JP2016008892A - Control rod insertion seismic qualification test device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To generate vibration in a horizontal plane in fuels within a test container by a plurality of vibrators connected to the fuels in a horizontal direction.SOLUTION: A control rod insertion seismic qualification test device of the present invention comprises: simulant fuels simulating fuels in a nuclear reactor; control rods inserted into clearances among the simulant fuels; a plurality of vibrators connected to the respective simulant fuels via connection jigs; and a reaction force wall fixed to the vibrators. According to the present invention, the vibrators connected to the fuels within a test container in a horizontal direction can generate vibration in a horizontal plane in the fuels.

Description

The present invention relates to a control rod insertion property seismic test apparatus.

  A nuclear power plant is a facility where various safety measures are taken so as not to affect the surrounding environment because radioactive materials are generated by operation. In Japan, one of the world's most earthquake-prone countries, an earthquake detector is installed in the reactor building, and the reactor is designed to automatically shut down by inserting a control rod into the reactor core when a large shake exceeding the set value is detected. Has been.

  According to the “JEAC4601-2008 Nuclear Power Station Seismic Design Technical Regulations” issued by the NEC Association, “Control rods must be urgently inserted even when the standard seismic motion Ss is occurring” and “BWR `` The sheath does not lose the function to hold the neutron absorber in the PWR in the PWR '', and the functions required for the control rod include the insertion function during earthquakes and the neutron absorber. The function to hold is mentioned. Furthermore, for these functions, it is stipulated that the conformity of acceptance criteria must be confirmed by analysis or testing.

An example of an apparatus for confirming the seismic resistance of the control rod insertion function during an earthquake by a test is disclosed in Japanese Patent Laid-Open No. 2012-8085. In this background art, a plurality of simulated fuels and control rods simulating the fuel in a nuclear reactor are housed in a liquid-filled vessel, and a control rod driving device for inserting the control rods between the simulated fuels is attached. A test container, a reaction force wall installed around the test container, a vibrator fixed to the reaction force wall to vibrate the test container in one direction, and the test container along the one direction And a supporting means for supporting the test container so as to be reciprocally movable. With this technology, we are trying to reduce the vertical load of the test vessel that the shaker bears when oscillating the test vessel in one direction, and to suitably excite the test vessel in a state close to an actual earthquake. .

Another example of a control rod insertion property seismic test apparatus is disclosed in Non-Patent Document 1. In this background art, a plurality of simulated fuels are stored inside a liquid-filled container, and an excitation mechanism installed outside the test container is connected to the simulated fuel in the test container with a jig. ing. With this technology, an attempt is made to generate a desired vibration in the fuel by directly oscillating the simulated fuel in the test vessel with a vibrator.

JP 2012-8085 JP

Watanabe, Y., and Motora, Y., “Analysis of CR scrammability characteristics on the condition of the forced vibration of fuel assemblies”, Trans. Int. Conf. Struct. Mech. React. Technol., Vol. 7th, No. F, (1983), pp.357-364.

  In the control rod insertion-type seismic test apparatus of Patent Document 1, although a plurality of shakers are connected to the test container, the excitation direction is limited to one direction. In the control rod insertion-type seismic test apparatus of Non-Patent Document 1, a plurality of simulated fuels are vibrated by a set of vibrators and jigs. Also in this case, the excitation direction of each fuel is limited to one direction.

  Reactors have different fuel shapes, placement in the reactor, and installation intervals depending on the model. As a result, depending on the type of the reactor, fuels may contact each other during an earthquake, and vibrations with different directions and amplitudes may occur in each fuel. If this effect is significant, the reliability of the evaluation is improved by a control rod insertion test in a state where each fuel is vibrated in different directions and amplitudes.

  An object of the present invention is to cause a fuel in a test vessel to generate a vibration in a horizontal plane by a plurality of vibrators connected in a horizontal direction.

The present invention includes a simulated fuel simulating a fuel in a nuclear reactor, a control rod inserted in a gap between the simulated fuels, a plurality of vibrators connected to each of the simulated fuels via a connecting jig, A reaction force wall fixed to the vibrator is provided.

According to the present invention, vibration in the horizontal plane can be generated in the fuel in the test container by the plurality of shakers connected in the horizontal direction.

BRIEF DESCRIPTION OF THE DRAWINGS It is the whole schematic diagram of the control-rod insertion property earthquake-proof test apparatus which concerns on Example 1 of this invention. It is sectional drawing in the AA cross section in FIG. It is the schematic of the control apparatus of the vibration exciter 80 in FIG. FIG. 3 is a schematic view of a periphery of a joint portion between a simulated fuel 20 and a connection jig 90 in FIG. 2. FIG. 6 is a schematic diagram of a simulated fuel 20, a connection jig 90, and a vibrator 80 according to a second embodiment. FIG. 6 is a schematic view of a simulated fuel 20, a connection jig 90, and a vibration exciter 80 according to a third embodiment. It is sectional drawing of the control-rod insertion property earthquake resistance test apparatus which concerns on Example 4. FIG.

  The present invention relates to an apparatus for testing the seismic resistance of a function of inserting a control rod into a core used in a nuclear power plant nuclear reactor. Hereinafter, each example will be described with reference to the drawings.

  This embodiment will be described with reference to FIGS. 1 is a diagram showing an overall schematic diagram of a control rod insertion seismic test apparatus according to this embodiment, FIG. 2 is a cross-sectional view taken along section AA in FIG. 1, and FIG. 3 is a control apparatus for a vibrator 80 in FIG. FIG. 4 is a schematic view of the vicinity of the joint between the simulated fuel 20 and the connecting jig 90 in FIG. This embodiment is directed to a boiling water reactor.

  Inside the test vessel 10, a simulated fuel 20 that simulates the fuel in the nuclear reactor, a control rod 30 that is inserted into a cross-sectional gap between the simulated fuels 20, a fuel support bracket 40 for installing the simulated fuel 20, and a fuel support A metal fitting 40 is installed, a simulated core support plate 50 that simulates a part of the core support plate in the reactor, and an upper part of the simulated fuel 20, and a simulated upper lattice that simulates a part of the upper grid plate in the reactor. A guide tube 70 in which the plate 60 and the non-inserted control rod 30 are housed is installed. Since the test target is one cell of the core structure of the boiling water reactor, the test body is composed of four simulated fuels 20 and one control rod 30, fuel support bracket 40, and guide tube 70 each. . Each simulated fuel 20 is connected to a shaker 80 via a connection jig 90, and the shaker 80 is fixed to the reaction force wall 100. A control rod drive mechanism housing 71 is connected to the lower end of the guide tube 70 and contains the control rod drive mechanism. Further, a water pressure control unit (not shown) for supplying drive energy of the control rod is connected to the control rod drive mechanism via a scram pipe 72. In order to simulate the environment of the actual machine, the test container 10 is filled with water, and the internal water is maintained at the same high temperature and high pressure as the actual machine by the pump 110 and the heater 120 connected to the test container 10.

  FIG. 2 is a cross-sectional view taken along the line AA in FIG. As shown in this figure, a vibration exciter 80 is connected to the simulated fuel 20 via a connection jig 90. In order to cause the simulated fuel 20 to generate a vibration in a horizontal plane that is closer to the vibration behavior at the time of the earthquake, a plurality of vibrators 80 are connected to the single simulated fuel 20 in the horizontal direction. Further, a plurality of vibrators 80 are connected to each simulated fuel 20 via connecting jigs 90 so that the control rod insertion test can be performed in a state where each fuel is vibrated in different directions and amplitudes. Connected horizontally.

  FIG. 3 is a schematic diagram of the vibration exciter control device in FIG. The control device 130 is a computer including a processing device (for example, a CPU) and a storage device, and controls the displacement of each vibrator 80. In the case of the control rod insertion seismic test, vibration analysis of the target reactor core structure is performed in advance, for example, by numerical simulation, and the vibration response displacement of the fuel group is calculated. From the vibration response displacement calculation results, the vibration response displacements of the four fuels constituting the cell set as the evaluation target are extracted. This vibration response displacement is set as a displacement generated in the four simulated fuels 20 as test bodies, that is, a target displacement in the test. The control device 130 controls each of the vibrators 80 so that the four simulated fuels have the target displacement.

  FIG. 4 is a schematic view of the vicinity of the joint portion between the simulated fuel 20 and the connection jig 90 in FIG. The connection jig 90 according to the present embodiment includes a movable portion 140 having a guide structure, and is connected to the simulated fuel 20 via the movable portion 140. The movable part 140 of the guide structure is achieved by guiding in the vibration direction of a separately connected vibration exciter, moving in the vibration right-angle direction, and restraining the rotational movement. For example, in the case of the shaker connected in the X-axis direction in FIG. 4, the movable portion 140 can move in the Y-axis direction, and therefore the vibration of the simulated fuel 20 provided by the shaker connected in the Y-axis direction. The vibration of the shaker is transmitted to the simulated fuel 20 while absorbing the displacement. According to the present embodiment, the fuel in the test container can generate vibrations in the horizontal plane by the plurality of vibrators connected in the horizontal direction. Furthermore, since a separate vibrator is connected to each fuel, vibrations with different directions and amplitudes can be generated in each fuel.

  FIG. 5 is a schematic diagram in the vertical direction of the simulated fuel 20, the connection jig 90, and the vibrator 80 according to the present embodiment. In the connection jig 90 according to the present embodiment, the structure on the side connected to the simulated fuel 20 has a bifurcated structure in the vertical direction, so that two places in the vertical direction of the simulated fuel 20 can be applied. Since the upper and lower ends of the simulated fuel 20 are supported by the simulated upper lattice plate 60 and the fuel support fitting 40, when two vertical positions are applied, the simulated fuel 20 is in a four-point bending state. Since the connection jig 90 according to the first embodiment has a structure in which one place of the simulated fuel 20 is applied in the vertical direction, the simulated fuel 20 is in a three-point bent state. Inertial forces act on the fuel during an earthquake, and evenly distributed loads act on fuel with a nearly uniform mass distribution. In this case, the distribution of the bending moment generated in the fuel is parabolic. On the other hand, the bending moment distribution acting on the simulated fuel 20 has a triangular shape in the case of three-point bending and a trapezoidal shape in the case of four-point bending. In general, the parabolic bending moment distribution can be approximated better by the trapezoidal bending moment distribution than by the triangular bending moment distribution, so that the bending moment distribution acting during an earthquake can be simulated more accurately. The second embodiment is advantageous because the simulated fuel 20 can be bent at four points.

  FIG. 6 is a schematic diagram in the vertical direction of the simulated fuel 20, the connection jig 90, and the vibrator 80 according to the present embodiment. A plurality of vibrators 80 arranged in the vertical direction are connected to the simulated fuel 20 according to the present embodiment via connection jigs 90. Since the simulated fuel 20 is energized by a plurality of vibrators 80 arranged in the vertical direction, the simulated fuel 20 is in a bending state due to other-point excitation, and the bending moment distribution acting during an earthquake can be simulated more accurately. Further, since the load required per one point of application can be reduced, there is an advantage that the connection jig 90 can be a lightweight structure with low rigidity and the capacity of the vibration exciter can be reduced.

FIG. 7 is a cross-sectional view of a control rod insertion seismic test apparatus according to this embodiment. This embodiment is intended for a next-generation boiling water reactor. The differences from the first embodiment of the nuclear reactor are that the cross-sectional shape of the simulated fuel 20 is hexagonal, the cross-sectional shape of the control rod 30 is Y-shaped, and the number of fuels constituting one cell is three. It is to be a body. As shown in this figure, similarly to the first embodiment, a vibration exciter 80 is connected to the simulated fuel 20 via a connection jig 90. In order to cause the simulated fuel 20 to generate a vibration in a horizontal plane that is closer to the vibration behavior at the time of the earthquake, a plurality of vibrators 80 are connected to the single simulated fuel 20 in the horizontal direction. Further, a plurality of vibrators 80 are connected to each simulated fuel 20 via connecting jigs 90 so that the control rod insertion test can be performed in a state where each fuel is vibrated in different directions and amplitudes. Connected horizontally. In addition, Example 2-3 can be applied also to a present Example. Generally, the fuel structure of a nuclear reactor is a long structure, and the control rod is inserted into a gap surrounded by a plurality of fuels constituting one cell, or each fuel structure as in a pressurized water reactor. It has the common point that it is inserted inside the. For this reason, although the required number of shakers 80 and connecting jigs 90 differ depending on the reactor type to be tested, the method for exciting simulated fuel 20, the structure of connecting jig 90, each shaker Since the control method of 80 can be the same, the control rod insertion seismic test apparatus of the present embodiment can be applied to various nuclear reactors.

DESCRIPTION OF SYMBOLS 10 Test container 20 Simulated fuel 30 Control rod 40 Fuel support metal fitting 50 Simulated core support plate 60 Simulated upper lattice plate 70 Guide tube 71 Control rod drive mechanism housing 72 Scram piping 80 Exciter 90 Connecting jig 100 Reaction force wall 110 Pump 120 Heater 130 Control device 140 Movable part

Claims (3)

Simulated fuel simulating fuel in a nuclear reactor, control rods inserted into the gap of the simulated fuel, a plurality of shakers connected to each simulated fuel via a connecting jig, fixed to the shaker A control rod insertion seismic test device characterized by comprising a reaction wall that is provided. A control rod insertion seismic test device according to claim 1,
A control rod insertion seismic test apparatus comprising a movable part having a guide structure at a tip of the connection jig. A control rod insertion seismic test device according to claim 1,
The control rod insertion seismic test apparatus characterized in that the structure of the connecting jig connected to the simulated fuel has a bifurcated structure in the vertical direction.