This article analyzes the thermal energy options available in the country to support the expansion of Brazil's electricity grid capacity. The country's electricity mix consists primarily of renewable sources of energy and this configuration will be maintained throughout the 21st century. However, grid expansion can no longer benefit from hydroelectric power plants with large reservoirs leading to a greater participation of thermal power plants. Among the thermal sources available in the country, nuclear power has important comparative advantages. Recognizing these benefits, the Brazilian government has established that expanding electricity grid capacity will amount to up to 8000 MW through nuclear energy by 2030. The use of nuclear technology for electricity generation has historically been a controversial issue worldwide and some countries have decided to review their nuclear programs in the aftermath of the 2011 Fukushima nuclear accident. This article shows that increasing the participation of nuclear energy in Brazil's electricity grid will provide important benefits for the country by ensuring energy security, keeping Brazil's electricity mix as one of the cleanest in the world, securing electricity grid reliability and safety and reducing operating costs. (C) 2013 Elsevier Ltd. All rights reserved.