JP2013104749A - Water level and temperature measurement facility for nuclear reactor containment vessel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water level and temperature measurement facility for a nuclear reactor containment vessel, capable of measuring presence or a fluid level (water level) of coolant and temperature in a reactor containment vessel even when the coolant such as water or sea water builds up in the reactor containment vessel due to a severe accident of a nuclear power plant.SOLUTION: A water level and temperature measurement facility for a nuclear reactor containment vessel includes a nuclear reactor containment vessel 3 which accommodates a reactor pressure vessel 2, and a plurality of temperature gauges 4 deployed inside the reactor containment vessel 3 along the height direction thereof to measure temperatures inside the reactor containment vessel 3. While temperature inside the reactor containment vessel 3 is being detected by each of the temperature gauges, a temperature value detected by each temperature gauge 4 is compared with a temperature value that should be detected when the temperature gauge is submerged in coolant such as water to check for presence of coolant inside the reactor containment vessel 3.

Description

  The present invention relates to a reactor containment vessel water level temperature measuring device.

  Conventional reactor containment vessels have a normal atmosphere inside the reactor containment vessel. Therefore, only a float type water level detector is installed as a water level detection facility for the reactor containment vessel. And are provided only at two locations on the vent line. In the conventional reactor containment vessel, a number of temperature detectors for measuring the internal atmospheric temperature are arranged.

  As shown in FIGS. 8A, 8B, and 8C, a conventional temperature detector a is connected to an MI cable b that is a temperature detection cable for detecting temperature via a terminal block c. And the MI cable b and the terminal block c are accommodated in the protective tube e. The MI cable b is filled with an electric insulator b2 in a stainless steel inner tube b1, and a pair or two pairs of thermocouples b3, b3,... They are placed side by side and embedded in the axial direction.

  However, if a reactor pressure vessel is damaged by a severe accident at a nuclear power plant and coolant such as water or seawater injected into the reactor pressure vessel has accumulated in the reactor containment vessel, In this water level detection facility, the water level of water or seawater can be detected only at the location of the installed water level detector.

  Further, when the temperature detector a is submerged or submerged in a coolant such as water or seawater, a short circuit occurs at the terminal block c in the middle of the temperature detector a or the cable d, and an accurate temperature cannot be detected. . Moreover, since the terminal block c fixes the connection cable d with screws, it is not easy to configure the terminal block c in a waterproof structure. In addition, it is impossible to determine whether or not the reactor pressure vessel is cooled by a coolant such as water or seawater injected into the reactor pressure vessel.

  Thus, even when coolant such as water or seawater has accumulated in the reactor containment vessel, it has not been assumed so far to monitor the water level.

  Even if coolant such as water or seawater accumulates in the reactor containment vessel due to a severe accident at a nuclear power plant, the present invention indicates the presence or absence of the coolant in the reactor containment vessel or the liquid level (water level). An object of the present invention is to provide a reactor containment vessel water level temperature measuring device capable of measuring temperature.

  The reactor containment vessel water level temperature measuring apparatus according to the present invention includes a reactor containment vessel that houses a reactor pressure vessel, and a plurality of reactor containment vessels disposed in the height direction in the reactor containment vessel. And a temperature detector for detecting. And while the temperature detector detects the temperature in the reactor containment vessel, the temperature detection value detected by each temperature detector is the temperature detection value when these temperature detectors are submerged by a coolant such as water. The presence or absence of the coolant in the reactor containment vessel is detected by comparing and referring to.

  According to the present invention, even when coolant such as water or seawater accumulates in the reactor containment vessel, it is possible to improve the accuracy of detecting the temperature in the reactor containment vessel with the temperature detector, and The presence or absence of coolant in the furnace containment vessel can be detected.

(A) is a schematic front view of the temperature detector of the reactor containment vessel according to the first embodiment of the present invention, (B) is the bottom end view of the temperature detector, (C) is the same (A), ( The expanded cross-sectional view of MI cable shown by B). The principal part schematic diagram of the nuclear reactor containment facility which concerns on the 1st Embodiment of this invention. (A) is a schematic front view of a temperature detector for a nuclear reactor containment vessel according to a second embodiment of the present invention, (B) is a bottom end view of the temperature detector, and (C) is the same as (A), The expanded cross-sectional view of MI cable shown by (B). The principal part schematic diagram of the nuclear reactor containment facility which concerns on the 3rd Embodiment of this invention. The principal part schematic diagram of the nuclear reactor containment facility which concerns on the 4th Embodiment of this invention. The principal part schematic diagram of the nuclear reactor containment facility which concerns on the 5th Embodiment of this invention. The principal part schematic diagram of the nuclear reactor containment facility which concerns on the 6th Embodiment of this invention. (A) is a schematic front view of a conventional temperature detector for a reactor containment vessel, (B) is a bottom end view of the temperature detector, and (C) is an MI cable shown in (A) and (B). FIG.

  Embodiments of the present invention will be described below with reference to the drawings. In addition, the same code | symbol is attached | subjected to the same or an equivalent part in several drawing.

(First embodiment)
As shown in FIG. 2, the reactor containment facility 1 according to the first embodiment includes a reactor containment vessel 3 that houses a reactor pressure vessel 2, and a plurality of reactor containment vessels 3 arranged in the reactor containment vessel 3. .., And float-type water level detectors 5a, 6a arranged as water level detectors for the reactor containment vessel 3 in the purge line 5 and the vent line 6, respectively. .

  The plurality of temperature detectors 4, 4,... Are arranged in the reactor containment vessel 3 at a predetermined interval in the height direction.

  Furthermore, the containment facility 1 cools the atmosphere in the reactor containment vessel 3 and also removes radioactive iodine from the containment vessel spray cooling system, and the containment vessel for the combustible gas generated by the water-metal reaction. A flammable gas concentration control system that prevents combustion of the reactor, a reactor building (secondary containment facility) that functions to prevent FP (fission products) leaking from the reactor containment vessel from being discharged directly to the outside, and this FP And an emergency gas treatment system (SGTS) that discharges at a high location from the exhaust stack. However, these systems are not shown in FIG.

  The reactor containment vessel 3 includes a dry well D for storing the reactor pressure vessel 2 and a cooling system recirculation loop (not shown), and a pressure suppression chamber 7 including a pressure suppression cable. Are connected by a steel vent pipe 8.

  For this reason, at the time of the loss of coolant accident, the steam and water mixture released into the dry well D of the containment vessel 3 is led into the pool water of the pressure suppression chamber 7 through the vent pipe 8, where the steam is cooled. And condensed. Thereby, the raise of the internal pressure of the reactor containment vessel 3 can be suppressed effectively. Further, an isolation valve (not shown) is provided in the penetration 9 which is a reactor containment vessel penetration portion of a pipe penetrating the inside and outside of the reactor containment vessel 3 to hold the released FP in the reactor containment vessel 3. it can.

  As shown in FIGS. 1A to 1C, the temperature detector 4 houses an MI cable 4b in a metal protective tube 4a. The protective tube 4a has an upper portion 4a1 in FIG. 1A and a hollow tubular lower portion 4a2 screwed to the upper portion 4a1, and a plurality of small holes 4c, 4c,... Are formed in the lower portion 4a2. Yes.

  The MI cable 4b is fixed to the protective tube 4a. The protective tube 4a is provided with a dome-shaped head portion 4a3 of an opening / closing lid on the upper portion 4a, and a waterproof connector 4d is disposed on the outer side surface of the head portion 4a3.

  The waterproof connector 4d has a waterproof function, and an MI cable 4b, which is an example of a temperature detection cable, and a connection cable 4e are detachably and waterproofly connected. Each connection cable 4e extends to the outside of the reactor containment vessel 3 through the penetration 9 of the reactor containment vessel 3 shown in FIG. 2, and is connected to a temperature water level detection device (not shown) such as a central operation panel (not shown). . This temperature / water level detection device detects the temperature and temperature distribution in the reactor containment vessel 3, the presence or absence of coolant such as water and seawater, and the liquid level (water level) based on the temperature detection value detected by the temperature detector 4. To do.

  As shown in FIG. 1C, the MI cable 4b is filled with an electrical insulator 4b such as magnesium oxide in an inner tube 4b1 made of, for example, stainless steel, and the temperature is approximately in the center of the filler 4b. One pair or two pairs of thermocouples 4b3, 4b3,... Which are detection members are juxtaposed in the radial direction at predetermined intervals and embedded in the axial direction, and these thermocouples 4b3, 4b3,. The temperature in the reactor containment vessel 3 is detected.

  Further, the temperature detection values of the temperature detectors 4, 4,.

  Therefore, according to the reactor containment facility 1, coolant such as water or seawater is accumulated in the reactor containment vessel 3 due to damage of the reactor pressure vessel 2, and the temperature detector 4 is submerged or submerged. Even in such a case, the MI cable 4b and the connection cable 4e are connected to each other by a waterproof connector 4d so that the connection portion between the MI cable 4b and the connection cable 4e is prevented from being short-circuited by a coolant such as water or seawater. Or it can be reduced.

  As a result, even if coolant such as water or seawater (hereinafter, also simply referred to as water) accumulates in the reactor containment vessel 3, the temperature detector 4 and the temperature water level detection device can contain the inside of the reactor containment vessel 3. The detection accuracy for detecting the temperature can be improved.

  Further, the presence or level of water in the reactor containment vessel 3 can be detected by the temperature / water level detection device.

  That is, the temperature detection value of each temperature detector 4 is different between when the temperature detector 4 is submerged and when it is not submerged (during the gas phase). Then, it is recorded as reference data in a memory or the like of the temperature water level detection device. In addition, in the memory of the temperature water level detection device, data on the arrangement height of the plurality of temperature detectors 4 in the reactor containment vessel 3 is stored in advance.

  For this purpose, by comparing and referring to the reference data for the temperature detection values detected by the respective temperature detectors 4, it is possible to detect whether or not each temperature detector 4 is submerged, that is, the presence or absence of water. Can do.

  Further, it is possible to determine that the arrangement height of the temperature detector 4 at the highest position among the temperature detectors 4 in which submersion is detected is the water level in the reactor containment vessel 3.

  The connection cables 4e, 4e,... For the plurality of temperature detectors 4, 4,... May be intensively inserted into one penetration 9 as shown in FIG. You may extend individually up to 9,.

(Second Embodiment)
3A is a schematic front view of the second temperature detector 41 of the containment facility 1A according to the second embodiment, FIG. 3B is a bottom end view of the second temperature detector 41, and FIG. (C) is an enlarged cross-sectional view of the MI cable 4b of the second temperature detector 41 shown in (A) and (B). The reactor containment facility 1A according to the second embodiment is characterized in that the temperature detector 4 in the reactor containment facility 1 is replaced with a second temperature detector 41.

  As shown in FIGS. 3A to 3C, the second temperature detector 41 has a metal circular tubular protective tube 41a. This protective tube 41a has the dome-shaped head 4a3 of the temperature detector 4 shown in FIG. One end (upper end in FIG. 3) of the protective tube 41a is provided with an electrically insulating end plug 41b and a compression screw compression fitting 41c in two stages, and the MI cable 41d is connected to the end plug 41b and the compression fitting 41c. It is fixed in a state of being electrically insulated from the protective tube 41a in a state where it is penetrated in a watertight manner, and is extended to the outside.

  As shown in FIG. 3C, the MI cable 41d has a plurality of, for example, two pairs of thermocouples in the substantially central portion of the cylindrical seal member 4b2 having electrical insulation accommodated in the inner tube 4a. 4b3 and 4b3 and a pair of heater wires 10 and 10 are juxtaposed in the radial direction at predetermined intervals, and embedded in the axial direction.

  When the heater wires 10 and 10 are energized to generate heat, the temperature detection values detected by the thermocouples 4b3 and 4b3 are subtracted when the second temperature detector 41 is submerged. Data at the time of no gas phase (gas phase) is recorded in advance for each temperature detector 41 and stored as reference data in, for example, a memory at a temperature water level detection position.

  For this purpose, the presence or absence of coolant such as water or seawater is detected by comparing the temperature detection values of the thermocouples 4b3 and 4b3 detected when the heater wires 10 and 10 are energized to generate heat. be able to.

  The plurality of second temperature detectors 41, 41,... Are arranged at a predetermined interval in the height direction in the reactor containment vessel 3, so that the first embodiment is different from the first embodiment. Similarly, the water level in the reactor containment vessel 3 can be detected from the arrangement height of the temperature detector 41 that has detected the presence of water.

  That is, according to the present embodiment, even when coolant such as water or seawater accumulates in the reactor containment vessel 3, the temperature and water level in the reactor containment vessel 3 are detected by the plurality of temperature detectors 41, 41,. Can be detected together.

  Then, the MI cable 41d may be extended directly to the penetration 9 without using the conventional terminal block c or the waterproof connector 4d. According to this, since the terminal block c which is submerged and easily short-circuited is deleted, it is possible to reduce short-circuiting. For this reason, even when water accumulates in the reactor containment vessel 3, the temperature in the reactor containment vessel 3, the presence or absence of water, and the water level can be detected.

  Furthermore, since the terminal block c and the waterproof connector 4d are deleted, the configuration can be simplified and the cost can be reduced.

  Furthermore, since the second temperature detector 41 fixes the temperature detection portion of the MI cable 41d to the protective tube 41a by means of an electrically insulating end plug 41b, the second temperature detector 41 can detect whether or not the second temperature detector 41 is submerged. It can be detected. That is, when the second temperature detector 41 is not submerged (during the gas phase), electrical insulation between the MI cable 4b and the protective tube 4a is ensured, so that the temperature can be detected with high accuracy. On the other hand, when the second temperature detector 41 is submerged, the MI cable 4b and the protective tube 4b are energized by water, so that the energized state of the MI cable b and the protective tube 4b is the temperature when not submerged (gas phase). It differs from the detected value. That is, since the energized state of the MI cable b and the protective tube 4b in the second temperature detector 41 is different between when submerged and when not submerged, it is possible to detect whether the second temperature detector 41 is submerged.

(Third embodiment)
FIG. 4 is a schematic diagram of a main part of a reactor containment facility 1A according to the third embodiment of the present invention. The reactor containment facility 1A includes the MI cable 41d of the second temperature detector 41 according to the second embodiment or the connection cable 4e shown in FIG. 1 in the vicinity of each second temperature detector 41. It is characterized in that each of the plurality of penetrations 9, 9,...

  According to the reactor containment facility 1A, even if the MI cable 41d or the connection cable 4e is short-circuited in some of the plurality of penetrations 9, 9,. The temperature, the presence / absence of water, and the water level in the reactor containment vessel 3 can be detected by using the temperature detectors 4 and 41 connected to the provided MI cable 41d or connection cable 4e.

(Fourth embodiment)
FIG. 5 is a schematic diagram of a main part of a reactor containment facility 1B according to a fourth embodiment of the present invention. The reactor containment facility 1B includes a pressure containment chamber pressure detector 11 that detects the pressure in the pressure containment chamber 7, and a reactor containment vessel pressure detector 12 that detects the pressure of the dry well D in the reactor containment vessel 3. And the difference between the detected pressure value in the pressure suppression chamber detected by the pressure suppression chamber pressure detector 11 and the detected pressure value in the reactor containment vessel 3 detected by the reactor containment vessel pressure detector 12. From the above, the water level in the reactor containment vessel 3 is detected.

  That is, the difference between the detected pressure in the pressure suppression chamber 7 detected by the pressure suppression chamber pressure detector 11 and the detected pressure in the reactor containment vessel 3 detected by the reactor containment vessel pressure detector 12 is the head pressure difference. Therefore, the water level of the reactor containment vessel 3 is calculated from the head pressure difference by comparing the difference between the two detection values with reference data in which the correlation with the water level in the reactor containment vessel 3 is recorded in advance. Can do.

(Fifth embodiment)
FIG. 6 is a schematic diagram of a main part of a reactor containment facility 1C according to the fifth embodiment of the present invention. The reactor containment facility 1C is provided with a reactor containment vessel pressure detector 12 and an ECCS system (emergency core cooling system) pump pressure detector 13, and an ECCS system pump detected by the ECCS system pump pressure detector 13. 15 is characterized in that the water level in the reactor containment vessel 3 is detected from the difference between the detected pressure value on the discharge side of 15 and the detected pressure value detected by the reactor containment vessel pressure detector 12.

  That is, the detected pressure on the discharge side of the ECCS system pump 15 of the ECCS system 14 detected by the ECCS system pump pressure detector 13, and the detected pressure of the reactor containment vessel 3 detected by the reactor containment vessel pressure detector 12 Therefore, the water level of the reactor containment vessel 3 is determined by referring to the reference data in which the correlation between the difference between these detected values and the water level in the reactor containment vessel 3 is recorded in advance. It can be calculated from the pressure difference.

(Sixth embodiment)
FIG. 7 is a schematic diagram of a main part of a reactor containment facility 1D according to the sixth embodiment of the present invention. This reactor containment facility 1D is characterized in that an ultrasonic sensor 16 with a built-in temperature sensor is provided, for example, at the bottom of the reactor containment vessel 3.

  The ultrasonic sensor 16 with a built-in temperature sensor transmits ultrasonic waves to the water surface of the water stored in the reactor containment vessel 3 and receives the reflected waves reflected by the water surface, so that the reservoir in the reactor containment vessel 3 is received. Detect the water level. The ultrasonic sensor 16 with a built-in temperature sensor is electrically connected to a cable 17. The cable 17 is inserted into the penetration 9 and extends to the outside of the containment vessel 3, and is electrically connected to a temperature water level detection device (not shown). Connected. The temperature / water level detection device gives a control signal for controlling the detection to the ultrasonic sensor 16 with built-in temperature sensor via the cable 17, while the water level detection signal and the temperature detection signal detected by the ultrasonic sensor 16 with built-in temperature sensor are used. Receiving and detecting the water level and temperature in the reactor containment vessel 3.

  Moreover, since the temperature sensor built-in ultrasonic sensor 16 can detect the temperature in the reactor containment vessel 3 by the built-in temperature sensor, the detection temperature corrects the influence of the ultrasonic temperature whose propagation time changes depending on the ambient temperature. can do.

  For this reason, the water level detection accuracy by the temperature sensor built-in ultrasonic sensor 16 can be improved. The water temperature can be detected directly.

  As described above, according to each embodiment of the present invention, the accuracy of temperature detection by the temperature detectors 4 and 41 in the reactor containment vessel 3 and the coolant such as water and seawater in the reactor containment vessel 3 are improved. The technical significance is common or closely related in that the presence or absence or the liquid level (water level) can be detected.

  And although some embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of this invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and changes can be made without departing from the scope of the present invention. These embodiments and modifications thereof are included in the scope and gist of the present invention, and are included in the invention described in the claims and the equivalents thereof.

1, 1A, 1B, 1C, 1D Reactor containment facility 2 Reactor pressure vessel 3 Reactor containment vessel 4 Temperature detector 4b, 41d MI cable (temperature detection cable)
4e Connecting cable 10 Heater wire 11 Pressure suppression chamber pressure detector 12 Reactor containment vessel pressure detector 13 ECCS system pump pressure detector 14 ECCS system 15 ECCS system pump 16 Temperature sensor built-in ultrasonic sensor 41 Second temperature detector 41b End plug (electrical insulator)

Claims (9)

A reactor containment that houses the reactor pressure vessel;
A plurality of temperature detectors arranged in the height direction in the reactor containment vessel to detect the temperature of the reactor containment vessel; and
Comprising
While the temperature detector detects the temperature in the reactor containment vessel, the temperature detection value detected by each temperature detector is compared with the temperature detection value when these temperature detectors are submerged by a coolant such as water. A reactor containment vessel water level temperature measuring device that detects presence or absence of coolant in a reactor containment by referring to the reactor containment vessel water level temperature measuring device. 2. The atom according to claim 1, wherein the liquid level of the coolant is detected from the height of the temperature detector disposed at the highest position among the temperature detectors that detected the presence of the coolant. Containment vessel water level temperature measurement device. A reactor containment that houses the reactor pressure vessel;
A temperature detector arranged in the reactor containment vessel and configured to be waterproof so that a connecting portion for connecting a temperature detection cable having a temperature detection member for detecting the temperature in the reactor containment vessel to the connection cable; ,
A reactor containment vessel water level temperature measuring device comprising: 4. The reactor containment vessel water level temperature measuring device according to claim 3, wherein the connecting portion is a waterproof connector. A reactor containment that houses the reactor pressure vessel;
A temperature detector having a protective tube disposed in the reactor containment vessel and containing a temperature detection cable having a temperature detection member for detecting the temperature in the reactor containment vessel and fixed by an electrically insulating member;
A reactor containment vessel water level temperature measuring device comprising: A reactor containment that houses the reactor pressure vessel;
A plurality of penetrations in the pipe penetration of this reactor containment vessel;
A plurality of temperature detectors provided in the reactor containment vessel and provided with a temperature detection cable having a temperature detection member for detecting the temperature in the reactor containment vessel;
Comprising
A reactor containment vessel water level temperature measuring apparatus, wherein temperature detection cables of the plurality of temperature detectors are extended to the plurality of penetrations, respectively. A reactor containment vessel containing a reactor pressure vessel and having a pressure suppression chamber;
A pressure suppression chamber pressure detector for detecting the pressure of the pressure suppression chamber;
A reactor containment vessel pressure detector for detecting the pressure in the reactor containment vessel;
Comprising
Reactor containment vessel water level temperature, wherein the water level in the containment vessel is detected based on the difference between both detected pressures detected by the pressure suppression chamber pressure detector and the reactor containment vessel pressure detector, respectively. Measuring device. A reactor containment that houses the reactor pressure vessel;
An emergency core cooling system having an ECCS pump for injecting coolant into the reactor pressure vessel;
An ECCS pump pressure detector for detecting the pressure on the discharge side of the ECCS pump;
A reactor containment vessel pressure detector for detecting the pressure in the reactor containment vessel;
Comprising
A water level in the reactor containment vessel is detected based on a difference between both detected pressures detected by the reactor containment vessel pressure detector and the ECCS pump pressure detector, respectively. Temperature measuring device. A reactor containment that houses the reactor pressure vessel;
An ultrasonic sensor that detects the temperature in the reactor containment vessel, detects the water level by transmitting ultrasonic waves into the reactor containment vessel, and
Comprising
A reactor containment vessel water level temperature measuring apparatus, wherein the ultrasonic sensor detects the water level of the reactor containment vessel, and corrects the detected water level based on the temperature detected by the temperature sensor.

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