HAL Id: hal-02338997
https://hal.archives-ouvertes.fr/hal-02338997
Submitted on 13 Dec 2019
HAL is a multi-disciplinary open access
archive for the deposit and dissemination of sci-entific research documents, whether they are pub-lished or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers.
L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
Acoustic Cavitation near Metal Surfaces Contaminated
with Radionuclides
R. Ji, M. Virot, R. Pflieger, Sergey I. Nikitenko
To cite this version:
R. Ji, M. Virot, R. Pflieger, Sergey I. Nikitenko. Acoustic Cavitation near Metal Surfaces Contami-nated with Radionuclides. XVemes Journees Nationales de Radiochimie et de Chimie Nucleaire, Sep 2016, Nice, France. 2018. �hal-02338997�
Mg surfaces immersed in oxalic acid saturated with argon at 18 ℃, agitation and sonication
• Mass Spectrometer (MS) monitors H
2
production in gas
• Scanning Electron Microscope (SEM) follows surface morphology
• Drop Shape Analyzer (DSA) measures contact angle of surface
Acoustic Cavitation near Metal Surfaces
Contaminated with Radionuclides
Ran Ji, Matthieu Virot, Rachel Pflieger, Sergey I. Nikitenko
Institut de Chimie Séparative de Marcoule (ICSM) – UMR 5257 CNRS/CEA/UM2/ENSCM
Site de Marcoule, BP17171, 30207 Bagnols sur Cèze, France
Ultrasonic cleaning is a widely used
technology in the areas of industry,
scientific
research
and
medical
application. It is able to decontaminate
items with complex surfaces with less
damages and erosion to the material
It is interesting and important to apply
this
method
to
nuclear
waste
decontamination process to remove
radioactive nuclides and finally reduce
the volume of radioactive solid wastes
Ultrasonic cleaning is based on acoustic cavitation, which creates extreme temperature and pressure
(plasma) inside bubbles, forms radicals and excited species, and induces mechanical effects (shock
wave, microjets) in solutions
In the vicinity of extended solid surfaces,
violent shock waves and micro-jets erode
the solid surfaces directly
Nucleation
Growth and
Diffusion
Maximum
Diameter
Implosion and
Shock Waves
Cycle Repeats and New bubbles grow
Gas (inlet)
CCD
Ultrasound
Transducer
Sample
Solution
Observation
Window
Gas (outlet)
Agitation
SL Spectroscopy
Standing Wave under 100 kHz within luminol solution
H
2
O →)))→ H˙ + OH˙
Luminol emits visible blue light
200 300 400 500 600 700 800 0 50 100 150 200 250 300
SL Continuum
Na
S
L in
t, A.U.
, nm
OH
0 2 4 6 8 10 12 14 16 18 4 5 6 7 8 9 10 11 12 13 14 15 16 N a i n te n si ty/ C o n ti n u u m in te n si tyz (mm)
Relative higher Na intensity
closer to the surface
During asymmetric cavitation (microjets), Na
+
ions
are injected inside the bubble and form Na atoms
H
2
production can be controlled by [H
2
C
2
O
4
]
and start/stop sonication
MS
SEM
500μm 500μm 500μm 500μmInitial Mg surface with
an oxide layer
1 hour treatment in
0,001M oxalic acid
Pits, whose average size
decreases with the
ultrasound frequency
Sonication results indicate that Mg decontamination is possible by controlled dissolute of surface. Mg surface morphology is transformed from
hydrophobic to hydrophilic, with pits and the appearance of precipitations or secondary phases. By modifying [H
2
C
2
O
4
] or start/stop ultrasound, it
is possible to control the generation of H
2
and the dissolution of Mg
In the presence of a metal surface, sonoluminescence spectra show that Na atom relative intensity increases. It proves the impact of solid surface
to the cavitation bubble deformation in solution, and this impact is only effective close to the surface ( ≈ 3 mm )
Mg Surface Sonication Experiments
Sonoluminescence Experiments
10 µm
