IRSN has been involved with CEA for some years in projects led by ONET Technologies (OT) and funded by Japanese government (METI). These projects aim at evaluating a strategy for the retrieval of fuel debris fell over the floor of Fukushima Dai-Ichi (1F) reactor pedestal, by a laser cutting technology developed by CEA and adapted by OT for a potential use in the 1F site. However, an important issue regarding aerosols dispersion and potential release into the environment is present around this well-proven technology and must be under control. To do that, IRSN has contributed in this project to provide quantitative information to assess the risk induced by aerosols generation and dispersion. Concomitant experimental and numerical simulations (CFD) studies were led in order to characterize the source term of aerosols from laser cutting of fuel debris simulants (Porcheron et al. 2020), to characterize their fate inside the reactor pedestal by the contribution of airflows coming from the laser cutting head (Gelain et al., 2019) (Gélain et al., 2018) and to propose solutions to help mitigating dispersed aerosols (Porcheron et al. 2019) (Sun et al., 2020) (Porcheron et al., 2021a) (Porcheron et al., 2021b). The present article is dedicated to summarizing a global CFD study led to evaluate the impact of fuel debris laser cutting in a representative design of 1F2 reactor pedestal in terms of aerosols dispersion and mitigation means. Given that laser cutting (as cutting in general) produces a large amount of aerosols, laser cutting head was first equipped with a local particle collection system close to the emission source. This system includes an extraction device (a flexible duct and filtration systems) allowing to catch a large part of emitted aerosols with a particle size distribution characterized by a mass median diameter of around 300 nm. However, even if this particle collection means is very efficient, a part of emitted aerosols is not collected and still dispersed in the pedestal. Hence, to collect them, IRSN proposed to implement a spray system, commonly used in French PWR to washout fission products in the event of a severe accident. This article presents different results of CFD calculations showing the necessity of mitigation means to avoid high aerosols concentration in the pedestal which could lead to a release into the environment. These calculations give also quantitative information about the performance of intended collection systems (extraction and spray) implemented in a representative geometry of 1F2 reactor pedestal of Fukushima and their complementarity. Finally, they highlight the evolution of the aerosols emitted during a cutting scenario as well for the phases during which the laser cutting (cutting phase) is activated as the phases during it is stopped (non-cutting phase). This last part will allow to discuss about the options to help decreasing faster the aerosol concentration during the non-cutting phase.