Water from the nearby Godavari river, purified from both suspended and dissolved impurities forms the process feed and the D₂0 content is enriched from 150 ppm (0.015%) to 15% D₂0 by chemical exchange with H₂S and later vacuum distilled to produce 99.8% D₂0. The exchange unit is arranged in a 3 stage cascade with first stage handling 

large quantities of  process water and H₂S gas and consisting of three pairs of cold and hot towers operating at 30 deg. C. and 130 deg.C. respectively. The second and third stages each consist of one pair of cold and hot towers. The purified water enters the top of cold tower and travels down while hydrogen sulphide gas entering the bottom of the tower meets the water in counter current way on tower internals and the exchange of deuterium takes place. In cold tower, the water gets enriched with respect

to deuterium while gas gets depleted in deuterium concentration. In hot tower, the reverse reaction takes place viz. the gas gets enriched while liquid gets depleted. By proper liquid and gas flow rates with gas in closed circuit in the pair of towers, a small quantity of enriched liquid can be withdrawn from the bottom of the cold tower as a net product.This will be further enriched in the similar manner in 2nd and 3rd stages. The hot tower bottom liquid coming from the first stage is divided for use in 2nd and 3rd stages. The hot tower bottom liquid coming from the first stage is divided into two parts. One part is recycled to the top of humidification section located at the bottom of hot tower for heat recovery while the other part constitutes the waste. Before discarding the waste to the environment, it is necessary to recover the H₂S dissolved in the waste. For this purpose a waste stripper is provided to strip H₂S by direct steam stripping and the evolved gas and steam is put back to first stage hot towers.

The enriched water from the 3rd stage  is stripped off its H₂S in a product stripper and fed to the distillation unit for further enrichment upto nuclear grade. The captive power plant is conventional type with coal coming to plant from Manuguru mines of Singareni Collieries by a combination belt conveyer and bi-cable aerial rope way system. The instrumentation of the CPP is quite modern with distributed microprocessor based controls and data acquisition systems. The CPP is an integrated one and has turbines with two extraction stages which provide steam for direct and indirect heating in the main Heavy water plant.