Classifications

• • G—PHYSICS
  • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
  • G21C—NUCLEAR REACTORS
  • G21C7/00—Control of nuclear reaction
  • G21C7/06—Control of nuclear reaction by application of neutron-absorbing material, i.e. material with absorption cross-section very much in excess of reflection cross-section
  • G21C7/08—Control of nuclear reaction by application of neutron-absorbing material, i.e. material with absorption cross-section very much in excess of reflection cross-section by displacement of solid control elements, e.g. control rods
  • G21C7/12—Means for moving control elements to desired position
  • G21C7/14—Mechanical drive arrangements
• • G—PHYSICS
  • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
  • G21C—NUCLEAR REACTORS
  • G21C7/00—Control of nuclear reaction
  • G21C7/06—Control of nuclear reaction by application of neutron-absorbing material, i.e. material with absorption cross-section very much in excess of reflection cross-section
  • G21C7/08—Control of nuclear reaction by application of neutron-absorbing material, i.e. material with absorption cross-section very much in excess of reflection cross-section by displacement of solid control elements, e.g. control rods
  • G21C7/12—Means for moving control elements to desired position
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E30/00—Energy generation of nuclear origin
  • Y02E30/30—Nuclear fission reactors

Definitions

• Control rod drive device Description: Control rod drive device, test method therefor, test device therefor, and torque transmission device
• the present invention relates to a control rod drive device, a test method and a test device therefor, and a torque transmission device that can be suitably used for the control rod drive device.
• the control rod drive mechanism which is integrated with the control rods, controls the reactivity of the reactor and is particularly important for plant operation and safety.
• Figure 7 shows a conventional electric control rod drive mechanism.
• FIG. 7 is a longitudinal sectional view showing an electric control rod drive mechanism (C R D) provided at the lower part of the reactor pressure vessel of the boiling water reactor (BWR) and driving the control rod (C R) up and down.
• the control rod drive mechanism has a motor assembly at a lower end, and a vertical rotating shaft 1 of the motor assembly is connected to an upper vertical drive shaft 3 via a gear coupling 2.
• a screw shaft 4 is rotatably connected to the drive shaft 3, and a nut 5 is screwed to the screw shaft 4 via a ball (not shown) to form a ball screw mechanism. The nut 5 moves up and down by the rotation of the screw shaft 4.
• the outer periphery of the nut 5 is provided with a plurality of pairs of rollers 6 arranged in pairs vertically, and these rollers 6 narrow the axial mounting plate 8 formed on the inner peripheral surface of the guide tube 7. It is attached to carry.
• a hollow piston 9 extending upward around the screw shaft 4, and a control rod 11 is connected to an upper end of the hollow piston 9 via a coupling 10.
• a ferrule tube 13 is installed in the CRD housing 12, and the CRD housing 12, the outer tube 13 and the spool bead 14 are connected by bolts 15.
• a spring 16 is provided below the screw shaft 4, and when the nut 5 is moved downward beyond the position where the control rod is completely pulled out, the nut 5 compresses the spring 16. Thus nut 5
• the state in which the spring 16 is compressing is referred to as a “mechanically lowest state” in this specification.
• a buffer 17 is provided at the upper part of the outer tube 13.When the nut 17 is moved upward beyond the state where the control rods are fully inserted, the buffer 17 is compressed by the hollow piston 9 installed at the upper part of the nut 5. You. The state in which the hollow piston 9 compresses the buffer 17 in this manner is referred to as a “mechanical uppermost state” in this specification.
• the motor assembly has a motor 18, an electromagnetic brake 19 and a position detecting device 20.
• the control rod is driven by the motor 18, the control rod position is held by the electromagnetic brake 19, and the position of the control rod is confirmed by the position detection device 20.
• a stepper motor is used as the motor 18 and an invertor power source is used as the motor power supply 21. I have.
• the motor assembly is connected to a spool bead 14 via a motor bracket 22.
• a gland packing 23 is used at a portion of the spool piece 14 where the drive shaft 3 penetrates.
• a coil spring 24 and a magnet housing 26 supported by the coil spring 24 and having a built-in separation detection magnet 25 are provided inside the spool piece 14.
• the load applied to the coil spring 24 decreases due to, for example, the hollow piston 9 being separated from the nut 5, the coil spring 24 expands, and the separation detection magnet 25 moves upward accordingly.
• a separation detection probe 27 having a built-in reed switch operated by magnetism is installed outside the spool bead 14 so that the movement of the separation detection magnet 25 can be detected.
• a scrum position detecting magnet 28 is built in the hollow biston 9. In the guide tube 7, a full-in detection magnet 29 that moves with the compression of the buffer 17 at the time of the scrum is installed.
• a scrum position detection probe 30 having a built-in magnetically operated reed switch is provided outside the control rod drive mechanism housing 12, and a scrum position detection magnet 28 and a screen detection magnet 29 are provided. Movement can be detected.
• the screw shaft 4 rotates via the rotation shaft 1 and the drive shaft 3, and the rotation of the screw shaft 4 causes the nut 5 to move up and down. Move.
• the rotation of the nut 5 is regulated by the mounting plate 7 via the roller 6 and moves up and down.
• the hollow screw 9 and the control rod 11 move up and down in conjunction with the up and down movement of the nut 5, and the up and down movement of the control rod 11 adjusts the amount of insertion and withdrawal into the core and controls the furnace power. .
• the hollow piston 9 connected to the control rod 11 via the coupling 10 is quickly pushed up by the water pressure supplied from the water pressure control unit and is separated from the nut 5, and the control rod 11 is quickly removed. Insert into the core. At this time, the separation of the hollow bistone 9 from the nut 5 is detected by the separation detection probe 27. The positions of the control rods 11 during and after the scrum are detected by the scrum position detection probe 30.
• control is performed by connecting a control rod friction measurement test device to the water pressure control unit and supplying water pressure to the control rod drive device via the test device. Insert the rod into the core. At this time, the operation of the control rod drive mechanism is the same as that of the scrum except that the insertion speed is low. In the control rod friction measurement test, the state of friction between the control rod and peripheral devices is confirmed by measuring the fluctuation of water pressure during the insertion.
• the control rod drive mechanism described above has a gland packing 23 as a shaft seal for the spool piece 14 and a stepper motor using an invertor power supply as the motor 18.
• improvements such as (1) removal of the spool bead shaft seal by adopting a magnetic coupling (magnet coupling) and (2) change of motor type (induction motor) are being studied.
• magnet coupling magnet coupling
• induction motor induction motor
• the conventional electric control rod drive mechanism shown in Fig. 7 employs a stepping motor as the motor and an invertor power supply as the motor power supply.
• the problem is that the system is complicated and the amount of power supply is large.
• the control rod drive mechanism using an induction motor which is currently being studied, requires a simplified power supply system.
• optimization of the power supply unit and control unit when applying an induction motor has not yet been performed, and no means has been established to confirm the soundness of the drive performance.
• the present invention has been made in view of the above circumstances, and establishes a control rod drive mechanism and related systems such as a power supply device and a control device, as well as maintenance means and test means, while providing a highly reliable control rod drive mechanism.
• the purpose is to provide.
• control rod driving device having any of the following features.
• the first feature is that an induction motor is used as a control rod driving force source in place of the conventional motor-powered motor that uses an overnight power supply in the FMCRD. Switches to be multiplexed and each switch can be switched independently. What you can do is in As a result, the power supply and the control device can be simplified and optimized, and control rod drive due to malfunction or the like can be prevented to improve reliability.
• a second feature resides in that an induction motor is used as a control rod driving force generation source, and the control rod drive speed calculated based on detection of the control rod position is monitored.
• the rotation speed of the induction motor fluctuates according to the load.
• the third feature is that the control rod drive is provided with means for measuring the control rod stop position or control rod drive distance, and the measured stop position or control rod drive distance and the control rod drive when the control rod drive is sound The purpose is to compare the assumed control rod stop position or control rod drive distance. As a result, it is possible to confirm whether the control rod drive mechanism has sound drive performance in consideration of load fluctuation, deterioration, etc. of the control rod drive mechanism, and to take appropriate measures such as status display and alarm according to the status Can be taken.
• the fourth feature is that a plurality of brakes are provided in the control rod drive mechanism, and the plurality of brakes are operated at different timings. As a result, the load on one brake can be reduced.
• the fifth feature is that multiple brakes are provided in the control rod drive mechanism, and the holding torque at standstill of each brake alone is set to be higher than the torque required to maintain the control rod position during normal operation of the reactor. . In this way, even if one brake loses its function, the position of the control rod can be reliably maintained, and the reliability can be improved.
• a sixth feature is that in a control rod drive mechanism in which a magnetic coupling is provided in a driving force transmission path from the electric motor to the control rod, a member on the motor side and a part on the control rod side with respect to the magnetic coupling. There is provided means for detecting the rotational position of the material. In this way, even if the magnetic coupling loses synchronism, it is possible to detect it by comparing the two rotational positions, and according to the state, display the status, alarm, and stop the drive. It is possible to take appropriate measures.
• a moving speed of the control rod is detected when driving the control rod, or
• a control rod drive device characterized by detecting current, voltage or power supplied to an induction motor, and measuring the friction between the control rod and the drive mechanism and its surrounding members based on the absolute value or fluctuation of the detected value.
• the rotation speed of the induction motor fluctuates according to the load. Also, when the load of the induction motor changes, the state of supply of electric energy to the induction motor changes. Therefore, by measuring the control rod drive speed or the absolute value of the energy supplied to the induction motor or its fluctuation, it is possible to confirm the load fluctuation such as control rod friction.
• Control rod friction measurement is performed during periodic inspections of boiling water nuclear power plants, but by performing measurement using the method described above, the work can be simplified and the work process can be shortened. It can be implemented outside the radiation control area, and it will be possible to improve workability and reduce exposure.
• a control rod drive device including a drive mechanism including: a motor assembly including a motor; a spool joint; and a magnetic joint having a pair of joint elements separated by a spool bead.
• the test apparatus includes a torque applying means capable of applying a torque to a joint element on the motor assembly side or a shaft connected to the joint element, which constitutes the magnetic joint, with the spool bead attached to the drive mechanism. And torque measuring means for measuring the applied torque.
• the test method is applicable when the drive mechanism has a ball screw mechanism that converts the rotary motion generated by the motor into a linear motion. This method is applicable when the spool piece is attached to the drive mechanism.
• the positions of the nuts that make up the ball screw mechanism Set the mechanical lower limit state or the mechanical upper limit state, and apply torque to the joint element on the motor assembly side that constitutes the magnetic coupling or the shaft connected to this coupling element, and check if there is any abnormality in the magnetic coupling. Is determined.
• the shaft of the motor assembly is rotated from the lower portion of the motor assembly, and connected to the joint element on the motor assembly side or this joint element via the shaft of the motor assembly. It is preferable to apply a torque to the bent shaft.
• test apparatus and test method it is not necessary to remove the spur piece for the purpose of confirming the soundness of the magnetic coupling, and it is possible to reduce the amount of work, processes, and exposure at the time of regular plant inspection.
• a control rod drive device including a drive mechanism including: a motor assembly including a motor; a spool piece; and a magnetic coupling having a pair of coupling elements separated by a spool piece.
• a new test apparatus is provided which is applicable and can check the integrity of the magnetic coupling and the spool piece while the spool piece is attached to the drive mechanism.
• This test device can be connected to the joint element on the control rod side or the shaft connected to this joint element that constitutes the magnetic joint, and controls the rotation of the joint element on the control rod side or the shaft connected to this joint element.
• the test apparatus is connectable to a control rod-side coupling element or a shaft connected to the control rod-side coupling element constituting the magnetic coupling, and is connected to the control rod-side coupling element or to this coupling element.
• Torque applying means for applying torque to the shaft, and a coupling element on the motor assembly side or a shaft connected to the coupling element which constitutes a magnetic coupling, and a coupling element on the motor assembly side or this coupling element.
• Rotation restricting means for restricting rotation of the shaft connected to the shaft.
• the test equipment shall be connected to one of the coupling element on the control rod side or the shaft connected to this coupling element, or the coupling element on the motor assembly side or the shaft connected to this coupling element. It can be configured to further include a torque limiter that is connectable and that limits the torque applied by the torque applying means.
• the test device can be connected to one of the joint element on the control rod side or the shaft connected to this joint element, or the joint element on the motor assembly side or the shaft connected to this joint element, and It may be further provided with a rotation angle measuring means for measuring a rotation angle of the joint element, a shaft connected to the joint element or a joint element on the motor assembly side or a shaft connected to the joint element.
• the soundness of the magnetic coupling can be checked by measuring the transmission torque of the magnetic coupling.
• the test can be performed in a place with a good working environment outside the PCV, and workability can be improved and exposure can be reduced.
• the test apparatus may further include pressure supply means for pressurizing the inside of the spool piece, and pressure measurement means for measuring the pressure inside the spool bead. According to this, the spool bead is removed. In this case, a pressure test can be performed by pressing the inside of the spool bead partition wall.
• an electric motor assembly including an electric motor, a spool bush, and a magnetic coupling having a pair of coupling elements separated by a spool piece, and a driving force generated by the electric motor.
• An inspection device for a control rod drive device including a drive mechanism for transmitting the control rod to a control rod via a magnetic coupling to raise and lower the control rod is provided.
• This inspection device includes a first radial position fixing means for fixing the position of one of the joint elements constituting the magnetic joint or a shaft connected to the joint element in the radial direction, and the other joint constituting the magnetic joint. Second radial position fixing means for fixing the position of the element or the shaft connected to the joint element in the radial direction. Using this inspection device, the spool piece is disassembled or assembled with the axis of the spool piece and each joint element fixed.
• the magnetic joint Since the magnetic joint has a strong magnet built in, if disassembly / assembly is performed with the axis not fixed, the magnetic joint will be pulled by the force that attracts the inner and outer magnetic joints or the magnetic joint and the surrounding magnetic material. May hit the spool bead bulkhead, etc., and cause damage to the magnetic joint. With the axis fixed, the inner magnetic joint and the outer magnetic joint By performing disassembly / assembly, it is possible to prevent damage to the equipment and safely perform disassembly / assembly.
• a novel torque transmission device suitable for use in a control rod drive device.
• the torque transmission device includes a first coupling element that includes a plurality of magnets and is connected to a first shaft, a second coupling element that includes a plurality of magnets and is connected to a second shaft,
• a torque transmission device having a magnetic coupling including: a first jacket that water-tightly or air-tightly covers all magnets of the first joint element; and a water-tight or air-tight seal that covers all magnets of the second joint element.
• a third jacket that water-tightly or air-tightly covers part or all of a magnet built in the first joint element inside the first jacket.
• the first coupling element of the torque transmission device is installed inside the spool rib partition, and the second coupling element of the torque transmission device is installed outside the spool bead partition wall.
• the joint element is configured to be installed, and the magnet covered by the third jacket of the first joint element functions, and the magnet is covered by the third jacket of the first joint element.
• the torque transmission device be configured so that the torque transmission device has a maximum transmission torque greater than or equal to the torque required to maintain the control rod position during normal operation of the nuclear reactor in a state where the magnet does not function. In this way, a highly reliable control rod drive mechanism using a magnetic coupling can be constructed.
• FIG. 1 is a diagram illustrating a first embodiment of the present invention, and is a cross-sectional view along an axial direction schematically illustrating an embodiment of a control rod driving device according to the present invention.
• FIG. 2 is a conceptual diagram illustrating the configuration of the magnetic coupling shown in FIG. 1,
• FIG. 3 is a diagram illustrating a second embodiment of the present invention, and is a schematic diagram illustrating an inspection method of a magnetic coupling and an apparatus therefor,
• FIG. 4 is a graph illustrating an example of a torque characteristic of a magnetic joint.
• FIG. 5 is a diagram illustrating a third embodiment of the present invention, and is a schematic diagram showing a spool bead test device
• FIG. 6 is a view for explaining a fourth embodiment of the present invention, and is a schematic view showing a spool bead inspection device, and
• FIG. 7 is a cross-sectional view along the axial direction schematically showing a conventional control rod driving device. Description of the preferred embodiment
• FIG. 1 schematically shows a lower structure of the control rod drive mechanism according to the first embodiment, that is, a structure of a spool bead portion and an electric motor assembly portion.
• the structure above the spool bead 14 is the same as that of the prior art described with reference to FIG. 7, and the same reference numerals as in FIG. Are omitted.
• C also, regarding the lower structure, members that are the same as or similar to the members described in FIG. 7 are denoted by the same reference numerals as those in FIG. 7, and redundant description is omitted.
• the control rod drive mechanism shown in Fig. 1 is composed of a magnetic joint composed of an inner magnetic coupling element 31 and an outer magnetic coupling element 32 separated by a spool piece 14, a partition, a separation detection magnet 25, a drive shaft 3, etc. have.
• An electric motor assembly is provided below the spool bead 14, and an outer magnetic coupling 32 on the spool bead 14 side and a rotating shaft 1 on the electric motor assembly side are connected via a force coupling 2.
• the motor assembly includes a holding brake 19, a position detection device (sync position resolver) 20, a transmission 33, and an induction motor 35 with a braking brake 34 attached.
• the holding brakes 19 and the braking brakes 34 are the torques required to maintain the control rod position during normal operation of the reactor. Has torque.
• both the holding brakes 19 and the braking brakes 34 set the holding torque at rest to the torque required to maintain the control rod position during normal operation. Even if the brake function is lost, the control rod position can be reliably maintained, and a highly reliable control rod drive mechanism can be constructed.
• thermometers 36 and 37 are provided between the outer magnetic coupling element 32 and the partition wall of the spool bead 14 and the winding of the induction motor 35.
• the thermometer 36 may be arranged near the outer peripheral surface of the outer magnetic coupling element 32, and the thermometer 37 is positioned near the winding of the induction motor 35 ⁇ at an appropriate position in the casing. May be placed at
• a separation detection probe 27 and a scrum position detection probe 30 are provided outside the spool bead 14. These probes 27 and 30 each have a magnetically operated lead switch. .
• a plurality of reed switches (not shown) of the scrum position detection probe 30 are arranged in the vertical direction, and 0, 10, 40, 60, 100% ( (0% means full extraction, 100% means full insertion state) It is possible to detect the corresponding position.
• the separation detection probe 27 has a separation detection lead switch 38 for detecting the position of the separation detection magnet 25 and a magnetic joint out-of-step detection lead switch 39 for detecting the magnetic field state near the magnetic joint. I have.
• An electric motor power supply 41 is connected to the induction motor 35.
• Motor power supply 4 1 is connected to a fixed frequency power supply 44 of, for example, 6 OHz.
• a variable frequency power supply 45 is provided separately from the fixed frequency power supply 44, and either the fixed frequency power supply 44 or the variable frequency power supply 45 is selectively connected to the motor power supply 41. can do.
• the variable frequency power supply 45 may be a type capable of changing the frequency in a stepped manner or a type capable of continuously changing the frequency.
• the synchronous rotation speed is proportional to the power supply frequency, and the rotation speed also varies depending on the load.
• multiple frequencies can be selected as the motor power supply.
• Medium-speed drive during reactor operation high-speed drive to reduce drive time when the reactor is stopped, and control implemented during plant inspection when the reactor is stopped During the bar friction measurement test, highly flexible operation is possible depending on the situation, such as low-speed drive.
• control rod friction measurement test it is possible to detect load fluctuations such as friction by driving the control rod at a low speed from the fully pulled state to the fully inserted state and measuring the drive speed.
• load fluctuations such as friction
• driving at a low speed makes it possible to clearly detect short-term load fluctuations, etc., and it is a highly reliable test.
• control rod friction measurement test can also be performed by confirming the detected values of these ammeters.
• the reactor since the fixed frequency power supply 44 and the variable frequency power supply 45 of 60 Hz are separately provided, the reactor is connected to the fixed frequency power supply 44 during reactor operation, and the reactor is stopped. During operation, it is possible to connect to the variable frequency power supply 45 as necessary, thereby eliminating the possibility of connecting to the wrong power supply during the operation of the reactor, enabling highly reliable operation.
• a plurality of types of frequencies can be selected.
• fixed voltage power supply 44 and variable voltage power supply 45 may be provided instead of fixed frequency power supply 44 and variable frequency power supply 45.
• the motor power supply device 41 has two switches 40, 40 connected in series. Each of the switches 40 can be independently controlled by a signal transmitted from the control device 42 via a command signal transmission path that is separate from each other.
• the motor power supply 41 is provided with a thermal relay 43 as a protective relay. When the load torque of the induction motor 35 increases, the drive current value supplied to the induction motor 35 increases, and the thermal relay 43 operates. Note that the protection relay is not limited to the thermal relay 43, and another protection relay may be used.
• the holding brake power supply device 46 is also connected to the holding brake 19.
• a fixed frequency power supply (not shown) is connected to the power supply 46.
• the holding brake power supply 46 also has two switches 47, 47 connected in series. Each of the switches 47 can also be independently controlled by a signal transmitted from the control device 42 through a command signal transmission path of a different system.
• the switches 40 and 47 may be contacts or semiconductor switches.
• the inner magnetic coupling element 3 1 that forms the magnetic coupling incorporates 8-pole magnets 50 and 51, and the outer magnetic coupling element 3 2 that forms the magnetic coupling also has an 8-pole magnet 4 8 , 49.
• Each of the magnets 48, 49, 50, 51 has a yoke 53, 54, 55, 56 made of a magnetic material for forming a magnetic circuit 52.
• the inner surfaces of the magnets 48, 49 of the outer magnetic coupling element 3 2 are covered and sealed by a sleeve 57, and the outer surfaces of the magnets 50, 51 of the inner magnetic coupling element 31 are sleeve 5 Covered and sealed by 7.
• the inner and outer magnetic coupling elements 31, 32 are magnetically coupled by the magnetic force of each magnet 48, 49, 50, 51. For this reason, Power can be transmitted between the inner and outer magnetic coupling elements 31 and 32 in a non-contact manner through the partition wall of the spool piece 14.
• magnet A is a smaller magnet than the other magnets 49 (hereinafter referred to as “magnet B”).
• magnet 50 hereinafter, referred to as “magnet C” with the symbol C of the inner magnetic coupling element 31 is the other magnet 51 (hereinafter, “magnet C”) with the symbol D.
• a yoke (hereinafter referred to as “Y”) that is in contact with magnet A of outer magnetic coupling element 32
• the "yoke A”) is smaller than the yoke labeled B (hereinafter “yoke B”). Also.
• the yoke with the symbol C (hereinafter referred to as “yoke C”) in contact with the magnet with the symbol C on the inner magnetic coupling element 31 is smaller than the yoke with the symbol D (hereinafter “yoke D”). It has become.
• the yoke A and the yoke B may be integrally molded, and the yoke C and the yoke D may be integrally molded.
• the small magnets ie, the magnets A and C
• a jacket 59 and have a spacer 60 at an upper portion thereof.
• Fig. 2 (b) shows only the magnet C and its surroundings
• the magnet A and its surroundings are also identical except that the yoke is located on the outer periphery of the magnet.
• the configuration is the same as magnet C and its surroundings (see Fig. 2 (a)).
• magnets A and C N yokes A and C are each provided two at a time, and are arranged at point-symmetric positions with respect to the axis. Are arranged so as to face each other.
• This magnetic joint does not expect the functions of magnets B and D, but uses only the magnetic attraction acting between magnets A and C as the torque required to maintain the control rod position during normal operation of the reactor.
• the maximum transmission torque of 0.3 kgfm or more in terms of shaft conversion is secured.
• the magnets 48 (magnet A) and magnet 50 (magnet C) for two poles are individually The control rod position holding torque during normal operation is exhibited without expecting the functions of the other magnets 49 (magnet B) and magnet 51 (magnet D).
• the step-out of the magnetic coupling can be detected.
• a small magnet is partially incorporated inside the magnetic joint.
• similar effects can be expected when magnets having different magnetic properties (for example, magnetic flux density) are incorporated.
• the controller 42 stops the power supply to the electric motor 35 to stop the drive of the control rod, or the output of the position detector 20. It is possible to display a message indicating that the output of the scrum position detection probe 30 is out of the predetermined relationship with the output of the scrum position detection probe 30 or to generate an alarm. Further later As a measure, it is possible to take appropriate measures such as isolating the control rod drive mechanism as an inoperable control rod, and to construct a highly reliable control rod drive mechanism.
• the control device 42 has the following functions.
• the control device 42 issues a control rod drive / stop command based on the operation of the operator.
• the power supply devices 41 and 46 controlled by the control device 42 start or stop supplying power to the induction motor 35, the braking brake 34 and the holding brake 19.
• control device 42 At the start of control rod driving, the control device 42 first controls the power supply device 46 and first releases the holding brake 19. Next, the controller 42 controls the power supply 41 to energize the braking brake 34 and the induction motor 35 at the same time. Note that the braking brakes 34 and 4 stop holding when they are energized and are released. This causes the rotating shaft 1 to start rotating.
• the control device 42 When stopping the drive of the control rod, the control device 42 first controls the power supply device 41, and first stops the power supply to the braking brake 34 and the induction motor 35 at the same time.
• the braking brake 34 performs a holding operation when the power is not supplied. Then, after the rotation of the rotation shaft 1 stops, the control device 42 controls the power supply device 46 to bring the holding brake 19 into the holding state.
• control device 42 can perform control to issue a drive stop command when the control rod is driven, for example, 4 mm before the stop target position. That is, considering the transmission delay, the capacity of the braking brake 35, and the like, it is considered that the control rod advances by 2 mm or more and stops after the control rod stop command is transmitted from the control device 42. Therefore, by issuing a stop command 4 mm before the target stop position, the accuracy of the stop position is improved.
• the control device 42 knows the position of the control rod based on the signal transmitted from the position detection device 20. C being monitored signal even together from over Bed 2 7 and scrum position detecting probe 3 0
• the controller 42 monitors (a) the temperature of the winding portion of the induction motor 35 by monitoring a signal transmitted from the thermometer 37 to the controller 42, and (b) The temperature of the magnetic joint is monitored by monitoring the signal transmitted from the total 36 to the control device 42, and (c) the control rod drive speed is monitored by monitoring the signal transmitted from the position detection device 20.
• the control rod drive speed can be calculated by differentiating the control rod position detected by the position detection device 20 with respect to time, or from the amount of change per unit time of the control rod position.
• an alarm is issued to the operator by an alarm generator (not shown). If the first predetermined value is exceeded, instead of or in addition to the generation of an alarm, information indicating that fact is displayed by an appropriate display means and transmitted to the operator. Is also good.
• control device 42 issues a drive stop command for the control rod.
• the first predetermined value and the second predetermined value are set, and when each of the predetermined values is exceeded, the control device 42 takes a predetermined action.
• a predetermined range of allowable values is set for the winding part temperature, the magnetic coupling part temperature, and the control rod drive speed of the induction motor 35, and the predetermined range in which each parameter is allowed is set.
• measures such as stopping the motor and generating an alarm may be taken in the same manner as described above.
• the control device 42 issues an alarm when the summary relay 43 is activated, and further issues a control rod drive stop command.
• the abnormality of the control rod be detected quickly, but also the excessive torque applied to the magnetic coupling can be prevented, and the magnetic coupling can be prevented from stepping out.
• an ammeter, a voltmeter or a wattmeter is provided in the power supply device 41, and monitoring is performed by monitoring a signal transmitted from the ammeter or the like to the control device 42.
• the first predetermined value is If it exceeds, instead of or in addition to the generation of an alarm, information indicating that fact may be displayed on an appropriate display means to inform the operator.
• the control device 42 may issue a drive stop command for the control rod.
• the control unit 42 compares the actual stop position after the drive stop of the control rod with the target stop position or the control rod position when the drive stop command is issued, and compares the actual stop position with the target stop position or drive stop.
• the difference from the control rod position at the time of command generation deviates from a predetermined range
• the deviation from the predetermined range is displayed on a display device (not shown), or an alarm is issued to an operator by an alarm generation device (not shown). Emit.
• control device 42 compares the stop position after the drive stop of the control rod with the initial position before the drive start of the control rod, and when the difference between the stop position and the initial position deviates from a predetermined range.
• the departure from the predetermined range is displayed on a display device (not shown) or an alarm is issued to the operator by an alarm generator (not shown).
• the control device 42 compares the output of the position detection device 20 with the output of the scrum position detection probe 30 and finds that the relationship between the two at the control rod full insertion position, control rod full withdrawal position, or other positions. If the specified relationship is not established, an alarm is issued and a control rod drive stop command is issued.
• the control device 42 issues an alarm when the thermal relay is activated, and stops the power supply to the motor.
• the control device 42 can execute a drive mode in which the control rod is inserted once beyond the target stop position during the control rod insertion operation, and then the control rod is automatically pulled out to the target stop position. it can.
• control performed by the control device 42 ensures the accuracy of the control rod drive, and also enables the generation of an alarm based on the state of the control rod drive mechanism and the stop of the control rod drive. It is possible, and the reliability of the control rod drive mechanism is improved.
• FIG. 3 shows a state where the motor assembly is removed from the control rod drive mechanism shown in FIG. In this case, the scrum position detection probe 30 and the separation detection probe 27 are also removed.
• the outer magnetic coupling element 32 has an opening 61 at a position corresponding to the pole of each magnet below the outer magnetic coupling element 32.
• the magnetic sensor 62 can be inserted between the spool piece 14 and the partition wall.
• a first inspection method of the magnetic coupling will be described.
• a first test apparatus having a magnetic sensor 62, a cable 63 connected to the magnetic sensor 62, and a recorder 64 was prepared.
• the magnetic sensor 62 is inserted between the outer magnetic joint 32 and the spool bead 14 partition.
• the magnetic coupling generates a transmission torque by magnetic interaction between the inner / outer magnetic coupling elements 31 and 32. Therefore, by measuring the magnetism (for example, magnetic field strength) between the inner / outer magnetic coupling elements 31 and 32, it is possible to confirm the tendency of the transmission torque to degrade.
• the magnetism for example, magnetic field strength
• a coil or the like is installed between the outer magnetic joint 32 and the spool piece 14 partition wall or in a location where the leakage magnetic field is strong outside the spool piece 14 and the magnetic field is measured. It is also possible to confirm the transmission torque of the magnetic joint by rotating the joint and measuring the induced electromotive force associated with the magnetic field fluctuation generated at that time.
• the magnetic sensor 62, cable 63, and recorder 64 should be installed when conducting the inspection, and removed during reactor operation. Of course, it is possible to always connect the magnetic sensor 62, the cable 63, and the recorder 64 to monitor the state of the magnetic joint.However, by temporarily connecting, the cable wiring required for constant monitoring is possible. A control device is not required.
• the first test equipment was stored outside the containment vessel during plant operation, and Inspection contributes to reduction of exposure during inspection work. By storing the magnetic sensors 62 and the like outside the containment during plant operation, the radiation irradiation conditions and the like to the magnetic sensors 62 and the like are relaxed, which is also effective in ensuring the integrity of equipment.
• the second test apparatus is composed of a shaft 69 to which a torque meter 65, a torque limiter 66, a rotation angle measuring device 67, and a hand-arm 68 are connected.
• the outer magnetic coupling element 32 rotates with respect to the inner magnetic coupling 31 according to the magnitude of the applied torque, and a phase difference occurs between the two.
• a maximum transmission torque is generated when the phase difference is about 22.5 degrees as shown in FIG. Therefore, when the torque applied to the arm 68 is gradually increased, the maximum transmission torque is exhibited near a torsion angle of about 22.5 degrees. If the arm 68 is turned any further, the torque will decrease and the magnetic coupling will step out.
• the following method can be used to confirm that the transmission torque of the magnetic joint is equal to or higher than a predetermined standard value.
• the transmission torque of the magnetic joint can be checked without removing the spool bead 14 from the control rod drive mechanism, and the work amount / process / exposure amount at the time of the regular inspection can be checked. Reduction can be achieved. Also, it is possible to check the transmission torque of the magnetic joint without removing the spool bead 14 from the control rod drive mechanism, and to reduce the amount of work / process / exposure during regular inspection. is there. In particular, in the second inspection method, the transmission torque is directly measured instead of measuring the magnetism, so that the transmission torque can be measured with higher accuracy than the first inspection method.
• an effective method for confirming the soundness of the magnetic coupling can be established, and by using the above method, a more reliable magnetic coupling can be used.
• a control rod drive mechanism can be constructed.
• the same test as described above can be performed without removing the motor assembly.
• the rotating shaft 1 of the motor assembly is configured to penetrate the casing from below the braking brake 34 to protrude, and the second test device is connected to the tip of the protruding rotating shaft 1. This is possible.
• the second embodiment relates to a method and an apparatus for inspecting a spool piece and a magnetic coupling that are part of a control rod drive mechanism.
• FIG. 5 shows a state in which the spool piece 14 removed from the control rod drive mechanism is installed in the spool bead testing device according to the present embodiment.
• the spool piece test apparatus has an upper lid 71 that closes an upper opening of the spool piece 14.
• the top lid 7 1 The shaft 72 is fixed via a fixing jig 73, and a coupling 70 a that can be connected to the inner magnetic coupling element 31 is provided at the lower end of the shaft 72.
• a pressure pump 76 for pressurizing the inside of the spool piece 14 and a pressure gauge 77 for pressure measurement are connected to the upper lid 71.
• the electric motor assembly and the spool bead 14 are removed from the control rod drive mechanism, and placed on the mount 70 of the spool bead test apparatus.
• the coupling 70a is coupled to a shaft of a member supporting the separation detection magnet 25.
• the drive shaft 3 connected to the inner magnetic coupling element 31 cannot rotate.
• the upper lid 71 is attached to the spool piece 14 by a port 74. At this time, the space between the upper lid 71 and the spool bead 14 is sealed with an O-ring 75.
• the second inspection device described in the second embodiment is connected to the coupling 2 coupled to the shaft of the outer magnetic joint 42 located below the spool bead 14.
• the inner magnetic coupling element 31 cannot rotate even if torque is applied to the arm 68. Therefore, the outer magnetic coupling element 32 rotates with respect to the inner magnetic coupling element 31 in accordance with the magnitude of the torque applied thereto, and a phase difference occurs between the two.
• the transmission torque it is possible to measure the maximum transmission torque of the magnetic joint as in the second embodiment.
• a pressure test of the spool bead 14 can be performed.
• the outer magnetic coupling element 32 is fixed, and the second inspection device is connected to the coupling 70a. Even when the inner magnetic coupling element 31 is rotated, the maximum transmission torque of the magnetic coupling can be measured.
• the spool piece 14 is removed from the control rod drive mechanism, and the test device according to the present embodiment installed outside the containment vessel is installed.
• the work can be performed easily as compared with the method described in the second embodiment, which contributes to the reduction of exposure.
• the fourth embodiment relates to a method and an apparatus for disassembling and inspecting a spool bead 14 and a magnetic coupling which form a part of a control rod drive mechanism.
• FIG. 6 shows a state in which the spool piece 14 is installed in the control rod drive mechanism inspection device according to the present embodiment, and the spool bead 14 is being disassembled / assembled.
• the inspection device has a water tank 78 that can accommodate a spool piece 14 and a magnetic coupling.
• a stand 79 on which the spool piece 14 is placed is provided in the water tank 78.
• rails 90 and 91 are laid in the water tank 78 along the axis of the spool bead 14 mounted on the stand 79. On these rails 90, 91, trucks 84, 85 are provided, and on rails 90, 91, c trucks 84, 85 are provided so as to be movable along them. Element 31 and outer magnetic coupling element 32 correspond respectively.
• a shaft 81 is rotatably mounted on the cart 84, and the shaft 81 is located on the same line as the axis of the spool bead 14 mounted on the platform 79.
• a coupling 81 is provided at the end of the shaft 83.
• the coupling 81 can be coupled to a shaft coupled to the inner magnetic coupling element 31.
• a shaft 82 is rotatably mounted on the cart 85, and the shaft 82 is located on the same line as the axis of the spool piece 14 placed on the platform 79.
• a coupling 80 is provided at the tip of the shaft 82.
• the coupling 80 can be connected to a shaft connected to the outer magnetic coupling element 32.
• trolleys 88, 89 are placed on rails 90, 91 and rails 90, 91.
• a spool bead 14 placed on a table 79 is provided so as to be movable in the axial direction.
• the cart 88 is provided with a magnetic jacket 86 that covers the periphery of the inner magnetic coupling element 31.
• the bogie 89 is provided with a magnetic material jacket 87 surrounding the outer magnetic coupling element 32.
• an ultrasonic oscillation facility 92 is provided in the water tank 78 so that the spool piece 14 and the like put in the water tank 78 filled with water can be ultrasonically cleaned.
• a movable magnet 93 is provided in the water tank 78.
• the inspection device has a hose 94 for supplying pressurized air.
• the inner magnetic coupling element 3 1 is fixed with the shafts of the inner magnetic coupling element 31 and the outer magnetic coupling element 32 fixed on the axis of the spool bead 14. Since the magnetic coupling element 32 and the outer magnetic coupling element 32 can be separated and connected, it is possible to prevent the magnetic coupling from being damaged by contact with other devices.
• the surrounding of the inner and outer magnetic coupling elements 31 and 32 are covered with magnetic jackets 86 and 87, respectively, to reduce magnetic field leakage to the surroundings and reduce the effect on peripheral equipment. can do.
• the magnetic powder and the like in the water tank 78 can be collected, and the surfaces of the inner magnetic coupling element 31 and the outer magnetic coupling element 32 can be recovered. Of magnetic powder and the like can be reduced.
• the outer shells 86, 87 of the magnetic material are provided to cover the inner and outer magnetic coupling elements 31 and 32 in the water tank 78. May be covered with a jacket. Also, when storing and transporting the inner and outer magnetic coupling elements 31 and 32 and the spool beads 14, it is possible to reduce the magnetic effect on peripheral devices by covering the surroundings with a magnetic material jacket. it can.

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• 1999
  • 1999-09-29 JP JP27748999A patent/JP2001099974A/ja active Pending
• 2000
  • 2000-09-29 WO PCT/JP2000/006785 patent/WO2001024197A1/ja active Application Filing
  • 2000-09-29 CN CNA2005100067407A patent/CN1645520A/zh active Pending
  • 2000-09-29 CN CN2006101416630A patent/CN101110279B/zh not_active Expired - Fee Related
  • 2000-09-29 CN CNB00802104XA patent/CN100468580C/zh not_active Expired - Fee Related
• 2001
  • 2001-05-28 FI FI20011107A patent/FI120924B/fi not_active IP Right Cessation
• 2007
  • 2007-05-02 FI FI20070349A patent/FI20070349L/fi not_active Application Discontinuation

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