{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,24]],"date-time":"2026-01-24T17:28:42Z","timestamp":1769275722232,"version":"3.49.0"},"reference-count":24,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2016,4,21]],"date-time":"2016-04-21T00:00:00Z","timestamp":1461196800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"European Union H2020","award":["662186"],"award-info":[{"award-number":["662186"]}]},{"name":"IWT-SBO","award":["110070"],"award-info":[{"award-number":["110070"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Excessive fuel assembly vibrations in nuclear reactor cores should be avoided in order not to compromise the lifetime of the assembly and in order to prevent the occurrence of safety hazards. This issue is particularly relevant to new reactor designs that use liquid metal coolants, such as, for example, a molten lead-bismuth eutectic. The flow of molten heavy metal around and through the fuel assembly may cause the latter to vibrate and hence suffer degradation as a result of, for example, fretting wear or mechanical fatigue. In this paper, we demonstrate the use of optical fiber sensors to measure the fuel assembly vibration in a lead-bismuth eutectic cooled installation which can be used as input to assess vibration-related safety hazards. We show that the vibration characteristics of the fuel pins in the fuel assembly can be experimentally determined with minimal intrusiveness and with high precision owing to the small dimensions and properties of the sensors. In particular, we were able to record local strain level differences of about 0.2 \u03bc\u03f5 allowing us to reliably estimate the vibration amplitudes and modal parameters of the fuel assembly based on optical fiber sensor readings during different stages of the operation of the facility, including the onset of the coolant circulation and steady-state operation.<\/jats:p>","DOI":"10.3390\/s16040571","type":"journal-article","created":{"date-parts":[[2016,4,21]],"date-time":"2016-04-21T10:25:21Z","timestamp":1461234321000},"page":"571","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":30,"title":["Vibration Monitoring Using Fiber Optic Sensors in a Lead-Bismuth Eutectic Cooled Nuclear Fuel Assembly"],"prefix":"10.3390","volume":"16","author":[{"given":"Ben","family":"De Pauw","sequence":"first","affiliation":[{"name":"Brussels Photonics Team (B-Phot), Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium"},{"name":"Acoustics and Vibration Research Group, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Alfredo","family":"Lamberti","sequence":"additional","affiliation":[{"name":"Acoustics and Vibration Research Group, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Julien","family":"Ertveldt","sequence":"additional","affiliation":[{"name":"Acoustics and Vibration Research Group, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2629-5401","authenticated-orcid":false,"given":"Ali","family":"Rezayat","sequence":"additional","affiliation":[{"name":"Acoustics and Vibration Research Group, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7571-1435","authenticated-orcid":false,"given":"Katrien","family":"Van Tichelen","sequence":"additional","affiliation":[{"name":"Belgian Nuclear Research Centre (SCK\u00b7CEN), Boeretang 200, Mol, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Steve","family":"Vanlanduit","sequence":"additional","affiliation":[{"name":"Acoustics and Vibration Research Group, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0822-233X","authenticated-orcid":false,"given":"Francis","family":"Berghmans","sequence":"additional","affiliation":[{"name":"Brussels Photonics Team (B-Phot), Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2016,4,21]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"4","DOI":"10.1016\/j.enconman.2012.02.025","article-title":"MYRRHA\u2014A multi-purpose fast spectrum research reactor","volume":"63","author":"Baeten","year":"2012","journal-title":"Energy Convers. Manag."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"25","DOI":"10.1016\/0149-1970(79)90008-8","article-title":"Flow-induced vibration in nuclear reactors: A review","volume":"4","author":"Blevins","year":"1979","journal-title":"Prog. Nucl. Energy"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"159","DOI":"10.1115\/1.4009458","article-title":"Cumulative damage in fatigue","volume":"12","author":"Miner","year":"1945","journal-title":"J. Appl. Mech."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"697","DOI":"10.1016\/j.nucengdes.2014.05.043","article-title":"Fretting of fuel cladding materials for Pb cooled fast reactors\u2014Approach to long term prediction using fretting maps","volume":"280","author":"Weisenburger","year":"2014","journal-title":"Nucl. Eng. Des."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"253","DOI":"10.1016\/0029-5493(72)90144-6","article-title":"Parallel-flow-induced vibration of fuel rods","volume":"18","author":"Chen","year":"1972","journal-title":"Nucl. Eng. Des."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"169","DOI":"10.1016\/j.nucengdes.2008.10.007","article-title":"Assessment of flow induced vibration in a sodium-sodium heat exchanger","volume":"239","author":"Prakash","year":"2009","journal-title":"Nucl. Eng. Des."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"350","DOI":"10.1016\/j.nucengdes.2013.06.008","article-title":"The behaviour of weldable strain gauges under nuclear reactor core conditions","volume":"263","author":"Pettigrew","year":"2013","journal-title":"Nucl. Eng. Des."},{"key":"ref_8","first-page":"1","article-title":"Signal-to-noise ratio evaluation of fiber Bragg gratings for dynamic strain sensing at elevated temperatures in a liquid metal environment","volume":"33","author":"Lamberti","year":"2015","journal-title":"J. Light. Technol."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"De Pauw, B., Lamberti, A., Vanlanduit, S., van Tichelen, K., Geernaert, T., and Berghmans, F. (2014, January 2). Signal-to-noise ratio evaluation with draw tower fiber Bragg gratings ( DTGs ) for dynamic strain sensing at elevated temperatures and corrosive environment. Proceedings of the 23rd International Conference on Optical Fibre Sensors, Santander, Spain.","DOI":"10.1117\/12.2059504"},{"key":"ref_10","unstructured":"De Pauw, B., Vanlanduit, S., Berghmans, F., van Tichelen, K., and Geernaert, T. (2012, January 22\u201327). Validation of deformation and vibration measurement techniques for nuclear fuel pins. Proceedings of the 15th International Conference on Experimental Mechanics (ICEM15), Porto, Portugal."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"3647","DOI":"10.1016\/j.measurement.2013.07.003","article-title":"Benchmarking of deformation and vibration measurement techniques for nuclear fuel pins","volume":"46","author":"Vanlanduit","year":"2013","journal-title":"Measurement"},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Othonos, A., and Kalli, K. (1999). Fiber Bragg Gratings: Fundamentals and Application in Telecommunications and Sensing, Artech House.","DOI":"10.1063\/1.883086"},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Cusano, A., Cutolo, A., and Albert, J. (2011). Fiber Bragg Grating Sensors: Recent Advancements, Industrial Applications and Market Exploitation, Bentham Science Publishers.","DOI":"10.2174\/97816080508401110101"},{"key":"ref_14","unstructured":"FBGS International. Available online: www.fbgs.com\/technology\/dtg-technology."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"19","DOI":"10.1016\/j.nucengdes.2014.11.040","article-title":"Operational modal analysis of flow-induced vibration of nuclear fuel rods in a turbulent axial flow","volume":"284","author":"Weijtjens","year":"2015","journal-title":"Nucl. Eng. Des."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"24258","DOI":"10.3390\/s141224258","article-title":"Influence of Fiber Bragg Grating Spectrum Degradation on the Performance of Sensor Interrogation Algorithms","volume":"14","author":"Lamberti","year":"2014","journal-title":"Sensors"},{"key":"ref_17","first-page":"53","article-title":"Draw-tower process creates high-quality FBG arrays","volume":"10","author":"Johnson","year":"2012","journal-title":"Laser Focus World"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1898","DOI":"10.3390\/s120201898","article-title":"Fiber Bragg grating sensors for harsh environments","volume":"12","author":"Mihailov","year":"2012","journal-title":"Sensors"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1627","DOI":"10.1021\/ac60214a047","article-title":"Smoothing and Differentiation of Data by Simplified Least Squares Procedures","volume":"36","author":"Savitzky","year":"1964","journal-title":"Anal. Chem."},{"key":"ref_20","unstructured":"Ko, W.L., Richards, W.L., and van Tran, T. (2007). Displacement Theories for In-Flight Deformed Shape Predictions of Aerospace Structures, NASA\/TP-2007-214612, H-2652."},{"key":"ref_21","unstructured":"Ko, W.L., and Richards, W.L. (2009). Method for Real-time Structure Shape-Sensing. (US7520176 B1), U.S. Patent."},{"key":"ref_22","unstructured":"Guillaume, P., Verboven, P., Vanlanduit, S., van der Auweraer, H., and Peeters, B. (2003, January 3\u20136). A poly-reference implementation of the least-squares complex frequency-domain estimator. Proceedings of the 2003 IMAC-XXI, Kissimmee, FL, USA."},{"key":"ref_23","unstructured":"Parloo, E. (2003). Application of Frequency-Domain System Identification Techniques in the Field of Operational Modal Analysis. [Ph.D. Thesis, Vrije Universiteit Brussel]."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"110","DOI":"10.1016\/j.jfluidstructs.2013.09.001","article-title":"Modal characteristics of a flexible cylinder in turbulent axial flow from numerical simulations","volume":"43","author":"Degroote","year":"2013","journal-title":"J. Fluid Struct."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/16\/4\/571\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T19:22:38Z","timestamp":1760210558000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/16\/4\/571"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2016,4,21]]},"references-count":24,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2016,4]]}},"alternative-id":["s16040571"],"URL":"https:\/\/doi.org\/10.3390\/s16040571","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2016,4,21]]}}}