The first VVER-1200 reactor at the first power unit of the Akkuyu NPP in Turkey successfully passed hydraulic tests of the primary circuit for strength. The pressure during the test was raised to 24.5 MPa – approximately one and a half times higher than the operating pressure, which is about 16 MPa.

The primary circuit includes the reactor, main circulation pumps, steam generators, pressurizer, and main circulation pipeline. During operation, demineralized water circulates through it: it heats up in the reactor and transfers heat to the secondary circuit through steam generators. The coolant temperature in operating mode can reach 330 °C.

For the tests, the circuit was filled with chemically demineralized water, and then the necessary pressure and temperature were created using the main circulation pump units. At the initial stage, the water temperature was 135 °C. The condition of the equipment and pipelines was monitored from the unit control room based on data from the automated process control system.

According to the press service of AKKUYU NUCLEAR JSC, the project criteria for the VVER-1200 reactor plant were met following the inspection. Hydraulic tests confirm the strength of the circuit elements and the quality of the installation and welding work before further commissioning operations.

The Akkuyu NPP is being built in Turkey according to a Russian project and includes four power units, each with a capacity of 1200 MW. The successful completion of the primary circuit inspection is another stage in preparing the first unit for operation, but it does not yet mean the station is ready to generate electricity.