Nuclear power often sounds like the perfect answer to Pakistan’s energy problems. It runs day and night, produces almost no carbon dioxide during plant operation, and is often seen as cheaper once a plant starts generating electricity. According to the US Energy Information Administration, nuclear reactors do not produce air pollution or carbon dioxide while operating, unlike fossil-fuel-fired power plants.
So the question seems obvious: if nuclear power is reliable and cleaner during operation, why does Pakistan not simply replace its expensive thermal power plants with nuclear reactors?
The answer is more complicated than it first appears. Nuclear power can help Pakistan reduce its dependence on imported fuel, but it cannot quickly replace coal, gas and oil-based generation. The issue is not only about building more reactors. It is also about cost, construction time, technology access, fuel supply, grid capacity, safety risks and long-term waste management.
Pakistan’s energy challenge is therefore not a simple choice between fossil fuels and nuclear power. It is a question of whether the country can build a large nuclear fleet fast enough, finance it without worsening power sector debt, and manage the technical and safety risks that come with it.
Pakistan’s current power system still depends heavily on thermal generation. According to Pakistan Economic Survey data for July to March FY2025, the country’s total installed electricity generation capacity stood at 46,605 MW. Thermal power accounted for 25,937 MW, or 55.65% of total installed capacity, while nuclear power accounted for only 3,620 MW, or 7.77%.
In terms of actual electricity generation, thermal power produced 41,734 GWh, or 46.3%, during the same period. Nuclear power generated 17,175 GWh, or 19.05%. This shows that nuclear plants contribute strongly to electricity production, but their total installed capacity is still far below fossil fuel-based generation.
The biggest challenge is scale. If Pakistan tried to replace thermal installed capacity with nuclear capacity on a simple capacity basis, it would need about 22,317 MW of additional nuclear capacity. This figure comes from subtracting the current nuclear capacity of 3,620 MW from the thermal capacity of 25,937 MW.
That gap cannot be closed quickly. It would require the construction of many large nuclear reactors, along with new transmission lines, safety systems, cooling arrangements, skilled workers, fuel supply contracts and long-term financing.
Pakistan currently operates six main nuclear reactors at Karachi and Chashma. These include Karachi K2 and K3, along with Chashma C1, C2, C3 and C4. The country is also working on Chashma C5, a 1,200 MW reactor, which is expected to increase nuclear capacity after completion.
However, even after C5 becomes operational, Pakistan’s nuclear capacity will remain far below its fossil-fuel-based capacity. One new reactor can improve the energy mix, but it cannot replace the country’s full thermal power fleet.
Nuclear generation may appear cheap when viewed only through fuel cost. For example, the fuel cost of electricity from K2 and K3 is around Rs. 1.5 per unit. However, the overall cost of generation is much higher, at about Rs. 15 per unit, because it includes capital cost, financing, operation, maintenance, safety systems and other fixed charges. This is why nuclear power cannot be judged only by its low fuel cost.
Nuclear power plants require a very high upfront investment. They are expensive to plan, finance, build, regulate and operate. For a country like Pakistan, where the power sector already faces circular debt, high tariffs and capacity payment pressure, this is a major barrier.
Large nuclear projects also require long-term financing on favorable terms. Without affordable financing, new reactors can increase pressure on electricity prices, especially if demand growth does not match new capacity additions.
Nuclear power plants take many years to complete. A project must pass through planning, site selection, regulatory approval, financing, construction, fuel loading, testing and commissioning before it can begin commercial operation.
This makes nuclear power unsuitable as a quick replacement for fossil fuel generation. Pakistan can use nuclear power as part of a long-term energy transition, but it cannot rely on nuclear plants to solve immediate power shortages or quickly remove thermal generation from the system.
Pakistan also faces restrictions in accessing international nuclear technology and materials because it is not a signatory to the Nuclear Non-Proliferation Treaty. This limits its ability to freely buy reactors, fuel-related technology and other nuclear equipment from many global suppliers.
As a result, Pakistan’s nuclear expansion has depended heavily on cooperation with China. While this partnership has helped Pakistan build and operate nuclear plants, dependence on a limited number of suppliers makes rapid expansion more difficult.
Nuclear power requires a reliable fuel supply chain. Although nuclear plants use far less fuel by volume than coal or gas plants, they still need secure access to uranium, fuel fabrication, spare parts and technical support.
Pakistan’s domestic uranium resources are limited. A major expansion of nuclear power would therefore require stronger long-term arrangements for nuclear fuel supply. Without this, the country cannot safely or reliably scale nuclear generation to replace fossil fuels.
Pakistan’s electricity problem is not only about generation capacity. The country also faces transmission, distribution and grid management challenges. In some cases, cheaper electricity cannot be fully dispatched because the grid cannot move power efficiently from generation sites to demand centers.
Adding more nuclear capacity without upgrading the grid would not solve the power sector’s core problems. Nuclear plants need strong transmission links because they are designed to run steadily and supply large amounts of electricity to the grid.
Nuclear power is highly useful for base load electricity because it can run continuously for long periods. However, Pakistan’s demand changes by season, time of day and region. The country needs a flexible mix of generation sources to manage peak demand, hydropower variation, solar output changes and industrial consumption.
Fossil fuel plants, despite their cost and emissions, have historically provided dispatchable power when other sources were unavailable. Replacing them completely would require not only more nuclear plants but also battery storage, better grid planning, flexible generation and demand side management.
A larger nuclear fleet would require stronger safety regulation, emergency planning, trained technical staff and long-term waste management systems. Nuclear plants also need reliable cooling water and strict operating standards.
Nuclear reactors also carry serious safety risks, even with strong safeguards. Enemy attacks, earthquakes, floods, cooling system failures or human error can damage a plant and create a major catastrophe. The Chernobyl disaster and the Fukushima Daiichi accident in Japan show how nuclear accidents can contaminate land, displace communities and create long-term cleanup challenges.
Nuclear power is often described as a clean energy source because it produces very low emissions during electricity generation. However, it is not completely free from environmental risks.
Uranium mining, fuel processing, plant construction, waste handling and decommissioning all have environmental costs. More importantly, radioactive waste and contaminated components must be stored and disposed of safely to prevent radiation damage to people, soil and water.
Nuclear power remains valuable for Pakistan. It can provide stable electricity, reduce reliance on imported fossil fuels and support the country’s long term energy security. Nuclear plants also produce low-carbon electricity during operation, which makes them useful for reducing emissions from the power sector.
However, nuclear power should be seen as one part of Pakistan’s energy transition, not as a complete and immediate replacement for fossil fuel generation.