Filter, filter mechanism and fuel assembly for separating particles from a coolant in a nuclear power plant

Abstract

A filter (1, 1', 1'', 1''') for separating particles from a coolant in a nuclear power plant is described. The filter (1, 1', 1'', 1''') comprises a filter portion (2) arranged in a filter frame (3, 3', 3'', 3''') configured to cooperate with a mounting portion (5, 5', 5'', 5''') of a component (7) of the nuclear power plant for mounting the filter (1, 1', 1'', 1''') in the component. The filter frame (3, 3', 3'', 3''') of the filter (1, 1', 1'', 1''') comprises at least one protrusion (9, 9', 9'') and / or at least one recess (11) extending along an extension direction (e, e') substantially perpendicular to a plane (p) along a surface portion (13) of an outer surface of the filter frame (3, 3', 3'', 3'''). The at least one protrusion (9, 9', 9'') and / or the at least one recess (11) are disposed around the entire circumference of the filter frame (3, 3', 3'', 3''') along an outer edge (15) of the filter frame (3, 3', 3'', 3'''). The at least one protrusion (9, 9', 9'') and / or the at least one recess (11) are disposed to form an obstacle for the particles flowing between the filter frame (3, 3', 3'', 3''') and the attachment portion (5, 5', 5'', 5'''). A filter mechanism and a fuel assembly are also described.

Description

[Technical field]

[0001] The present disclosure relates to a filter for separating particles from a coolant in a nuclear power plant. Further, the present disclosure relates to a filter mechanism and a fuel assembly. [Background technology]

[0002] In nuclear power plants, e.g. BWR, PWR, VVER, etc., it is important to filter the coolant, because debris and other particles carried by the cooling liquid can cause defects in the cladding of the fuel rods. If the cladding of the fuel rods is defective, the nuclear fuel, i.e. uranium, can leak into the cooling water. If the defect becomes large, the operation of the reactor may have to be interrupted in order to replace the damaged fuel. Such a replacement is time-consuming and expensive. Debris and other particles can also cause defects in other components of the nuclear power plant, e.g. pumps. Debris can consist of metal pieces and wires, which are formed, for example, during repairs of components inside the plant. Debris can also reach the power plant from outside.

[0003] JP4005891B2 describes an example of a filter for a nuclear power plant. The filter is arranged to prevent debris from entering the coolant passage, and the filter is welded to the tie plate of the fuel assembly. The document describes improvements regarding the welding of the filter.

[0004] Although currently used filters work well, what is needed is an improved filter that is positioned to reduce the flow of coolant through the passageway between the filter and the mounting structure for mounting the filter. What is needed is a filter that is configured to inhibit the flow of debris and particles through the passageway between the filter and the mounting structure. It is also desirable to provide a filter that is easy to assemble and disassemble. Summary of the Invention

[0005] The object of the present disclosure is to overcome at least some of the above-mentioned drawbacks and problems. The above-mentioned object is achieved by the subject matter defined by the independent claims.

[0006] The object of the present disclosure is achieved by a filter for separating particles from a coolant in a nuclear power plant. The filter comprises a filter part arranged in a filter frame configured to cooperate with a mounting part of a component of a nuclear power plant to mount the filter to the component. Thus, the filter frame is configured by its shape and dimensions to be able to position the filter frame in the mounting part for mounting the filter to the mounting part of the component of the nuclear power plant. The filter is configured for separating particles from a coolant in a nuclear power plant, meaning that the mounting part is part of the component that allows the coolant to flow through the mounting part and to the component. For example, the component may be part of a flow path of the coolant in the nuclear power plant.

[0007] The filter frame of the filter comprises at least one protrusion and / or at least one recess extending along an extension direction substantially perpendicular to a plane along the surface of the outer surface of the filter frame, the at least one protrusion and / or the at least one recess being disposed along the entire circumference of the filter frame along the outer edge of the filter frame, the at least one protrusion and / or the at least one recess being disposed so as to form an obstacle for particles flowing between the filter frame and the attachment part.

[0008] At least one protrusion and at least one recess are parts of the filter frame. Therefore, at least one protrusion and at least one recess are not members arranged so as to be attached to the filter frame. In addition, the outer surfaces of at least one protrusion and at least one recess are part of the outer surface of the filter frame. The outer surface of the filter frame is the surface facing the mounting part where the filter frame is positioned.

[0009] The surface portion of the outer surface of the filter frame is included in the plane. At least one protrusion and / or at least one recess extends from the surface portion along an extension direction substantially perpendicular to the surface portion. Therefore, at least one protrusion and / or at least one recess is disposed substantially perpendicular to the surface portion of the outer surface of the filter frame.

[0010] Furthermore, at least one protrusion and / or at least one recess is arranged along the entire circumference of the filter frame. The filter frame, which is cuboid-shaped, for example rectangular, has two bottom plates and four side plates and has two outer edges of the two bottom plates. The outer edges are created by secondary edges formed at the connections of the bottom plates and the side plates. Here, the outer circumference of the filter frame means the entire outer circumference of each bottom plate. The filter frame is configured to cooperate with the mounting part along its entire circumference. Thus, the outer circumference of the filter frame is determined along the part of the filter frame that cooperates with the mounting part of the component of the nuclear power plant by positioning the filter frame in the mounting part of the filter frame.

[0011] The filter frame comprises at least one protrusion and / or at least one recess, the direction of extension of which along the surface of the outer surface of the filter frame is substantially perpendicular to the plane, and the at least one protrusion and / or at least one recess are arranged along the entire circumference of the filter frame along the outer edge of the filter frame, so that when the filter is attached to the attachment part, an additional curvature is generated in the space between the outer surface of the filter frame and the surface of the attachment part. This curvature, in particular a labyrinth-shaped flow path having several curves, forms an obstacle for debris or particles that try to flow between the filter frame and the attachment part across the at least one protrusion and / or at least one recess. In the space between the filter frame and the attachment part, debris or particles may get caught in the curvature of the labyrinth-shaped flow path. Thus, the at least one protrusion and / or at least one recess acts as a seal against debris or particles when the filter is assembled, i.e. when the filter is attached to the attachment part.

[0012] This provides an improved filter with conditions for reducing the flow of cooling liquid between the filter and the mounting part due to the labyrinth-shaped flow path when the filter is used. The reduced flow of cooling liquid means that the number of debris and particles flowing in the cooling liquid is reduced. Furthermore, the labyrinth-shaped flow path makes it difficult for debris and particles to flow through the space between the filter and the mounting part. In this way, an improved filter is provided that has improved protection properties against debris and particles compared to known filters, and in particular has improved conditions for preventing debris and particles from flowing through the space between the filter frame and the mounting part. In addition, since there is no need to weld the entire circumference of the filter to seal the gap between the filter frame and the mounting part, an improved filter is provided that can be assembled and disassembled efficiently, and the at least one convex portion and / or at least one concave portion makes it easier to assemble the filter. Furthermore, the at least one convex portion and / or at least one concave portion makes it easier to position the filter at a desired position relative to the mounting part. This achieves the above object.

[0013] At least one protrusion and / or one recess comprises a first portion arranged on a surface portion of the outer surface of the filter frame and a second portion extending from the first portion along an extension direction, the first portion having a dimension greater than the second portion at least in a direction perpendicular to the extension direction, thereby achieving a double curvature with improved protection against debris and particles that may flow into the space between the filter frame and the attachment portion. The first portion may be wider than the second portion, since the first portion has a dimension greater than the second portion at least measured perpendicular to the extension direction. The first portion may be longer or shorter than the second portion measured along the extension direction.

[0014] Optionally, the filter frame comprises at least two recesses and / or at least two protrusions arranged parallel to one another, thereby providing a further improved barrier against debris and particles when the filter is attached to the mounting portion.

[0015] Optionally, the at least two protrusions and / or the at least two recesses have similar shapes and dimensions, which may facilitate the manufacture of the filter.

[0016] Optionally, the at least one protrusion and / or the at least one recess has a height and a respective depth measured along the extension direction, the height and depth being different along the periphery of the filter frame, preferably forming a sinusoidal or zigzag pattern along the periphery of the filter frame. Thus, when the filter frame is attached to the attachment part, an additional curvature is formed between the filter frame and the attachment part by the at least one protrusion and / or the at least one recess along the entire circumference of the filter frame along the outer edge of the filter frame. This provides a three-dimensional curvature, i.e. a three-dimensional obstacle, which acts as a better obstacle to debris or particles that try to flow between the filter frame and the attachment part, across the at least one protrusion and / or the at least one recess, and along the at least one protrusion and / or the at least one recess. In this way, a further improved filter is provided.

[0017] The extending direction is parallel to the desired direction of the coolant passing through the filter. Therefore, at least one convex portion and / or at least one recessed portion can be arranged, for example, parallel to the desired flow direction of the coolant flowing through the filter. For example, at least one convex portion and / or at least one recessed portion can be arranged at the bottom of the filter. The extending direction may also be perpendicular to the desired direction of the coolant passing through the filter. Therefore, at least one convex portion and / or at least one recessed portion can be arranged, for example, perpendicular to the desired direction of the coolant flowing through the filter. For example, at least one convex portion and / or at least one recessed portion can be arranged on the side of the filter frame. Here, the bottom surface and the side surface of the filter refer to the desired mounting position of the filter relative to the mounting portion of the filter. The orientation of the filter frame relative to the mounting portion may be different depending on the position in the nuclear power plant where the filter is mounted.

[0018] Furthermore, the tip of at least one protrusion and / or at least one recess has an end face arranged substantially perpendicular to the extension direction, and the end face is provided with at least one groove and / or at least one ridge, which can provide an even more improved obstacle to debris or particles and thus an even more improved filter can be realized.

[0019] Optionally, the nuclear power plant component is part of a fuel assembly in a core of the nuclear power plant, in particular the component is an inlet to the fuel assembly, such that the filter can be used to filter coolant for the fuel assemblies in the core of the nuclear power plant.

[0020] The object of the present invention is also achieved by a filter arrangement configured to be placed in a nuclear power plant, the filter arrangement comprising a mounting part of a component of the nuclear power plant and a filter according to any embodiment described herein, the mounting part comprising at least one further recess and / or at least one further protrusion respectively arranged to receive at least one protrusion of the filter frame and / or to be inserted into at least one recess of the filter frame.

[0021] The shapes of the at least one further recess and the at least one further protrusion of the mounting portion correspond to the shapes of the at least one protrusion and the at least one recess of the filter frame, respectively, such that the at least one protrusion and / or the at least one recess of the filter frame can be positioned in the corresponding at least one further recess and / or the corresponding at least one further protrusion can be received in order to mount the filter on the mounting portion.

[0022] The filter of the filter arrangement has properties corresponding to those of the filters described above. The filter with the attachment of the nuclear power plant component forms a filter arrangement, i.e. a unit with the filter and the attachment connected to each other, which unit can be installed in the nuclear power plant.

[0023] One of the advantages of the filter mechanism is that an additional curvature is formed in the space between the outer surface of the filter frame and the surface of the mounting part, and this curvature, i.e. the labyrinth-like flow path with several curves, forms an obstacle for debris or particles trying to flow between the filter frame and the mounting part over the at least one convex part and / or the at least one concave part. In such a space between the filter frame and the mounting part, the debris or particles may get caught in the curvature. Therefore, when the filter mechanism is assembled, i.e. when the filter is mounted on the mounting part, the at least one convex part and / or the at least one concave part and the corresponding at least one further concave part and / or the at least one further convex part act as a seal for debris or particles.

[0024] This provides an improved filter mechanism with improved protection against debris and particles compared to known filter mechanisms, in particular with improved conditions for preventing debris and particles from flowing through the space between the filter frame and the mounting part.Furthermore, the improved filter mechanism provides conditions for efficient assembly and disassembly of the filter mechanism.Furthermore, the at least one protruding portion and / or at least one recessed portion and the corresponding at least one further recessed portion and / or at least one further protruding portion facilitate positioning of the filter in a desired position relative to the mounting part.This achieves the above-mentioned object.

[0025] Optionally, the at least one further recess and / or the at least one further protrusion have a further depth and a respective further height measured along the extension direction of the at least one further recess and / or the at least one further protrusion, the depth and the respective height varying along the circumference of the mounting part, preferably forming a sinusoidal or zigzag pattern of the at least one further recess and / or the at least one further protrusion corresponding to the sinusoidal or zigzag pattern of the at least one protrusion and / or the at least one recess of the filter frame. This results in a further curvature between the filter frame and the mounting part around the entire circumference of the filter. This provides a three-dimensional curvature, i.e. a three-dimensional obstacle, which acts as a better obstacle for debris or particles trying to flow between the filter frame and the mounting part over and along the at least one protrusion and / or the at least one recess. This provides a further improved filter mechanism.

[0026] Optionally, the nuclear power plant component is part of a fuel assembly in the core of the nuclear power plant. In particular, the component is an inlet to the fuel assembly. As such, a filter mechanism may be provided within the fuel assembly and used to filter the fuel assembly coolant.

[0027] Optionally, the at least one further recess and / or the further tip of the further protrusion of the mounting part further comprises a further end face arranged substantially perpendicular to the extension direction, said further end face being provided with at least one further groove and / or at least one further ridge, thereby providing a further improved obstacle to debris or particles and achieving a further improved filtering mechanism.

[0028] The above objectives are further achieved by a fuel assembly comprising a filter mechanism according to some embodiments described herein, the fuel assembly comprising an improved filter mechanism, thereby providing an improved fuel assembly, thereby achieving the above objectives.

[0029] Further features and advantages of the present invention will become apparent from a consideration of the appended claims and the following detailed description. [Brief description of the drawings]

[0030] The various aspects of the present invention, particularly its features and advantages, will be readily understood from the following detailed description and the examples illustrated in the accompanying drawings. [Figure 1] FIG. 1 is a top view of a schematic filter arrangement. [Diagram 2] FIG. 2 is a cross-sectional view of the filter arrangement shown in FIG. 1 according to one embodiment. [Diagram 3] FIG. 3 is a cross-sectional view of a filter mechanism according to another embodiment. [Figure 4] FIG. 4 is a cross-sectional view showing a part of a filter mechanism according to still another embodiment. [Diagram 5] FIG. 5 is a cross-sectional view showing a part of a filter mechanism according to still another embodiment. [Figure 6] FIG. 6 is another cross-sectional view of a portion of a filter mechanism according to some embodiments. [Figure 7] FIG. 7 is a schematic cross-sectional view of a BWR fuel assembly including a filter mechanism according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] Hereinafter, embodiments of the present invention will be described in more detail. Note that throughout, the same elements are given the same reference numerals and descriptions thereof are omitted. For the sake of brevity and / or clarity, well-known functions or structures are not necessarily described in detail.

[0032] 1 shows a schematic top view of a filter arrangement 21, 21', 21'', 21''' configured to be placed in a nuclear power plant. The filter arrangement 21, 21', 21'', 21''' comprises a mounting 5, 5', 5'', 5''' of a component 7 of a nuclear power plant and a filter 1, 1', 1'', 1''' according to some embodiments. The component 7 may be, for example, part of a fuel assembly, of which FIG. 7 shows an example, namely a fuel assembly for a BWR reactor.

[0033] The filter 1, 1', 1'', 1''' is arranged to separate particles from a coolant in a nuclear power plant. The filter 1, 1', 1'', 1''' comprises a filter frame 3, 3', 3'', 3''', configured to cooperate with a mounting part 5, 5', 5'', 5''' of a component 7 for mounting the filter 1, 1', 1'', 1''' in the component 7 of the nuclear power plant. The filter 1, 1', 1'', 1''' comprises a filter part 2 arranged in the filter frame 3, 3', 3'', 3'''. Between the filter frame 3, 3', 3'', 3''' and the mounting part 5, 5', 5'', 5''' a space 4 is provided which forms a tight flow path through which the coolant flows. It is desirable to restrict the flow of the coolant in the space 4 and to trap debris and particles which attempt to flow. The distance between the filter frame 3, 3', 3'', 3''' and the mounting part 5, 5', 5'', 5''' is minimized during the design and manufacture of the component to fit as closely as possible. However, due to limitations due to manufacturing tolerances such as the flatness of the component surfaces, the distance between them may vary, for example, up to about 0.3 mm. This allows fine debris, such as wires with a diameter of less than 0.3 mm, to flow through the space 4. The coolant flows mainly through the passage 6 shown in Figure 2.

[0034] The filter frame 3, 3', 3'', 3''' has at least one convex portion 9, 9', 9'' (schematically shown by a dashed line) and / or at least one concave portion 11 (schematically shown by a dashed line) that is substantially perpendicular to the extension directions e, e' in which a plane p along a surface portion 13 of the outer surface of the filter frame 3, 3', 3'', 3''' extends. The plane p, the surface portion 13 and the extension directions e, e' are shown in Figures 2 and 3.

[0035] At least one protrusion 9, 9', 9'' and / or at least one recess 11 is arranged along the outer edge 15 of the filter frame 3, 3', 3'', 3''', all around the filter frame 3, 3', 3'', 3'''.

[0036] At least one protrusion 9, 9', 9'' and at least one recess 11 are parts of the filter frame 3, 3', 3'', 3''' included in the filter frame 3, 3', 3'', 3''', respectively. Therefore, at least one protrusion 9, 9', 9'' and at least one recess 11 are not elements arranged so as to be attachable to the filter frame 3, 3', 3'', 3'''. Furthermore, the outer surfaces of at least one protrusion 9, 9', 9'' and at least one recess 11 are parts of the outer surface of the filter frame 3, 3', 3'', 3'''. The outer surface of the filter frame 3, 3', 3'', 3''' is the surface facing the mounting portion 5, 5', 5'', 5''', on which the filter frame 3, 3', 3'', 3'''' is arranged.

[0037] 2 is a cross-sectional view of the filter mechanism 21 shown in FIG. 1 according to one embodiment. The filter mechanism 21 includes a filter 1 together with a filter frame 3 having a protrusion 9. According to the embodiment shown in FIG. 2, the protrusion 9 is arranged as one protrusion 9 that is inserted into a further recess 23 of the mounting part 5 for mounting the filter 1 to the mounting part 5. The height h of the protrusion can be, for example, in the range of 5 to 10 mm. As a result, the corresponding further recess 23 has a corresponding depth.

[0038] FIG. 3 is a cross-sectional view of a filter arrangement 21''' according to another embodiment. The filter arrangement 21''' comprises a filter 1''' together with a filter frame 3''' with recesses 11. According to the embodiment shown in FIG. 3, the recesses 11 are arranged as one recess 11 arranged to receive a further protrusion 25 of the mounting part 5''' for mounting the filter 1''' to the mounting part 5'''. The depth de of the recess 11 can for example be in the range of 5 to 10 mm. Thereby, the corresponding further protrusion 25 has a corresponding height.

[0039] FIG. 4 is a cross-sectional view of a part of a filter mechanism 21' according to yet another embodiment. According to the embodiment shown in FIG. 4, at least one protrusion 9' comprises a first portion 17 arranged on the surface portion 13 of the outer surface of the filter frame 3' and a second portion 19 extending from the first portion 17 along an extension direction e. The first portion 17 has a larger dimension than the second portion 19 in a direction d perpendicular to the extension direction e. Thus, the first portion 17 may be wider than the second portion 19. According to some embodiments, the first portion 17 may be longer or shorter than the second portion 19 measured along the extension direction e.

[0040] FIG. 5 is a cross-sectional view of a part of a filter mechanism 21″ according to yet another embodiment. According to the embodiment shown in FIG. 5, the filter frame 3″ comprises two protrusions 9″ arranged parallel to each other. The two protrusions 9″ have similar shapes and similar dimensions, which facilitates the manufacture of the filter 1″. The two protrusions 9″ are arranged to be inserted into corresponding further recesses of the mounting part 5″. Alternatively, although not shown, the filter frame may have one protrusion and one recess, and the mounting part may have one corresponding further recess and one further protrusion.

[0041] FIG. 6 is a cutaway view of a portion of a filter mechanism 21, 21', 21'', according to some embodiments. According to the embodiment shown in FIG. 6, the filter frame 3, 3', 3'' comprises at least one protrusion 9, 9', 9'', and the mounting portion 5, 5', 5'' comprises at least one further recess 23 arranged to receive the at least one protrusion 9, 9', 9''. However, the filter frame may also comprise a recess and the mounting portion may comprise a further protrusion arranged to be inserted into the recess of the frame.

[0042] Alternatively, although not shown, the frame may have at least one protruding portion and at least one recessed portion along the outer periphery of the frame. That is, the frame may have a section having at least one protruding portion and a section having at least one recessed portion along the outer periphery of the frame. The attachment portion is then disposed in correspondence with the at least one further recessed portion and the at least one further protruding portion.

[0043] 6, the at least one further recess 23 has a further depth de1 measured along a further extension direction e1 of the at least one further recess 23. The further depth d1 varies along the periphery of the mounting part 5, 5', 5'' (not shown but corresponding to the periphery of the filter frame) and preferably forms a zigzag pattern of the at least one further recess 23 corresponding to the zigzag pattern of the at least one protrusion 9, 9', 9'' to enable coupling of the filter frame with the mounting part.

[0044] In the embodiment shown in this disclosure, the extension directions e, e', e1 are parallel to the desired direction of coolant flow through the filters 1, 1', 1'', 1''', and passages 6. However, the extension directions e, e', e1 may be perpendicular to the desired direction of coolant flow through the filters 1, 1', 1'', 1''', and passages 6.

[0045] 7 is a schematic cross-sectional view of a BWR fuel assembly 7 including a filter 1 according to one embodiment. The filter 1 is attached to an inlet fitting 5 to the fuel assembly 7. It should be noted that according to some embodiments, the fuel assembly 7 may be a fuel assembly for a PWR or VVER reactor, or may be a fuel assembly for other reactor types.

Claims

1. A filter (1, 1', 1'', 1''') for separating particles from a coolant in a nuclear power plant, comprising: the filter (1,1',1'',1''') comprises a filter part (2) arranged in a filter frame (3,3',3'',3''') configured to cooperate with a mounting part (5,5',5'',5''') of a component (7) for mounting the filter (1,1',1'',1''') in the component (7) of the nuclear power plant, the filter frame (3, 3', 3'', 3''') of the filter (1, 1', 1'', 1''') comprises at least one convex portion (9, 9', 9'') and / or at least one concave portion (11) extending along an extension direction (e, e') substantially perpendicular to a plane (p) along a surface portion (13) of the outer surface of the filter frame (3, 3', 3'', 3'''); the at least one protrusion (9, 9', 9'') and / or the at least one recess (11) are arranged along an outer edge (15) of the filter frame (3, 3', 3'', 3''') over the entire circumference of the filter frame (3, 3', 3'', 3''', the at least one protrusion (9, 9', 9'') and / or the at least one recess (11) are arranged to form an obstacle for the particles flowing between the filter frame (3, 3', 3'', 3''') and the mounting part (5, 5', 5'', 5'''), filter(1, 1', 1'', 1'').

2. the at least one convex portion (9') and / or one concave portion (11) comprises a first portion (17) disposed on a surface portion (13) of the outer surface of the filter frame (3') and a second portion (19) extending from the first portion (17) along an extension direction (e); At least in a direction (d) perpendicular to the extension direction (e), the first portion (17) has a dimension larger than that of the second portion (19); A filter (1') according to claim 1.

3. The filter frame (3'') comprises at least two recesses and / or at least two protrusions (9'') arranged parallel to each other; A filter (1'') according to claim 1 or 2.

4. the at least two protrusions (9 ″) and / or the at least two recesses have similar shapes and dimensions; A filter (1'') according to claim 3.

5. said at least one projection (9, 9', 9'') and / or at least one recess (11) having a height (h) and a respective depth (de) measured along said extension direction (e, e'), said height (h) and depth (de) respectively vary along the circumference of said filter frame (3, 3', 3'', 3'''), preferably such that along the circumference of said filter frame (3, 3', 3'', 3'''), said at least one protrusion (9, 9', 9'') and / or at least one recess (11) form a sinusoidal or zigzag pattern, A filter (1, 1', 1'', 1''') according to any one of claims 1 to 4.

6. said extension direction (e, e') being parallel to the desired direction of cooling liquid flow through said filter (1, 1', 1'', 1'''); A filter (1, 1', 1'', 1''') according to any one of the preceding claims.

7. The nuclear power plant component (7) is part of a fuel assembly in the core of the nuclear power plant. A filter (1, 1', 1'', 1''') according to any one of the preceding claims.

8. A filter arrangement (21, 21', 21'', 21''') arranged in a nuclear power plant, comprising: said filter arrangement (21, 21', 21'', 21''') comprising a mounting (5, 5', 5'', 5''') for a component (7) of the nuclear power plant and a filter (1, 1', 1'', 1''') according to any of claims 1 to 7, the mounting portion (5, 5', 5'', 5''') is respectively arranged to receive the at least one protrusion (9, 9', 9'') of the filter frame (3, 3', 3'', 3''') and / or comprises at least one further recess (23) and / or at least one further protrusion, respectively arranged to be inserted into the at least one recess (11) of the filter frame (3, 3', 3'', 3'''); Filter mechanism.

9. Comprising a filter (1, 1', 1'', 1''') according to any one of claims 5 to 7, the at least one further recess (23) and / or the at least one further protrusion have a further depth (de1) and a respective further height, measured along an extension direction (e1) of the at least one further recess (23) and / or the at least one further protrusion, said depth (d1) and said respective heights vary along the circumference of said mounting portion (5, 5', 5'', 5''') to preferably form a sinusoidal or zigzag pattern of said at least one further recess (23) and / or at least one further protrusion (11) corresponding to a sinusoidal or zigzag pattern of said at least one protrusion (9, 9', 9'') and / or at least one recess (11) of said filter frame (3, 3', 3'', 3'''); A filter arrangement (21, 21', 21'', 21''') according to claim 8.

10. The nuclear power plant component (7) is part of a fuel assembly in the core of the nuclear power plant. A filter arrangement (21, 21', 21'', 21''') according to claim 8 or 9.

11. Equipped with a filter arrangement (21, 21', 21'', 21''') according to any one of claims 8 to 10, Fuel assembly (7).

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