The way of equipment and inspection of fuel elements

 

(57) Abstract:

The invention relates to nuclear energy and may find application in the manufacturing of fuel elements rod type. The technical result of the invention is to increase the yield of fuel elements. In the way of equipment and inspection of fuel elements from scrapped curb fuel tablets membranes remove the clips using a stripper in the form of a corkscrew, marriage along the length of the column of fuel pellets in running the shell corrected by adding or removal of the fuel pellets to the defined length of the column of fuel pellets. Simultaneously corrected length compensation space to the set. Curb shell after correction of marriage together with filled shells discarded by clamps, sent for re-rolling retainers, and filled the shell with the marriage of chips, a single gap total gap between the fuel pellets are sent to the release, where they are stacked welded blanks in the direction of application of force vibration. Through the open end of the shell, remove the tablet from the shell is subjected to separation is open end to receive the column of fuel pellets and carry out its wyposarzenie. To extract the split sleeve clamps from the curb shell use the extractor in the form of a corkscrew thread on the working part, and to extract the spring retainer from the curb shell use the extractor in the form of a corkscrew with a spiral groove on the working part, the shape of the coils of the spring retainer. 2 C.p. f-crystals, 3 ill.

The invention relates to nuclear energy and may find application in the manufacturing of fuel elements (FE) rod type.

A known method of manufacture of a fuel rod, including welding the lower plug shell, gear fuel pellets into the casing through its open end, the insert retainer and seal welding of the upper stub under the pressure of the inert gas under cover (see Russian Federation Patent 2092915, IPC 6 G 21 3/10, 21/00, from 27.03.96 year).

It is known that the equipment of the fuel rod is not excluded cases obtain a marriage of correct Assembly of the main components of a fuel rod, comprising determining the length of a column of fuel pellets, the gap between the fuel pellets, the length of the gas collector (back space), nalisa fuel pellets, fuel pellets or chips of fuel pellets caught in the gap between the fuel pellets.

All of the above parameters are strictly regulated and have certain valid values (see Development, production and operation of fuel cell power reactors, book 2, edited by F. G. Reshetnikov. - M.: Energoatomizdat, 1995, S. 282, table 21.4).

Currently valid values for these parameters have been tightened and are strictly binding, since violations of these parameters can lead to an emergency situation in a nuclear reactor.

However, the formula for patent RU 2092915 does not control the above parameters and sorting the loaded fuel rod according to deviations from the permissible values for these parameters.

Known the way of equipment and inspection of a fuel rod rod type, including the use of shell welded to the bottom cover of the gear in the open end of the shell of the column of fuel pellets, the input latch, the vacuum in the internal volume of the fuel rod, filling it with helium, seal welding the upper stub under pressure helium under the shell and the control of gamma-absorption method of previento power reactors, book 2, edited by F. G. Reshetnikov. - M.: Energoatomizdat, 1995 , S. 159, 160, 280-282). The most typical types of defects are shown on page 281, Fig. 21, 13 (see ibid.).

Gamma-ray absorption method the correct Assembly of the main components of a fuel rod will identify deviations permissible parameters only after sealing of the fuel element.

When regeneration of defective fuel elements must break the shell to extract the fuel pellets, but at the same time destroyed the shell will fit only to be melted, which reduces the yield as membranes and fuel pellets, which can be damaged by the destruction of the shell.

There is a method of destruction of the fuel Rods enclosed in a metal sheath on the basis of zirconium, comprising the hydrogenation of the shell when heated gaseous hydrogen at 200-550oC and a hydrogen pressure of 1.5 to 50 bar (see Patent Czech 631454, IPC G 21 19/36, from 21.03.75. This way, destroying the shell of zirconium, pollutes the sheath material fuel pellets that before using again, you want to clear from the destroyed material of the shell.

The closest to the technical conditions and the achieved effect is ways welded to the bottom cover, control density fuel pellets gamma-ray absorption method, gear fuel pellets in the open end of the shell by the method of vibration, vacuum cleaning of the open end of the filled shell dust from the fuel, the injection clamps into the open end of the filled casing, determining the length of the column of fuel pellets in running the shell gap between the fuel pellets, the length of the compensation space (gas collector), clamps and the availability of chips fuel pellets gamma-ray absorption method (see Russian Federation Patent 2140674 on the application 98103785/06, IPC 6 G 21 21/02, from 03.03.98, publ. 27.10.99. The method of manufacture and Assembly of fuel elements in the fuel cartridge). Prototype method provides detection of marriage filled shells on stage before sealing, i.e., immediately after the equipment shell fuel tablets and pressing the latch that secures the column of fuel pellets in the shell. As you know, the tabs spring or split sleeve is placed in the inner cavity of the shell with an interference fit to lock the column of fuel pellets in the shell to prevent from razbaltyvaniya when transportation TVEL is the end of the shell without removing the clamps impossible. Requires a special device for the removal of the clamps, allowing no damage to the fuel pellets and the cladding to carry out this operation.

The technical challenge is to improve the yield of the fuel element.

This technical problem is solved in that in the way of equipment and inspection of fuel elements, including the use of shell with welded bottom bracket, control density fuel pellets gamma-ray absorption method, gear fuel pellets in the open end of the shell by the method of vibration, vacuum cleaning of the open end of the filled shell dust from the fuel, the injection clamps into the open end of the filled casing, determining the length of the column of fuel pellets in running the shell gaps are isolated and the total between the fuel pellets, the length of the compensation space (gas collector), the presence of pins and their length, presence of fractures, crumbs fuel pellets gamma-ray absorption method and the rejection mentioned above, according to the invention of defective curb fuel tablets membranes remove the clips using a stripper in the form of a corkscrew, marriage along the length of the column of fuel pellets in with the different tablets, simultaneously corrected length compensation space (gas collector) to a predetermined filled shell after correction of marriage together with filled shells discarded by clamps, sent for re-rolling retainers, and filled the shell with the marriage of chips, a single gap total gap between the fuel pellets are sent to the release, where they are stacked welded blanks in the direction of application of force vibration through the open end of the shell remove the tablets from the shell is subjected to separation from chipping fuel pellets are sent to wyposarzenie, rassharennuju shell deploy 180oopen end to receive the column of fuel pellets and carry out its wyposarzenie.

Another difference is that to extract the split sleeve clamps from the curb shell use the extractor in the form of a corkscrew thread on the working part, and to extract the spring retainer from the curb shell use the extractor in the form of a corkscrew with a spiral groove on the working part, the shape of the coils of the spring retainer.

The proposed method allows to identify, raspakovati and stranacku for re-equipment, that makes it possible to increase the yield of the fuel element.

The drawings show the way of equipment and inspection of the fuel element, where:

in Fig.1 - layout of equipment and inspection TVEL;

in Fig. 2 - puller corkscrew to retrieve waypoints in the form of a split bushing;

in Fig.3 - puller corkscrew to retrieve the spring retainer.

An example of the method.

Operations 1 gamma-ray absorption method control density fuel pellets 2 and control external geometric dimensions and sent to operation 3 equipment, where they carry out the formation of a column of fuel pellets and their equipment vibrating method in the open end of the shell 4 with welded bracket to the other end when the amplitude of 0-4,8 mm, angle vibration 301oand the oscillation frequency 10-118 Hz. After equipment on the open end of the filled shell 4 are traces of dust fuel material, which hit in the welding seam is not desirable, because it leads to marriage welding. Remove the fuel dust carry on operations 5 vacuum pump (not shown). At operation 6 exercise donnaregina. At operation 7 are press-fit clamps 8 in an effort to 2-4 ATM in the open end with the and or in the form of a spring, rasklinivanie inside the shell 4. At operation 9 conduct gamma-absorption control curb shell 4 with determining the length of a column of fuel pellets 2, gaps between the tablets as a single, and the total length of the compensation space (gas collector), the presence of clamps 8 and their length, the presence of chips pellets and chips. Good curb shell 4 is directed to the sealing operation 10, and a marriage filled shells 4 operation 11 eject latch 8 of defective curb shell through its open end.

Removing the retainer 8 slotted sleeve carried out with the use of a stripper-rod 12, in which the working part has a thread 13. The working end 13 is introduced into the open end of the shell 4 into the cavity of the retainer 8, by turning the handle 14 thread 13 comes into contact with the internal cavity of the retainer 8 and the latch 8 is freely removed from the open end of a filled shell 4.

Removing the spring retainer 8 is performed with the use of a stripper-rod 12, which is the working part with a spiral groove 15 is injected into the open end of the filled shell 4, turn the handle 14, the coils of the spring retainer 8 when this is fixed in the helical groove 15 and the latch 8 coalitio clamps and marriage 17 along the length of the tabs are sent to operation 7 mounting clamps 8.

Marriage 18 along the length of the column of fuel pellets 2 and married 19 along the length of the compensating space (gas collector) sent to operation 6 donnaregina tablets 2. Married 20 chips, crumbs, married 21 single gaps between the 2 tablets, marriage is 22 for the total gap between the 2 tablets sent for release on operation 3, where the filled shell is placed open end in the opposite direction from the application of vibration. When this column of fuel pellets 2 through the open end is withdrawn from the shell 4 and is directed to the operation 23, where, after separation from chips and crumbs pills 2 go to step 3 equipment, and the shell 4 after demilitarization is rotated 180oand the open end is joined to the input of a column of fuel pellets with 2 operations 3.

The method has been tested and received positive results for the conservation of fuel pellets and shells at disarming, allowing the use of fuel pellets and the sheath again.

1. The way of equipment and inspection of fuel elements, including the use of shell with welded bottom bracket, control density fuel pellets gamma-ray absorption method, snaryazhennoi shell fuel from dust, the mounting clamps into the open end of the filled casing, determining the length of the column of fuel pellets in running the shell gaps and isolated total between fuel pellets, length compensatory spaces, tabs and their length, chips, crumbs fuel pellets gamma-ray absorption method and the rejection mentioned above, characterized in that the rejected curb fuel tablets membranes remove the clips using a stripper in the form of a corkscrew, marriage along the length of the column of fuel pellets in running the shell corrected by adding or removal of the fuel pellets to the defined length of the column of fuel pellets, simultaneously correct length compensation space to a predetermined filled shell after correction of marriage together with filled shells discarded by clamps, sent for re-rolling retainers, and filled the shell with the marriage of chips, a single gap total gap between the fuel pellets are sent to the release, where they are stacked welded blanks in the direction of application of force vibration through the open end of the shell output table is part of the shell deploy 180oopen end to receive the column of fuel pellets and carry out its wyposarzenie.

2. The method according to p. 1, wherein to extract the split sleeve clamps from the curb shell use the puller corkscrew thread on the working part.

3. The method according to p. 1, characterized in that the extraction of the spring retainer from the curb shell use the puller corkscrew with a spiral groove on the working part, the shape of the coils of the spring retainer.

 

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