There have been fewer application for desalination than for district heating. As for the latter case, the majority of applications have been with plants operating in co-generation mode, i. e. electricity and desalination. Desalination plants have been operated in Japan (Ikata, Ohi, Genkai, Takahama, Kashiwazaki). A range of different desalination processes have been used. There has also been some experience from a plant operating in the USA at the Diablo Canyon.

Other experience has been gained in Kazakhstan (Aktau) where the liquid metal cooled fast reactor BN-350 has been operating as a multi-energy source for electricity, drinking water and heat.

A non-nuclear facility was built in Israel for testing the nuclear desalination process. The heat source was produced by an oil-fired power plant N. B. this operated for only a short period.

Desalination is the process of obtaining freshwater suitable for drinking or industrial processes through the removal of salt from saline, usually seawater. This can be achieved using either distillation processes or via membrane processes using osmosis (IAEA-TECDOC-1056, 1998). Desalination processes include:

— Multi-stage-flash (MSF) distillation;

— Multiple-effect distillation (MSD);

— Reverse osmosis (RO).

Typical energy requirements and energy consumption rates for the three processes are shown in Table 14.4. These can be compared with the theoretical minimum energy requirement of 0.73 kW h m_3 for 35,000 ppm saline water at 25°C. The discrepancies are due to significant thermal processes and irreversibility that occur during the separation process.