Small modular reactors (SMRs) represent a key area of interest to nuclear industry developers, which have been making significant progress during the past few years. Generally, these reactors are promising owing to their improved safety due to passive systems, enhanced containment efficiency, and fewer capital costs in comparison to traditional nuclear reactors. An important advantage of SMRs is their adaptability in being coupled to other energy-consuming systems, such as desalination plants (DPs) to create a cogeneration plant. Considering the serious challenges regarding the freshwater shortage in many regions of the world and the necessity of using low-carbon energy sources, it is advantageous to use SMR for supplying the required heat and electricity of DPs. As a high-performance desalination technology, the hybrid desalination (HD) systems can be exploited, which retain the advantages of both thermal and membrane desalination methods. In this study, several SMR coupling schemes to HD plants have been suggested. In performing a thermodynamic analysis of integrated SMR-DP, the International Atomic Energy Agency (IAEA) Desalination Thermodynamic Optimization Program (DE-TOP) has been utilized. It has been found that the use of relatively hot water from the SMR condenser leads to about 6.5 to 7.5% of total desalination cost reduction, where the produced electricity and hot steam extracted from low-pressure turbine were used to drive the HD system.

The problem of ensuring the continuously growing needs of people for freshwater is becoming more acute in Iran. In order to resolve the serious water crisis in arid regions of the country near the Gulf, several desalination units have been used. However, most of the installed units of seawater desalination are based on fossil fuels consumption, which suffers from several disadvantages. According to the demand for clean energy to provide water and electricity, nuclear technology is gaining higher attention as compared to other energy sources. Bushehr NPP as the first commercial nuclear reactor in the country can be included the establishment of a large-scale desalination plant. In this study, after reviewing pertinent aspects of commercial desalination technologies, the history of seawater desalination in Iran is presented. This paper is focused on economic assessment of coupling the Bushehr NPP with different types of desalination systems, namely, Multiple Effect Desalination (MED), Multi-Stage Desalination (MSF), Reverse Osmosis (RO), and RO + MSF, RO + MED (hybrid methods) by using the Desalination Economic Evaluation Program (DEEP) package. By considering the obtained results and advantages of hybrid methods, RO + MED process with thermal/RO ratio of 0.7 and the total capacity of 150 000 m³/day is suggested.

Nowadays, several technologies for desalination processes are available and widely employed. However, they consume a considerable amount of energy and involve high capital and operating costs. Therefore, the techno-economic analysis of a system coupling different energy sources with the desalination processes is of value. The possibility of coupling a small gas turbine combined heat and power system (GT CHP) with hybrid desalination plants (HDPs) has been assessed in this study. The proposed gas turbine power generation system, based on a single-stage centrifugal compressor and an uncooled centripetal turbine, provides design simplicity and reasonable installation costs for the power generating plant. The hybrid desalination technique, based on the use of two different desalination technologies, i.e., Reverse Osmosis (RO) and a thermal desalination process, has been chosen to better exploit the electrical and thermal energy produced by the mini CHP plant. The proposed solution is numerically investigated from both thermodynamic and economic points of view, and the results of the thermodynamic analysis of the cycle are used as input for the evaluation of the amount of freshwater produced and of costs. The economic assessment of standalone desalination systems is also shown for the comparison with the hybrid solutions here proposed. Results show that the total cost of the water produced by MED + RO was less than the total cost of the water obtained by MSF + RO, and that the energy cost of MED + RO hybrid desalination system was about 15% less than that for stand-alone RO desalination technology. Thus, the MED + RO hybrid desalination system can be considered a promising solution for the coupling with the proposed mini GT CHP plant, which, due to the small size and cost, as well as the easy installation, can be easily applied in off-grid or remote areas.

Nowadays, the problem of supplying fresh water to scarcer regions of the world is still acute. The seawater desalination has been touted as the main solution of closing the water gap in the Middle East and North Africa. However, seawater desalination is expensive and energy-intensive and influences the environment, extremely. Using nuclear power is a viable alternative energy resource to decrease the set of problems of consuming fossil fuels in the desalination plants. Iran, which is located in the arid belt of the eastern hemisphere, as a member state of IAEA (International Atomic Energy Agency) has announced his interest in the implementation of dual-purpose nuclear desalination in the existing nuclear power plant of the country. The Bushehr nuclear power plant is the first commercial nuclear reactor in the Middle East and can be used as a multi-purpose atomic complex to meet the demand for energy and supply of water to arid regions in the south of the country. This paper performs a thermo-economic assessment study for different desalination strategies in the second block of Bushehr NPP.