Rooppur plant achieves first nuclear chain reaction in Unit 1

The first controlled nuclear chain reaction at Unit 1 of the Rooppur Nuclear Power Plant was achieved at 3:34pm on today (11 October), marking a major milestone in Bangladesh’s first nuclear power project as the reactor entered its initial criticality stage ahead of electricity generation.

The chain reaction marks the first of four stages before the plant can generate electricity. The subsequent stages involve thermal energy transfer, mechanical energy conversion, and finally electricity generation and supply to the national grid.

Md Anwar Hossain, secretary of the Ministry of Science and Technology, confirmed the development to The Business Standard, saying the reaction was initiated after the required compliance procedures, technical parameters and external certifications had been completed.

“Today at 3:34pm, we were able to achieve the chain reaction smoothly. By the grace of Allah, the parameters were within the desired ranges, and the reactor was very stable,” he said.

Inside a nuclear reactor, a controlled chain reaction splits uranium atoms through nuclear fission, releasing energy as heat. That heat is used to generate steam, which drives turbines to produce electricity.

The achievement marks the beginning of the reactor’s nuclear power generation process, but electricity is not yet being supplied to the national grid.

Hossain said the team had completed the preparations and followed the required protocols before starting the process. Work began the previous night, and the chain reaction was successfully established on Sunday afternoon.

Russian specialists, Bangladeshi experts and other technical specialists were present to observe the process and assess the reactor’s performance, he added.

“They observed everything and confirmed that the transition was smooth and successful,” Hossain said.

He said nuclear fuel had already been loaded into the reactor and the fission process had now begun.

Further tests needed before power generation

The plant must undergo several more technical tests and follow step-by-step safety protocols before progressing towards electricity generation.

The reactor’s transition to criticality is an important stage in commissioning the plant. During this phase, engineers monitor neutron activity and other operating parameters to ensure the nuclear chain reaction remains controlled and stable.

The next steps will involve further testing and technical checks under established protocols before the unit can advance towards power generation and eventual connection to the national grid.

Hossain said technical teams were working to complete the remaining processes as quickly as possible, while stressing that every stage must comply with the required procedures and safety standards.

Plant designed to generate 2,400MW

The Rooppur Nuclear Power Plant in Ishwardi, Pabna, is being built with two VVER-1200 pressurised water reactor units using Russian technology supplied by Rosatom.

Each unit has a planned generation capacity of 1,200 megawatts (MW), giving the plant a combined capacity of 2,400MW.