Heavy Water- Meaning, Purpose and Heavy Water plants in India

High purity heavy water is used in PHWRs for serving as the moderator and the primary coolant.

An ideal moderator:

Heavy water, D{-2}O, is water in which both hydrogen atoms have been replaced with deuterium, the isotope of hydrogen containing one proton and one neutron.It is an ideal moderator and not an absorber of neutrons.

How much Heavy Water is used by a Nuclear Plant?

• A typical 220 MWe pressurised heavy water reactor needs about 275 tonnes of heavy water. Heavy water technology is complex as it involves concentrating and separating the heavy water or deuterium fraction by processing large quantities of an appropriate raw material.
• The first heavy water plant was set up in India at Nangal in 1962 based on electrolysis of water.

Heavy Water Plant in Operation

Other Methods of Producing Heavy Water:

• Distillation of water or hydrogen or chemical exchange between hydrogen sulphide and water or ammonia and hydrogen are the processes adopted to produce heavy water.
• The Heavy Water Plant at Manuguru, Andhra Pradesh is based on the Bithermal Hydrogen Sulphide-Water (H2S-H20) Exchange Process.

Sites of Heavy Water Plants in India

• Kota- Rajasthan
• Tuticorin-  Tamil Nadu
• Thalcher-Odisha
• Baroda - Gujarat
• Thal - Maharastra
• Hazira - Gujarat
• Manuguru - Khammam, Andhra Pradesh.