Top 20 Largest Nuclear Power Plants 2025: Country Leaders

🌍 Top 20 Largest Nuclear Power Plants in 2025: Clean Energy Giants Ranked

As the world transitions to carbon-free electricity, nuclear power remains a critical pillar of global energy production. In 2025, the largest nuclear power plants from Japan’s Kashiwazaki-Kariwa (7,965 MWe) to Canada’s Bruce Station and Ukraine’s Zaporizhzhia combine cutting-edge technology with unmatched reliability, delivering clean energy to millions while reducing greenhouse gas emissions. These engineering feats aren’t just power generators; they’re lifelines for energy security and sustainable development.

This ranked list explores the Top 20 Largest Nuclear Power Plants in 2025, showcasing their capacity (MWe), operational history, and groundbreaking innovations. Discover how Palo Verde the only desert-powered nuclear plant defies geographical limits, or why Finland’s Olkiluoto leads in nuclear waste storage solutions. Whether you’re an energy professional, student, or eco-conscious reader, learn how these mega-power stations shape the future of zero-emission electricity. Which country dominates the list? Let’s explore! ⚛️🔋

🚀 Exploring the Giants: A Closer Look at the Top 5

1️⃣ Kashiwazaki-Kariwa (Japan) – 7,965 MWe

The Sleeping Giant of Niigata Coast, Japan.

Despite being the largest nuclear power plant in the world, it remains offline since 2011 following the Fukushima disaster. TEPCO has been pushing for the restart of Units 6 & 7, aiming for 2029 and 2031 respectively. If reactivated, it could power millions of homes and significantly reduce Japan's reliance on fossil fuels.

2️⃣ Bruce (Canada) – 6,232 MWe

Canada's Energy and Medical Giant on the shores of Lake Huron.

Operational since 1977, Bruce is not just a powerhouse for electricity but also a crucial source of Cobalt-60, which is used for cancer treatment and sterilization of medical equipment. Its eight reactors provide around 30% of Ontario's electricity.

3️⃣ Zaporizhzhia (Ukraine) – 5,700 MWe

Europe's Largest Powerhouse and a symbol of resilience.

The plant has been under Russian control since 2022, making it a focal point of international concern. It supplies about 20% of Ukraine's electricity, making its stability critical for the region's energy security.

4️⃣ Hanbit (South Korea) – 5,577 MWe

South Korea's Energy Powerhouse, formerly known as Yeonggwang.

With six reactors, Hanbit provides around 6% of South Korea's total electricity. Renamed in 2013, it stands as a testament to local influence and national energy independence.

5️⃣ Hanul (South Korea) – 5,489 MWe

A beacon of South Korean nuclear technology, formerly Ulchin.

This massive plant is home to Korea's APR-1400 reactors, known for enhanced safety and efficiency. Two new reactors, Shin Hanul Units 1 & 2, are now operational, adding to its already significant capacity.

Index No. Project Name Country Name Capacity (MWe) Starting Date

01 Kashiwazaki-Kariwa Japan 7965 1985

02 Bruce Canada 6232 1977

03 Zaporizhzhia Ukraine 5700 1984

04 Hanbit (Yeonggwang) South Korea 5577 1986

05 Hanul (Ulchin) South Korea 5489 1988

06 Gravelines France 5460 1980

07 Palo Verde United States 3937 1986

08 Olkiluoto Finland 3900 1979

09 Fukushima Daiichi Japan 3800 1971

10 Chernobyl Ukraine 3600 1977

11 Tianwan China 3500 2007

12 Yangjiang China 3400 2014

13 Fangchenggang China 3300 2015

14 Hinkley Point United Kingdom 3260 2027

15 Flamanville France 3200 2007

16 Taishan China 3150 2018

17 Khmelnitski Ukraine 3000 1987

18 Kursk Russia 2950 1976

19 Leningrad Russia 2900 1973

20 Akkuyu Turkey 2800 2025

1. Kashiwazaki-Kariwa: The Sleeping Nuclear Giant

As of May 2025, the Kashiwazaki-Kariwa Nuclear Power Plant in Japan holds the title of the world's largest nuclear power plant by net electrical capacity, boasting a total of 7,965 megawatts (MW). Operated by Tokyo Electric Power Company (TEPCO), this facility comprises seven boiling water reactors (BWRs), including two advanced boiling water reactors (ABWRs) .

However, it's important to note that the plant has been offline since 2012 following the Fukushima Daiichi disaster. Efforts to restart the plant have been ongoing, with TEPCO seeking regulatory approval and local consent to resume operations. In December 2023, Japan's nuclear regulator lifted the operational ban on the plant, and TEPCO applied for approval to load nuclear fuel into reactor No. 7 in March 2024 . Despite these steps, the plant remains non-operational as of now.

Given Kashiwazaki-Kariwa's inactive status, the Kori Nuclear Power Plant in South Korea is currently the largest operational nuclear power plant globally, with a net capacity of 7,489 MW. Located in Busan and operated by Korea Hydro & Nuclear Power, the Kori plant consists of multiple pressurized water reactors (PWRs), including the Shin Kori units, which have been brought online progressively since 2011 .

Another notable facility is the Hanul Nuclear Power Plant (formerly Ulchin) in South Korea, which has a net capacity of 7,338 MW, making it the third-largest nuclear power plant worldwide .

RankRed

In summary, while Kashiwazaki-Kariwa remains the largest by design, the Kori Nuclear Power Plant currently holds the distinction of being the largest operational nuclear power facility in the world.

🌊 Location: Niigata Coast, Japan

💡 Capacity: World’s largest nuclear plant enough power for millions of homes

🏭 Reactor Count: 7 reactors (including two advanced models)

🛌 Status: Shut down since 2011

Why It’s Asleep:

1️⃣ 2007: 6.8 earthquake caused leaks and fires shut down for safety upgrades

2️⃣ 2011: Fukushima disaster led to a nationwide nuclear freeze

The Long Road Back:

⏳ Restart Plans: TEPCO aims to restart Units 6 & 7

🔧 Delays: Anti-terror upgrades and worker shortages push timelines to 2029 (Unit 7) and 2031 (Unit 6)\

🏞️ Local Resistance: Despite regulatory approval, local communities remain cautious

Why It Matters:

✅ 8% of Japan's Power: If reactivated, it could significantly cut fossil fuel use

✅ Trust Test: Would measure Japan's confidence in nuclear energy post-Fukushima

2. Bruce Nuclear: Canada’s Energy and Medical Giant

🌊 Location: Shores of Lake Huron, Ontario

💡 Total Capacity: 6,232 MW (enough for millions of homes)

🏭 Reactor Count: 8 CANDU reactors (Bruce A & Bruce B)

Why It’s Special:

✅ Huge Power Output: Provides 30% of Ontario's electricity

✅ Decades of Service: Running since 1977 with major upgrades for safety

✅ Medical Miracle: Produces Cobalt-60, used to sterilize medical equipment and treat cancer in 40+ countries

More Than Just Energy:

🌐 Global Impact: Supplies lifesaving isotopes worldwide

👷 Job Creator: Supports thousands of jobs in Ontario.

3. Zaporizhzhia Nuclear Plant: Europe's Largest Powerhouse in Danger

🌍 Location: Along the Dnieper River, Ukraine

💡 Total Capacity: Largest in Europe, powers millions of homes

📅 Operational Since: 1985 (all six reactors running by 1995)

Why It’s Important:

✅ Supplies 20% of Ukraine's Electricity – Half of the country's nuclear power

✅ Massive Output: Each reactor can power a medium-sized city

The Crisis:

⚠️ Under Russian Control: Taken over in March 2022

⚠️ Safety Risks: Ongoing conflict nearby threatens stability

⚠️ Global Concern: An accident here could impact multiple countries

IAEA’s Mission:

✔️ Stabilize Reactors: Prevent overheating and damage

✔️ Avoid Radiation Leaks: Keep the plant secure

✔️ Protect Ukrainian Staff: Brave workers continue operations despite risks

4. Hanbit Nuclear Power Plant: South Korea's Energy Powerhouse

🌏 Location: Jeollanam-do Province, South Korea

💡 Total Capacity: 5,875 MW (enough to power millions of homes)

🏷️ Former Name: Yeonggwang (renamed in 2013 after local fishermen's request)

The Reactor Lineup

1️⃣ Unit 1: The pioneer, started in 1986

2️⃣ Unit 2: Joined the family in 1987

3️⃣ Units 3 & 4: Added in the mid-90s

4️⃣ Units 5 & 6: The "new kids," running since 2002

Why It Matters

✅ Powering Millions: Generates about 6% of South Korea's electricity

✅ Community Impact: Name change to "Hanbit" (Korean light) shows local influence

✅ Safety Commitment: Faced challenges in 2012 with fake safety documents reactors paused for checks, proving safety is a top priority

Did You Know?

Hanbit's total power output is like running 5 million hairdryers at once!

🔋 Looking Ahead: Hanbit remains a crucial part of South Korea's clean energy strategy, balancing power and safety responsibly.

5. Hanul Nuclear Power Plant: South Korea's Energy Giant

🌏 Location: Uljin County, East Coast of South Korea

💡 Total Capacity: Over 8,000 MW (powers millions of homes)

🏷️ Formerly Known As: Uljin Nuclear Power Plant (renamed in 2013)

The Powerhouse Lineup

1️⃣ Original Six Reactors (1988–2005):

Units 1 & 2: 950 MW each

Units 3 to 6: 1,000 MW each

2️⃣ Shin Hanul (New Generation):

Units 1 & 2: 1,340 MW each (launched 2022–2023)

Units 3 & 4: Coming by 2033 currently under construction

Why It Matters

✅ Power for Millions: Keeps South Korean homes and industries running smoothly

✅ Homegrown Tech: Uses Korea's APR-1400 reactors 35% more powerful and super safe

✅ Clean & Reliable: Part of Korea's mission to cut carbon emissions

Did You Know?

The APR-1400 reactors are so advanced they can automatically shut down in emergencies—no human intervention needed!

🔋 Looking Ahead: With two more reactors planned, Hanul is set to remain a leader in clean, safe energy for South Korea.

6. Gravelines Nuclear Power Plant: France's Energy Workhorse

🌍 Location: Northern coast of France

💡 Power Output: 5,460 MW (powers ~5 million homes!)

🏆 First Powered Up: 1980–1985 (all six reactors running)

What Makes It Special?

✅ Record Holder: In 2010, it became the second plant worldwide to generate over 1,000 TWh of electricity enough to power France for two years!

✅ Unexpected Origins: Two of its reactors were originally built for Iran, but the 1979 revolution canceled the deal, so France kept them.

✅ Safe and Reliable: Only minor issues like a stuck fuel rod in 2009—strict maintenance keeps it running smoothly.

Looking Ahead

🚀 Possible Expansion: France is planning to add two new EPR2 reactors, boosting its power and extending its legacy.

Why It Matters

🔋 Supplies 6% of France's electricity a huge part of its clean energy.

🌎 Helps cut carbon emissions by reducing reliance on fossil fuels.

Fun Fact: Gravelines is so large, it even has its own fishing zone workers catch fish right in the cooling water channels! 🎣⚡

7. Palo Verde: America's Desert Power Giant

🌵 Location: Tonopah, Arizona (in the desert!)

💡 Power Output: 3,937 MW (powers 4 million homes)

🏆 Title: Largest U.S. nuclear power plant by electricity produced

What Makes It Special?

✅ No Ocean Needed! Uses treated wastewater from nearby cities to cool reactors recycling champ!

✅ Three Strong Reactors:

Unit 1: Running since 1986

Unit 2: Added in 1986

Unit 3: Added in 1988

✅ Built to Last: Operates until 2045-2047 (over 60 years of service!)

Who Runs It?

🔌 Arizona Public Service (APS) with partners from California, New Mexico, and Los Angeles.

Safety & Improvements

After operational hiccups in 2007, the plant fixed issues by 2009 and is now a top performer.

Why It Matters

⚡ Supplies clean, reliable power to the Southwest.

🌎 Reduces carbon emissions by replacing fossil fuels.

💧 Pioneers water recycling showing nuclear plants can thrive in dry areas.

Fun Fact: Palo Verde produces more electricity than most entire U.S. states!

8. Olkiluoto: Finland's Powerhouse Island

🌍 Where? Eurajoki, Finland

💡 Power Output: 3,380 MW (powers ~3 million homes)

🏆 Key Fact: Produces 31% of Finland's electricity

Meet the Reactors

1️⃣ OL1 & OL2 (1979 & 1982)

Type: Boiling Water Reactors (BWR)

Capacity: 890 MW each (like two giant electric kettles!)

Fun Fact: Reliable for over 40 years

2️⃣ OL3 (2023) – The New Superstar

Type: European Pressurized Reactor (EPR)

Capacity: 1,600 MW (Europe's most powerful single reactor!)

Construction: 18 years to complete (2005-2023)

Why It's Special

✅ Clean Energy Leader: Reduces reliance on fossil fuels

✅ Spent Fuel Storage: Special facility to store used fuel safely for 50+ years

✅ National Pride: OL3's launch marked a key moment in Finnish energy independence

Did You Know? The island hosts ONKALO, the world’s first deep geological nuclear waste repository (450m underground!)

In Simple Terms: This small Finnish island helps fight climate change while powering the whole country with advanced nuclear tech!

9. Fukushima Daiichi: From Powerhouse to Cautionary Tale

📍 Location: Ōkuma, Fukushima, Japan

⚡ Original Capacity: 4,696 MW (6 reactors)

📅 Operating Years: 1971–2011

What Happened Here?

✅Date: March 11, 2011

✅ Cause: 9.1 earthquake + tsunami knocked out power and cooling systems

✅ Result: 3 reactors melted down, hydrogen explosions occurred

✅Aftermath: Worst nuclear accident since Chernobyl (Level 7)

The Reactors’ Story

1️⃣ Unit 1: Oldest, first to fail

2️⃣ Units 2–5: Middle reactors

3️⃣ Unit 6: Youngest and strongest

All reactors shut down by 2014 and are now in complex decommissioning.

Current Challenges (2025)

✅Water Issue: Slowly releasing treated radioactive water into the Pacific (controversial but approved)

✅ Cleanup: Expected to take 30-40 more years

✅ Global Impact: Changed nuclear safety standards globally

Why It Matters

✅ Highlights the importance of safety backups

✅ Demonstrates that even advanced countries can face disasters

✅ Continues shaping global nuclear energy policies

10. Chernobyl: The Nuclear Disaster That Changed the World

📍 Location: Near Pripyat, Ukraine (then Soviet Union)

⚡ Original Capacity: 4,000 MW (4 reactors)

📅 Operating Years: 1977–2000

What Went Wrong?

✅ Date: April 26, 1986

✅ Cause: A failed safety test led to Reactor 4 exploding

✅ Impact: Worst nuclear accident ever; created a 30km Exclusion Zone still present today

The Reactors’ Story

1️⃣ Reactors 1–3: Continued running until 2000

2️⃣ Reactors 5–6: Never completed after the disaster

3️⃣ Reactor 4: Sealed under a giant steel dome in 2019

Cleanup Timeline

✅ 1986: First concrete sarcophagus built

✅ 2019: New Safe Confinement steel arch installed

✅ Future Goal: Full cleanup expected by 2065

Why It Still Matters

✅ Changed global nuclear safety standards

✅ Highlighted the need for transparency in nuclear operations

✅ The Exclusion Zone is now a surprising wildlife sanctuary

11. Tianwan: China’s Growing Nuclear Giant

📍 Location: Lianyungang, China

⚡ Current Capacity: ~6,000 MW (6 reactors)

🚀 Future Capacity: Over 9,000 MW with 8 reactors

How It Grew: Step by Step

1️⃣ Phase I (2007):

✅ Reactors 1 & 2: Russian VVER-1000 design

✅ Safety: Built with reinforced containment

2️⃣ Phase II (2018):

✅ Reactors 3 & 4: Upgraded Russian models

3️⃣ Phase III (2021):

✅ Reactors 5 & 6: China’s own ACPR-1000 design

4️⃣ Coming Soon:

✅ Reactors 7 & 8: New Russian VVER-1200—more powerful and safer

Why It Matters

✅ Cuts coal use, boosting clean energy

✅ Blends Russian and Chinese nuclear tech

✅ Powers homes and industries in Jiangsu Province

12.Yangjiang Nuclear Power Plant: China’s Clean Energy Powerhouse

🌏 Location: Guangdong Province, China

⚡ Total Capacity: 6,516 MW (powers ~15 million people)

🏗️ Operated by: China General Nuclear Power Group (CGN)

🌿 Purpose: Reducing coal use, boosting clean energy

Meet the Reactors

🔵 Units 1–4 (2014–2017):

✅ Design: CPR-1000 (upgraded French tech)

✅ Features: Enhanced safety upgrades

🟢 Units 5–6 (2018–2019):

✅ Design: ACPR-1000 (China's improved version)

✅New Tech: Advanced safety and digital controls

Why It Matters

✅ Cuts pollution, replacing coal power

✅ Strengthens China’s energy security

✅ Highlights China’s innovation in nuclear tech

13. Fangchenggang: China's Growing Nuclear Powerhouse

🌏 Location: Guangxi coast, China

⚡ Current Capacity: ~4,000 MW (powers 10 million homes!)

🔄 Operated by: CGN & Guangxi Investment Group

🌱 Goal: Cut China’s coal dependence

How It’s Growing

Phase 1 (2016):

✅ Units 1 & 2: CPR-1000 design, upgraded French tech

✅ Output: 1,000 MW each clean and reliable

Phase 2 (2023–2024):

✅ Units 3 & 4: Hualong One design China’s own tech

✅ More efficient and safer reactors

Coming Soon:

✅ Units 5 & 6: More clean power planned

Why It Matters

✅ Creates local jobs

✅ Powers homes with zero air pollution

✅ Showcases China’s nuclear tech leadership

14. Hinkley Point C: Britain’s Future Energy Giant

🌍 Location: Somerset, England

💡 Planned Power: 3,200 MW (powers ~6 million homes)

📅 Expected Opening: 2029–2030s (originally 2027)

💰 Cost: £31–34 billion

What’s Being Built?

⚛️ 2 EPR Mega-Reactors Europe’s safest design

🤝 Partners: EDF (66.5%) & CGN (33.5%)

🌱 Goal: 7% of the UK’s electricity clean and reliable

Why the Delay?

⏳ Construction challenges big projects, big risks

📈 Costs doubled from £18B to £34B

🌍 Still crucial for UK’s climate goals and energy security

The Bright Side

✅ Cuts 9 million tons of CO2 yearly

✅ Creates 25,000+ jobs during construction

✅ First new UK nuclear plant in 30 years

Did You Know? Its concrete shell is strong enough to withstand an airplane crash! ✈️

15. Flamanville: France's Nuclear Power Story

🌊 Location: Normandy coast, France

💡 Total Power: 4,250 MW (powers ~4 million homes)

Reactors at a Glance

✅Units 1 & 2 (1986/87): Reliable 1,300 MW each

✅ Unit 3 (2024): Next-gen EPR reactor with 1,650 MW

The Rollercoaster Project

⏳ Planned: 6 years (2007–2013)

📅 Actual: 17 years (2007–2024)

💰 Cost: From €3.3B to €13.2B—€10B over budget!

Why the Delay?

🔧 Technical hurdles

🛡️ Safety upgrades after Fukushima

🔩 First-of-its-kind design

Why It Matters

✅ Powers France with clean energy

🌍 Sets an example for European projects

Fun Fact: Its steel lid is as heavy as 16 blue whales! 🐋

16. Taishan: Home of the World's First Mega-Reactors

🌏 Location: Guangdong, China

⚡ Power: 3,320 MW (powers ~7 million homes!)

🏆 Record Holder: First operational EPR reactors

Meet the Giant Reactors

✅ Unit 1 (2018): 1,660 MW—equivalent to 1,000 wind turbines!

✅ Unit 2 (2020): Same powerful design with auto-shutdown safety

Why It's Special

✅ Cuts coal use, boosting clean energy

🔒 Self-cooling tech for extra safety

🌱 Showcases China's advanced nuclear tech

Fun Fact: Built in just 9 years faster than Europe’s projects!

17. Khmelnitsky Nuclear Power Plant: Ukraine's Energy Workhorse

🌻 Location: Netishyn, Western Ukraine

💡 Current Power: 1,900 MW (powers ~2 million homes)

🔧 Operator: Energoatom

Meet the Reactors

✅Unit 1 (1988): VVER-1000, Soviet-era design still going strong

✅Unit 2 (2005): Same design; took 19 years to complete

Coming Soon (2030?)

🚧 Units 3 & 4: Modern VVER reactors adding 2,070 MW another 2 million homes

Why It Matters

✅ Powers Ukraine’s grid securely

♻️ Reduces coal dependence

🛡️ Proven resilience during conflict

18. Kursk Nuclear Power Plant: Russia's Energy Transition

🏭 Location: Near Kursk city, Western Russia

⚡ Current Power: 2,000 MW from 2 reactors

🔄 Transition: Upgrading to modern reactors

The Original Reactors (1977-2024)

✅ 4 RBMK-1000 reactors (Chernobyl design, but upgraded)

✅Units 1 & 2: Retired after 45+ years

✅ Units 3 & 4: Active until ~2035

The New Generation (Kursk II)

✅ 4 VVER-TOI reactors planned

✅1,115 MW each stronger and safer

✅Under construction with 21st-century safety tech

Why It Matters

✅ Powers the Kursk region reliably

🛡️ Safer design, replacing outdated technology

⚡ More power with less fuel, boosting efficiency

19. Leningrad Nuclear Power Plant: Russia's Energy Evolution

🏭 Location: Sosnovy Bor, near St. Petersburg

⚡ Current Status: 2 operational reactors, transitioning to modern tech

The Original Reactors (1970s-2020s)

✅ 4 RBMK reactors (like Chernobyl, but upgraded)

✅Units 1 & 2: Retired after 45+ years

✅Units 3 & 4: Active until ~2026-2030

The New Generation (Leningrad II)

🚧 6 VVER-1200 reactors planned

✅ 2 units running (since 2018/2020)

✅2 more under construction

✅ Each with 1,150 MW capacity—stronger and safer

Why It Matters

✅ Powers St. Petersburg Russia's 2nd largest city

🛡️ 5x more safety systems in new reactors

🌱 Clean energy, reducing fossil fuel dependency

Did You Know? Cooling towers are visible from space!

Key Points:

✔ Clear transition from old to new

✔ Enhanced safety and capacity

✔ Major impact on Russian energy security

20. Akkuyu: Turkey’s Nuclear Leap (2025)

🌍 Where? Mersin, Turkey

💡 Power: 4,800 MW (10M homes!)

🚧 Status: Unit 1 launching 2025

Quick Facts:

✔ Turkey’s first nuclear plant

✔ 4 Russian VVER-1200 reactors

✔ 10% of Turkey’s electricity when complete

Why It Matters:

✅ Cuts fossil fuel use

✅ Creates 10,000+ jobs

⚠️ Earthquake-proof design

Challenges:

⏳ Delays (supply chain issues)

🌐 Geopolitical tensions

Fun Fact: Reactors can survive major quakes!

Why This Works?

✔ 50% shorter but keeps key data

✔ Retains viral elements (emoji hooks, fun fact)

✔ Balanced view (benefits + challenges)

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