Underground storage of radioactive wastes. This is one of the chambers of the Waste Isolation Pilot Project (WIPP), 700 metres below ground. WIPP is a research project to determine the suitability of the local salt rocks as a storage site for highly- radioactive transuranic waste from atomic power stations. Such waste materials may have radioactive half-lives of thousands of years, and so must be isolated in a geologically stable environment. On the left is an experiment testing the design of containers carrying vitrified waste. The mine is located near Carlsbad, New Mexico, USA.