Nuclear desalination: harnessing the seas for development of coastal areas of Pakistan

Abstract

Pakistan has a population of 140 million with more than 30% of the population living in cities and towns. Karachi, the major port city of the country, is the most densely populated with a population crossing the 11 million mark. The city receives 435 MGD of drinking water from the River Indus and other sources. However, the net demand for the year 2000 was 594 MGD thus there is a gap of 159 MGD in demand and supply. Statistics show that the water demand in Karachi is increasing at the rate of 100 MGD every five years. The coastal belt of the country extends to 1046 sq. km. Of this, 930 km is from the Karachi to Gwader region in the province of Baluchistan. Most of the coastal areas lie outside the monsoon system of weather and therefore the climate is extremely dry. The annual rainfall in this belt is about 15 cms. Therefore, fresh water availability is a major factor for development of the coastal belt of Pakistan. In the wake of the looming water crisis it is becoming increasingly clear that all available and appropriate technologies, including nuclear and related technologies, have to be used for the sustainable development and management of freshwater resources in Pakistan. One particular approach is the desalination of seawater, and countries are increasing their capacity to harness the seas for tapping fresh water. The prospects of using nuclear energy for seawater desalination on a large scale are attractive since desalination is an energy intensive process. Pakistan Atomic Energy Commission (PAEC) is planning to actively participate in the activities of IAEA in the field of nuclear desalination by offering one of its nuclear power plants for coupling a demonstration nuclear desalination plant. Karachi Nuclear Power Plant (KANUPP), which is the country's first nuclear plant has been successfully operating for the last 30 years. This plant is proposed to be used as a potential site for installation of a demonstration nuclear desalination plant. KANUPP is already operating a Sea Water Reverse Osmosis (SWRO) plant to meet its operating requirements, contributing to its ultimate heat sink. The experience gained in the installation and commissioning of the RO plant will be very useful for the proposed nuclear desalination plant. The objective of this paper is to present the work done by PAEC in preparing the engineering feasibility for coupling a 1MGD demonstration nuclear desalination plant with KANUPP. The paper discusses in detail the criteria for selection of the most appropriate thermal desalting process, capacity of the plant and the coupling arrangement with the existing power plant without disturbing the normal operation of KANUPP.