The use of thorium for nuclear power generation is an important element of the Indian atomic energy programme. The design and development of the Advanced Heavy Water Reactor (AHWR) is a step in this direction. Intensive design activity is underway to set up a 300-MWe AHWR. The design of the AHWR incorporates several features to simplify the design and to eliminate certain systems and components, making it economically competitive with other available options for power generation. Utilisation of low-grade or waste heat is an additional feature incorporated in the overall design of the reactor system. A proposal to utilise waste heat from the Main Heat Transport (MHT) purification circuit to produce high-quality desalinated water by the low-temperature evaporation process has been envisaged. This paper presents the proposed nuclear desalination system utilising MHT purification circuit waste heat of AHWR along with its coupling arrangement and technical details. Copyright © 2007 Inderscience Enterprises Ltd.