JPS61239112A - Fuel channel measuring instrument - Google Patents

Abstract

PURPOSE:To reduce the contamination of an instrument, and to measure simultaneously, quickly and exactly a sectional deformation, a bend, and a twist by providing a U-shaped sensor holding frame having plural pieces of non-contact type sensors, and a measuring means. CONSTITUTION:A fuel channel 8 to be measured is hung by a crane, and placed in a sensor holding frame 4. In this case, it is placed so that a center line for linking the centers of the upper end part and the lower end part of the channel 8 becomes parallel to the holding frame 4, and intervals to each sensor which has been placed on an inner wall 40 and side walls 42, 43 becomes roughly constant. Subsequently, a measurement of a sectional deformation, a measurement of a twist, and a measurement of a bend are executed by measuring internals l1-l6 between the side walls 42, 43 and the channel 8 by a sensor 5 of the center part, intervals l1, l3, l4 and l6 between the holding frame 4 and the channel 8 by each sensor of the upper and the lower parts and the center part, and also intervals l2-l5 by the sensor of the center part of the width direction of both the side walls 42, 43, respectively, and by measuring and recording its result by a measuring and recording device, the sectional deformation, the twist and the bend can be measured simultaneously.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a device that can easily measure strain in a fuel channel.

(Prior Art) A fuel channel box in a nuclear reactor is subjected to thermal stress due to heat generated by the nuclear fission reaction of the fuel rods inside, resulting in distortions such as bending in the length direction, deformation in cross section, and twisting.

If this strain exceeds a certain level, it will cause problems in the withdrawal and insertion of the control rods and in the control of nuclear fission reactions by the control rods, so it is necessary to measure the strain quickly and accurately.

As a device for measuring the strain in the fuel channel, a device as disclosed in, for example, Japanese Unexamined Patent Publication No. 55-6202 is known. In this system, a frame holding multiple detectors moves along the fuel channel, which is the object to be measured, and the signal from each detector is converted into the amount of strain using a measuring device. be. However, this device is configured to measure strain by moving along the fuel channel surface while the upper and lower guide supports are in contact with the fuel channel, and therefore has the following problems. That is, (1) only cross-sectional deformation can be measured.

(2) Since it slides in contact with the channel surface, the measuring device is likely to be contaminated.

(3) There is a risk of deforming the fuel channel.

(Objective of the Invention) The present invention has been made to solve the above-mentioned conventional problems, and is to provide a method for quickly and accurately measuring not only cross-sectional deformation but also bending and torsion at the same time with less contamination of the device. The purpose is to provide a device that can do this.

(Structure of the Invention) The present invention provides a sensor holding frame having a cross-section shape in horizontal cross section consisting of a back wall and both side walls, a holding column for vertically maintaining the sensor holding frame in a pool, and eight walls of the sensor holding frame. The fuel channel includes a plurality of non-contact sensors arranged in each of the fuel channels, and a measuring means for measuring the distance between each sensor and the facing surface of the fuel channel based on the signals from each of the sensors. In addition, in the sensor holding frame of the part facing the upper and lower ends of the fuel channel in the height direction and the central part,
The non-contact type sensor may be arranged at a central portion in the width direction of the back wall and at portions of both side walls corresponding to the central portion in the width direction and near both ends of the fuel channel.

(Example) In FIGS. 1 to 3, a holding post 3 is provided along the surrounding wall 1 in a pool 2 surrounded by a surrounding wall 1, and the sensor holding frame 4 is held vertically by this holding post 3. ing. The sensor holding frame 4 has a horizontal cross-sectional shape consisting of a back wall 40 and both side walls 42 and 43, and is formed in the shape of an opening. The signal from the sensor is measured and recorded outside the pool 6
The cross-sectional deformation, torsion, and bending described below are measured and recorded. And the fuel channel 8 to be measured
is suspended by a wire 7 by a crane (not shown) and placed in the sensor holding frame 4 to perform various measurements as will be described later.

The arrangement of the sensor 5 with respect to the sensor holding frame 4 is as follows. That is, on the side wall '42, sensors are arranged at nine positions A, B, C, ..., ■ from the top, at the center of the width direction of the side wall 42, and on both sides of the sensor A at the upper end. One sensor 5 of each A-IA-2 is arranged near both measurement parts of the fuel channel 8 to be measured, and one sensor 5 of each A-IA-2 is arranged at opposite positions near both measurement parts of the fuel channel 8 to be measured. One each of sensors 5 is arranged for E-2, and one each of sensors 5 for L-1 and I-2 are arranged on both sides of sensor I at the lower end. Further, on the side wall 43, J-R, J-1, and J-2 are arranged opposite to each sensor arranged on the side wall 42.
, N-1, N-2, R-1, and R-2 are arranged. Further, one sensor 51T1U is arranged at each of the upper end, center, and lower end of the back wall 40.

For example, an ultrasonic sensor is suitable as the non-contact type sensor 5, but an eddy current sensor or the like may also be used.

Next, the operation of this device will be explained. First, the fuel channel 8 to be measured is suspended by a crane (not shown) and placed in the sensor holding frame 4. That is, as shown in FIGS. 3 and 6, the center line connecting the centers of the upper and lower ends of the fuel channel 8 is parallel to the sensor holding frame 4, and the rear wall 40 and side walls 42, 43 Make sure that the gap between each sensor placed in the sensor is approximately constant. This position adjustment is performed by measuring the dimensions of ρ1 to ρ7 using each sensor.

First, the cross-sectional deformation is measured by measuring the distances ρ1, Ω2, .
It is possible to determine the cross-sectional deformation of the two opposing surfaces by measuring the difference between the measured values of both sides and the central part and by each numerical value. Next, by rotating the fuel channel 8 by 90 degrees, the same measurement as above is performed on the adjacent opposing surfaces, thereby measuring the entire cross-sectional deformation.

As shown in Fig. 5, the torsion is measured by each sensor A-1, E-1, 1-1, A-2, upper lower part and central part.
E-2, 1-2, J-1, N-1°R-1 and J-2
, N-2, R-2 by measuring the distances Ω1, ρ3, Q4, and QB between the opposing parts of the fuel channel 8, and the twist is determined by the difference between the upper, lower, and central portions of these values. be able to.

Furthermore, the bending measurement is performed on both side walls 42 as shown in FIG.
Sensors A to ■ and J- in the width direction central part of 43
This is done by measuring the distances Q2 and Q5 between the opposing surfaces of the fuel channel 8 along the height direction using R, and can be determined by the fluctuation of these values in the height direction.

By performing each of the measurements of ρ1 to mulberry 8 at the same time and recording the results using the measurement and recording device W6, cross-sectional deformation, twist, and bending can be measured simultaneously. Therefore, it is only necessary to suspend the fuel channel 8 to be measured using a crane and place it in the sensor holding frame 4, and during the measurement, the fuel channel 8 only needs to be rotated by 90 degrees as shown in FIG.
No other operations are necessary, the measurement can be carried out in a short time, and since the measurement is carried out without any contact with the fuel channel 8, the degree of contamination of the measuring device is very small.

(Effects of the Invention) As explained above, the present invention includes a mouth-shaped sensor holding frame having a plurality of non-contact sensors, and signals between each sensor and the facing surface of the fuel channel based on signals from each of the sensors. The measurement is performed using a device that has a measuring means for measuring distance, and since the measurement is performed without contact, there is less contamination of the device, and it is possible to quickly and accurately measure not only cross-sectional deformation but also bending and torsion. It is something that can be done.

[Brief explanation of the drawing]

Fig. 1 is a side view of the entire device showing an embodiment of the present invention, Fig. 2 is a perspective view of the sensor holding frame, Fig. 3 is a plan view of the measurement state, and Fig. 4 is an explanation showing a method for measuring cross-sectional deformation. Figure, 5th
The figure is an explanatory diagram showing a method for measuring twist, and FIG. 6 is a front view showing a method for measuring bending. 2... Pool, 3... Holding column, 4... Sensor holding frame, 5... Sensor, 8... Fuel channel,
40...Back wall, 42.43...Side wall. Patent Applicant: Kobe Steel, Ltd. Agent: Patent Attorney: Etsushi Kotani; Patent Attorney: Chief 1) Masayuki; Patent Attorney: Yasuo Itaya Figure 1: 2
Figure 3 Figure 4 Figure 6
Figure 5

Claims (1)

[Claims] 1. A sensor holding frame having a U-shaped horizontal cross section and consisting of a back wall and both side walls, a holding column that maintains the sensor holding frame vertically within the pool, and each wall of the sensor holding frame A fuel channel measuring device comprising: a plurality of non-contact sensors; and a measuring means for measuring the distance between each sensor and the opposing surface of the fuel channel based on signals from the sensors. 2. In the sensor holding frame in the part facing the upper and lower ends in the height direction and the central part of the fuel channel, in the part corresponding to the central part in the width direction of the back wall and the part of both side walls corresponding to the central part in the width direction of the fuel channel and near both ends. 2. The fuel channel measuring device according to claim 1, wherein said non-contact type sensor is arranged respectively.