Kudankulam Nuclear Power Plant : Overview

• The Kudankulam Nuclear Power Plant (KKNPP), located in Tamil Nadu’s Tirunelveli district, is India’s largest nuclear power facility and a critical component of long-term national energy planning. 
• KKNPP is developed jointly by the Nuclear Power Corporation of India Limited (NPCIL) and Russia’s Atomstroyexport using VVER-1000 pressurised water reactors.
• Construction began in March 2002, and once all 6 units are commissioned, the complex will generate 6,000 MW of electricity. 
• Unit 1 was connected to the grid in October 2013, followed by sequential progress of other units, making Kudankulam a major contributor to the southern electricity grid.

Historical Evolution

• The project traces its origin to a 1988 Indo-Soviet agreement signed by Rajiv Gandhi and Mikhail Gorbachev for constructing two reactors.
• The fall of the Soviet Union and global nuclear restrictions under the Nuclear Suppliers Group stalled progress for almost a decade. A revival came in 1998, renewing India–Russia cooperation in civilian nuclear technology.
• Construction began in 2002, supported by the creation of a dedicated port in 2004 to transport heavy reactor components safely. Later discussions explored additional reactors, but local opposition and technical considerations slowed the process.
• Units 3 and 4 received regulatory clearances in 2017, and construction on Units 5 and 6 began in 2021. Commissioning of the final two units is expected between 2026 and 2027.

Reactor Units at Kudankulam

KKNPP is designed for six VVER-1000 reactors. Two are functional, while the remaining four are under construction.

• Unit 1: Operational since 2014.
• Unit 2: Operational since 2016.
• Unit 3: Construction began in 2017; expected commissioning 2026.
• Unit 4: Under construction alongside Unit 3; commissioning expected soon after.
• Unit 5: Concrete pour completed in 2020; expected by late 2026.
• Unit 6: Under construction since 2021; expected by 2027.

Key Features of the Kudankulam Reactors

The Kudankulam plant uses Russian VVER-1000/V-412 reactors (AES-92 design), a proven pressurised water reactor model with strong safety and performance characteristics.

Key features include:

• Thermal capacity of 3,000 MW per unit.
• Gross electrical output of ~1,000 MW per reactor (917 MW net).
• Double containment structures for enhanced accident resistance.
• Post-Fukushima safety improvements, including emergency core-cooling systems.
• Updated design and safety standards incorporated in Units 3–6 for higher efficiency.

Currently, the plant provides 2,000 MW of operational nuclear power, making it India’s largest nuclear complex.

Criticism and Public Concerns

• Kudankulam has been at the centre of environmental and safety debates for decades.
• Opposition began as early as the late 1970s and intensified after the Fukushima disaster in 2011, when thousands of residents from coastal villages organised protests. Concerns centred on evacuation feasibility, environmental impact, and radiation risks.
• A PIL filed in 2011 demanded independent safety review, but the Supreme Court allowed the project to proceed in 2013, considering national energy priorities and existing safety assurances.
• Community resistance persisted in several areas, and allegations surfaced of external funding influencing protests, while various civil society and church groups supported local concerns.