RNPP starts nuclear reaction in first unit

Rooppur Reaches First Criticality in Major Nuclear Power Milestone

Thebangladaily.com – Bangladesh moved closer to producing electricity from nuclear energy on Sunday as the first unit of the Rooppur Nuclear Power Plant began a controlled nuclear reaction at about 3:30pm. The development, known in the nuclear industry as “first criticality,” is a key technical stage before a reactor can begin supplying power.

At this point, the reactor is operating at extremely low power while its systems are assessed in carefully managed conditions. Engineers use the phase to confirm that safety equipment, control systems and other critical mechanisms respond as designed before the plant moves toward higher output and grid connection.

The Rooppur project is Bangladesh’s first nuclear power initiative. Its first unit’s progress places the country on the path to becoming the world’s 33rd nation to generate electricity from nuclear power once the facility is linked to the national grid.

Testing and Grid Connection Ahead

The first-criticality process is expected to take roughly 30 to 40 days. As reactor power is increased, the turbine is due to be brought into operation. The generator will then be connected to the national grid, allowing electricity to be supplied initially on a trial basis.

Power generation will not immediately begin at full scale. The plant is set to start at around 3 per cent of capacity, with output later raised step by step to approximately 20 to 30 per cent. Each increase will depend on the outcome of technical checks and operational testing.

If the results are satisfactory, the first unit could begin trial electricity supply to the national grid. Around 300MW is expected to be delivered on a trial basis by the end of December. Output would continue rising gradually after that initial connection.

Before regular commercial operation begins, the reactor will undergo further test production even after reaching full-capacity generation. The overall transition from initial grid supply to commercial production may require around seven to eight months.

Regulatory Approvals

The Bangladesh Atomic Energy Regulatory Authority approved the start of the nuclear reaction on November 8. Two additional approvals will still be required before electricity from the plant can be delivered to the national grid.

Such staged approvals are an important part of bringing a nuclear facility into service. First criticality does not mean that the plant has completed commissioning; instead, it signals that the reactor has entered a closely monitored operating phase in which its performance can be examined at very low power.

For readers, the distinction is significant. A reactor must demonstrate stable, controlled performance through several stages before it can reliably provide large-scale electricity. The planned gradual increase in output gives operators time to test the interaction between the reactor, turbine, generator and grid systems.

A New Source of Power for Bangladesh

The Rooppur Nuclear Power Plant has two units with a combined installed generation capacity of 2,400MW. About 2,300MW is expected to be generated from the two units. Construction and related work on the second unit are continuing alongside commissioning activity for the first.

Once both units are connected to the grid, the facility is expected to add a major new source of electricity to Bangladesh’s power system. The project is also expected to help reduce load-shedding and lower the need for imported fuels, creating potential savings in foreign exchange.

Nuclear generation is expected to cost less than electricity produced using oil or coal. Its role in the energy mix could therefore extend beyond adding capacity: it may also help diversify how Bangladesh produces power and reduce reliance on fossil-fuel-based generation.

The project has broader technological significance as well. Operating a nuclear power plant requires specialized safety procedures, regulatory oversight, skilled personnel and long-term technical capability. The commissioning of Rooppur’s first unit represents an important step in building that capacity within Bangladesh.

What First Criticality Means

First criticality occurs when a reactor achieves a self-sustaining nuclear chain reaction under controlled conditions. It is not the same as full electricity production. At this early stage, reactor power remains very low, allowing operators to observe the behavior of systems and verify their performance before moving to later commissioning milestones.

From there, the plant must progress through power escalation, turbine operation, generator synchronization and trial supply to the grid. The sequence is designed to ensure that each part of the facility performs properly before the reactor is allowed to produce electricity at higher levels.

Sunday’s achievement therefore marks both a technical breakthrough and the beginning of an intensive testing period. If the remaining approvals and operational checks proceed successfully, Rooppur’s first unit will move from controlled reaction to trial generation and eventually commercial electricity supply.

With the second unit also advancing, the project is set to play a significant role in Bangladesh’s future power landscape. The completion of both units would bring substantial generation capacity to the national grid while opening a new chapter in the country’s use of nuclear technology.