Assessing the production and dispersion of aerosols carrying contamination during Fukushima fuel debris retrieval is an IRSN’s contribution to a research project undertaken by a French consortium jointly with ONET Technologies and CEA on behalf of the Mitsubishi Research Institute. The objective is to obtain quantified data for evaluating the risks related to airborne particle contamination when implementing cutting tools such as laser or others, over the next few years, in the process of decommissioning the damaged reactors at the Fukushima-Daiichi plant.

The characterization of the aerosol source terms release during cutting of the fuel debris is one of the key issues to evaluate the aerosols dispersion that can lead to the release of radionuclides into the environment, in the unlikely case of containment breach. The determination of the size distribution, the morphology and the mass rate production of aerosols allows to predict their transport and deposition. In addition, those input data are necessary to develop and optimize strategies and technologies to ensure the containment, the collection and the filtration of particulate pollutants.

Therefore, aerosols characterization have been performed during cuttings of non-radioactive simulants of fuel debris designed and manufactured by the CEA (Cadarache), whose characteristics are representative of in-vessel and ex-vessel ones.

Different cutting tools have been enforced such as laser technique for air and underwater configurations in the DELIA laser cutting platform (CEA). Mechanical tools have also been implemented such as grinder and reciprocating saw in IRSN facilities.

Aerosol source term characterization will be then discussed regarding containment function and aerosol collection system using spray scrubbing mechanism.


Aerosol Source Terms Characterization During Cutting of Fuel Debris Simulants With Different Tools in the Context of Fukushima Daiichi Decommissioning

Division / Sponsors: 
Power Division & Nuclear Engineering Division (NED)

Power Conference
Paper Proceedings: https://asmedigitalcollection.asme.org/POWER/POWER2020/volume/83747

International Conference on Nuclear Engineering
Paper Proceedings: https://asmedigitalcollection.asme.org/ICONE/ICONE2020/volume/83761

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