RAPP-8 begins fuel loading, commercial operations targeted this fiscal

The 700 MWe indigenous pressurised heavy water reactor will next approach criticality and begin power generation before entering commercial operation in FY27 at Rawatbhata

Unit 8 of the Rajasthan Atomic Power Project (RAPP) at Rawatbhata has entered a crucial stage of commissioning with the start of initial fuel loading (IFL), bringing the 700 MWe indigenous pressurised heavy water reactor (PHWR) closer to beginning commercial electricity generation.

 

Nuclear Power Corporation of India Limited (NPCIL) on Sunday said initial fuel loading began after the unit received regulatory permission from the Atomic Energy Regulatory Board (AERB) and completed the prescribed pre-commissioning requirements.

 

The start of fuel loading marked the transition of the reactor from the construction and system-testing stage to the nuclear commissioning phase. Before fuel could be loaded, the reactor and its associated systems had undergone integrity checks, safety evaluations, audits and site-readiness reviews, with AERB assessing whether the unit met the conditions required to proceed.

 

“It is a major milestone in the construction and commissioning journey of a nuclear power reactor. The commencement of initial fuel loading at the fourth indigenous 700 MWe PHWR represents an important achievement. It further strengthens the standardisation of the 700 MWe PHWR design and supports its continued deployment in fleet mode,” NPCIL said in a statement.

 

RAPP-7 and 8 comprise two indigenous 700 MWe PHWRs. After IFL, the next major steps for Unit 8 will include the first approach to criticality (FAC), marking the start of a controlled fission chain reaction, followed by the beginning of power generation. The unit is expected to begin commercial operation during the current financial year.

 

“The fuel loading places the reactor on the path towards achieving criticality, the stage at which a controlled nuclear fission chain reaction is established. Once fuel loading and associated commissioning activities are completed, the next major milestone will be the FAC. This will be followed by a carefully controlled increase in reactor power, during which various systems and operating parameters will be tested before the unit can enter commercial operation,” said an official.

 

RAPP-8 is the fourth reactor in the series of 16 indigenous 700 MWe PHWRs being developed in the country. The first two reactors in this series — Kakrapar Atomic Power Project Units 3 and 4 in Gujarat — entered commercial operation in 2023-24, while RAPP-7 followed in March 2025. The progress of these units is important for India’s strategy of deploying a standardised reactor design in fleet mode rather than developing each reactor as an entirely separate project.

 

The standardisation is expected to facilitate the repeated deployment of the 700 MWe design and provide greater predictability in construction, commissioning and operation as more reactors in the series are brought into service. The reactors incorporate advanced safety features and are being developed as part of India’s indigenous nuclear power programme.

 

NPCIL currently operates 24 nuclear power reactors with an aggregate capacity of 8.78 GWe, while another 17 reactors with a combined capacity of about 13 GWe are at various stages of implementation. The addition of RAPP-8’s 700 MWe will not only increase NPCIL’s installed nuclear generation base but also add another operating unit to India’s expanding fleet of indigenous 700 MWe PHWRs.

 

The Centre has set an ambitious long-term target of developing 100 GWe of nuclear power capacity by 2047. NPCIL has indicated that it aims to contribute more than half of this envisaged capacity.