Akkuyu Unit 1 primary circuit passes hydraulic pressure testing

What happened

Akkuyu Nuclear Power Plant has finished hydraulic pressure testing on the reactor installation’s primary circuit at Unit 1 in Mersin. The work examined the circuit’s resistance under elevated operating conditions and has met the criteria specified for the VVER-1200 reactor design.

Pressure in the circuit was raised to 24.5 MPa, which Enerji Günlüğü reported was approximately 1.5 times the reactor installation’s normal operating pressure. In the first part of the procedure, the water temperature in the circuit reached 135°C.

For the test, operators filled the primary circuit with chemically demineralised water. Main circulation pump units established the required pressure and temperature conditions. Personnel followed the status of equipment and pipelines from the main control room using data from the automation control system.

What readers should watch next: the reported result is a further technical step on the route to Unit 1’s first criticality. No timing for that milestone was given in the source.

Why it matters

The primary circuit is an essential part of a reactor installation. Its equipment, piping and welded joints must meet demanding technical requirements because their reliability is important to the safe operation of the generating unit.

Hydraulic testing provides an integrated check of the circuit after installation work, welding and commissioning activities. At Akkuyu Unit 1, the completed test indicates that the primary-circuit assembly has satisfied the applicable VVER-1200 design requirements at the reported test conditions.

For those monitoring Türkiye’s nuclear programme, the result marks progress at the first unit rather than commercial operation or first criticality. The source does not state a date for either subsequent stage, so the next material update will be confirmation of further commissioning progress.

Test conditions and monitoring

• The primary circuit was charged with chemically demineralised water.
• Main circulation pumps were used to create the test environment.
• Pressure rose to 24.5 MPa during the procedure.
• Water reached 135°C in the initial test stage.
• Control-room staff monitored equipment and pipelines through automation-system data.

The source characterises the outcome as confirmation that the VVER-1200 design criteria were fulfilled. It does not provide further technical measurements, a test date or a schedule for the next commissioning phase.