KR200269662Y1 - lips-type multi-purposed nuclear fuel assembly spacer grid - Google Patents

Abstract

The present invention relates to a support grid for supporting nuclear fuel rods loaded in a reactor, the purpose of which is different from the prior art support grid (7) fuel rod 8 and the support grid spring 16 or dimple (15) Dispersing contact force by making the contact between the two sides conformal to each other, thereby reducing the magnitude of the peak stress, and reducing the possibility of fretting wear of the fuel rod by alleviating the vibration phenomenon of the fuel rod 8, allowing the spring elastic behavior Its wider range allows the remaining spring force to support the fuel rods soundly and provides a lip-type multi-purpose fuel support grid that minimizes the pressure loss due to the flow mixing wing and minimizes the flow interference, thereby improving the cooling performance. It is.

The present invention consists of a plurality of support grids 12, 13 arranged horizontally and vertically to support the fuel rods 8 of the nuclear fuel assembly 1, springs are formed in the central openings, and dimples formed on upper and lower portions of the springs. In the support grid 7; Curved and protruded in the direction of the fuel rod in the central opening of the support grid plate, and an elliptical arcuate incision is formed in the upper / lower side, and a salt-tight spring is connected to the grid plate and supported and supported by four points; Upper and lower portions of the salty springs protrude in a direction opposite to the protruding direction of the salty springs to form a curvature, and an elliptical arcuate incision is formed on the upper and lower portions, and an lip shape having an janggu shape dimple installed in contact with another fuel rod is installed. To provide a multipurpose fuel support grid.

Description

Lips-type multi-purposed nuclear fuel assembly spacer grid}

The present invention relates to a support grid for supporting nuclear fuel rods charged in a nuclear reactor, wherein the contact surface of the fuel rod 8 and the support grid spring is conformal curved surface, so that a larger area is contacted than the existing grid spring, so that the support integrity is stable. Due to the maintenance and structure, the load applied to the spring can be applied to the entire lattice surface. A flow mixing wing which has increased the fluid contact area of the coolant is attached to the upper part of the support grid, and foreign substances in the coolant using the lattice structure can be filtered. The present invention relates to a multipurpose support grid shaped like a lip with the ability to function.

1 schematically illustrates a typical fuel assembly.

The role of the nuclear fuel assembly support grid is constant so that the springs and dimples support the fuel rods 8 and the guide tube 5 so that the fuel rods in each lattice do not deviate from the predetermined positions at equal intervals. It maintains the cooling water flow path by maintaining the gap and maintains the cooling function of the core.It is possible to add the cooling water fluid mixing function in the reactor by attaching the flow mixing wing at the top of the lattice, and the structural shape of the lattice. Using this function can be added to enable the foreign matter filtration function. These features are being used to develop high-burning and flawless fuels. In order to develop high-combustion fuel, the thermal performance of the fuel must be improved, and the first consideration is to improve the flow of reactor coolant flowing around the fuel rod. To this end, the shape of the support grid itself is mainly changed, for example, the attachment of the mixing blade and the design change thereof or the efficient configuration of the flow channel. However, most of the methods for improving the thermal performance are based on making the flow of coolant around the fuel rod to be a more turbulent flow, which can cause the fuel rod to vibrate due to the turbulence of the coolant flow around the fuel rod. This can cause vibration of the fluid. Fluid-induced vibration of the fuel rod causes the fuel rods to move relative to each other (slip) at the contact surface of the support grid springs or dimples, from which local wear occurs on the contact surface of the fuel rod, causing the fuel rod to be progressively damaged. Causing fretting damage ".

The spring of the support grid undergoes prolonged neutron irradiation in the core, which results in a change of material properties and a gradual loss of the spring's elastic force. This result brings about a reduction in the bearing capacity of the fuel rod 8 and provides a cause for the fuel rod to vibrate. Such vibrations cause fretting wear damage of the fuel rods at the contact points between the fuel rods 8 and the fuel rod support elements of the lattice plate. Until now, such an accident has caused the fuel rods 8 to be punctured to leak radioactive materials. It has been reported several times. It is known that an important factor in terms of geometrical fretting wear damage of the fuel rod is the contact shape of the contact materials. Conventional fuel rods 8 and springs or fuel rods 8 and dimples have a shape that is mainly in point contact or line contact. In terms of fretting wear, the line contact shape is relatively more resistant to vibration than the point contact shape. It is known to have high abrasion resistance. This is because if the contact area is increased when the spring elastic force is constant, the peak value of the contact pressure is reduced to suppress fretting wear damage of the fuel rod 8. In addition, when setting the initial spring force, the material property change by neutron irradiation should be considered and reflected in the spring design. If the spring force is too small, it is possible to lose the support rod's integrity. If the spring force is too high, it may cause scratches on the fuel rod's surface due to excessive frictional resistance when the fuel rod is inserted into the support grid. Longitudinal growth of fuel rods due to neutron irradiation may not be adequately accommodated, which may cause bending of the fuel rods. The springs and dimples of the support grid 7 must maintain the proper force to ensure the support integrity of the fuel rods.

On the other hand, fuel rods 8 have a non-uniform output distribution in the core, which causes the temperature of the coolant to increase around the high temperature fuel rods 8, causing local bubbles to develop on the fuel rod surface and causing heat transfer. The efficiency is sharply lowered. When this phenomenon occurs, the temperature rise of the heating surface is caused, so that the temperature of the fuel rod 8 or the uranium sintered body 11 in the fuel rod can reach the melting point. Therefore, as another function of the support grid 7, by forcibly mixing the cooling water flowing around the fuel rod of the nuclear fuel assembly 1 as shown in FIG. 3, the temperature is uniformed and the heat transfer performance of the surface of the fuel rod 8 is improved. It also plays a role of restraining nuclear boiling deviations so that the reactor can be operated safely with sufficient margin. To this end, in addition to the fuel rod 8 support device, a flow mixing device for improving heat transfer performance is also attached to the support grid 7. In general, the flow mixing method is a method of promoting temperature uniformity through flow mixing between channels by generating a strong vortex when the cooling water passes through the support grid.It causes forced rotational flow, causing the cooling water in the flow structure channel to rotate to the centrifugal force. As a result, a liquid having a high density is directed toward the surface of the fuel rod 8 and a small density of bubbles are collected toward the rotational center of the flow to prevent a decrease in heat transfer by the bubble layer to improve the cooling performance of the fuel rod 8. have. Such rotational flow mixing is known to gradually attenuate relatively slowly compared to the vortex mixing while passing through the support grid 7, and recent support grids have been developed with a focus on the occurrence of such rotational flow. The pressure loss problem is caused by the excessive attachment of the flow mixer, which increases the load on the pump, which reduces the flow rate of the cooling water flowing in the reactor. Therefore, in the case of attaching the fluid mixing apparatus, the design must minimize the pressure loss in the same projected area.

Recently, in order to prevent nuclear fuel damage caused by foreign materials, foreign material filtering devices are installed in the fuel assembly. Foreign materials such as small bolts and wires in the core of the reactor move with the coolant at a high flow rate to damage the fuel rods. To prevent this, the filtration device is mainly attached to the flow path plate of the lower fixing body (3), and the filtration function is supported. The lattice 7 is separately installed at the bottom. The foreign matter filtration device using the support grid 7 is designed to minimize the interference of the flow rather than the function of the spring force or dimple and to trap the foreign matter in the lattice.

Due to the high fuel consumption, the neutron dose to the support grid increases as the service life of the nuclear fuel increases, which is more important for the reduction of spring force due to the change of material properties. Complementary mechanism of spring force for fuel rod vibration suppression is urgent. In the case of high combustion, it may be accompanied by an increase in the fuel concentration, which intensifies the phenomenon of the power peak that the output is considerably larger than the average fuel rod output in some fuel rods 8, causing severe boiling on the fuel rod surface. This sudden worsening is likely to occur. Therefore, it is required to develop a support grid having better cooling performance than the conventional support grid. In addition, there is a need for a fuel rod damage prevention device due to foreign matter in consideration of technical aspects such as pressure loss and manufacturability.

In consideration of the problems described above,

The object of the present invention, unlike the support grid 7 of the prior art, the contact between the fuel rod 8 and the support grid lattice spring 16 or dimple (15) to make a conformal surface contact to distribute the contact force according to the vibration It is to provide a support grid to reduce the possibility of fretting wear of the fuel rods and to widen the elastic behavior tolerance of the springs so that the remaining spring force supports the fuel rods in a sound manner.

Further, another object of the present invention is to reduce the magnitude of the peak stress at the contact surface by allowing the load received by the spring to be distributed in all directions only up and down or right and left, and force or pressure from any direction acting on the fuel rod 8. It supports the fuel rod stably even in the change of the field, and forms the flow mixing wing to extend on one side of the dimple to minimize the pressure loss due to the flow mixing wing attached to generate excessive vortex and forced rotational flow of the coolant and to minimize the flow interference. Minimize the flow mixing wing by giving a spoon-like bend and maximizing the contact area where the coolant hits the wing by using twice the size of the existing wing. Pressure is reduced to half of the supporting grid with the existing mixing blade As a result, the dimples and springs have arcuate incisions to secure the side flow path of the coolant to allow foreign substances to be trapped in the dimples and springs, thereby providing a support grid that minimizes nuclear fuel damage caused by foreign substances. .

1 is a schematic perspective view of a typical fuel assembly.

Figure 2 is a perspective view showing a support grid according to the present invention.

3 is an elevation view showing a horizontal lattice board and a vertical lattice board constituting the support grid body according to the present invention.

Figure 4 is a plan view and a bottom view showing a support grid according to the present invention.

Figure 5 is a front view showing a unit grid according to the present invention.

Figure 6 is a front view perspective view and a planar cross-sectional view showing a salt drunk type spring according to the present invention.

Figure 7 is a front view, a top view and a left and right side view showing the upper dimple coupled to the mixing blade according to the present invention.

8 is a front view and a bottom view showing a lower dimple according to the present invention.

9 is a perspective view and a plan view showing a unit cell and a cross grid of the support grid body according to the present invention.

* Explanation of symbols for main parts of the drawings

1 nuclear fuel assembly 8 fuel rod

12,13: horizontal and vertical lattice plate (strap) 14: floating mixing wing

15: upper dimple 16: spring

17: lower dimple 18: unit cell

20: dimple bend 21: dimple extension

23: conformal bend 24: spring bend

25: horizontal support beam 28: spring legs

29: picking part 35: slit

36,37: left and right extension part 40: longitudinal support beam

45: unit grid 50: support grid

The present invention for realizing this,

In order to support a nuclear fuel rod assembly composed of a plurality of nuclear fuel rods, a plurality of unit grids are formed in parallel to each other, and horizontal and vertical grids in which a slit of a predetermined length cut from an upper or lower portion is formed at a connection portion between each unit grid. In the supporting lattice itself, arranged so as to intersect longitudinally and horizontally, to form a plurality of unit cells in which each of the nuclear fuel rods is charged and positioned,

The unit grids constituting the horizontal and vertical lattice plates include two longitudinal supports arranged in parallel with a predetermined width in the axial direction, and horizontally extending at the same distance from each end of the longitudinal supports, respectively. A supporting part including a horizontal support for connecting the vertical support and forming an opening in a rectangle at the center thereof;

Is coupled to the opening position, the curvature to be in contact with the outer circumferential surface of the fuel rod in the width direction to be curved by a predetermined width and is formed long in the axial direction, respectively in the opposite direction on the boundary between both ends of the conformal bend A left / right extension portion that is bent and extended by a predetermined width, and four spring legs further extending laterally and laterally from the upper and lower ends of the left end of the left extension and the right end of the right extension, respectively; The salt brim type springs are connected to each of the upper and lower ends of each of the side incision lines of the opening and coupled to each other to protrude to one side;

It is coupled to each of the upper and lower portions of the salt-damp spring, the dimple bent portion is formed curved by a predetermined width at the curvature so as to be in surface contact with the outer peripheral surface of the fuel rod in the center in the width direction, respectively opposite the boundary between the both ends of the dimple bent portion It is configured to include a left / right dimple extension extending in the direction, the upper and lower incisions are formed to form an arc, including the upper and lower dimples protruding in a direction opposite to the protruding direction of the salt spring It provides a lip-type multi-purpose fuel support grid, characterized in that.

In addition, the unit grid may be further provided with a flow mixing wing extending further from the upper end of one side dimple extension of the upper dimple located at the top end.

Hereinafter, embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

Figure 2 is a perspective view showing a support grid according to the present invention, Figure 3 is an elevation view showing a horizontal grid and a vertical grid constituting the support grid according to the present invention, Figure 4 is a support grid according to the present invention 5 is a plan view and a bottom view, and FIG. 5 is a front view showing a unit grid according to the present invention.

6 is a front view perspective view and a planar cross-sectional view showing a salted spring according to the present invention, Figure 7 is a front view, a plan view and a left / right side view showing the upper dimple coupled to the flow mixing wing according to the present invention, 8 is a front view and a bottom view showing a lower dimple according to the present invention, and FIG. 9 is a perspective view and a plan view showing a unit cell and a cross grid of a support grid body according to the present invention.

The support grid 50 according to the present invention, in order to support the fuel rod 8 so as not to deviate from a predetermined position at equal intervals, as shown in FIG. 3, respectively, the sprinkler type spring 16 and the upper and lower dimples 15. The unit grid plate 45 having a plurality of units 17 is connected to each other in parallel, and the connecting portions between the unit grid plates 45 are horizontally and vertically formed with slits 35 having a predetermined length cut from an upper portion or a lower portion. The lattice plates 12 and 13 are arranged to be perpendicular to each other vertically and horizontally to form a plurality of square unit cells therein, as shown in FIGS. 2 and 4, and one nuclear fuel rod 8 in each of the unit cells. It is configured to be loaded and positioned.

5 to 7, the unit grid 45 according to the present invention constituting the horizontal and vertical gratings 12 and 13 is largely provided in a support part serving as a skeleton and an opening formed in the center of the support part. The upper and lower dimples (15) and (17) coupled to the upper and lower portions of the salted spring 16, the upper and lower ends of the support, that is, the salted spring 16, respectively, It comprises a flow mixing wing 14 extending further upward from one side of the upper incision line.

For reference, the salt-like spring (16), belonging to the insects and has a morphological similarity with the salt worms having a morphological feature of four legs, except for the fore short legs of the six legs extending long left and right around the body According to the definition of salt spring.

The support portion has two longitudinal supports 40 arranged in parallel with a predetermined width in the axial direction, and extends horizontally at positions of the same distance from the upper and lower ends of the vertical support 40, respectively, so that the two vertical supports are supported. It comprises a horizontal support beam 25 for connecting the beam 40 and forming a rectangular opening in the center. In addition, in the upper and lower positions of the opening formed in the support portion, the upper and lower openings which are opened to the upper and lower portions are formed.

The salted spring 16 is coupled to the opening position formed in the center of the support, the curvature to be in contact with the outer circumferential surface of the fuel rod in the width direction to be curved by a predetermined width and is formed in an axial direction long ( 23) left and right extension parts 36 and 37, which are bent in opposite directions, respectively, on both sides of the conformal bend part 23, extending by a predetermined width, and left ends of the left extension parts 36 and It is configured to include four spring legs 28 that extend further in the upper side and the lower side at the upper and lower ends of the right end of the right extension portion 37, respectively. Four spring legs 28 provided with four are respectively connected to the uppermost and the lowermost ends of both side cutting lines of the opening so that the salted spring 28 is combined with the support, thereby having a four-point support structure. Protrude to one side based on the surface of the.

The upper and lower dimples 15 and 17 are respectively coupled to the upper / lower positions of the salted spring 16 and have a predetermined width at a curvature to be in surface contact with the outer circumferential surface of the fuel rod 8 at the center in the width direction. It is configured to include a dimple bent portion 20 is formed as much as bent, and the left and right dimple extension portion 21 is bent in the opposite direction, respectively, bordering both ends of the dimple bent portion 20.

The upper and lower dimples 15 and 17 are provided such that the front shape of each of the upper and lower incisions forms an arc, and protrudes in a direction opposite to the protruding direction of the salted spring 16.

The curvature of the conformal bend 23 of the salted spring 16 is formed to a degree slightly finer than the curvature of the fuel rod in order to induce accurate surface contact with the fuel rod to maintain the support integrity to the vibration and external impact of the fuel rod. That is, the curvature of the conformal bend 23 before the fuel rod is charged is slightly larger than that of the fuel rod 8, but when the actual fuel rod 8 is charged, the spring surface is pressed so that the fuel rod and the radius of curvature coincide.

In the center of the conformal bent portion 23 is formed a window picking portion 29 in the axial direction long and narrow in the width direction. Formation of the window pick-up section 29 prevents nuclear boiling escape due to local heat transfer suppression, even though a small amount of fluid is isolated between the fuel rod surface and the conformal bends 23.

Each spring leg 28 of the salted spring 16 may be provided with a bent portion 24 that is bent again in the opposite direction to the bending direction of the left and right extension parts 36 and 37. In this case, the bent portion 24 protrudes in a direction opposite to the protruding direction of the conformal bent portion 23 with respect to the surface of the support portion. In addition, by adjusting the bending angle of the bent portion 24 it is possible to adjust the bearing force for the fuel rods.

The upper incision line and the lower incision line of the salty spring 16, that is, the upper incision line of the conformal bend 23 and the left / right extension portion 36, 37 and the two spring legs 28 extending from both sides and The front shape of the concave bend 23 and the left / right extension parts 36 and 37 and the lower cut line connected to the two spring legs 28 extending from both lower sides are respectively formed in an arcuate shape of mutual symmetry. In other words, the upper incision is concave up and the lower incision is formed into an arcuate concave down.

As formed as described above, as can be seen in the figure shown in Figure 4b, salt-like spring 16 is formed in a flat cross-sectional shape of the lower lip, the flat cross-sectional shape of the upper and lower dimples in the upper lip shape Is formed. In addition, since the protruding directions of the salted spring 16 and the upper and lower dimples 15 and 17 are opposite to each other, the fuel rods support different fuel rods, and thus, when viewed from a flat or bottom surface, the lip shape as a whole It will be provided.

As shown in FIG. 9, the flow mixing wing 14 is further upward from the upper cut line of the one side dimple extension part 21 of the upper dimple 15 to protrude in the same direction as the salty spring 16. As it is extended, it is gradually curved to form a concave spoon shape of the fuel rod side. As can be seen in the figures shown in Figures 7c and 7d, the bending angle with respect to the surface of the support of the flow mixing blade 14 is preferably not more than 90 °. That is, the angle between the uppermost normal line and the axial vertical line is formed at an acute angle.

In addition, the flow mixing wing 14, as shown in Figure 9b, is formed so that the planar shape of the top end incision line corresponds to an arc of a radius larger than the radius of the fuel rod (8) of the fuel rod when charging the fuel rod Make sure the surface is not scratched.

As shown in FIG. 4, the support grid 50 according to the present invention is configured by vertically and horizontally arranging horizontal and vertical gratings 12 and 13 formed by connecting a plurality of unit grids 45 in parallel. In the support grid 50, a plurality of square unit cells surrounded by four unit grid plates 45 are formed, and one nuclear fuel rod is loaded and supported in the unit cell.

Since the protruding directions of the salt-damp spring 16 and the dimples 15 and 17 formed in the unit grids 45 are opposite to each other, 4 forming the inside of the unit cell as shown in FIG. Of the two unit grid plates 45, the salt-tight spring 16 protrudes from the two adjacent unit grid plates toward the center of the unit cell, and the upper and lower dimples 15 and 17 are respectively unit cells from the remaining two unit grid plates. The fuel rod 8, which protrudes to the center and is charged, supports six points as a whole.

In addition, the flow mixing blade 14 extending from the upper dimple 15 has a fuel rod 8 charged in an adjacent unit cell as the protruding direction of the end thereof is in the same direction as the salt-shaped spring 16 on the same unit grid. ).

As shown in FIG. 4A, the support grid 50 according to the present invention as described above has a radius of curvature of the fuel rod in a state where the contact surface of the upper dimple 15 and the salted spring 16 supports the fuel rod. The flow mixing wing 14 is positioned to face an adjacent unit cell on one side of the upper dimple 15. As shown in FIG. 4B, it can be seen from the bottom that the contact surfaces of the lower dimple 17 and the salted spring 17 are similar to the radius of curvature of the fuel rod while the fuel rod is supported.

9 shows the unit cell 18 of the support grid according to the present invention, and when the fuel rod 8 is mounted, the contact state of the upper and lower dimples 15 and 17 and the spring 16 can be confirmed. Referring to the drawing shown in Figure 9d it can be seen the flow path change direction of the cooling water by the flow mixing wing. As the flow mixing blade is provided, it is possible to improve cooling performance through forced mixing of the fluid.

As the lower cut line 32 of the upper dimple 15 and the upper cut line 31 of the lower dimple 17 are provided in an arc shape, the amount of pressure drop inside the support grid 50 is reduced, and the prior art. As there is no horizontal cross beam at the bottom of the lower dimple, which is commonly seen in the support grid 50 of the body, when foreign matter flows through the lower part of the support grid body by the flow of the fluid, the foreign material can be captured. .

As the conformal bent portion 23 of the salted spring is formed up and down, the contact area of the fuel rod 8 is formed up and down to supplement the axial support force of the fuel rod, and the fuel rod support integrity is easily maintained, and the conformal bend 23 The load transmitted through) is evenly distributed throughout the unit grid 45 through the four spring legs 28 provided in the form of salty legs.

By providing the lip-type multipurpose support grid according to the present invention as described above, the salty spring and the upper and lower dimples may be caused by changes in the furnace environment that may occur during operation of the reactor through the conformal surface contact with the fuel rods, respectively. It is possible to support stable fuel rods against loads in any direction, and in particular, as the fuel rods increase the contact area of the spring, the fuel rods may have increased resistance to fretting wear damage when the fuel rods vibrate. Support health is further expanded.

In addition, the four spring legs have a salt-like leg structure, each bent portion is formed can easily adjust the spring force to the appropriate level, there is an effect of expanding the elastic range of the spring.

In addition, the upper and lower incisions of the salted spring are formed in an arc shape so that the torsional force is transmitted to the lattice when the load is under load. can do.

In addition, by having a window picker in the conformal bend, it is possible to prevent the occurrence of nuclear boiling deviation due to the suppression of heat transfer from the fuel rod, and to adjust the spring force that can be too large, thereby excessively loading and withdrawing nuclear fuel. The force is not required and the possibility of damaging the surface of the nuclear fuel rod is reduced, thereby preventing corrosion of the fuel rod and preventing shortening of the fuel rod life.

In addition, by having a spoon-shaped flow mixing wing which is provided to be connected to the upper dimple, by moving the fluid in the transverse direction in each unit cell to enable effective mixing of the cooling water, the upper dimple and the lower dimple As the upper and lower incisions are arcuate, they not only reduce the pressure drop of the fluid, but also induce a flow change of the fluid flowing from the lower end of the support grid and induce foreign substances that may be mixed in the fluid. By being able to capture between dimples and salted springs, this has the effect of minimizing damage to the fuel rods due to foreign matter.

Although the present invention has been illustrated and described with reference to specific embodiments, it is intended that various modifications and changes can be made without departing from the spirit and scope of the invention as indicated by the appended utility model registration claims. Anyone who owns it can easily know.

Claims (9)

In order to support a nuclear fuel rod assembly composed of a plurality of nuclear fuel rods, a plurality of unit grids are formed in parallel to each other, and horizontal and vertical grids in which a slit of a predetermined length cut from an upper or lower portion is formed at a connection portion between each unit grid. In the supporting lattice itself, arranged so as to intersect longitudinally and horizontally, to form a plurality of unit cells in which each of the nuclear fuel rods is charged and positioned, The unit grids constituting the horizontal and vertical lattice plates include two longitudinal supports arranged in parallel with a predetermined width in the axial direction, and horizontally extending at the same distance from each end of the longitudinal supports, respectively. A supporting part including a horizontal support for connecting the vertical support and forming an opening in a rectangle at the center thereof; Is coupled to the opening position, the curvature to be in contact with the outer circumferential surface of the fuel rod in the width direction to be curved by a predetermined width and is formed long in the axial direction, respectively in the opposite direction on the boundary between both ends of the conformal bend A left / right extension portion that is bent and extended by a predetermined width, and four spring legs further extending laterally and laterally from the upper and lower ends of the left end of the left extension and the right end of the right extension, respectively; The salt brim type springs are connected to each of the upper and lower ends of each of the side incision lines of the opening and coupled to each other to protrude to one side; It is coupled to each of the upper and lower portions of the salt-damp spring, the dimple bent portion is formed curved by a predetermined width at the curvature so as to be in surface contact with the outer peripheral surface of the fuel rod in the center in the width direction, respectively opposite the boundary between the both ends of the dimple bent portion It is configured to include a left / right dimple extension extending in the direction, the upper and lower incisions are formed to form an arc, including the upper and lower dimples protruding in a direction opposite to the protruding direction of the salt spring Lip type multi-purpose fuel support grid, characterized in that. The method of claim 1; Lip is a multi-purpose nuclear support grid body, characterized in that the isometric bent portion of the salt spring type is formed in the axial direction long and narrow in the width direction. The method of claim 1; Each spring leg of the salter type spring is a lip-type multi-purpose fuel support grid, characterized in that it has a bent portion is bent again in the opposite direction to the bending direction of the left and right extensions. The method of claim 3, wherein The bent portion of the lip-type multi-purpose fuel support grid, characterized in that protruding to the opposite side of the conformal bend relative to the base. The method of claim 1, The salt-like spring has an upper end incision line of the two bent legs extending from both the right bend and the left / right extension part and the upper side, and a front end of the connected lower incision line of the two bent legs extending from both the conformal bend and left / right extension part and the lower part. Lip-type multi-purpose fuel support grid, characterized in that the shape is formed in the mutually symmetrical arcuate shape. The method of claim 1; The unit grid is a lip-type multi-purpose fuel support grid, characterized in that it may further include a flow mixing wing that extends further from the upper end of one side of the dimple extension of the upper dimple located at the top. The method of claim 6; The flow-mixed wing is a lip-type multi-purpose fuel support grid, characterized in that it is formed to be gradually bent so as to protrude in the same direction as the salt spring-shaped spring. The method of claim 7, wherein And an angle between an upper end normal of the flow mixing blade and a vertical line in the axial direction is an acute angle. The method of claim 6, The flow-mixed wing is a lip-shaped multi-purpose fuel support grid, characterized in that the planar shape of the upper end portion is formed so as to correspond to the arc of a radius larger than the radius of the fuel rod.