Safety confirmed and power delivered: tests were completed on the reactor containment structure and the main transformers were brought online at Unit 1 of the Rooppur Nuclear Power Plant under construction, bringing the plant closer to commissioning.
Tightness and integrity tests were successfully completed on the containment structure of Rooppur Unit 1, which is being built by Rosatom’s engineering division in Bangladesh. The tests confirmed full compliance with design specifications and the highest safety standards.
During the testing, pressure inside the containment was raised to the design level of 4.6 kgf/cm² (approximately 0.45 MPa) using compressors. This allowed engineers to assess the structure’s airtightness and its ability to withstand internal loads that could occur in emergency situations.
The airtight containment is designed to prevent the release of radioactive materials into the environment in case of an accident, keeping them inside the containment structure. It also protects the reactor from external impacts.
“Some of the operations conducted during these tests are one-off and carried out only once, after all construction and installation work in the reactor building has been completed. Their results confirm that the airtight containment fully meets all design and regulatory requirements. This is an important milestone on the path to commissioning the first power unit and proves the high quality of work at all stages of construction,” said Alexey Deriy, Vice President for Bangladesh Projects at AtomStroyExport.
Also at Rooppur Unit 1, step-up transformers and auxiliary transformers have been successfully put into operation.
The step-up transformers are among the most critical components of the power unit: they convert 24 kV generated by the turbine generator into 400 kV, enabling electricity to be fed into the national grid. The transformer can transmit up to 1,599 MW of power—more than the unit’s own output of 1,200 MW. Each phase of the transformer weighs approximately 400 tonnes. More than 150 kilometers of cable were required for its connection.
Simultaneously, the station service transformers were connected to supply power to all internal systems of the power unit. The transformers operate in two modes, either receiving electricity from the external grid or drawing it directly from the generator during unit operation. Previously, internal consumers were powered through backup transformers, but now the main power supply is employed.
“Connecting the transformers is a major milestone made possible through precise coordination among all project stakeholders. The team handled the challenges of difficult logistics and climate conditions excellently,” Alexey Deriy said.
In the near future, the Rooppur NPP will undergo a series of hot functional tests using heated coolant from the primary circuit and steam under nominal parameters.
Various reactor safety modes will be tested, including the activation of clean steam relief valves. The noise accompanying these tests is an ordinary event and completely safe for the local population.
Safety remains Rosatom’s top priority, with all mandatory standards and requirements being strictly met.
Photo by: Rosatom Engineering Division
