Nuclear desalination in Iran, current status and perspectives

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.

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.

The research addressed the economic evaluation of nuclear energy, coal, oil and natural gas in various cycle configurations with different distillation technologies. A comparison between fossil and nuclear energy sources is discussed. A comprehensive review of all desalination plants using fossil and nuclear energy with cogeneration is also included and discussed. Computational model was used to evaluate nuclear and non-nuclear desalination plants. Four possibilities were discussed. In this first case, a nuclear gas cycle integrated with a MED desalination plant was found to have the lowest cost in the gas cycle. While the nuclear steam cycle integrated with RO has the lowest cost compared to oil and natural gas. In the third case, the combined nuclear cycle was discussed and it was found that the combined nuclear cycle associated with RO has the lowest cost. In the last case, the evaluation of a heat-only desalination plant was conducted among all sources, and it was found that the nuclear plant with RO and MED has the lowest cost. In addition, the completed nuclear desalination plant was subjected to five scenarios to calculate and estimate at which capacity the plant provides the best values. The results show that nuclear desalination with gas cycle is the most economical among the oil and natural gas options.

The development of a small-sized nuclear heat-only plant with maximized safety features dedicated to seawater thermal desalination was proposed to address both a serious water crisis and nuclear safety issues, which continue to be perennial problems. In this study, the feasibility of a dedicated nuclear heat-only desalination system for a target country was evaluated in comparison with a target nuclear thermal desalination system. First, the target country was selected, and its current energy and desalination status was investigated. The suitable nuclear desalination options for the target country were then selected. Finally, using corresponding analysis tools, performance and economic analyses were conducted for a dedicated nuclear heat-only desalination system and the target nuclear thermal desalination system. The results of the analyses indicate that operating the small-sized nuclear heat-only plant at low pressures coupled with a seawater thermal desalination plant will considerably improve both the safety and economy without a significant loss in desalination performance. In conclusion, the proposed dedicated nuclear heat-only desalination system is expected to have high potential for solving both problems.

IAEA coordinated research activity on nuclear desalination: the quest for new technologies and techno-economic assessment

Although current water desalination technologies are mature enough and advanced, the shortage of freshwater is still considered as one of the most pressing global issues. Therefore, there is a strong incentive to explore and investigate new potential methods with low energy consumption. It is well-known that polymer hydrogel network has the ability to absorb water via swelling. In the case of polyelectrolyte hydrogels, the charges localized on the polymer chains, which mainly drive the swelling pressure inside the hydrogel, can also separate added salt via charge-based selectivity (Donnan exclusion). When combining this material with a temperature-sensitive polymer, the heat generated by solar energy can trigger the desorption process via conformational change of polymer chains. Hence, hydrogels designed from both materials, polyelectrolyte and thermo-responsive polymer can reduce the salinity of water, such as brackish water by means of reversible thermally-induced absorption and desorption desalination processes. In addition, the desorption process can also be achieved based solely on a polyelectrolyte hydrogel system by altering the ionization of charges within the hydrogel via pH. In this thesis, hydrogel-based water desalination process were developed using acrylic acid (AAc)/sodium acrylate (SA)-based polyelectrolytes as the charge-based separation function, alone or with a combination of N-isopropylacrylamide (NIPAAm) as thermo-responsive comonomer. In the latter case, a series of chemically cross-linked polymeric hydrogels were synthesized via either free radical-initiated copolymerization or reversible addition-fragmentation chain transfer (RAFT) polymerization, thus realizing different macromolecular architecture. According to the nature of hydrogels, the reversible sorption/desorption state were triggered by either chemical stimulus (pH), or physical stimulus (heat) as the thermo-responsive polymer introduced into the hydrogels. In detail, the effect of hydrogel composition as well as the influence of the macromolecular architecture on the swelling/deswelling behavior for the synthesized hydrogels were studied. For this, their properties including their responses to external stimuli were investigated, and their ability to desalinate brackish water as well as the effciency of such desalination process were evaluated. Generally, the results demonstrated correlations between macromolecular architecture of the network structure and their performance in the proposed desalination process, such as salt rejection and desalination capacity. Moreover, the potential of the best performance materials for applications was also discussed.

With rapid increase in human population, the demand of fresh water has been increased significantly and the world will encounter enormous water crisis by 2040. The sea contains nearly 97% of available water on earth. To fulfill the demand of fresh water, desalination of sea water can be best solution. As desalination process can be performed by using low grade energy, the use of solar energy for desalination is very popular. The most popular solar thermal desalination system is conventional solar still but its productivity is very low. In the present study, a new desalination system based on evacuated tube collectors (ETC) is developed and its performance is compared with conventional solar still experimentally. The present system consists of 15 evacuated tubes, an insulated storage tank, a heat exchanger, a condenser, and a thermic fluid as working medium. The performance of both systems is compared on the basis of daily productivity, energy and exergy efficiency, and economic viability. It is observed that the ETC‐based desalination system performed better as compared to the solar still. The average energy and exergy efficiency, productivity and produced fresh water cost of desalination systems based on ETC and conventional solar still are 43.74%, 9.52%, 4.2 L/m2/day, 0.022 $/L and 19.23%, 1.4%, 1.975 L/m2/day, 0.024 $/L respectively. Further, the pay‐back time for ETC based desalination system is also less (104 days) as compared to solar still (113 days).

Nuclear desalination: A sustainable route to water security

Desalination of sea water through thermal and membrane based techniques and production of hydrogen through low temperature water electrolysis at facilities co-located with nuclear power plants are two areas identified for deploying co-generation projects in India in the near term. Nuclear desalination meets the requirements of clean drinking water in and around the nuclear facility, as well as to the in-house demand for high purity water for steam generation and other processes like hydrogen generation, coupled to it. Nuclear assisted hydrogen production also provides means to generate and distribute clean hydrogen which is envisaged as an important component of the decarbonized energy system of the near future. Currently the technologies for indigenous design, manufacture and quality assurance of desalination and medium scale compact water electrolysis plants are commensurate with the 220 MW(e) PHWRs presently operating in India. This work provides an overview of the research, development and deployment work carried out in these two areas in India, analyses the applicability of the IAEA Milestones Approach to nuclear cogeneration projects and discusses the problems and prospects of setting up and integrating more such facilities all over the country.

One of America’s best kept secrets is the success of its nuclear electric power industry. This paper presents data which support the construction and operating successes enjoyed by energy companies that operate nuclear power plants in the US. The result—the US nuclear industry is alive and well. Perhaps it’s time to start anew the building of nuclear power plants. Let’s take the wraps off the major successes achieved in the nuclear power industry. Over 20% of the electricity generated in the United States comes from nuclear power plants. An adequate, reliable supply of reasonably priced electric energy is not a consequence of an expanding economy and gross national product; it is an absolute necessity before such expansion can occur. It is hard to imagine any aspect of our business or personal lives not, in some way, dependent upon electricity. All over the world (in over 30 countries) nuclear power is a low-cost, secure, safe, dependable, and environmentally friendly form of electric power generation. Nuclear plants in these countries are built in six to eight years using technology developed in the US, with good performance and safety records. This treatise addresses the success experienced by the US nuclear industry over the last 40 years, and makes the case that this reliable, cost-competitive source of electric power can help support the economic engine of the country and help prevent experiences like the recent crises in California and the Northeast. Traditionally, the evaluation of electric power generation facility performance has focused on the ability of plants to produce at design capacity for high percentages of the time. Successful operation of nuclear facilities is determined by examining capacity or load factors. Load factor is the percentage of design generating capacity that a power plant actually produces over the course of a year’s operation. This paper makes the case that these operating performance indicators warrant renewed consideration of the nuclear option. Usage of electricity in the US now approaches total generating capacity. The Nuclear Regulatory Commission has pre-approved construction and operating licenses for several nuclear plant designs. State public service commissions are beginning to understand that dramatic reform is required. The economy is recovering and inflation is minimal. It’s time, once more, to turn to the safe, reliable, environmentally friendly nuclear power alternative.

SYNOPSES In the UK, the Electricity Act of 1989 was amended in 2000 to remove the distinction between private and public electric supply companies. The customers in the UK saved £ 700 million in one year under de-regulation. In the US, Congress passed the Energy Policy Act in 1992 that de-regulated the wholesale electric market and mandated electric utilities to open up the transmission system on an equal basis to all who utilize it. During the past decade, the demand for electricity in the United States has increased by 35 percent, whereas, the generation has increased only by 18 percent. With the bulk power transactions and reservations, the transmission system now operates closer to its stability limits. Voltage instability occurs when the balance between the reactive power producing sources and the VAR losses cannot be maintained. The limited construction of new transmission lines has pushed the power industry toward the development of advanced technologies such as flexible ac transmission system (FACTS), static VAR compensators (SVC), static synchronous compensators (STATCOM), unified power controllers (UPFC), and distributed superrconducting magnetic energy storage (D-SMES). In a nuclear power plant, offsite and onsite electric power systems are required to provide sufficient capacity and capability to assure that the containment integrity be maintained during power operation or in case of a postulated accident. Analyses must verify that the electric grid remains stable in case of loss of the nuclear unit, the largest other unit on the grid or the most critical transmission line and a change it due to deregulation would affect those analyses. Nuclear Regulatory Commission (NRC) staff ensures that the licensees maintain adequate voltages to the Class 1E (safety) buses. If the operator has failed to restore adequate voltages, the Class 1 E buses should be automatically separated from the offsite power system and connected to the emergency diesel generators. Most utilities use on-line contingency analysis and the control centers notify them when the offsite power system in their nuclear plant is degraded. The control centers use load conservation procedures to provide the plant a stable offsite power system. The control centers have assured the NRC staff that the nuclear power plants are their preferred customers and that they will be provided with an adequate offsite power system even under reduced grid generation availability. This paper discusses the voltage stability, power transfer limits, reactive reserves, methods of improving voltage stability (such as superconductivity), load conservation procedures and effects of deregulation on nuclear power generating stations.

Preliminary thermoeconomic analysis of combined parabolic trough solar power and desalination plant in port Safaga (Egypt)

Load following with Small Modular Reactors (SMR): A real options analysis

Korea has been achieving the world best safety and economic performance of nuclear power plants through continuous technology development and asset management optimization since its first nuclear power reactor was introduced in the late 1970s. While most countries have stopped building new nuclear power plants since the severe accident in TMI nuclear plant in 1979, Korea has been steadily developing its own reactor models and constructing new nuclear plants. In addition, Korea won recent new nuclear plant project of United Arab Emirates (UAE) as a result of these efforts. A nuclear power plant consists of a great variety of complex equipment having state-of-the-art technologies, and the highest nuclear safety and equipment reliability are required. Therefore, the most sophisticated systematic engineering asset management is essential to the nuclear power plant. As a responsible company of operating and constructing all nuclear power plants in Korea, Korea Hydro and Nuclear Power Co. (KHNP) has developed its own asset management model for the nuclear power plants in operation and expanded the model into the new plants under construction. Since the asset management model was developed for the various equipment types in the nuclear power plant, it can be easily utilized in other industries as a highly effective asset management model. This paper presents new and innovative methods to refine and improve existing asset management practices in general plants by diagnosing KHNP’s physical asset management model. It contributes to the development and improvement of an advanced asset management model for general plant industries and utilities to meet the objectives of securing a clean environment, improved public health and safety, and general community well being.

Chapter 10 - Desalination and sustainability