Unit-1 of the Rooppur Nuclear Power Plant has reached its minimum control level, the Embassy of Russia in Bangladesh said today (13 October) in a Facebook post.
This means that a self-sustaining, controlled nuclear chain reaction has begun in the reactor for the first time, it said.
The next stage is testing the reactor at various power levels, followed by connection of the unit to the national power grid, the embassy added.
"Reaching the minimum control level is an important milestone in the implementation of the Rooppur NPP project and a major achievement for the entire team," said Alexey Likhachev, director general of Rosatom, the Russian state corporation headquartered in Moscow that is building the plant.
"We expect [connection to the Bangladesh power grid] to occur by the end of November," he added.
The first controlled nuclear chain reaction at Unit 1 of the Rooppur Nuclear Power Plant was achieved on Sunday (11 October), a major milestone for Bangladesh's first nuclear power project as the reactor entered its initial criticality stage ahead of electricity generation.
The chain reaction is the first of four stages before the plant can generate electricity. The next stages are thermal energy transfer, mechanical energy conversion and finally electricity generation and supply to the national grid.
According to Md Anwar Hossain, secretary of the Ministry of Science and Technology, the reaction was initiated after the required compliance procedures, technical parameters and external certifications had been completed.
Inside a nuclear reactor, a controlled chain reaction splits uranium atoms through nuclear fission, releasing energy as heat. The heat generates steam, which drives turbines to produce electricity.
Russian specialists, Bangladeshi experts and other technical specialists had been present to observe the process and assess the reactor's performance, Anwar added.
He said nuclear fuel had already been loaded into the reactor and the fission process had now begun.
Anwar said technical teams were working to complete the remaining processes as quickly as possible, but stressed that every stage must comply with the required procedures and safety standards.
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 capacity of 1,200 megawatts, giving the plant a combined 2,400MW.