JPS5915893A - Method of confirming nuclear fuel assembly position in sipping inspection device for fuel assembly - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides four noping inspection devices 1c used for determining whether a spent nuclear fuel assembly is damaged or not, and a shipping can in which one of the inspection devices is installed underwater in a swimming pool. f) When loading the nuclear fuel assembly by operating a crane or taking out the same assembly after inspection,
This invention relates to a method for confirming the relative positional relationship between the assembly and the shipping can during crane operation.

As described above, a crane operation is used to load and unload the nuclear fuel assembly to be inspected.At this time, the conventional means of confirming the position of the nuclear fuel assembly is to connect the assembly in a suspended state. The present invention focuses on the hanging rope of a crane, and attempts to detect when the hanging rope reaches a position directly above the shipping can by the response of a separately provided limit switch.

For this reason, when using the above conventional method, the hanging rope directly presses against the limit switch f, which tends to damage the limit switch and is not satisfactory in terms of reliability.
Even if, for some reason, the crane is operated without a load without suspending the nuclear fuel assembly, the suspension rope may activate the limit switch, and therefore the relevant If the known shipping cap, such as that provided on the above-mentioned/topping can, is configured to be opened or closed by an air cylinder or the like, with the operation being interlocked, the shipping cap will open or close involuntarily. It will happen.

In addition, when using the above limit switch, when in a suspended state, it is not possible to confirm the height position of a nuclear fuel assembly in the pool water in a suspended state tC, so the lower nozzle, etc. of the relevant assembly does not reach the vicinity of the shipping can. When the shipping cap is reached, the shipping cap may be opened by mistake, resulting in the cap coming into contact with the assembly and causing damage.

In view of the above-mentioned defects, the present invention focuses not on the suspension rope of the crane, but on the suspension rod of the handling jig that is connected and suspended from the suspension rope and from which the lower end tC nuclear fuel assembly is suspended. F
This method attempts to solve the above-mentioned problems of the conventional method by making it possible to measure not only the horizontal position of the rod but also its height position using an ultrasonic transceiver and comparing the measurement results with the position of the shipping can. is its purpose.

To explain the present invention in detail based on the drawings, as shown in FIG. Although it is installed at a predetermined position in the water (3), in the present invention, the pool (2)
poolside (4), the above shipping camp (1)
) (1)..., each ultrasonic transceiver (5) is installed, and in the illustrated example, the ultrasonic transceiver (5) is installed corresponding to
) is the X-axis ultrasonic transceiver (5)' and the Y-axis transceiver 15.
)"(5)"..., and these ultrasonic transceivers (5) are connected to a detector (6).

Next, in Fig. 2, (7) shows the suspension rope of the crane, in which the suspension rod (9) of the handling jig (8) is suspended in a fixed manner. 8) is a hanging rod (9) as is known.
A locking arm (not shown) is pivotally attached to the jig main body OQl provided at the lower end of the jig, and by removably engaging the locking arm with the upper nozzle B of the nuclear fuel assembly A,
The assembly At- can be suspended from the jig main body aθ, and On in the figure is the shipping can +I)
(11) is a shipping cap that can be opened and closed by the operation of an air cylinder or the like (not shown).

The shipping inspection device for nuclear fuel assemblies described above stores the spent nuclear fuel assemblies A in its shipping can +11 tll...
The purpose of this method is to detect whether water-soluble fission products or gaseous fission products leak out from the Al aggregate, and to check whether there is any damage to the Al aggregate, as shown in Figure 2. By operating the crane, when attempting to load and unload the nuclear fuel assembly A't-, which is suspended from the handling jig (8) I as described above, into the shipping can t+l [11...], the poolside ( 4) From the ultrasonic transmitter/receiver (5) installed in the
An ultrasonic pulse parallel to the water surface of the pool water (3) is emitted in this direction, and the ultrasonic wave hits the hanging rod (9) of the jig (8).
By measuring the time it takes for the ultrasonic transceiver (5) to be reflected by the ultrasonic transceiver (5),
) to the hanging rod (9) is determined by the detector (6), and by measuring this distance, the shipping can f101+... installed at a predetermined position t is detected.
It is determined whether the nuclear fuel assembly A exists directly above the strain force.

Further, ultrasonic pulses are emitted at predetermined intervals to repeatedly measure the distance between the ultrasonic transceiver 15) and the hanging rod (9) as described above, and at this time the crane is operated. ) f) If nuclear fuel assembly A is descending at a predetermined speed to Shinping Can +11 (11...), then depending on how many times the above distance measurement is performed, Since we can also know the height position of the lower nozzle B' of the same assembly A, /rubbing can ill ill...
...and! It is also possible to grasp the gap a, and therefore the shipping cap θ0 can be opened or closed in a timely manner without the occurrence of a situation where the camp θ comes into contact with the lower nozzle B', etc. Of course, in this case, the driving mechanism for the shipping cap θ0) may be operated based on the detection signal l from the detector (6) as shown in FIG.

In addition, in the embodiment shown in FIG. 1, as mentioned above, an ultrasonic transceiver (
5) In addition to providing one for each of the 7 tubing canisters i11+11..., ultrasonic transceivers for the X and Y axes (5)', [51", [51"...・Since it is designed to provide (5) “(5) # ・・
The position of the nuclear fuel assembly A is more accurately determined by the shipping can [11 (11-...
It is possible to accurately determine whether or not there is a

As embodied by the above-mentioned embodiment, the present invention connects and suspends the suspension rod (9) of the handling jig (8) to the suspension rope (7) of the crane, and the handling jig (8) Nuclear fuel assembly A
By suspending the Ae and operating the above-mentioned crane, the shipping inspection device for nuclear fuel assemblies is placed underwater in the pool (3).
When loading and unloading the car/rubbing can (IHI+...), the ultrasonic transmitter/receiver (5) installed on the poolside i4 emits tc ultrasonic pulses every predetermined time, and thereby By repeatedly receiving the reflected wave from the hanging rod (9), the distance to the hanging rod (9) is determined, and based on these distance measurements, the position of the shipping can m + I1 body A is determined. It can be confirmed in a completely non-contact state, rather than by means of contact with a limit switch, etc. Therefore, there is no damage to the switch, so operational reliability can be guaranteed, and only the hanging cable (7) of the crane can be checked. Even if the nuclear fuel assembly A is operated by the crane operation, it will not be mistaken that the nuclear fuel assembly A is suspended, so the unnecessary opening and closing of the rubbing cap 00 will also be eliminated.

Also, since it is possible to check how far the hanging rod (9) has entered the pool water (3), it is possible to avoid opening/closing the knotting cap 4 at the wrong timing and damaging the nuclear fuel assembly A etc. To be/become.

[Brief explanation of drawings]

FIG. 1 is an explanatory plan view showing the main parts of a shipping inspection device for nuclear fuel assemblies prepared for implementing the nuclear fuel assembly position confirmation method according to the present invention, and FIG. 2 is a plan view of the same device. 0 (1)...1 Shipping can (3)...Pool underwater] 4)...L boule side (5)...Ultrasonic transceiver 15) '... Ultrasonic transceiver for Y-axis (5) #... Ultrasonic transceiver for Y-axis (7)... Crane suspension rope (8)... Handling Jig (9)... Hanging rod aω ■ ■ Shipping cap A... Nuclear fuel assembly patent applicant representative Patent attorney Makoto Ito

Claims (2)

[Claims] (1) The suspension rope of the crane is connected and suspended from the suspension rod of the handling jig, the nuclear fuel assembly is suspended from the handling jig, and the nuclear fuel assembly is moved by the operation of the crane.
When loading and unloading a nuclear fuel assembly/rubbing inspection device into a shipping can underwater in a pool, an ultrasonic transmitter/receiver installed on the pool side emits ultrasonic pulses at predetermined intervals and transmits By repeatedly receiving reflected waves from the suspension rod, the distance to the suspension rod is determined, and based on these distance measurements, the planar positional relationship and height of the nuclear fuel assembly and the nuclear fuel assembly are determined. 1. A method for confirming the position of a nuclear fuel assembly in a shipping inspection device for nuclear fuel assemblies, characterized in that the positional relationship is confirmed. (2) A pair of ultrasonic transmitters and receivers are provided, and each ultrasonic transmitter and receiver measures the same distance in the X-axis direction and the same distance in the X-axis direction of the suspension rod, thereby determining the plane position with respect to the nuclear fuel assembly. 2. A method for confirming the position of a nuclear fuel assembly in a nuclear fuel assembly pink inspection apparatus according to claim 1, wherein the relationship is confirmed by f: percentage.