LUCIANO ONDIR FREIRE
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Artigo IPEN-doc 28529 RANS-based CFD calculation for pressure drop and mass flow rate distribution in an MTR fuel assembly2021 - SCURO, N.L.; ANGELO, G.; ANGELO, E.; UMBEHAUN, P.E.; TORRES, W.M.; SANTOS, P.H.G.; FREIRE, L.O.; ANDRADE, D.A.This work presents a Reynolds-averaged Navier Stokes–based computational fluid dynamics methodology for the calculation of pressure drop and mass flow rate distribution in a material test reactor flat-plate-type standard fuel assembly (SFA) of the IEA-R1 Brazilian research reactor to predict future improvements in newer SFA designs. The results improve the understanding of the origin of fuel plate oxidation due to high temperatures, and consequently, due to the internal flow dynamics. All numerical analyses were performed with the ANSYS-CFX® commercial code. The observed results show that the movement pin decreases the central channel mass flow due to the length of the vortex at the inlet region. However, the outlet nozzle showed greater general influence in the flow dynamics. It should have a more gradual cross-section transition being away from the fuel plates or a squarer-shaped design to get a more homogeneous mass flow distribution. Optimizing both regions could lead to a better cooling condition. The validation of the IEA-R1 numerical methodology was made by comparing the McMaster University’s dummy model experiment with a numerical model that uses the same numerical methodology. The experimental data were obtained with laser Doppler velocimetry, and the comparison showed good agreement for both pressure drop and mass flow rate distribution using the Standard k-ω turbulence model.Artigo IPEN-doc 25205 Economically feasible mobile nuclear power plant for merchant ships and remote clients2019 - FREIRE, LUCIANO O.; ANDRADE, DELVONEI A. deRecent studies point to a reduction of atmospheric pollution using nuclear energy for merchant ships. This work examines the development of an economically competitive nuclear power solution for merchant ship propulsion. The solution also addresses the requirements of a wider market, like islands, offshore oil platforms, and remote cities. System engineering and analysis at various product breakdown levels also propose architectural options to improve competitiveness of nuclear power in mobile nuclear power plants (MNPPs). Analyses include market research on clients and technical considerations on nuclear energy costs. The results show that an enterprise that delivers electric power to remote clients and dedicates to management of all nuclear aspects seems to be the best organizational and technical choice. Besides, ships should be of modular type and the MNPPs should be easily detachable at sea. Only container ships and remote islands demand enough power to justify the use of nuclear power. Nuclear power has high probability to be economically competitive for large container ships, however, only if public policies impose levels of risks akin to other industries.Artigo IPEN-doc 21261 Historic survey on nuclear merchant ships2015 - FREIRE, LUCIANO O.; ANDRADE, DELVONEI A.This work provides a survey on past nuclear merchant ships experience. On light of new regulations on CO2, SOx and NOx, the options for clean naval propulsion need to be studied. Despite many efforts, the only already sea proven emissions-free energy is nuclear power of pressurized water reactor type. Given the past experience on the field, this work provides some information on history, architectures and hints of reasons for the success or failures of each project. It is found that adequate requirements identification must be done keeping economics always in the center of design. Experience shows, except after major catastrophic accidents, public trust may be earned by open dialog and sound engineering practices.