Method of replacing the function of a heat shield flexure, a heat shield flexure member, and a system including a heat shield flexure member

Abstract

It can be used to replace the function of any one of the heat shield flexures and can be installed from the outside of the core barrel without welding.SOLUTION: A method of installing a heat shield flexure member to a heat shield, a core barrel, and a heat shield flexure in a cold water nuclear reactor, the method comprising: removing a stem portion of the heat shield flexure; modifying the heat shield; removing a bolt passing through an opening in the core barrel and threadably engaging the heat shield flexure; and inserting a heat shield flexure member through an opening in the core barrel, the heat shield flexure member comprising: Modifying the core barrel after removing the bolts threadedly engaging the heat shield flexure, and connecting the heat shield flexure member to the heat shield, the core barrel, and the heat shield flexure after all of the foregoing steps have been completed.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims the benefit under 35 U.S.C. § 119(e) of the earlier filing date of U.S. Provisional Patent Application No. 62 / 975,957, entitled "Method Of Replacing A Functionality Of A Thermal Shield Flexure, A Thermal Shield Flexure Member, And A System Including The Same," filed February 13, 2020, the entire contents of which are incorporated herein by reference. [Background technology]

[0002] In some pressurized water reactors, multiple heat shield flexures are utilized to connect the core barrel to the heat shield at multiple locations around the reactor vessel. A top view of exemplary heat shield flexure locations around the reactor vessel is shown in FIG. 1. Because the core barrel and heat shield are geometrically different and vary in proximity to the fuel, the core barrel and heat shield may expand at different rates in the axial and radial directions. One function of the heat shield flexures is to provide axial flexibility to accommodate the differential axial expansion of the core barrel and heat shield. Another function of the heat shield flexures is to provide radial stiffness to suppress undesirable shell mode vibrations of the core barrel and heat shield.

[0003] For such pressurized water reactors, the heat shield flexure is typically a T-shaped member having an arm portion (the top of the T) and a stem portion (the vertical portion of the T). For each heat shield flexure, the arm portion of the heat shield flexure lies against the inner surface of the core barrel, and the stem portion of the heat shield flexure extends radially outward from the arm portion through the core barrel to the heat shield. The arm portion is secured to the core barrel by a plurality of bolts that extend from the outer surface of the core barrel through openings in the core barrel to receptacles defined by the arm portion of the heat shield flexure. For the exemplary heat shield flexure shown in FIG. 2, there are eight bolts that collectively secure the arm portion of the heat shield flexure to the core barrel, with four of the eight bolts located "above" the stem portion of the heat shield flexure and the other four of the eight bolts located "below" the stem portion of the heat shield flexure. The stem portion of the heat shield flexure may be secured to the heat shield by a weld joint and may also be welded to the arm portion of the heat shield flexure by a weld joint (see FIG. 2).

[0004] The heat shield flexures are installed during construction of a pressurized water reactor before the reactor is operational. Over time, due to thermal expansion of the core barrel and heat shield and vibration of the core barrel, one or more of the weld joints may deteriorate or break, thereby potentially affecting the desired function of the heat shield flexure. Given that each arm portion of the heat shield flexure is located inside the core barrel, replacing any one of the heat shield flexures with the same type of heat shield flexure may require significant on-site effort (schedule and cost). What is needed is a different heat shield flexure that can be used to replace the function of any one of the above-mentioned heat shield flexures and that can be installed from outside the core barrel without welding. [Brief explanation of the drawings]

[0005] The novel features of the aspects described herein are set forth with particularity in the appended claims, however, the aspects, both as to organization and method of operation, may be better understood by reference to the following description taken in conjunction with the accompanying drawings.

[0006] [Figure 1] FIG. 1 shows a top view of an exemplary heat shield flexure location around a reactor vessel.

[0007] [Figure 2] FIG. 2 shows an exemplary heat shield flexure secured to the core barrel and heat shield of a reactor vessel.

[0008] [Figure 3] FIG. 3 illustrates a front view of a heat shield flexure member according to at least one embodiment of the present disclosure.

[0009] [Figure 4] FIG. 4 illustrates a rear view of the heat shield flexure member of FIG. 3 in accordance with at least one embodiment of the present disclosure.

[0010] [Figure 5] FIG. 5 illustrates another heat shield flexure member in accordance with at least one other aspect of the present disclosure.

[0011] [Figure 6] FIG. 6 illustrates a system including the heat shield flexure member of FIG. 3 in accordance with at least one embodiment of the present disclosure.

[0012] [Figure 7] FIG. 7 illustrates a bolt of the system of FIG. 6 according to at least one embodiment of the present disclosure.

[0013] [Figure 8] FIG. 8 illustrates a recess defined by an opening in the heat shield flexure member of FIG. 3, according to at least one embodiment of the present disclosure.

[0014] [Figure 9] FIG. 9 illustrates a cross section of the system of FIG. 6 according to at least one embodiment of the present disclosure.

[0015] [Figure 10] FIG. 10 illustrates a method for replacing the function of a heat shield flexure in accordance with at least one embodiment of the present disclosure.

[0016] [Figure 11] FIG. 11 illustrates the heat shield and outer surface of the core barrel of the system of FIG. 6 during a step of the method of FIG. 10 according to at least one embodiment of the present disclosure. Detailed Description of the Invention

[0017] It should be understood that at least some of the drawings and descriptions of the present invention have been simplified to show relevant elements for a clearer understanding of the present invention, and have excluded other elements for purposes of clarity, and those skilled in the art will appreciate that such other elements may also form part of the present invention. However, because such elements are well known in the art and do not facilitate a better understanding of the present invention, descriptions of such elements are not provided herein.

[0018] In the following detailed description, reference is made to the accompanying drawings, which form a part of this specification. In the drawings, like symbols and reference characters generally identify like parts among the several views, unless the context dictates otherwise. The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other embodiments may be applied and other changes may be made without departing from the scope of the technology described herein.

[0019] The following description of some examples of the present technology should not be used to limit its scope. Other examples, features, aspects, embodiments, and advantages of the present technology will become apparent to those skilled in the art from the following description, which is illustrative and illustrates one of the best modes contemplated for carrying out the present technology. As will be understood, the technology described herein is capable of other different and obvious aspects, all without departing from the present technology. Therefore, the drawings and descriptions should be regarded as illustrative in nature, and not restrictive.

[0020] It should be further understood that any one or more of the teachings, expressions, aspects, embodiments, examples, etc. described herein can be combined with any one or more of the other teachings, expressions, aspects, embodiments, examples, etc. described herein. Accordingly, the teachings, expressions, aspects, embodiments, examples, etc. described below should not be considered in isolation from one another. Various suitable ways to combine the teachings herein will be readily apparent to those skilled in the art in light of the teachings herein. Such modifications and variations are intended to be included within the scope of the claims.

[0021] Before describing various aspects of the heat shield flexure member in detail, it should be noted that the various aspects disclosed herein are not limited in their application or use to the details of construction and arrangement of parts shown in the accompanying drawings and specification. Rather, the disclosed aspects may be arranged or incorporated in other aspects, embodiments, variations, and modifications, and may be practiced or carried out in various ways. Accordingly, the aspects of the heat shield flexure member disclosed herein are exemplary in nature and are not meant to limit their scope or application. Furthermore, unless otherwise indicated, the terms and phrases used herein are chosen for the purpose of describing the aspects for the convenience of the reader and are not meant to limit their scope. Furthermore, it should be understood that any one or more of the disclosed aspects, aspect expressions, and / or examples thereof can be combined, without limitation, with any one or more of the other disclosed aspects, aspect expressions, and / or examples.

[0022] It should also be understood that in the following description, terms such as inward, outward, upward, downward, above, top, bottom, left, right, side, interior, exterior, etc., are terms of convenience and should not be construed as limiting terms. The terms used herein are not meant to be limiting insofar as the devices described herein, or portions thereof, may be mounted or utilized in other orientations. Various aspects are described in more detail with reference to the drawings.

[0023] FIG. 3 illustrates a front view of a heat shield flexure member 10 according to at least one embodiment of the present disclosure, and FIG. 4 illustrates a rear view of the heat shield flexure member 10 according to at least one embodiment of the present disclosure. The heat shield flexure member 10 can be used as a "replacement" for one of the heat shield flexures described above. The heat shield flexure member 10 includes a first side 12, a second side 14, and a third portion 16 connected to the first and second sides 12, 14. For the exemplary embodiment shown in FIGS. 3 and 5, the third portion 16 generally exhibits a thickness change and a radius near the transition to the first and second sides 12, 14. According to various embodiments, the third portion 16 is integrally formed with the first and second sides 12, 14.

[0024] The first face 12 defines a plurality of openings 18 extending therethrough from a first surface 20 thereof to a second surface 22 thereof (see FIG. 4). While four openings 18 are shown in FIG. 3, according to other embodiments, the number of openings 18 may be less than or greater than four. Each of the openings 18 is a countersunk hole in the first face 20. According to various embodiments, each of the openings 18 includes a recess 24 (see FIG. 8) machined into the sidewall of the opening 18. The second face 22 defines four bosses 26 (see FIG. 4) or protrusions surrounding the openings 18. As described in more detail below, when the heat shield flexure member 10 is used to replace the function of one of the heat shield flexures described above, the first face 12 is bolted to the heat shield by bolts that pass through each of the openings 18 and into corresponding receptacles defined by the heat shield. The bosses 26 facilitate alignment of the openings 18 with the receptacles defined by the heat shield during installation of the heat shield flexure member 10, and also act to carry shear loads, reducing stress on the bolts securing the heat shield flexure member 10 to the heat shield.

[0025] The second face 14 defines a plurality of openings 28 extending therethrough from the first surface 30 of the second face 14 to the second surface 32 of the second face 14 (see FIG. 4 ). While four openings 28 are shown in FIG. 4 , according to other embodiments, the number of openings 28 may be less than or greater than four. Each of the four openings 28 is countersunk in the first face 30, although the countersinks of the openings 28 may not be as deep as the countersinks of the openings 28. According to various embodiments, each of the openings 28 defines a recess machined in the sidewall of the opening 28, which recess is similar or identical to the recess 24 shown in FIG. 8 . In the second face 32, each of the openings 28 is configured to receive a press-fit bushing 34 (see FIG. 4 ), which, when installed, lies against the second face 32 and surrounds the opening 28 in the second face 32. According to various aspects, the heat shield flexure member 10 includes an installed bushing 34 .

[0026] As described in more detail below, when the heat shield flexure member 10 is used to replace the function of one of the heat shield flexures described above, the second face 14 is bolted to the core barrel by bolts that pass through each of the openings 28 and corresponding bushings 34, through corresponding openings defined by the core barrel, and into corresponding receptacles defined by the arm portions of the heat shield flexure. The bushings 34 facilitate alignment of the openings defined by the core barrel with the openings 28 during installation of the heat shield flexure member 10 and also act as shear load bearers, reducing stress on the bolts securing the heat shield flexure member 10 to the core barrel (by securing the heat shield flexure member 10 to the arm portions of the “replaced” heat shield flexure). The bushings 34 may be machined to a custom length to allow for better installation of the heat shield flexure member 10. According to various embodiments, the bushing 34 may have a length that allows it to protrude from the second face 14 the same distance as the boss 26 protrudes from the first face 12. According to other embodiments, the bushing 34 may have a length that allows it to protrude from the second face 14 a greater distance than the boss 26 protrudes from the first face 12 (see FIG. 5).

[0027] The third section 16 includes a first bend 40 connected to the first face 12 and a second bend 38 connected to the second face 14. The third section 16 also includes legs 36 connected to the first and second bends 38, 40, which act to accommodate axial deflection of the core barrel and / or heat shield.

[0028] The first and second faces 12, 14 may be of any suitable size and shape. The third section 16 may be of any suitable length, thickness, and shape. Generally, the less material utilized in the third section 16, the greater its ability to absorb axial deflection. Similarly, the longer the legs 36 of the third section 16, the greater the axial flexibility of the heat shield flexure member 10.

[0029] FIG. 5 illustrates another heat shield flexure member 10A according to at least one other embodiment of the present disclosure. The heat shield flexure member 10A is similar to, but different from, the heat shield flexure member 10. The heat shield flexure member 10A includes the first and second faces 12, 14 (including the bushing 34) described above and a third portion 16A connected to the first and second faces 12, 14. However, the third portion 16A is different from the third portion 16 described above. The third portion 16A includes a first leg 36A similar to or identical to the leg 36, a bent portion 38A similar to the bent portion 38 described above, and a second leg 42 connected to the bent portion 38A and the second face 14. Of course, heat shield flexure members having sizes and shapes different from those illustrated in FIGS. 3-5 may be used as long as they provide functionality similar to that provided by the exemplary embodiment illustrated in FIGS. 3-5. For simplicity, the heat shield flexure member will hereinafter be described in terms of heat shield flexure member 10, although heat shield flexure member 10A and other embodiments of heat shield flexure members are equally applicable.

[0030] 6 illustrates a system 50 according to at least one embodiment of the present disclosure. Once the heat shield flexure member 10 is connected to the heat shield and core barrel as described above, the heat shield flexure member 10 may be considered part of the system 50. The system 50 includes the heat shield flexure member 10, a core barrel 52, a heat shield 54, bolts 56 connecting the heat shield flexure member 10 to the heat shield 54, and bolts 58 connecting the heat shield flexure member 10 to the core barrel 52 (by securing the heat shield flexure member 10 to the arm portion of the “replacement” heat shield flexure). According to various embodiments, the system 50 also includes an arm portion 60 of the “replacement” heat shield flexure and bolts 62 connecting the arm portion 60 of the “replacement” heat shield flexure to the core barrel 52.

[0031] 7 illustrates bolt 56 of the system of FIG. 6 in accordance with at least one embodiment of the present disclosure. According to various embodiments, bolt 56 may include an integral locking member 64 that helps maintain bolt 56 secured to heat shield flexure member 10. According to various embodiments, bolt 56 is similar to or identical to that described in U.S. Pat. No. 6,164,886, the contents of which are incorporated herein by reference in their entirety. According to various embodiments, bolt 58 and / or bolt 62 may also include an integral locking member similar to or identical to integral locking member 64.

[0032] 8 illustrates recesses 24 defined by openings 18 in heat shield flexure member 10, according to at least one embodiment of the present disclosure. Each recess 24 is configured to receive an integral locking member 64 of a corresponding bolt 56 and cooperates with the integral locking member 64 to help maintain the bolt 56 secured to the heat shield flexure member 10. Although not shown for purposes of redundancy, according to various embodiments, openings 28 may also define recesses similar to or identical to recesses 24, each configured to receive an integral locking member 64 of a corresponding bolt 58 to help maintain the bolt 58 secured to the heat shield flexure member 10.

[0033] 9 illustrates a cross section of a system 50 according to at least one embodiment of the present disclosure. The cross section of system 50 also illustrates a cross section of heat shield flexure member 10, with first face 12 of heat shield flexure member 10 shown bolted to heat shield 54 and second face 14 of heat shield flexure member 10 shown bolted to arm portion 60 of a “replacement” heat shield flexure. As shown in the exploded cross section of the connection of first face 12 to heat shield 54, opening 18 includes recess 24 and bolt 56 includes integral locking member 64. As shown in the exploded cross-sectional view of the connection of the second face 14 to the arm portion 60 of the "replaced" heat shield flexure, the bushing 34 on the back of the second face 14 is received in the countersunk opening in the core barrel 52, the bolt 58 is seated in the countersunk opening 28 in the second face 14, and the bolt 58 passes through the core barrel 52 and threads into the arm portion 60 of the "replaced" heat shield flexure.

[0034] FIG. 10 illustrates a method 70 for replacing the functionality of a heat shield flexure, according to at least one embodiment of the present disclosure. Prior to installation of a heat shield flexure member 10 that replaces the functionality of the “replaced” heat shield flexure, the heat shield fixture (flexure) is modified (70) by removing the stem portion (see FIG. 2 ) of the heat shield fixture. Removal of the stem portion may be accomplished in any suitable manner. For example, according to various embodiments, the weld joint connecting the stem portion to the arm portion 60 and / or heat shield 54 may be removed by mechanical inversion (e.g., by using a grinder or milling tool) or by thermal inversion, such as, for example, electrical discharge milling (EDM). Once the weld joint is removed, the stem portion of the heat shield flexure can then be removed. Once the stem portion is removed, the bolt connecting the bottom of the modified heat shield flexure’s arm portion 60 to the core barrel 52 is removed (74). The bolts connecting the tops of the modified heat shield flexure arm portions 60 to the core barrel 52 remain in place.

[0035] After the bolts connecting the bottom of the modified heat shield flexure arm portions 60 to the core barrel 52 are removed, the core barrel 52 is modified (76) to accept the heat shield flexure member 10. Before, after, or simultaneously with the modifications to the core barrel 52, the heat shield 54 is also modified (78) to accept the heat shield flexure member 50. The modifications may be accomplished in any suitable manner. For example, according to various embodiments, conventional machining (tapping tools) may be utilized to create a new threaded receptacle in the heat shield 54 to receive the threads of the bolt 56. Conventional machining using a milling cutter or EDM may be utilized to countersink the threaded receptacle in the heat shield 54 to receive the boss 26 of the first face 12 (see FIG. 11 ) and to create the recess 24 that receives the integral locking member 64 of the bolt 56. Conventional milling or EDM may also be utilized to countersink the opening in the core barrel 52 (see FIG. 11) to receive the bushing 34 of the second face 14. The mating surfaces of the boss 26 and bushing 34 of the heat shield flexure member 10, as well as the threaded receiving portion of the countersunk hole in the heat shield 54 and the countersunk hole opening in the core barrel 52, can be tightly controlled to ensure the tolerances necessary for installation of the heat shield flexure member 10 with minimal prestress.

[0036] After machining of the heat shield 54 and core barrel 52 is complete, the heat shield flexure member 10 can be installed (80). As described above, installing the heat shield flexure member 10 involves positioning the heat shield flexure member 10 so that the bosses 26 and bushings 34 are received by the countersunk threaded receivers of the heat shield 54 and the countersunk openings of the core barrel 52. Once the heat shield flexure member 10 is properly positioned, the first face 12 is connected to the heat shield 54 using bolts 56 (threads of the bolts 56 are threadedly engaged with the threaded receivers of the heat shield 54), and the second face 14 is connected to the core barrel 52 using bolts 58 by threading with the arm portions 60 of the modified / "replacement" heat shield flexure.

[0037] In view of the above, it will be appreciated that the configuration of the heat shield flexure member 10 allows for installation of the heat shield flexure member 10 from outside the core barrel / heat shield without welding and without the need to access the interior of the core barrel, thereby significantly reducing the cost, outage impact, and installation risk of replacing a heat shield flexure with a similar or identical heat shield flexure. It will also be appreciated that the opening in the core barrel 52 that originally served to connect the modified / "replacement" heat shield flexure member 10 to the core barrel 52 is reused to connect the heat shield flexure member 10 to the core barrel 52 (by way of bolts 58 connecting the heat shield flexure member 10 to the arm portions 60 of the modified / "replacement" heat shield flexure), eliminating the need to create additional openings in the core barrel 52. The method 70 and heat shield flexure member 10 provide a permanent repair for a damaged heat shield flexure, regardless of the current extent of the damage. The heat shield flexure member 10 directly replaces the function of the existing heat shield flexures while minimizing changes to stiffness characteristics, restoring the vibration behavior of the reactor vessel lower internal assembly to its designed condition. The system 50 also provides better access to the bolts 56, 58 and the heat shield flexure member 10 for future inspection.

[0038] example Example 1 - A heat shield flexure member is provided. The heat shield flexure member includes a first surface, a second surface, and a third portion. The first surface defines a plurality of openings configured to align with the receiving portions of the heat shield. The second surface defines a plurality of openings configured to align with the plurality of openings in the core barrel and with the plurality of openings in the arm portion of a modified heat shield flexure connected to the core barrel. The third portion is connected to the first surface and the second surface and includes a bent portion. The heat shield flexure member is configured to provide (1) axial flexibility to accommodate differential axial expansion of the core barrel and heat shield, and (2) radial stiffness to suppress undesirable shell mode vibrations of the core barrel and / or heat shield.

[0039] Example 2 - The heat shield flexure of example 1, wherein the plurality of openings defined by the first surface are countersunk holes in the first surface of the first surface.

[0040] Example 3 - The heat shield flexure of Example 1 or 2, wherein a sidewall of at least one of the plurality of openings defined by the first surface defines at least one recess configured to receive an integral locking member of a bolt.

[0041] Example 4 - The heat shield flexure of Examples 1, 2 or 3, wherein the first surface further defines a plurality of bosses on a second surface of the first surface.

[0042] Example 5 - The heat shield flexure of example 4, wherein at least one of the plurality of bosses surrounds one of the plurality of openings defined by the first surface portion.

[0043] Example 6 - The heat shield flexure of Examples 1, 2, 3, 4 or 5, wherein the plurality of openings defined by the second surface are countersunk holes in the first surface of the second surface.

[0044] Example 7 - The heat shield flexure of Examples 1, 2, 3, 4, 5 or 6, further comprising a plurality of bushings disposed on the second surface of the second surface portion.

[0045] Example 8 - The heat shield flexure of example 7, wherein at least one of the plurality of bushings surrounds one of the plurality of openings defined by the second surface.

[0046] Example 9 - The heat shield flexure of Examples 1, 2, 3, 4, 5, 6, 7 or 8, wherein the third portion further comprises a second bend and a leg connected to the bend and the second bend.

[0047] Example 10 - The heat shield flexure of Examples 1, 2, 3, 4, 5, 6, 7 or 8, wherein the third portion further comprises a first leg connected to the bend and a second leg connected to the bend.

[0048] Example 11 - A system is provided. The system includes a core barrel, a heat shield, a modified heat shield flexure arm portion, and a heat shield flexure member. The arm portion is located inside the core barrel and is bolted to the core barrel. The heat shield flexure member is positioned outside the core barrel and includes a first face portion bolted to the heat shield, a second face portion bolted to the arm portion of the modified heat shield flexure, and a third portion connected to the first and second face portions, the third portion including a flexure.

[0049] Example 12 - The system of Example 11, wherein the heat shield flexure member further comprises a plurality of bushings disposed adjacent the second surface.

[0050] Example 13 - The system of Example 11 or 12, wherein the third portion further comprises a first leg connected to the first surface and the flexure, and a second leg connected to the second surface and the flexure.

[0051] Example 14 - The system of Example 11 or 12, wherein the third portion further comprises a second bend connected to the first surface and a leg connected to the bend and the second bend, the bend being connected to the second surface.

[0052] Example 15 - The system of Examples 11, 12, 13 or 14, further comprising a plurality of heat shield flexure members.

[0053] Example 16 - The system of Examples 11, 12, 13, 14 or 15, further comprising a plurality of bolts, at least one of the plurality of bolts comprising an integral locking member.

[0054] Example 17 - A method is provided for replacing the function of a heat shield flexure in a pressurized water nuclear reactor. The method includes modifying a heat shield flexure by removing a stem portion of the heat shield flexure, the modified heat shield flexure being located inside a core barrel and having an arm portion bolted to the core barrel; removing at least one bolt less than all of the bolts connecting the arm portion to the core barrel; modifying the core barrel; modifying a heat shield located outside the core barrel; and installing a heat shield flexure member outside the core barrel.

[0055] Example 18 - The method of example 17, wherein removing the stem portion of the heat shield flexure includes removing at least one weld joint.

[0056] Example 19 - The method of example 17 or 18, wherein modifying the heat shield includes creating a threaded receiver in the heat shield.

[0057] Example 20 - The method of example 17, 18 or 19, wherein the step of installing the heat shield flexure member includes bolting the heat shield flexure member to the arm portion of the heat shield and modified heat shield flexure.

[0058] While various embodiments of the heat shield flexure member 10 have been described herein with reference to certain disclosed embodiments, many modifications and variations thereto may be made. Also, where a material is disclosed for an element, other materials may be used. Furthermore, according to various embodiments, a single element may be replaced by multiple elements, and multiple elements may be replaced by a single element, to perform a given function or functions. The foregoing description and the appended claims intend to cover all such modifications and variations as fall within the scope of the disclosed embodiments.

[0059] While the present invention has been described as having an exemplary design, the described invention may be further modified within the spirit and scope of the present disclosure. Accordingly, this application is intended to cover any variations, uses, or adaptations of the invention using its general principles. For example, while the present invention has been described in terms of pressurized water nuclear reactors, the general principles of the invention are equally applicable to other types of nuclear reactors.

[0060] Any patent, patent application, publication, or other disclosure material said to be incorporated herein by reference, in whole or in part, is incorporated herein only to the extent that the incorporated material does not contradict existing definitions, descriptions, or other disclosure material set forth in this disclosure. Accordingly, and to the extent necessary, the disclosure expressly set forth herein supersedes any conflicting material incorporated herein by reference. Any material, or portion thereof, said to be incorporated herein by reference that contradicts existing definitions, descriptions, or other disclosure material set forth herein is incorporated only to the extent that no contradiction arises between the incorporated material and the existing disclosure material.

Claims

1. 1. A thermal field flexure member, comprising: a first surface defining a plurality of openings configured to align with the receiving portions of the heat shield; a second surface defining a plurality of openings configured to align with a plurality of openings in the core barrel and a plurality of openings in the arm portion of a modified heat shield flexure connected to the core barrel; a third portion connected to the first surface and the second surface and including a bent portion; It is equipped with configured to provide axial flexibility to accommodate differential axial expansion of the core barrel and the heat shield, and radial stiffness to suppress undesired shell mode vibrations of at least one of the core barrel and the heat shield. Heat shield flexure member.

2. 2. The heat shield flexure member of claim 1, wherein the plurality of openings defined by the first surface are countersunk holes in a first surface of the first surface.

3. 2. The heat shield flexure member of claim 1, wherein a sidewall of at least one of the plurality of openings defined by the first surface defines at least one recess configured to receive an integral locking member of a bolt.

4. 2. The heat shield flexure member of claim 1, wherein said first surface further defines a plurality of bosses on a second surface of said first surface.

5. 5. The heat shield flexure member of claim 4, wherein at least one of said plurality of bosses surrounds one of said plurality of openings defined by said first surface portion.

6. 2. The heat shield flexure member of claim 1, wherein the plurality of openings defined by the second surface are countersunk holes in a first surface of the second surface.

7. 2. The heat shield flexure member of claim 1, further comprising a plurality of bushings disposed on the second surface of the second surface portion.

8. 8. The heat shield flexure member of claim 7, wherein at least one of said plurality of bushings surrounds one of said plurality of openings defined by said second surface.

9. The heat shield flexure member of claim 1 , wherein the third portion further comprises a second bend and a leg connected to the bend and the second bend.

10. The heat shield flexure member of claim 1 , wherein the third portion further comprises a first leg connected to the bend and a second leg connected to the bend.

11. A core barrel and A heat shield and a modified heat shield flexure arm portion located inside the core barrel and bolted to the core barrel; a heat shield flexure member disposed outside the core barrel, The heat shield flexure member comprises: a first surface portion bolted to the heat shield; a second surface bolted to the arm portion of the modified heat shield flexure; a third portion connected to the first surface portion and the second surface portion and including a bent portion; system.

12. The system of claim 11 , wherein the heat shield flexure member further comprises a plurality of bushings disposed against the second surface.

13. 12. The system of claim 11, wherein the third portion further comprises a first leg connected to the first surface and the bend, and a second leg connected to the second surface and the bend.

14. the third portion further includes a second bent portion connected to the first surface portion, and a leg portion connected to the bent portion and the second bent portion, The bent portion is connected to the second surface portion. The system of claim 11.

15. The system of claim 11 further comprising a plurality of heat shield flexure members.

16. Further comprising a plurality of bolts; The system of claim 11 , wherein at least one of the plurality of bolts includes an integral locking member.

17. 1. A method for replacing the function of a heat shield flexure in a pressurized water nuclear reactor, comprising: modifying a heat shield flexure by removing a stem portion of the heat shield flexure, the modified heat shield flexure being located within a core barrel and including arm portions bolted to the core barrel; removing at least one bolt less than all of the bolts connecting said arm portion to said core barrel; modifying the core barrel; modifying a heat shield located outside the core barrel; installing a heat shield flexure member on the exterior of the core barrel; A method comprising:

18. The method of claim 17 , wherein the step of removing the stem portion of the heat shield flexure includes removing at least one weld joint.

19. The method of claim 17 , wherein the step of modifying the heat shield includes creating a threaded receiver in the heat shield.

20. 18. The method of claim 17, wherein the step of installing the heat shield flexure member includes bolting the heat shield flexure member to the heat shield and the arm portion of the modified heat shield flexure.

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