In this book an attempt has been made to present various properties of heavy water and the dependence of these on temperature and pressure, various methods of separation both on small and large scale, the problems encountered in industrial processes, and a variety of analytical techniques involved in the processes which are capable of giving a high degree of precision and accuracy. This book also covers major heavy water production techniques as well as processes based on laser separation of deuterium and tritium, heavy water enrichment techniques including final enrichment methods and processes for upgrading and detritiation of heavy water. Experience gained and problems encountered during the operation of heavy water plants are also elaborated