Alternatives of steam extraction for desalination purposes using SMART reactor

Nuclear energy is playing an important role in electricity generation, producing 16% of the world’s electricity. However, most of the world’s energy consumption is in the form of heat, in which case nuclear energy could also play an important role. In particular, process heat for seawater desalination using nuclear energy has been of growing interest to some Member States of the International Atomic Energy Agency over the past two decades. This growing interest stems from increasingly acute freshwater shortages in many arid and semi-arid zones around the world. Indeed, several national and international nuclear desalination demonstration programs are already under way or being planned. Of particular interest are projects for seawater nuclear desalination plants in coastal regions, where saline feed water can serve the dual purpose of cooling water for the nuclear reactor and as feed water for the desalination plant. In principle any nuclear reactor can provide energy (low-grade heat and/or electricity), as required by desalination processes. However, there are some additional requirements to be met under specific conditions in order to introduce nuclear desalination. Technical issues include meeting more stringent safety requirements (nuclear reactors themselves and nuclear-desalination integrated complexes in particular), and performance improvement of the integrated systems. Economic competitiveness is another important factor to be considered for a broader deployment of nuclear desalination. For technical robustness and economic competitiveness a number of design variants of coupling configurations of nuclear desalination integrated plant concepts are being evaluated. This paper identifies and discusses various factors, which support the attractiveness of nuclear desalination. It further summarizes some of the key approaches recommended for nuclear desalination complex design and gives an overview of various design concepts of nuclear desalination plants, which are experienced, being implemented or evaluated by several IAEA Member States. Operating experience with nuclear desalination using a liquid-metal reactor BN-350 in Kazakhstan and several Pressurized Water Reactor units in Japan is discussed. Results of economic analyses of nuclear desalination are also presented in order to illustrate the competitiveness of this technology with other conventional desalination operations.

Economic evaluation of nuclear desalination systems

Sea-water desalination with nuclear and other energy sources: the EURODESAL project

Detailed reviews of a past advanced nuclear reactor–based integrated energy system, as well as other nuclear reactor and fossil fuel–based integrated energy systems, have been performed for this work. A review of the utilization of heat from nuclear reactors for various applications and cogeneration has been done. The heat can be utilized by extracting the steam from the turbine while the steam is still at a desired temperature. While the use of nuclear process heat for district heating in countries like Finland, France, China, Poland, and elsewhere is discussed, more focus of the review has been given to nuclear desalination processes. Integrated energy systems (IESs), where distinct types of reactors like pressurized water reactors, boiling water reactors, sodium-cooled fast reactors, heavy water reactors, and other advanced reactors are coupled with various nuclear desalination processes, like multi-effect distillation (MED), multistage flashing, and reverse osmosis methods, are discussed. The nuclear desalination plant at Aktau is discussed in more detail due to its decades of successful operation. The IES of the Aktau plant coupled with a five-effect MED desalination plant was taken as a reference for modeling the Open Modelica (OM)–based IES in this work. The OM IES model shows good agreement with the MED plant output of Aktau and can be extended for future applications of IESs.

CHP (combined heat and power) retrofit for a large MED-TVC (multiple effect distillation along with thermal vapour compression) desalination plant: high efficiency assessment for different design options under the current legislative EU framework

This paper summarises our recent investigations undertaken as part of the EURODESAL project on nuclear desalination, which were carried out by a consortium of four EU and one Canadian, Industrials and two leading EU RD verification that the integrated system design does not adversely affect nuclear reactor safety. 2. The development of codes and methods for an objective assessment of the competitiveness and sustainability of proposed solutions through comparison, in European conditions, with fossil and renewable energy based solutions. The results obtained so far seem to be quite encouraging as regards the economical viability of nuclear desalination options. Thus, for example, specific desalination costs ($/m³ of desalted water) for nuclear systems such as the AP600 and the French PWR900 (reference base case), coupled to Multiple Effect Distillation (MED) or the Reverse Osmosis (RO) processes, are 30% to 60% lower than fossil energy based systems using pulverised coal and natural gas with combined cycle, at low discount rates and recommended fuel prices. Even in the most unfavourable scenarios for nuclear energy (discount rates = 10%, low fossil fuel prices) desalination costs with the nuclear options with the nuclear reactors are 7% to 15% lower, depending upon the desalination capacities. Furthermore, with the high performance coupling schemes developed by the EURODESAL partners, the specific desalination costs of nuclear systems are reduced by another 2% to 14%, even without system and design optimisation.

When a nuclear reactor is used to supply steam for a desalination plant, the method of coupling has a significant technical and economic impact. The exact method of coupling depends on the type of reactor and the type of desalination plant. As a part of Nuclear Desalination Demonstration Project (NDDP), BARC has successfully commissioned a 4500 m 3 /day multi-stage flash desalination plant coupled to Madras Atomic Power Station at Kalpakkam. A desalination plant coupled to nuclear reactor of pressurised heavy water reactor type is a good example of dual-purpose nuclear desalination plant. This paper presents the thermal coupling system analysis of this plant along with technical and safety aspects.

Several ways to overcome dependence on fossil fuels/energy sources of petroleum for national energy procurement have been performed, such as replacing petroleum with liquid coal/gas, and other renewable energy such as hydrogen. This has been stated in the Government Regulation no. 79 of 2014 on National Energy Policy and Law no. 17 of 2007 on the 2005-2025 National Long-Term Plan. To support national energy growth, the government has enacted the use of new and renewable energy contributing to more than 23% of total energy consumption and that the use of oil should be reduced to less than 25%. Experimental Power Reactor or called Reaktor Daya Eksperimental (RDE) is built to demonstrate for electricity generation or cogeneration purpose, which utilizes nuclear heat for producing electricity and for providing process heat for an industry, for example desalination. Cogeneration system can also improve the economical benefit of the RDE by thermal utilization. Seawater desalination is an attractive solution, of which the technologies have been well established over the past 50 years. The two most commonly used desalination technologies are multistage flash (MSF) and reverse osmosis (RO) systems. Basically, almost all PLTUs in Indonesia have applied desalination technology to supply the process water needs, but they still use fossil energy to supply heat. In order to overcome electricity deficiency and water scarcity in some areas of Indonesia, then to accommodate a government regulation on energy mix, it is necessary to study nuclear heat utilization for desalination (Nuclear Desalination) through cogeneration system. The Nuclear Desalination is conducted by coupling the RDE with desalination units, so it can simultaneously produce electricity and freshwater. An intermediate heat exchanger is incorporated between the nuclear reactor and the desalination unit to ensure no radioactive contamination in secondary system or to protect the desalinated water. The objective of study is to choose the most optimum options of the steam extraction points that will be used for desalination process. The result of this study showed that heat can be extracted in the heat application line before the steam turbine (coupling option 1) and the downstream of steam turbine (coupling option 2). For coupling option 1, the steam (0.94 kg/s) with the temperature of 520°C can be extracted to produce a 27 m3/h fresh water. Meanwhile, using the low-pressure steam rejected from turbine (coupling option 2), the fresh water of 16.5 m3/h (396 m3/d) flow rate can be produced from the desalination unit.

This paper summarises our on-going investigations on the elaboration of a strategy for the possible application of nuclear energy for seawater desalination in a North African country such as Tunisia. The basic aim of the work undertaken is to estimate the realistic costs (under Tunisian conditions) of an integrated nuclear desalination system, operating in the co-generation mode at a specific site in Tunisia, la Skhira, situated between the towns of Sfax and Gabes. However, in order to furnish a choice of technical options, our investigations include studies with two nuclear reactors: the first an existing reactor, the PWR-900 as a reference base case and the second a new generation safe integral reactor, SCOR-600). These reactors were coupled to three desalination processes: the Multiple Effect Distillation, (MED); the Reverse Osmosis process (RO) and an advanced Reverse Osmosis process, (Roph), based on the utilisation of waste heat. Comparisons have also been made with two fossil energy based systems, currently being used in Tunisia: the oil fired plant (DP) and the gas turbine combined cycle plant (CC). First results indicate that desalination by nuclear options is not only technically feasible but also the least expensive solution for the la Skhira site in Tunisia.

Energy cost contributes a large portion of the overall cost of desalinated water. Improving the energy efficiency of desalination plants is therefore a primary design goal. However, accurately evaluating and comparing the energy consumption of desalination plants that use different forms and grades of energy is difficult, especially for power–water coproduction systems in which primary energy (PE) consumption leads to both salable electricity and potable water. The power plant converts PE into grades of thermal energy and electricity usable by the desalination plant. To fully capture the thermodynamic and economic cost of energy, and to fairly compare desalination systems that use different grades of input energy, we must compare energy consumption not at the point where energy enters the desalination plant itself, but as PE consumption entering the power plant. This paper investigates a variety of metrics for comparing the energy and exergy consumption attributable to desalination in coproduction plants. Previous results have shown that reverse osmosis (RO) is approximately twice as efficient as multiple effect distillation (MED) on a PE basis. We then compare the PE consumption of MED and RO from a thermoeconomic perspective. The entropy generation at the RO membrane and in the MED effects are derived in similar terms, which enables a comparison of the overall heat transfer coefficient in an MED system to the permeability of an RO membrane. RO outperforms MED in energy efficiency because of a balance of material costs, transport coefficients, and cost of energy.

Nuclear desalination: A state-of-the-art review

Over the past decade, the author, Roger Francis, has looked at some very expensive corrosion failures in desalination plants. Avoiding Corrosion in Desalination Plants tells the reader how to avoid existing corrosion problems and how to avoid them in new builds. This book looks at corrosion problems specific to MSF, MED, and SWRO desalination plants, describing their causes, some solutions, and the relative performance of various materials. It gives advice on procuring materials for desalination plants to avoid quality problems. The world’s population is steadily increasing and with it is an increasing demand for water—for both drinking and irrigation. In many areas of the world, particularly in warmer climates, there are limited sources from rivers and wells, so desalination is being increasingly used to produce water to satisfy both requirements. Although desalination is sometimes carried out on brackish waters and highly saline well waters, most desalination plants generate fresh water from seawater. There are three main processes used in desalination plants, the oldest of which is multistage flash (MSF), where the water is essentially boiled at low pressure and the steam that flashes off is condensed for drinking water. The second process is multiple-effect distillation (MED), in which low-pressure steam is used to force evaporation of seawater and the vapor is then condensed for drinking water. Although actual MSF and MED plants (large-scale) are land based, small-scale units have been fitted to large ships, such as cruise liners, to generate fresh water. The third process is seawater reverse osmosis (SWRO), where chloride is selectively removed from water by forcing it at high pressure through a special membrane. This method involves no heat transfer but requires enough electricity to power the high-pressure pumps that are required. All three of these methods have advantages and disadvantages. This book looks at corrosion problems specific to MSF, MED, and SWRO desalination plants, describing their causes, some solutions, and the relative performance of various materials. It gives advice on procuring materials for desalination plants to avoid quality problems.

Nuclear power can be categorized as a clean energy source for producing electricity and supplying the required energy to a desalination plant, promising less atmospheric emission in comparison to fossil fuels. Considering the fact that fresh water-related issues are acute in many countries of the world, the utilization of desalination technologies seems to be the key solution to these problems. Desalination processes are known to be “energy-intensive”, emphasizing the potential advantages of its integration to a nuclear power plant in mediumto large-scale seawater desalination projects. The demand for electricity and fresh water in Iran compels the country to search for a feasible option. We suggest nuclear desalination as a suitable alternative, in which the recovered heat can be used in thermal desalination systems. In this article, the status of currently operating desalination plants and future developments are described. Several possible schemes for coupling nuclear power plant and fossil fuel-based plants with desalination technologies are suggested and some thermo-economic analysis (based on the specific characteristics of the country) are presented. Results of calculations reveal some advantages of nuclear desalination complex and its competitiveness with other options. It should be noted that the research has been conducted by cooperation of two SPbPU PhD students with Iranian citizenship.

Nuclear desalination concept and implementation spanning 50 years are recognized as an economical viable option for water and electricity production but could not receive wider applications. This is due to various factors, in addition to technical design parameters, other factors, such as social, economic, and environmental issues, need to be considered. For this purpose, the current studies start with performing a critical and up-to-date literature review on previous investigations in the field of nuclear reactors and integrated nuclear power with desalination plants with a specific focus on performance criteria, technical specifications, etc. Reviewing and compiling the most updated technical specifications, cost estimations, and environmental data related to nuclear power and desalination plants are also important steps. Previous studies show a special focus on other important issues on nuclear desalination characteristics in countries including Saudi Arabia, Egypt, United Arab Emirates, Pakistan, India, and Kuwait. This work presents a concise review of previous works on the relevancy of other issues, such as economic, environmental, and social, associated with the use of nuclear energy in power generation and fresh water production. Preliminary assessment of possible hybrid configurations of nuclear and desalination technologies is developed and assessed by a computational program. Both operating and capital cost of the integrated plants are calculated. The simulation model is then extended to compare with other heating reactors as well for the verification analysis. The results obtained from comparative assessment depicts the accuracy of the simulation model used for preliminary assessment of the integrated nuclear desalination option. The main objective of the research is to assess the nuclear desalination plant development in terms of social, economic and environmental aspects. The results will pave the way for countries interested in developing nuclear desalination plants.

Impact of desalination plants fluid effluents on the integrity of seawater, with the Arabian Gulf in perspective