Overview
On 6 April 2026, Prime Minister Narendra Modi announced on X that the PFBR has attained criticality. This is the first time a fast breeder reactor in India has reached a self‑sustaining nuclear reaction, paving the way for larger scale use of indigenous thorium resources.
Key Developments
- PFBR reached criticality after fuel loading on 18 October 2025.
- Design capacity: 500 MWe with a projected life of 40 years.
- Six additional 600 MW fast breeder units (FBR‑600) are planned, with twin units to be co‑located at Kalpakkam.
- The FRFCF is slated for completion by December 2027.
Important Facts
India’s nuclear fleet currently comprises 18‑20 PHWRs, totalling about 7.48 GW(e). These reactors generate the plutonium needed for the second stage, where fast neutrons in the PFBR convert fertile U‑238 into fissile Pu‑239. The ultimate goal is to breed U‑233 from abundant thorium‑232.
The PFBR uses MOX fuel and a blanket of U‑238. Its coolant is liquid