This study aims to enhance the principle of environmental sustainability through applications of nuclear energy in seawater desalination and hydrogen production. The importance of seawater desalination in contributing to overcome the water deficit problem comes that Egypt suffers from. Studies have shown that in 2050, the per capita share of water may reach a quarter of the globally recommended value. The effect of carbon dioxide emitted from the use of fossil fuels negatively affects climate change, which is one of the biggest challenges of the twenty-first century. since the use of nuclear energy in the production of hydrogen will lead to a reduction in carbon dioxide emissions, which will reflect positively on climate change. In this research, the role of nuclear energy in environmental sustainability was highlighted through its various uses in different sectors such as (industrial - medical - agricultural - transportation... etc.). in addition, discussion of the technology of seawater desalination and hydrogen production with nuclear energy. The study clarified the role of nuclear energy in contributing to reducing climate change by reducing greenhouse gas emissions and its contribution to solve the water deficit problem. Reducing the demand for fossil fuels can be achieved by securing our requirements for carbon-free fuel such as hydrogen through the supply of (Seawater desalination plants/Electrolyzes) using electrical or thermal energy generated from nuclear power plants. This study also presented a comparison between different water desalination methods using various energy sources. The results of this comparison showed that the least expensive method used is the reverse osmosis method powered electrically from a nuclear station.