RU2774084C2 - End damper of a container - Google Patents

Abstract

FIELD: nuclear engineering.

SUBSTANCE: end damper of a container consists of two horizontally located round plates and a set of vertically standing radial ribs of varying heights. Part of the ribs is rigidly connected with both plates, and the remaining part of ribs of lower height is rigidly connected only with one of the plates. The ribs of varying heights are grouped according to height and are evenly arranged along the diameter of the horizontally located round plates. The variation of height of the rib has a pitch of 40 to 60 mm. Each of the ribs at a height from 1/3 to 2/3 is made with a curve at an angle from 3° to 10° from the vertical.

EFFECT: manufacturability during transport and processing operations with the container is increased, weight and size characteristics of the container are reduced, smooth damping of the kinetic energy is ensured when the container falls.

3 cl, 5 dwg

Description

The invention relates to the field of nuclear energy and can be used at nuclear power plants to prevent accidents with transport containers for spent fuel from nuclear reactors.

A shock-absorbing device for a transport packaging complex for transporting fuel assemblies of a reactor plant is known (No. 2552536 of December 24, 2013, published on June 10, 2015).

The dampers are formed by horizontal annular plates with outer diameter stepwise changing from bottom to top, between which are placed radially mounted lamellar ribs, made with a preliminary bend in the central part.

The disadvantages of this device are:

- variable stiffness of the damper is provided by layers of different diameters with ribs of the same height, i.e. each layer has its own specific rigidity, which leads to a complication of the design, an increase in weight and size characteristics and, as a result, the cost of the damper;

- the dimensions of the damper go beyond the diameter of the transport and packaging complex (TPC), which leads to the need to increase the "transport corridor" when handling the TPC or to dismantle the dampers during certain technological operations. If it is necessary to tilt the TUK, it is also necessary to dismantle the damper;

- the TUK cover is not protected by a damper against falling building structures and equipment on the TUK when considering the issue of a possible earthquake and an aircraft crash on a nuclear facility (NF).

Also known damping device container (No. 121639, dated March 29, 2012, published October 27, 2012), consisting of two parts: end and side.

The end part of the device consists of two plates, on the inner side of the lower plate and the inner side of the upper plate, elements of a conical shape are mirrored, between which tubular elements are installed with an inner diameter greater than the diameter of the top of the conical element, but smaller than the diameter of its base.

The tubular elements are interconnected by means of spacers.

The lateral part of the device consists of two: inner and outer cylindrical surfaces. Between the inner and outer cylindrical surfaces, on which the conical elements are mirrored, there are tubular elements with an inner diameter greater than the diameter of the top of the conical element, but less than the diameter of its base. The tubular elements are interconnected by means of spacers.

The disadvantages of this device are:

- high labor intensity of manufacturing due to the presence of structural elements of complex geometry and a large number of welds lead to a high cost of the product. In turn, a large number of welds leads to embrittlement of the materials of the damper components being welded, which cannot but affect the reduction of its damping abilities;

- the dimensions of the damper go beyond the diameter of the TUK, which leads to the need to increase the "transport corridor" when handling the TUK or to dismantle the dampers during certain technological operations. If it is necessary to tilt the TUK, it is also necessary to dismantle the damper.

The closest in terms of most essential features and the achieved technical effect is the end damper of the container (p. m. No. 8761 dated 04.27.1998, F16F 7/12), consisting of two horizontally arranged round plates and a set of unevenly high, vertically standing, radial ribs, and part of the total number of ribs is rigidly connected to both plates, and the remaining part of the ribs of smaller height is rigidly connected to only one of the plates.

The disadvantages of this device are:

- straight lines. The graph of kinetic energy damping during fast processes of high intensity, in structures with rectilinear ribs, as a rule, has a stepped jump-like character, due to the fact that at the initial moment of impact the stiffness of the ribs is high, and then they sharply lose stability, this process is complex and unpredictable at mathematical modeling. The straight ribs in the design do not provide a stable damper deformation pattern;

- low damping capacity, especially when TUK falls at an angle. Due to the lack of shock-absorbing elements in the central part of the damper, it leaves the central part of the TUK cover unprotected from external dynamic influences in the form of heavy objects falling onto the TUK.

The technical objective of this invention is to create a device that reduces the dynamic loads on the container to acceptable values in emergency conditions (falling from a height of 9 m) during interobject transportation of the container.

The technical result of solving the task is to increase manufacturability when performing transport and technological operations with the container, reduce the weight and size characteristics of the container, smooth damping of kinetic energy when the container falls.

The specified technical result is achieved by the fact that in the end damper of the container intended for storage and transportation of spent assemblies of nuclear reactors, consisting of two horizontally arranged round plates and a set of unevenly high, vertically standing, radial ribs, some of which are rigidly connected to both plates, and the remaining part ribs of lower height is rigidly connected to only one of the plates, ribs of different heights are combined into groups in height and evenly spaced along the diameter of horizontally arranged round plates, and the change in the height of the rib has a step of 40-60 mm, with each of the ribs at a height of 1/3 to 2/3 is made with a bend at an angle of 3° to 10° from the vertical.

The number of edge groups is from 6 to 10, i.e. groups of ribs with the same configuration are repeated from 36° to 60°.

The height of the ribs are from 3 to 6 sizes.

This design of the end damper provides a stable model of its deformation (possibility of mathematical modeling). The graph of kinetic energy dissipation during high-speed high-intensity processes has a smooth character, due to the fact that sequential plastic deformation of the ribs occurs (in the beginning, ribs of greater height with the transition to collapse of ribs of lower height), and at the initial moment of impact, the rigidity of the ribs is low, compared with rectilinear ribs.

Also, the end damper of this design has a high damping capacity even when the TUK falls at an angle.

The maximum overlapping of the cover with a damper provides protection of the TUK from the fall of building structures and equipment on the TUK when considering the issue of a possible earthquake and an aircraft crash on a nuclear facility.

The design of the container is represented by the following drawings:

Fig. 1 - container on a horizontal base.

Fig. 2 - end damper (general view).

Fig. 3 - vertical fall of the container.

Fig. 4 - crushing of the ribs upon impact.

Fig. 5 - collapse of the ribs when the container falls on the corner.

The end damper of the container consists of two horizontally arranged round plates 1 and 2 and a set of unevenly high, vertically standing, radial ribs 4, 5 and 6 (see Fig. 1, 2).

The end damper is attached to the lower end of the container 3.

Ribs 5 are rigidly connected to both plates 1 and 2, and the rest of the ribs of smaller height 5 and 6 are rigidly connected to only one plate 1.

Ribs of different heights 4, 5 and 6 are combined into groups in height and are evenly spaced along the diameter of horizontally arranged round plates 1 and 2. The number of such groups evenly spaced along the diameter of round plates is from six to ten. That is, groups of ribs (with the same configuration) are repeated every 36° ... 60°.

The height of the ribs are from 3 to 6 sizes. The height of the ribs varies with a step of 40-60 mm, and each of the ribs at a height of 1/3 to 2/3 is made with a bend at an angle of 3° to 10° from the vertical.

During normal installation of container 3 with an end damper on a horizontal base 7, the weight of container 3 is perceived by ribs 4.

The shape, geometrical parameters and the number of ribs 4 are selected in such a way that the stresses in the ribs 4 from the weight load of the container do not exceed the allowable value, and the ribs do not lose stability from this load.

Ribs 5 and 6 do not work during normal installation of container 3 on horizontal base 7.

When the container 3 falls in a vertical position, when the end damper collides with the horizontal base 7, the ribs 4 are the first to lose stability and plastically deform, repaying the kinetic energy of the container. Then, sequential plastic deformation of the ribs occurs: first, ribs of greater height with a transition to collapse of ribs of lower height (see Fig. 4).

When container 3 falls onto a horizontal base 7 by the angle of the end damper (see Fig. 5), there is a loss of stability and plastic deformation of the ribs 4, 5 and 6 that fall into the zone of contact with the horizontal base 7. The ribs are sequentially deformed, while smoothly extinguishing the kinetic the energy of the falling container.

The damper dimensions do not go beyond the outer diameter of the TUK, which ensures that all transport and technological operations with the TUK are performed without dismantling the damper, including tilting and installation in the reload well.

Provision of damper variable stiffness with one layer of ribs made from one rolled section provides a low cost of the product.

The maximum overlapping of the cover with a damper provides protection of the TUK against falling building structures and equipment on the TUK when considering the issue of a possible earthquake and an aircraft crash on the nuclear facility.

Thus, the combination of unevenly high ribs into groups in height and a uniform arrangement of horizontally arranged round plates along the diameter, with a change in the height of the rib 40-60 mm, each of the ribs at a height of 1/3 to 2/3 is made with a bend at an angle of 3 ° up to 10° from the vertical, allows you to increase the manufacturability of the container when performing transport and technological operations with it, reduce the weight and size characteristics of the container as a whole, and also smoothly extinguish the kinetic energy when the container falls.

Claims (3)

1. The end damper of a container designed for storage and transportation of spent assemblies of nuclear reactors, consisting of two horizontally arranged round plates and a set of vertically standing radial ribs of different heights, some of which are rigidly connected to both plates, and the remaining part of the ribs of a lower height is rigidly connected only to one of the plates, characterized in that the ribs of different heights are combined into groups in height and evenly spaced along the diameter of the horizontally arranged round plates, and the change in the height of the rib has a step of 40-60 mm, with each of the ribs at a height of 1/3 to 2/3 made with a bend at an angle of 3° to 10° from the vertical. 2. The end damper of the container intended for storage and transportation of spent assemblies of nuclear reactors according to claim 1, characterized in that the number of groups of ribs is from 6 to 10, i.e. groups of ribs with the same configuration are repeated from 36° to 60°. 3. The end damper of the container intended for storage and transportation of spent assemblies of nuclear reactors according to claim 1, characterized in that the ribs have from 3 to 6 standard sizes in height.

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