Analysis of Aerosol Emission and Dispersion During the Laser Cutting of Fukushima Fuel Debris Simulants

2018 ◽  
Author(s):  
Emmanuel Porcheron ◽  
Samuel Peillon ◽  
Thomas Gelain ◽  
Christophe Chagnot ◽  
Christophe Journeau ◽  
...  
Keyword(s):  
Size Distribution ◽  
Laser Cutting ◽  
Source Term ◽  
Aerosol Size Distribution ◽  
General Context ◽  
Aerosol Sampling ◽  
Aerosol Transport ◽  
Distribution Measurement ◽  
Aerosol Emission ◽  
Wall Deposition

The general context of the article is related to the development of the laser cutting technique for the fuel debris retrieval on the damaged reactors of Fukushima Dai-ichi. IRSN and CEA are involved in a project, led by ONET, to bring relevant elements to analyze the risk occurred by the dispersion of aerosols emitted by the dismantling operations. Results regarding the aerosols source term characterization emitted during laser cutting of non-radioactive fuel debris simulants were acquired during experiments undertaken on the DELIA cutting laser platform from CEA. IRSN realized aerosol sampling, aerosol size distribution measurement and CFD calculation of aerosol transport and wall deposition. The evaluations performed will enable the Japanese teams responsible for extracting corium from the damaged reactors of Fukushima Dai-ichi to define the best strategies to implement containment, and ultimately to limit the dissemination of radionuclides in the environment.

Development of a variable configuration cascade impactor for aerosol size distribution measurement

2010 ◽  
Vol 44 (6) ◽  
pp. 795-802 ◽  
Author(s):  
Sanjay Singh ◽  
B.K. Sapra ◽  
Arshad Khan ◽  
P.K. Kothalkar ◽  
Y.S. Mayya
Keyword(s):  
Size Distribution ◽  
Cascade Impactor ◽  
Aerosol Size Distribution ◽  
Distribution Measurement ◽  
Variable Configuration

scholarly journals Application of centrifugal filter to aerosol size distribution measurement

2017 ◽  
Vol 51 (11) ◽  
pp. 1254-1261 ◽  
Author(s):  
Yutaka Tanaka ◽  
Hyun-Jin Choi ◽  
Kosuke Shimadzu ◽  
Hidenori Higashi ◽  
Takafumi Seto ◽  
...  
Keyword(s):  
Size Distribution ◽  
Aerosol Size Distribution ◽  
Distribution Measurement ◽  
Centrifugal Filter

On Aerosol Size Distribution Measurement by Laser and White Light Optical Particle Counters

1985 ◽  
Vol 28 (3) ◽  
pp. 19-24
Author(s):  
Benjamin Liu ◽  
Wladyslaw Szymanski ◽  
Kang-Ho Ahn
Keyword(s):  
Size Distribution ◽  
Measurement Accuracy ◽  
Aerosol Particles ◽  
Optical Design ◽  
Aerosol Size Distribution ◽  
Distribution Measurement ◽  
Response Characteristics ◽  
Optical Particle Counter ◽  
Measured Size Distribution ◽  
Counter Data

Light scattering optical particle counters are widely used for size distribution measurement of aerosol particles. The accuracy of the measured size distribution is dependent upon the response of the counter, which is affected by the refractive index and shape of the particles as well as by the optical design of the instrument, including the light source used. This paper addresses the measurement accuracy of the optical particle counter. Data are presented showing the response characteristics of several widely used commercial optical counters and the comparative size distribution measurement made by means of these instruments.

CFD Simulations of Aerosol Dispersion and Agglomeration During the Laser Cutting of Fukushima Fuel Debris Simulants

2018 ◽  
Author(s):  
Thomas Gelain ◽  
Emmanuel Porcheron ◽  
Christophe Chagnot ◽  
Damien Roulet
Keyword(s):  
Laser Cutting ◽  
Aerosol Deposition ◽  
Companion Paper ◽  
General Context ◽  
Aerosol Transport ◽  
Cfd Simulations ◽  
Safety Issues ◽  
Fukushima Daiichi ◽  
Aerosol Dispersion ◽  
Dynamics Simulations

The general context of this article is related to the development of the laser cutting technique for the fuel debris retrieval on the damaged reactors of Fukushima Daiichi. IRSN is involved in a project led by ONET with CEA, to bring relevant elements to analyze the risk occurred by the dispersion of aerosols emitted by the dismantling operations. In this context, CFD (Computational Fluid Dynamics) simulations of dispersion of aerosols (including the transport, the deposition on the walls and the agglomeration), emitted during laser cutting of non-radioactive fuel debris simulants undertaken on the DELIA cutting laser platform from CEA, have been conducted. Indeed, evaluating the amount of aerosols likely to deposit on the walls and those to be released into the environment is one of the key safety issues in the dismantling actions of reactors of Fukushima Daiichi. The CFD simulations have been carried out with the commercial code ANSYS CFX in which models of aerosol transport and deposition, developed and validated by IRSN, have been implemented. In a first time, airflow simulations have allowed to visualize the flow in the vessel of the DELIA laser cutting facility from CEA by the way of streamlines before injecting aerosols. Aerosol input data (size and morphology) have been acquired by IRSN team on the DELIA facility during the laser cutting of non-radioactive simulants of fuel debris for air and underwater configurations. Those simulants of fuel debris are representative of the fuel debris present in the Fukushima reactors [1]. The simulation results allow to obtain the cartography of the aerosol deposition in the vessel for different aerosol sizes and to evaluate the amount of dispersed aerosols. These simulations also show the time evolution of the aerosols properties with the agglomeration phenomena that can influence their size evolution and therefore their dispersion and deposition. Similar simulations have also been carried out on the geometry of a Fukushima Daiichi reactor pedestal in which laser cutting could be performed. This paper presents the aerosol dispersion simulations, the model implemented for aerosol transport and deposition as well as for agglomeration, and finally a comparison with experimental data presented in a companion paper (ICONE26-81531).

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