Is nuclear desalination better value than RO?

Despite public concerns, the low energy costs and convenience of nuclear evaporation desalination make it the preferred option, according to a paper just published by an Indian-Italian team.

Writing in the International Journal of Nuclear Desalination, Marco Rognoni of Saline Water Specialists in Gallarate, Italy, working with colleagues MP Ramaswamy and J Justin Robert Paden of SWS & GB Saline Water Specialists (P) Ltd in Tiruchirappalli, India, report work on the cost:benefit balance of nuclear evaporative desalination against conventional reverse osmosis (RO).

In their paper Energy cost for desalination evaporation versus reverse osmosis, the researchers says that the main factor is often the running cost of the plant, and specifically the cost of the consumed energy. Evaporation, they say, is considered to be less efficient than RO, supposedly requiring twice as much energy.

Rognoni and his colleagues, however, have recalculated the energies involved and suggest that this is a serious over-estimate. Calculations were previously based, not on the efficiency of the water purification process but as a loss of energy from steam turbines.

Their paper intends to demonstrate that the real value of the steam bleed in nuclear plants is a function of several factors, mainly of the cost of fuel and of its importance in the total cost of the energy. The lower the cost of fuel, the less is the value of the steam bleed up to the extent that the cost of the energy consumption can be lower for evaporation than for RO.