring device of the present embodiment includes a reference pressure conduit 2, a water level pressure conduit 3, a differential pressure gauge 4, and a balance tube 8 as in the first embodiment. In the present embodiment, the height h1 of the branch portion 6 of the reference pressure conduit 2 is intermediate between the height of the effective fuel top (TAF) and the height of the effective fuel bottom (BAF). The balance pipe 8 is provided with a balance valve 9. Although not shown in detail, the balance valve 9 is controlled according to a signal from a manual operation unit, or is manually operated directly or via a link mechanism.

  The reference pressure conduit 2 is connected to the gas phase part of the reactor pressure vessel 1 via the condensing tank 22. Further, a reference pressure conduit 24 branched from the branch portion 23 of the reference pressure conduit 2 is provided, and a water level pressure conduit 26 branched from the branch portion 25 of the water level pressure conduit 3 is provided. A differential pressure gauge 27 disposed outside the reactor containment vessel 5 and connected to the reference pressure conduit 24 and the water level pressure conduit 26 is provided. This differential pressure gauge 27 corresponds to the normal operation (details will be described later).

  In the present embodiment, the branch portion 23 of the reference pressure conduit 2 is located on the lower end side from the branch portion 6 and outside the reactor containment vessel 5, but is located on the upper end side from the branch portion 6. Alternatively, it may be located inside the reactor containment vessel 5. Further, the branching portion 25 of the water level pressure conduit 3 is located on the lower end side from the merging portion 7 and outside the reactor containment vessel 5, but may be located on the upper end portion side from the merging portion 7. It may be located inside the furnace containment vessel 5.

  As shown in FIG. 7, during normal operation, the water level in the reactor pressure vessel 1 is above the effective fuel top (TAF). At this time, the balance valve 9 is closed, and the water surface height h3 in the condensing tank 22 is kept constant. Thereby, the 1st reference head by the water level height h3 in the condensation tank 22 can be obtained.

  The differential pressure gauge 27 calculates a differential pressure between the reference pressure introduced from the reference pressure conduits 2 and 24 and the water level pressure introduced from the water level pressure conduits 3 and 26 as a state quantity corresponding to the water level in the reactor pressure vessel 1. It comes to measure. During normal operation, the reference pressure introduced into the differential pressure gauge 27 from the reference pressure conduits 2 and 24 is the first reference head due to the water surface height h3 in the condensing tank 22 and the gas phase pressure in the condensing tank 22. (In other words, approximately the pressure of the gas phase in the reactor pressure vessel 1). The water level pressure introduced into the differential pressure gauge 27 from the water level pressure conduits 3 and 26 includes a liquid phase pressure (water level head) that varies depending on the water level in the reactor pressure vessel 1 and a gas phase in the reactor pressure vessel 1. It is the sum of the pressure. The differential pressure gauge 27 measures the differential pressure between the reference pressure and the water level pressure (that is, the differential pressure between the first reference head and the water level head), and outputs a water level signal based on the differential pressure to a display device or the like. It is like that.

  The differential pressure gauge 27 is set in advance so as to correspond to the first reference head described above. Specifically, the zero point is calibrated with the first reference head described above, and a water level signal corresponding to the first reference head is output. Therefore, the display device can accurately display the water level in the reactor pressure vessel 1 based on the water level signal from the differential pressure gauge 27 during normal operation.

  On the other hand, as shown in FIG. 8, in the case of an emergency in which the temperature in the reactor containment vessel 5 rises from the normal operation and the water level in the reactor pressure vessel 1 falls from the normal operation, the reactor pressure vessel 1 In some cases, the water level inside is lower than the middle between the effective fuel top (TAF) and the effective fuel bottom (BAF). In such a case, the balance valve 9 is switched to the open state, and water on the upper end side from the branch portion 6 of the reference pressure conduit 2 flows out to the reactor pressure vessel 1 through the balance tube 8 and the water level pressure conduit 3. Let Thereby, the 2nd reference head by the water surface height h1 in the branch part 6 of the reference | standard pressure conduit 2 can be obtained. Since the portion from the branching portion 6 to the lower end portion (in other words, the differential pressure gauge 4) of the reference pressure conduit 2 is located outside the reactor containment vessel 5, it is hardly affected by the high temperature in the reactor containment vessel 5. . Therefore, the second reference head can be maintained even in an emergency.

  Further, the differential pressure gauge 4 is set in advance so as to correspond to the above-described second reference head. Specifically, the zero point is calibrated with the second reference head described above, and a water level signal corresponding to the reference head is output. Therefore, the display device can accurately display the water level in the reactor pressure vessel 1 based on the water level signal from the differential pressure gauge 4 in an emergency.

  As described above, in the present embodiment, the water level in the reactor pressure vessel 1 can be accurately measured during normal operation and emergency.

  A seventh embodiment of the present invention will be described with reference to FIGS. Note that in this embodiment, the same parts as those in the first and sixth embodiments are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  9 and 10 are schematic views showing the configuration of the reactor water level measuring device in the present embodiment. FIG. 9 shows the water level in the reactor pressure vessel and the water surface height on the reference pressure conduit side during normal operation, and FIG. 10 shows the water level in the reactor pressure vessel and the water surface on the reference pressure conduit side in an emergency. Shows the height.

  The reactor water level measuring device of this embodiment includes a reference pressure conduit 2, a water level pressure conduit 3, a differential pressure gauge 4, and a balance tube 8 as in the first and sixth embodiments. Similarly to the sixth embodiment, the height h1 of the branch portion 6 of the reference pressure conduit 2 is intermediate between the height of the effective fuel top (TAF) and the height of the effective fuel bottom (BAF).

  Further, as in the sixth embodiment, the reference pressure conduit 2 is connected to the gas phase portion of the reactor pressure vessel 1 via the condensing tank 22. The balance pipe 8 is provided with a balance valve 9. Although not shown in detail, the balance valve 9 is controlled according to a signal from a manual operation unit, or is manually operated directly or via a link mechanism.

  Further, as in the first and sixth embodiments, the differential pressure gauge 4 is set in advance so as to correspond to the second reference head due to the water surface height h1 at the branch portion 6 of the reference pressure conduit 2. Specifically, the zero point is calibrated with the second reference head described above, and a water level signal corresponding to the second reference head is output. Therefore, in the present embodiment, the first output line 28 that directly outputs the water level signal from the differential pressure gauge 4 to the display device and the water level signal from the differential pressure gauge 4 are corrected so as to correspond to the first reference head. A second output line 29 for outputting to a display device or the like is provided. The second output line 29 is provided with an arithmetic unit 30 that corrects the water level signal from the differential pressure gauge 4 so as to correspond to the first reference head.

  As shown in FIG. 10, in an emergency where the temperature in the reactor containment vessel 5 rises from the normal operation and the water level in the reactor pressure vessel 1 falls from the normal operation, the reactor pressure vessel 1 In some cases, the water level inside is lower than the middle between the effective fuel top (TAF) and the effective fuel bottom (BAF). In such a case, the balance valve 9 is switched to the open state, and water on the upper end side from the branch portion 6 of the reference pressure conduit 2 flows out to the reactor pressure vessel 1 through the balance tube 8 and the water level pressure conduit 3. Let Thereby, the 2nd reference head by the water surface height h1 in the branch part 6 of the reference | standard pressure conduit 2 can be obtained. Since the portion from the branching portion 6 to the lower end portion (in other words, the differential pressure gauge 4) of the reference pressure conduit 2 is located outside the reactor containment vessel 5, it is hardly affected by the high temperature in the reactor containment vessel 5. . Therefore, the second reference head can be maintained even in an emergency.

  During this emergency operation, the reference pressure introduced into the differential pressure gauge 4 from the reference pressure conduit 2 is the second reference head due to the water surface height h1 at the branch portion 6 of the reference pressure conduit 2, and the reference pressure conduit 2 Gas phase pressure (in other words, substantially the gas phase pressure in the reactor pressure vessel 1). The water level pressure introduced into the differential pressure gauge 4 from the water level pressure conduit 3 includes the liquid phase pressure (water level head) that varies depending on the water level in the reactor pressure vessel 1 and the gas phase pressure in the reactor pressure vessel 1. And the sum. The differential pressure gauge 4 measures the above-described differential pressure between the reference pressure and the water level pressure (that is, approximately the differential pressure between the second reference water head and the water level water head), and outputs a water level signal based thereon. The display device accurately displays the water level in the reactor pressure vessel 1 based on the water level signal of the differential pressure gauge 4 via the first output line 28 (that is, the water level signal corresponding to the second reference head). Can do.

  On the other hand, as shown in FIG. 9, during normal operation, the water level in the reactor pressure vessel 1 is above the effective fuel top (TAF). At this time, the balance valve 9 is closed, and the water surface height h3 in the condensing tank 22 is kept constant. Thereby, the 1st reference head by the water level height h3 in the condensation tank 22 can be obtained.

  During this normal operation, the reference pressure introduced into the differential pressure gauge 4 from the reference pressure conduit 2 is the first reference head due to the water surface height h3 in the condensing tank 22 and the gas phase pressure in the condensing tank 22 ( In other words, it is approximately the sum of the pressure in the gas phase in the reactor pressure vessel 1). On the other hand, the water level pressure introduced into the differential pressure gauge 4 from the water level pressure conduit 3 includes the liquid phase pressure (water level head) that fluctuates according to the water level in the reactor pressure vessel 1 and the gas phase in the reactor pressure vessel 1. It is the sum of the pressure. The differential pressure gauge 4 measures the above-described differential pressure between the reference pressure and the water level pressure (that is, approximately the differential pressure between the first reference water head and the water level water head), and outputs a water level signal based on this. The second output line 29 corrects the water level signal from the differential pressure gauge 4 so as to correspond to the first reference head. The display device accurately displays the water level in the reactor pressure vessel 1 based on the water level signal of the differential pressure gauge 4 corrected by the second output line 29 (that is, the water level signal corresponding to the first reference head). be able to.

  As described above, in the present embodiment, the water level in the reactor pressure vessel 1 can be accurately measured during normal operation and emergency.

  In the seventh embodiment, the first output line 28 that outputs the water level signal from the differential pressure gauge 4 as it is and the water level signal from the differential pressure gauge 4 are corrected so as to correspond to the first reference head. However, instead of these, an output line that can be switched between the presence and absence of correction may be provided. That is, for example, an arithmetic device 30 is provided in the output line, and this arithmetic device 30 is configured to correct the water level from the differential pressure gauge 4 in accordance with a signal from the manual operation unit or the temperature switch (command for presence or absence of correction). May be. In this case, the same effect as described above can be obtained.

  In the sixth and seventh embodiments, the balance valve 9 is controlled according to a signal from the manual operation unit, or is manually or directly operated via a link mechanism. However, the present invention is not limited to this, and modifications can be made without departing from the technical idea and spirit of the present invention. That is, for example, a temperature switch that detects the temperature in the reactor containment vessel 5, determines whether or not the detected temperature is within a range during normal operation, and outputs a signal to the balance valve 9 according to the determination result. It may be provided. Thereby, during normal operation, the balance valve 9 is closed, and when the temperature in the reactor containment vessel 5 starts to rise from that during normal operation, the balance valve 9 is automatically controlled to be switched to the open state. Also good.

  Further, similarly to the second or third embodiment, the differential pressure switch 10 or the temperature switch 15 may be provided, and the balance valve 9 may be automatically controlled according to a signal from the differential pressure switch 10 or the temperature switch 15. That is, the balance valve 9 may be switched to the closed state when the water level in the balance pipe 8 falls by a predetermined value Δh or more from the branch portion 6 of the reference pressure conduit 2. In such a case, as in the second or third embodiment, the measurement accuracy of the differential pressure gauge 4, that is, the measurement accuracy of the water level in the reactor pressure vessel 1 can be increased.

  Moreover, in the said 6th and 7th embodiment, although demonstrated taking the example of the structure provided with the balance pipe | tube 8 and the balance valve 9, it replaces with them, for example similarly to the said 4th Embodiment, a drain collection | recovery part 16, a drain pipe 17, and a drain valve 18 may be provided. Or it is good also as a structure provided with the pressurized gas supply part 19, the blow pipe 20, and the blow valve 21, for example like the said 5th Embodiment. In these cases, the same effect as described above can be obtained.

  In the first to seventh embodiments, the water level pressure conduit 2 has been described as an example in which it is connected to a portion between the lowest part of the reactor pressure vessel 1 and the effective fuel bottom (BAF). For example, as shown in FIG. 11, it may be connected to the lowermost part of the reactor pressure vessel 1 so that the water level can be measured up to the lowermost part of the reactor pressure vessel 1. Further, for example, a pipe connected to the reactor pressure vessel 1 (specifically, for example, a reactor purification system (CUW) bottom drain pipe or the like) may be connected. In such a case, the same effect as described above can be obtained.

DESCRIPTION OF SYMBOLS 1 Reactor pressure vessel 2 Reference pressure conduit 3 Water level pressure conduit 4 Differential pressure gauge 5 Reactor containment vessel 6 Branch part 8 Balance pipe (branch pipe)
9 Balance valve (open / close valve)
10 Differential pressure switch (water level detector)
15 Temperature switch (temperature detector)
16 Drain recovery unit 17 Drain pipe (branch pipe)
18 Drain valve (open / close valve)
19 Pressurized gas supply unit 20 Blow pipe (branch pipe)
21 Blow valve (open / close valve)
22 Condenser 24 Reference pressure conduit 26 Water level pressure conduit 27 Differential pressure gauge 28 First output line 29 Second output line

Claims (10)

In the reactor water level measurement device that measures the water level in the reactor pressure vessel,
A reference pressure conduit connected to the gas phase portion of the reactor pressure vessel and extending outside the reactor containment vessel through the reactor containment vessel;
A water level pressure conduit connected to the liquid phase portion of the reactor pressure vessel and extending through the reactor containment vessel to the outside of the reactor containment vessel;
The difference between the reference pressure introduced from the reference pressure conduit and the water level pressure introduced from the water level pressure conduit as a state quantity corresponding to the water level in the reactor pressure vessel, which is arranged outside the reactor containment vessel A differential pressure gauge for measuring pressure,
A branch pipe connected to branch from a branch portion located outside the reactor containment vessel in the reference pressure conduit,
The branch pipe connects the branch portion of the reference pressure conduit in an emergency in which the temperature in the reactor containment vessel is higher than that in normal operation and the water level in the reactor pressure vessel is lower than in normal operation. It is configured to allow water on the upper end side to flow out from the branch portion of the reference pressure conduit so that a predetermined reference head having a water surface height is obtained,
The reactor water level measuring device according to claim 1, wherein the differential pressure gauge is set in advance so as to correspond to the predetermined reference head. In the reactor water level measuring device according to claim 1,
The branch pipe is a balance pipe connected to branch from the branch portion of the reference pressure conduit and connected to join the water level pressure conduit,
In the emergency, as the water level in the reactor pressure vessel falls below the height of the branch portion of the reference pressure conduit, water on the upper end side from the branch portion of the reference pressure conduit is supplied to the balance pipe. And a reactor water level measuring device for flowing out into the reactor pressure vessel through the water level pressure conduit. In the reactor water level measuring device according to claim 2,
An opening / closing valve is provided in the balance pipe;
The on-off valve is opened when water on the upper end side flows out from the branch portion of the reference pressure conduit, and then the predetermined reference head having the branch portion of the reference pressure conduit at a water surface height. The reactor water level measuring device is switched to a closed state when measurement of the differential pressure gauge is performed in a state where is obtained. In the reactor water level measuring device according to claim 3,
A water level detector for detecting the water level in the balance pipe is provided,
A reactor water level measuring device configured to control the on-off valve in accordance with a water level in the balance pipe detected by the water level detector. In the reactor water level measuring device according to claim 3,
A temperature detector for detecting the temperature in the reactor containment vessel is provided,
A reactor water level measuring device configured to control the on-off valve in accordance with the temperature in the reactor containment vessel detected by the temperature detector. In the reactor water level measuring device according to claim 1,
The branch pipe is connected to branch from the branch portion of the reference pressure conduit, and is a drain pipe connected to a drain recovery portion,
An open / close valve is provided in the drain pipe,
In the emergency, the on-off valve is opened, and the water on the upper end side from the branch portion of the reference pressure conduit is allowed to flow out to the drain pod or the drain line through the drain pipe. Reactor water level measuring device. In the reactor water level measuring device according to claim 1,
The branch pipe is connected to branch from the branch portion of the reference pressure conduit, and is a blow pipe connected to a pressurized gas supply section,
An open / close valve is provided in the blow pipe,
In the emergency, the on-off valve is opened and pressurized gas is supplied from the pressurized gas supply unit to the reference pressure conduit through the blow pipe, and the upper end side of the branch portion of the reference pressure conduit The reactor water level measuring device is characterized in that the water in the reactor flows out into the reactor pressure vessel. In the reactor water level measuring device according to claim 1,
The reactor water level measuring device, wherein the water level pressure conduit is connected to a lowermost part of the reactor pressure vessel. In the differential pressure type reactor water level measurement device that measures the water level in the reactor pressure vessel,
A reference pressure conduit connected to the gas phase part of the reactor pressure vessel via a condensing tank, extending through the reactor containment vessel and extending outside the reactor pressure containment vessel;
A water level pressure conduit connected to the liquid phase portion of the reactor pressure vessel and extending through the reactor containment vessel to the outside of the reactor containment vessel;
The difference between the reference pressure introduced from the reference pressure conduit and the water level pressure introduced from the water level pressure conduit as a state quantity corresponding to the water level in the reactor pressure vessel, which is arranged outside the reactor containment vessel A first differential pressure gauge and a second differential pressure gauge for measuring pressure;
A branch pipe connected to branch from a branch portion located outside the reactor containment vessel in the reference pressure conduit,
The branch pipe does not flow out water on the upper end side from the branch portion of the reference pressure conduit so that a first reference head can be obtained by a water surface height in the condensing tank during normal operation. In an emergency where the temperature in the reactor containment vessel rises higher than usual and the water level in the reactor pressure vessel falls lower than usual, a second reference head having the branch portion of the reference pressure conduit as the water surface height is obtained. The water on the upper end side is caused to flow out from the branch portion of the reference pressure conduit,
The first differential pressure gauge is preset to correspond to the first reference head,
The reactor water level measuring device, wherein the second differential pressure gauge is preset to correspond to the second reference head. In the differential pressure type reactor water level measurement device that measures the water level in the reactor pressure vessel,
A reference pressure conduit connected to the gas phase part of the reactor pressure vessel via a condensing tank, extending through the reactor containment vessel and extending outside the reactor pressure containment vessel;
A water level pressure conduit connected to the liquid phase portion of the reactor pressure vessel and extending through the reactor containment vessel to the outside of the reactor containment vessel;
The difference between the reference pressure introduced from the reference pressure conduit and the water level pressure introduced from the water level pressure conduit as a state quantity corresponding to the water level in the reactor pressure vessel, which is arranged outside the reactor containment vessel A differential pressure gauge for measuring pressure,
A branch pipe connected to branch from a branch portion located outside the reactor containment vessel in the reference pressure conduit,
The branch pipe does not flow out water on the upper end side from the branch portion of the reference pressure conduit so that a first reference head can be obtained by a water surface height in the condensing tank during normal operation. In an emergency where the temperature in the reactor containment vessel rises higher than usual and the water level in the reactor pressure vessel falls lower than usual, a second reference head having the branch portion of the reference pressure conduit as the water surface height is obtained. The water on the upper end side is caused to flow out from the branch portion of the reference pressure conduit,
The differential pressure gauge is preset to correspond to the second reference head,
A first output line for outputting the water level signal from the differential pressure gauge as it is, and a second output line for correcting and outputting the water level signal from the differential pressure gauge so as to correspond to the first reference head. Reactor water level measuring device characterized by that.

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