Unit 1 of Bangladesh's Rooppur Nuclear Power Plant Achieves First Criticality, Realizing First Nuclear Fission Chain Reaction

Unit 1 of the Rooppur Nuclear Power Plant, Bangladesh's first nuclear power plant, officially initiated its first nuclear fission reaction on the afternoon of October 11, marking a breakthrough milestone for the country's first major nuclear energy project.

Md Anwar Hossain, Permanent Secretary of the Ministry of Science and Technology of Bangladesh, confirmed to the media that, after obtaining formal approval from the nuclear safety regulatory authority, the unit successfully initiated a self-sustaining nuclear fission chain reaction at approximately 3:34 p.m. that day.

Hossain stated that the on-site commissioning team conducted the fission reaction startup operation at Unit 1 for the first time that day, and the entire startup process proceeded very smoothly, with all key operating parameters fully meeting the initial engineering design requirements.

The achievement of this milestone marks the reactor's formal attainment of First Criticality, meaning the reactor established a stable critical condition at its minimum thermal power level and achieved a self-sustaining continuous nuclear fission chain reaction for the first time.

On-site engineering technicians noted that the operations and commissioning team is closely monitoring reactor core parameters, dedicated safety systems, and control system equipment status throughout the process. The entire physical startup phase, including first criticality, is expected to last approximately 30 to 40 days, after which the unit's power level will be gradually increased based on the results of a series of physics tests.

The Bangladesh Atomic Energy Regulatory Authority (BAERA) formally issued the "B-2 Phase" commissioning license last Thursday, approving Unit 1 to initiate the nuclear fission reaction procedure. Mahamudul Hasan, Chairman of the authority, stated that only after completing nuclear fuel loading and all B-1 Phase tests and confirming their qualification did the regulatory body grant approval for the project to proceed to the B-2 Phase in accordance with regulations.

Hasan also emphasized that after successfully completing all scheduled tests in the B-2 Phase, the unit must still undergo further regulatory review and obtain the corresponding license in accordance with regulations before formally commencing power generation and grid connection.

Dr Md Zahedul Hassan, Managing Director of the Nuclear Power Plant Company Bangladesh Ltd, explained that the thermal energy released by nuclear fission will drive the working fluid to convert into high-pressure steam, which in turn drives the turbine-generator set to achieve electrical output; currently, operators will continue to closely monitor the reactor's operating conditions to strictly ensure that all physical parameters and safety standards are fully under control.