N-Reactor Cost Soars 55%: What's Really Driving Nuclear's Price Problem

One Number, Two Different Diseases: Why Kudankulam and Rawatbhata Overran for Opposite Reasons

Here's what's actually happening: two nuclear projects just posted enormous cost overruns - Kudankulam at 55%, Rawatbhata at 86% - and it would be easy to read both as one story about "nuclear energy getting more expensive." That reading misses the point entirely, because these two overruns have almost nothing in common except the word "nuclear."

Kudankulam: A Supply Chain Shock With an Expiry Date

Kudankulam's reactors are Russian-designed VVER units, built through technical collaboration with Russia. When the Russia-Ukraine war disrupted global supply chains for components, financing and specialised equipment tied to Russian industry, Kudankulam's costs absorbed that shock directly - pushing Units 3 and 4 up 72.9% and Units 5 and 6 up 39.9%.

This is a geopolitical cost, not a design or execution flaw. It rises and falls with a specific, external, time-bound conflict - meaning it is, in principle, reversible once supply chains normalise or diversify.

Rawatbhata: A Domestic Reactor With No War to Blame The Rajasthan Atomic Power Project's

86% overrun tells a completely different story. Its reactors are indigenous Pressurised Heavy Water Reactors - Indian design, Indian components, no Russian supply chain exposure. There is no war explaining this number. An 86% overrun on a domestically built, domestically sourced reactor points toward structural issues in project execution: land acquisition delays, financing costs compounding over extended construction timelines or systemic underestimation at the sanctioning stage - the same execution problems that plague large Indian infrastructure projects generally, nuclear or not.

Why the Difference Matters for LCOE

Nuclear power's Levelised Cost of Electricity is dominated by capital cost - at least 60% of it, per the World Nuclear Association - which means construction-phase overruns don't just inflate a project budget, they permanently raise the price of every unit of electricity that plant will ever sell.

A temporary geopolitical shock at Kudankulam can ease as supply chains adjust. A structural execution problem at Rawatbhata will recur on the next indigenous reactor built the same way, project after project, regardless of what's happening in Ukraine.

For an aspirant, the exam-relevant insight is this: "nuclear cost overruns" is not one policy problem with one policy fix. Separating a geopolitical shock from a structural execution gap tells you whether India's nuclear expansion needs supply-chain diversification or project-management reform - and conflating the two, as the headline number invites you to, gets the diagnosis wrong before any solution is even proposed.