# US 8,787,517 B2 · Absorber tube for BWR control rods > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,787,517 B2 - Document ID: US8787517B2 - Status: Granted - Kind: B2 - Application number: 11/325,459 - Filed: 2006-01-05 - Published: 2007-07-05 - Granted: 2014-07-22 - Earliest claimed: 2006-01-05 - Assignees: General Electric Company - Applicants: Dennis S. Nelson; Stephen J. Studer - Inventors: Dennis S. Nelson; Stephen J. Studer - Web page: https://patentgrep.com/patent/US8787517B2 ## CPC - G21C 7/113: Control elements made of flat elements; Control elements having cruciform cross-section - Y02E 30/30: Nuclear fission reactors - G21C: NUCLEAR REACTORS (fusion reactors, hybrid fission-fusion reactors G21B; nuclear explosives G21J) - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract In a control rod having a plurality of elongated members for absorbing neutrons within a nuclear reactor to control a nuclear reaction, each elongated member may include a cylindrical inner capsule configured to contain neutron absorbing material therein. The elongated member may also include an absorber tube enclosing the cylindrical inner capsule, the absorber tube having an outer surface configured with a plurality of generally flat, planar sides between adjacent rounded corners. ## Claims ### Claim 1 In a control rod having a plurality of elongated members for absorbing neutrons within a nuclear reactor to control a nuclear reaction, each elongated member comprising: a cylindrical inner capsule configured to contain neutron absorbing material therein; and an absorber tube enclosing the cylindrical inner capsule, the absorber tube having an outer surface with two opposing generally flat, planar, mating sides each of which is configured to mate flushly with a planar mating side of an adjacent absorber tube without the existence of a gap between the mated absorber tubes, the opposing flat, planar, mating sides each being located directly in between respective adjacent rounded corners that are convex in relation to the center of the capsule, wherein a line bisecting each of the flat, planar, mating sides is substantially collinear with a central axis of the control rod. ### Claim 2 (depends on 1) The control rod of claim 1, wherein the plurality of elongated members are arranged in side-by-side relation. ### Claim 3 (depends on 1) The control rod of claim 1, wherein the plurality of elongated members extend from the central axis of the control rod to form a cruciform shape of the control rod. ### Claim 4 (depends on 2) The control rod of claim 2, wherein each flat, planar, mating side provides a weld surface area for attachment to an adjacent absorber tube. ### Claim 5 A control rod for absorbing neutrons within reactor core, comprising: four planar members extending from a central axis to form a cruciform shape, each of the planar members including a plurality of elongated members configured in side-by-side relation, wherein each elongated member further comprises: a cylindrical inner capsule configured to contain neutron absorbing material therein; and an absorber tube enclosing the cylindrical inner capsule, the absorber tube having an outer surface configured with two opposing generally flat, planar, mating sides each of which is configured to mate flushly with a planar mating side of an adjacent absorber tube without the existence of a gap between the mated absorber tubes, the opposing flat, planar, mating sides each being located directly in between respective adjacent rounded corners that are convex in relation to the center of the capsule, wherein a line bisecting each of the flat, planar, mating sides is substantially collinear with the central axis of the control rod; a cruciform-shaped tie segment provided along the central axis to brace the four planar members with respect to each other; a velocity limiter attached to the control rod at a lower end thereof; and a handle to the control rod at an upper end thereof. ### Claim 6 (depends on 5) The control rod of claim 5, wherein planar mating sides of the absorber tubes provide weld area surfaces for attachment to an adjacent absorber tube. ### Claim 7 (depends on 5) The control rod of claim 5, wherein the cruciform-shaped tie segment includes a plurality of cruciform-shaped tie segments arranged intermittently along the central axis. ### Claim 8 (depends on 5) The control rod of claim 5, wherein the cruciform-shaped tie segment extends an entire length of the absorber tube. ### Claim 9 An absorber-tube for a BWR control rod, comprising: an elongate member having a generally cylindrical inner surface enclosing an inner capsule that is configured to contain neutron absorbing material therein, the elongate member having an outer surface with two opposing generally flat, planar, mating sides each of which is configured to mate flushly with a planar, mating side of an adjacent elongate member, the opposing flat, planar, mating sides each being located directly in between respective adjacent rounded corners that are convex in relation to the center of the capsule, wherein a line bisecting each of the flat, planar, mating sides is substantially collinear with a central axis of the control rod. ### Claim 10 (depends on 9) The absorber tube of claim 9, wherein a cylindrical gap is provided between the inner capsule and inner cylindrical surface of the elongate member. ### Claim 11 (depends on 9) The absorber tube of claim 9, wherein the neutron-absorbing material is boron carbide powder. ### Claim 12 (depends on 1) The control rod of claim 1, wherein the two opposing mating sides each include only one generally flat, planar, mating surface configured to mate with an opposing mating side of an adjacent absorber tube. ### Claim 13 (depends on 1) The control rod of claim 1, wherein the two opposing mating sides each include a generally flat, planar, mating surface configured to mate with an opposing mating side of an adjacent absorber tube, the generally flat, planar, mating surface extending from one of the rounded corners to another of the rounded corners. ### Claim 14 (depends on 5) The control rod of claim 5, wherein the two opposing mating sides each include only one generally flat, planar, mating surface configured to mate with an opposing mating side of an adjacent absorber tube. ### Claim 15 (depends on 5) The control rod of claim 5, wherein the two opposing mating sides each include a generally flat, planar, mating surface configured to mate with an opposing mating side of an adjacent absorber tube, the generally flat, planar, mating surface extending from one of the rounded corners to another of the rounded corners. ### Claim 16 (depends on 9) The absorber tube of claim 9, wherein the two opposing mating sides each include only one generally flat, planar, mating surface configured to mate with an opposing mating side of an adjacent absorber tube. ### Claim 17 (depends on 9) The absorber tube of claim 9, wherein the two opposing mating sides each include a generally flat, planar, mating surface configured to mate with an opposing mating side of an adjacent absorber tube, the generally flat, planar, mating surface extending from one of the rounded corners to another of the rounded corners. ### Claim 18 (depends on 9) The absorber tube of claim 9, wherein an outside perimeter of the absorber tube includes only four curved corners and four flat sides.