# US 2021/0241931 A1 · Method of detecting an existence of a loose part in a steam generator of a nuclear power plant > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0241931 A1 - Document ID: US20210241931A1 - Status: Published application - Kind: A1 - Application number: 17/152,157 - Filed: 2021-01-19 - Published: 2021-08-05 - Earliest claimed: 2011-04-07 - Assignees: Westinghouse Electric Corp. - Applicants: Westinghouse Electric Company LLC - Inventors: Qui V. LE - Web page: https://patentgrep.com/patent/US20210241931A1 ## CPC - G21C 17/017: Inspection or maintenance of pipe-lines or tubes in nuclear installations - F01K 13/02: Controlling, e.g. stopping or starting - F22B 37/002: {specially adapted for nuclear steam generators, e.g. maintenance, repairing or inspecting equipment not otherwise provided for} - G01N 27/902: {by moving the sensors} - G21C 19/207: {Assembling, maintenance or repair of reactor components (G21C3/334 takes precedence)} - G21D 1/006: {primary side of steam generators (secondary side of steam generators F22B1/00, F22B35/00 or F22B37/00)} - G21D 3/001: {Computer implemented control} - Y02E 30/00: Energy generation of nuclear origin - Y02E 30/30: Nuclear fission reactors - G21C: NUCLEAR REACTORS (fusion reactors, hybrid fission-fusion reactors G21B; nuclear explosives G21J) - F01K: STEAM ENGINE PLANTS; STEAM ACCUMULATORS; ENGINE PLANTS NOT OTHERWISE PROVIDED FOR; ENGINES USING SPECIAL WORKING FLUIDS OR CYCLES (gas-turbine or jet-propulsion plants F02; nuclear power plants, engine arrangements therein G21D) - F22B: METHODS OF STEAM GENERATION; STEAM BOILERS - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - G21D: NUCLEAR POWER PLANT - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract A plurality of signal anomalies are identified in a number of tubes in a steam generator. Since the geometry of the steam generator is known, the location of each signal anomaly along each tube is converted into a location within the interior of the steam generator. If a plurality of signal anomalies are at locations within the steam generator that are within a predetermined proximity of one another, such a spatial confluence of signal anomalies is determined to correspond with a loose part situated within the steam generator. Additional methodologies can be employed to confirm the existence of the loose part. Historic tube sheet transition signal data can be retrieved and subtracted from present signals in order to enable the system to ignore the relatively strong eddy current sensor signal of a tube sheet which would mask the relatively weak signal from a loose part at the tube sheet transition. ## Claims ### Claim 1 A method of non-destructively detecting an existence of a loose part within a steam generator of a nuclear power plant, the steam generator having a plurality of tubes within an interior thereof, the method comprising: identifying in a first eddy current signal a first signal anomaly at a first tube position along a first tube from among the plurality of tubes, and converting the first tube position along the first tube into a three-dimensional first generator location within the interior of the steam generator; identifying in a second eddy current signal a second signal anomaly at a second tube position along a second tube from among the plurality of tubes different from the first tube, and converting the second tube position along the second tube into a three-dimensional second generator location within the interior of the steam generator; making a determination that the first generator location and the second generator location are within a predetermined proximity of one another; and responsive to the determination, determining that a loose part exists in the vicinity of the first and second generator locations. ### Claim 2 (depends on 1) The method of claim 1, further comprising employing a first type of detection in the identifying of the first and second signal anomalies and, responsive to the determining that a loose part exists, instructing a further analysis of at least the first and second tube positions with a second type of detection different from the first type of detection. ### Claim 3 (depends on 1) The method of claim 1, further comprising: identifying the first and second signal anomalies from a data stream output by a data source that contemporaneously generated the data stream and at least one alternative data stream; and confirming the existence of the loose part by: identifying from the at least one alternative data stream an alternative first signal anomaly at the first tube position along the first tube, and identifying from the at least one alternative data stream an alternative second signal anomaly at the second tube position along the second tube. ### Claim 4 (depends on 1) The method of claim 1, further comprising detecting as the first signal anomaly a signal change between a signal from a data stream with respect to the first tube position along the first tube and a signal from the data stream with respect to an adjacent tube position along the first tube. ### Claim 5 (depends on 4) The method of claim 4, further comprising ignoring a signal change that fails to meet a predetermined threshold. ### Claim 6 (depends on 4) The method of claim 4, further comprising ignoring a signal change between a signal from a data stream with respect to the first tube position along the first tube and a signal from the data stream with respect to the adjacent tube position along the first tube when: at least one of the first tube position and the adjacent tube position is situated adjacent a tube sheet of the steam generator, and the data stream indicates that a minority of the tubes among the plurality of tubes each possess a similar signal change at a similar location therein. ### Claim 7 (depends on 4) The method of claim 4, further comprising when at least one of the first tube position and the adjacent tube position is situated adjacent a tube sheet of the steam generator: retrieving a historic signal change between a previous signal from a previous data stream with respect to the first tube position along the first tube and a previous signal from the previous data stream with respect to the adjacent tube position along the first tube; subtracting the historic signal change from the signal change to generate a net signal change; and employing the net signal change as the first signal anomaly. ### Claim 8 (depends on 1) The method of claim 1, further comprising detecting as the first signal anomaly a change between a signal from a data stream with respect to the first tube position along the first tube and a signal from a previous data stream with respect to the first tube position along the first tube. ### Claim 9 (depends on 1) A machine readable storage medium having stored thereon instructions which, when executed on a processor of a computing device, cause the computing device to perform the operations of claim 1. ### Claim 10 A computer which can non-destructively detect an existence of a loose part within a steam generator of a nuclear power plant, the steam generator having a plurality of tubes within an interior thereof, the computer comprising: a processor; and a memory having stored therein one or more routines comprising instructions which, when executed on a processor, cause the computer to perform operations comprising: identifying in a first eddy current signal a first signal anomaly at a first tube position along a first tube from among the plurality of tubes, and converting the first tube position along the first tube into a three-dimensional first generator location within the interior of the steam generator; identifying in a second eddy current signal a second signal anomaly at a second tube position along a second tube from among the plurality of tubes different from the first tube, and converting the second tube position along the second tube into a three-dimensional second generator location within the interior of the steam generator; making a determination that the first generator location and the second generator location are within a predetermined proximity of one another; and responsive to the determination, determining that a loose part exists in the vicinity of the first and second generator locations. ### Claim 11 (depends on 10) The computer of claim 10, further comprising employing a first type of detection in the identifying of the first and second signal anomalies and, responsive to the determining that a loose part exists, instructing a further analysis of at least the first and second tube positions with a second type of detection different from the first type of detection. ### Claim 12 (depends on 10) The computer of claim 10, further comprising: identifying the first and second signal anomalies from a data stream output by a data source that contemporaneously generated the data stream and at least one alternative data stream; and confirming the existence of the loose part by: identifying from the at least one alternative data stream an alternative first signal anomaly at the first tube position along the first tube, and identifying from the at least one alternative data stream an alternative second signal anomaly at the second tube position along the second tube. ### Claim 13 (depends on 10) The computer of claim 10, further comprising detecting as the first signal anomaly a signal change between a signal from a data stream with respect to the first tube position along the first tube and a signal from the data stream with respect to an adjacent tube position along the first tube. ### Claim 14 (depends on 13) The computer of claim 13, further comprising ignoring a signal change that fails to meet a predetermined threshold. ### Claim 15 (depends on 13) The computer of claim 13, further comprising ignoring a signal change between a signal from a data stream with respect to the first tube position along the first tube and a signal from the data stream with respect to the adjacent tube position along the first tube when: at least one of the first tube position and the adjacent tube position is situated adjacent a tube sheet of the steam generator, and the data stream indicates that a minority of the tubes among the plurality of tubes each possess a similar signal change at a similar location therein. ### Claim 16 (depends on 13) The computer of claim 13, further comprising when at least one of the first tube position and the adjacent tube position is situated adjacent a tube sheet of the steam generator: retrieving a historic signal change between a previous signal from a previous data stream with respect to the first tube position along the first tube and a previous signal from the previous data stream with respect to the adjacent tube position along the first tube; subtracting the historic signal change from the signal change to generate a net signal change; and employing the net signal change as the first signal anomaly. ### Claim 17 (depends on 10) The computer of claim 10, further comprising detecting as the first signal anomaly a change between a signal from a data stream with respect to the first tube position along the first tube and a signal from a previous data stream with respect to the first tube position along the first tube. ### Claim at position 18 18-33. (canceled) ### Claim 34 (depends on 1) The method of claim 1, further comprising determining the nature of the loose part. ### Claim 35 (depends on 9) The system of claim 9, wherein the instructions which, when executed on a processor, further cause the computerized device to determine the nature of the loose part. ### Claim 36 (depends on 9) The system of claim 9, wherein the instructions which, when executed on a processor, further cause the computerized device to distinguish the loose part from sludge, based at least in part on the first and second generator location.