The role of nuclear energy to cut down on greenhouse gas emissions continues to be a contentious issue in many countries. Public debate is often convoluted and largely revolves around price and costs of energy production technologies as well as their contribution to climate change. Here, we first dissect two interwoven factors bound to produce confusion in the price-cost debate: temporal discounting and external costs. We then explore how a stronger focus on risk ethics could contribute to the debate on nuclear energy for sustainability.