Climate Action 2012-2013

AGRICULTURE, FOOD AND WATER
About 1 million tonnes of CO 2
is released when
1 TWh of electricity is produced by using coal,
gas or oil.
Interest in using nuclear energy for producing
potable water has been growing worldwide.
This has been motivated by variety of factors,
from the economic competitiveness of nuclear
energy to energy supply diversification, from
conservation of limited fossil fuel resources
to environmental protection, and the spinoff
effects of nuclear technology in industrial
development. In a nuclear desalination facility,
both the reactor and the desalination system are
located on a common site, with some degree of
shared facilities, services, staff, seawater intake
and outfall structures. These nuclear plants can
be dedicated to desalination, or combined with
power production facilities.
Co-location of desalination and power plants
has the obvious benefit of sharing infrastructure
resources such as a common intake and outfall
of sea water. In recent years a number of projects
have been carried through using the co-location
concept. Dual purpose plant (power together with
desalination) has inherent design advantages in
optimising thermodynamic efficiency, in addition
to its economic benefits.
Pioneering thermal and hybrid nuclear
desalination
Development of thermal desalination
technologies using low grade and waste heat for
seawater desalination is well estabished at the
Bhabha Atomic Research Centre (BARC) in
India. Technology was evolved using a 15,000
litres/day capacity three-stage multi-stage flash
(MSF) system. A pilot plant of 425,000 litres/
day capacity was setup in BARC Trombay. The
experience helped in the design, installation
and commissioning of a 4,500,000 litres/day
(4.5 MLD) MSF system as a part of the Nuclear
Desalination Demonstration Plant (NDDP) at
Kalpakkam.
The use of low grade waste heat as energy input
for desalination was pioneered in the islands of
Lakshadweep, producing 10,000 litres/day of
distilled quality water using the waste heat of
a diesel generator facility. Other value-added
thermal desalination technologies are being
developed, such as multi-effect distillation vapour
compression (MED-VC) and low temperature
evaporation (LTE).
Figure 1
“Interest in using nuclear
energy for producing potable
water has been growing
worldwide.”
It is possible to save product costs through a mix
of different techniques. This is known as a hybrid
system, using both steam and electricity as power
sources. MSF uses thermal energy from low grade
steam, while the reverse osmosis (RO) process
operates with the help of electricity. The concept
takes into account the product quality
requirements for different uses, such as providing
high quality boiler feed water, process water for
industrial applications, and potable water for
human use.
“Significant waste heat is
available in the moderator
system of a pressurised heavy
water reactor.”
The NDDP at Kalpakkam (Figure 1) makes use
of hybrid technology. NDDP consists of a hybrid
MSF-RO desalination plant of 6.3 million litres
per day (MLD) capacity (4.5 MLD MSF and 1.8
MLD by RO) coupled to Madras Atomic Power
Station (MAPS), Kalpakkam. The requirement of
seawater, steam and electrical power for the
desalination plant are met from MAPS. The RO
plant has been operating and producing potable
water from seawater. The plant incorporates the
necessary pretreatment and an energy recovery
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