Construction and Simulation of a Novel Phased Array Borehole Probe for Ultrasonic Investigations at Sealing Structures in Radioactive Repositories
- A novel ultrasonic borehole probe is developed for the quality assurance of sealing structures in radioactive waste repositories using existing research boreholes. The goal is to examine the sealing structures made of salt concrete for possible cracks, delamination, and embedded objects. A prototype probe uses 12 individual horizontal dry point contact (DPC) shear wave transducers separated by equidistant transmitter/receiver arrays of six individual transducers each. It is operated with a commercially available portable ultrasonic flaw detector used in the civil engineering industry. To increase the generated acoustic pressure of the borehole probe, the number of transducers in the novel probe is increased to 32. In addition, a timed excitation of each probe directs a focused beam of sound to a specific angle and distance based on calculated time delays. This limits the sensitive test volume and improves the signal-to-noise ratio of the received signals. This paper presents theA novel ultrasonic borehole probe is developed for the quality assurance of sealing structures in radioactive waste repositories using existing research boreholes. The goal is to examine the sealing structures made of salt concrete for possible cracks, delamination, and embedded objects. A prototype probe uses 12 individual horizontal dry point contact (DPC) shear wave transducers separated by equidistant transmitter/receiver arrays of six individual transducers each. It is operated with a commercially available portable ultrasonic flaw detector used in the civil engineering industry. To increase the generated acoustic pressure of the borehole probe, the number of transducers in the novel probe is increased to 32. In addition, a timed excitation of each probe directs a focused beam of sound to a specific angle and distance based on calculated time delays. This limits the sensitive test volume and improves the signal-to-noise ratio of the received signals. This paper presents the validation of the newly developed phased array borehole probe by investigating the directivity through beam computation in the CIVA software and experimental investigations on a semi-cylindrical test specimen. It is expected that an optimised radiation pattern of the probe in combination with geophysical reconstruction methods will improve the signal quality and thus increase the reliability of the imaging results. This is of great importance for the construction of safe sealing structures needed for the disposal of radioactive or toxic waste.…
Autor*innen: | Prathik PrabhakaraORCiD |
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Koautor*innen: | Frank Mielentz, Heiko Stolpe, Matthias Behrens, Vera Lay, Ernst Niederleithinger |
Dokumenttyp: | Vortrag |
Veröffentlichungsform: | Präsentation |
Sprache: | Englisch |
Jahr der Erstveröffentlichung: | 2022 |
Organisationseinheit der BAM: | 8 Zerstörungsfreie Prüfung |
8 Zerstörungsfreie Prüfung / 8.2 Zerstörungsfreie Prüfmethoden für das Bauwesen | |
DDC-Klassifikation: | Technik, Medizin, angewandte Wissenschaften / Ingenieurwissenschaften / Angewandte Physik |
Freie Schlagwörter: | Borehole probe; Engineered barrier; Monitoring; Phased array technique; SealWasteSafe |
Themenfelder/Aktivitätsfelder der BAM: | Energie |
Energie / Kerntechnische Entsorgung | |
Veranstaltung: | ISNT NDE 21 |
Veranstaltungsort: | Online meeting |
Beginndatum der Veranstaltung: | 09.12.2021 |
Enddatum der Veranstaltung: | 11.12.2021 |
Verfügbarkeit des Dokuments: | Datei im Netzwerk der BAM verfügbar ("Closed Access") |
Datum der Freischaltung: | 21.03.2022 |
Referierte Publikation: | Nein |
Eingeladener Vortrag: | Nein |