Nuclear power is recognized as safe and is the most dependable energy source, being 2.5 to 3.5 times more reliable than wind and solar. It also boasts the highest capacity among energy sources, providing significant energy output within a much smaller physical footprint.
However, a lesser-known requirement of nuclear energy is its considerably higher water consumption compared to most other renewable energy sources.
Water from Nuclear Power Plants
In nuclear power stations, water is essential for cooling the radioactive cores, but it becomes contaminated with radionuclides in the process.
According to the International Atomic Energy Agency (IAEA), 45% of nuclear plants utilize seawater for once-through cooling, while 25% rely on cooling towers fed by water mains. Additionally, 15% use lakes, and 14% use rivers, based on proximity. The Nuclear Energy Institute estimates that each nuclear reactor requires between 1,514L and 2,725L of water per MWh, amounting to billions of gallons annually, all of which must be filtered.
Both Boiling Water Reactors (BWR) and Pressurized Water Reactors (PWR) require significant amounts of water. In BWRs, the cooling water becomes mildly radioactive but is contained within the plant, recirculating in a loop to cool the reactor cores. This water undergoes demineralization, filtration, and distillation for treatment.
In contrast, PWRs do not allow the water to contact the core, meaning it remains uncontaminated and can be released into the environment. However, the release of nuclear water—regardless of contamination status—often faces public backlash.
For instance, Japan’s government approved plans to release Fukushima water into the Pacific in 2021, leading to strong opposition from environmentalists. Despite a UN review, Japan’s plans may proceed. In the future, more nuclear power stations might consider releasing water, but it is generally wiser to treat it on-site for reuse.
Strategies for Effective Water Management in Nuclear Power Plants
Efficient water management is crucial throughout the construction, operation, and maintenance phases of nuclear power plants. This management encompasses securing water for condenser cooling during operation, facilitating construction (particularly during the flushing phase), and controlling inventory, which includes replenishing the primary coolant system and managing discharge from radioactive liquid waste treatment systems. Providing guidance and options will assist newcomer countries considering nuclear power in developing their water management strategies.
Countries facing water scarcity and contemplating the introduction of nuclear power may express concerns about the need to secure water resources for plant operations and seek effective water management strategies. Experience has demonstrated that nuclear power plants can be vulnerable to extended droughts, which may necessitate reactor shutdowns or significant reductions in output. Additionally, environmental issues have led to regulations that restrict water withdrawal and discharge. Given the intrinsic link between water and energy, minimizing water use in nuclear power plants is likely to benefit countries interested in integrating nuclear energy into their energy portfolios.
Efficient Recycling of Nuclear Water
In Boiling Water Reactors (BWR) and Pressurized Water Reactors (PWR), cooling water is purified and reused through advanced recycling systems. These systems are among the most efficient in the industry, capable of recirculating water indefinitely while supplementing with fresh water as needed.
Nuclear power stations implement sophisticated water recycling methods that significantly reduce freshwater consumption. For instance, water heated by fission powers a turbine to generate electricity, and any unused steam condenses back into water for reactor use. However, what happens to the water that cannot be reused in nuclear processes?
The recycling system treats this water to eliminate strontium and radionuclides through filtration, distillation, and vaporization, ensuring it is decontaminated to a level safe for release or repurposing.
When recycled, the water can be reused or, at the end of its lifecycle, the plant operator may request its release into nearby water bodies.
Regarding solid waste, the plant stores materials based on their risk levels. Approximately 90% of nuclear waste is low-level, which can be disposed of at ground level, while high-level waste is stored at depths of up to 5,000 meters.
Conclusion
Nuclear power plants, while less water-friendly than wind or solar energy, remain a competitive and beneficial option for future electricity generation. The Nuclear Energy Institute recommends building most new plants near coastlines to use ocean saltwater, reducing drought-related shutdowns and enabling desalination to offset freshwater use. This approach enhances the sustainability perception of nuclear energy, positioning it as a leading thermal electricity generation method.
Reference
1.Efficient Water Management in Nuclear Power Plants
2.Nuclear Power Plant Water Usage and Consumption
http://large.stanford.edu/courses/2017/ph241/styles2/
