The first large research reactor of India that uses U-233 as fuel is

KAMINI (Kalpakkam Mini Reactor) is the first large-scale research reactor in India to utilize Uranium-233 (U-233) as its primary fuel [t2][t8]. Commissioned in 1996 at the Indira Gandhi Centre for Atomic Research (IGCAR) in Kalpakkam, it is a 30 kWth tank-type reactor [t3][t7]. KAMINI is significant as it represents a key milestone in the third stage of India's three-stage nuclear power program, which focuses on utilizing the country's vast thorium reserves [t6][t10]. The U-233 fuel used in KAMINI is produced by the irradiation of thorium in other reactors, such as the Fast Breeder Test Reactor (FBTR) or CIRUS [t6][t8]. While other reactors like the PURNIMA series conducted criticality experiments with various fuels, KAMINI remains the definitive research reactor dedicated to U-233 fuel applications, including neutron radiography and material testing [t2][t10].