JPS6225760Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an insert for a nuclear reactor fuel element.

It is proposed that nuclear reactor fuel elements of the type in which nuclear fuel material is enclosed in a protective sheath should be individually identified by providing in each sheath an insert that is unique to that fuel element. There is. Such inserts typically include indicia capable of generating a digital output train of pulses when the fuel element is passed through an active eddy current head;
A decoding device that reads these series of pulses can be easily devised. However, this is a function of time, and when the position of the indicia is to be correctly identified, it is necessary to tightly control the relative movement of the insert and the indicia detector.
This may be difficult.

In accordance with the present invention, an insert for a nuclear reactor fuel element that allows fuel elements to be individually identified is arranged at spaced apart positions to generate a series of signals when the insert is applied to a detector. A row of indentations as positioning indicia, and indentations as identification indicia only at certain of the positions to change the series of signals generated when the insert is applied to the detector. has. The insert thus emits clock pulses from a row of spaced apart positioning recesses and numeric identification pulses from the identification recesses to ensure that the insert is timed as it passes the detector.

Preferably the insert is a metal bar;
The recesses are all holes passing through the bar, and the identification recesses are spaced apart and perpendicular to the row of positioning recesses. The recess may be a groove as a modification of the hole, of which the identification recess is created by deepening the groove. The bar may be hollow, ie tubular in shape.

Regarding the identification indentations that provide individual identification,
Binary coded decimal system, i.e. 8, 4, 2, for each set
The one with four indentations representing 1 is selected.
Similarly, an identification indentation may be provided for producing the first pulse for each set.

The invention will now be described with reference to the drawings.

In the insert 10 shown in FIG. 1 of the drawings,
The recess as a positioning mark is a hole passing through the insert. Holes 11 provide clock pulses, and the larger holes perpendicular to these holes are recessed as identification indicia to provide numeric identification, as indicated in the drawings, and the letter L designates the starting position of each set. are doing. Typically 6.35mm in diameter (1/4
For inch) inserts, hole 11 is 1.2mm
(3/64 inch) diameter and hole 12 is 1.59 mm
(1/16 inch) in diameter. Similarly, Figure 2 of the drawings shows an insert 13 whose recesses are grooves 14,15. Groove 15 is deeper than groove 14 and forms an identification recess for providing numerical identification and starting position as in FIG. Typically 6.35mm diameter
(1/4 inch) insert, groove 14 is
It has a nominal depth of 0.1778 mm (0.007 inch) and groove 15 has a nominal depth of 0.3556 (0.014 inch).

FIG. 3 of the drawings shows the insert 10 of FIG. 1 crimped into a nuclear fuel element 17 containing nuclear fuel pellets 18 within the sheath 16. In FIG. 4 of the drawings, the fuel element 17 is attached to the eddy current reading head 19 by arrow 2.
It is shown passing in the direction of 0. In the eddy current head, the electrical pulse from the oscillator 21 is
These modulated pulses are modulated according to the indentations in the insert in the fuel element, and these modulated pulses are
It is compared with the pulse from the oscillator 21 in an amplifier 22, and a high level pulse and a low level pulse are obtained from the mixer/amplifier 22. A hole such as hole 12 (see Figures 1 to 3) has a cut size of
A recess, such as hole 11, causes a large disturbance to the eddy current detector and therefore produces a high level pulse, whereas a recess such as hole 11 produces a low level pulse because of its small size. The low level pulses are used as clock pulses to prevent the information data on the insert from being accidentally read. These high level pulses and low level pulses are processed by pulse height discriminator 2.
3, where the high-level pulses are distinguished and the combination of high-level pulses and low-level pulses (clock pulses) is applied to the logic circuit containing the decoder, which is obtained by the high-level pulses. Convert the data to decimal for normal visual printing.

[Brief explanation of the drawing]

1 and 2 are side views of an insert according to the invention, FIG. 3 is a side view of a nuclear fuel element having an insert according to the invention, and FIG. 4 is a schematic diagram of a reading device for the fuel element of FIG. 3. Show the diagram. 10, 13... insert, 11, 12... hole (dent), 14, 15... groove (dent), 16... sheath, 17... nuclear fuel element.

Claims (1)

[Claims for Utility Model Registration] (1) An insert for a nuclear reactor fuel element having mechanically formed identification indentations at various spaced apart locations suitable to be scanned by a detector. The insert is of elongated shape, and the identification recesses are arranged along the insert and emit a sequence of identification signals when scanned along the insert, and are mechanically formed and equally spaced apart. locating indentations are disposed parallel to the variously spaced identification indentations and have different dimensions than the identification indentations and/or are located in the insert at a different location than the identification indentations; An insert for a nuclear reactor fuel element, characterized in that it emits a signal train for positioning when scanned by a detector. (2) The insert is a metal rod, and all the recesses are holes penetrating the metal rod perpendicular to the axis of the rod, and the identification recess and the positioning recess are perpendicular to each other. The insert for a nuclear reactor fuel element according to claim (1) of the utility model registration, characterized in that the insert is in a plane. (3) The insert is a metal rod, all of the recesses are grooves of the rod, and the groove for identification is deeper than the groove for positioning. Inserts for nuclear reactor fuel elements as described in paragraph (1).