At power unit No.1 of the Rooppur NPP, which is being built in the People's Republic of Bangladesh by the Rosatom State Corporation Engineering Division, tightness and strength tests have been successfully conducted at the containment of the reactor compartment. The tests confirmed full compliance with the design requirements and the highest safety standards of the reactor containment.During the tests, a compressor was used to increase the pressure inside the containment to the design value of 4.6 kgf/cm² (which corresponds to approximately 0.45 MPa) and a series of tests were conducted to confirm the structure’s tightness and ability to withstand internal loads that occur in abnormal conditions.The tests were successful to confirm that the containment complies in full scope with the design requirements. This is especially important at the stage of preparation for nuclear fuel loading, since the containment acts as the last protective barrier in the event of a hypothetical accident.The containment is a physical barrier made of pre-stressed reinforced concrete with an internal sealing steel lining. It is designed to prevent the release of radioactive substances into the environment in the event of an emergency and to localize them inside the containment, as well as to protect against possible external impacts.“A number of operations are unique and carried out once during these tests, only after the construction and erection works have been completed in the reactor building. The tests results confirm that the containment system fully complies with all design and regulatory requirements. This is an important step towards commissioning of power unit 1 which testifies to high quality of work at all stages of construction,” said Alexey Deriy, Atomstroyexport JSC Vice President for Projects in Bangladesh.As soon as these tests are completed, the NPP will proceed to a series of hot media tests, namely, the primary coolant circuit heated to rated values and the generated steam.Various safety modes of the NPP operation will be tested, including the operation mode of the devices providing steam discharge into the atmosphere. The tests are accompanied at the NPP by noise which is planned and absolutely safe for the public.Rosatom's most important priority is safety, therefore the project focuses on meeting all mandatory standards and requirements.The Rooppur NPP equipped with two VVER-1200 reactors of the total 2400 MW capacity is being constructed under the Russian design 160 km from Dhaka, the capital of Bangladesh, in accordance with General Contract dated December 25, 2015.