Sustainability is characterized by the environmental friendly process best fitted for eco-systems and the capacity to maintain a process smoothly indefinitely. Maintaining sustainability in every aspect is the key for continuing human race in the long run. Recent energy insecurity problem and global climate change has led the concerned to take a fresh look at the benefits and risks of nuclear power for better future and find out a sustainable solution. Risk from fatal accident and radioactive waste management for a long period of time surely diminish the benefits of nuclear power, such as no green house gas emission and significant amount of power supply with minimum infrastructural development. As nuclear power is all about balancing the benefit and the risk, therefore this paper summarizes the benefit and risk causing from nuclear power to find out a sustainable choice for future energy demand.