Slovenske elektrárne has successfully tested the primary circuit pressure at the Mochovce 3 nuclear power plant, under construction in Slovakia.

During the test, the unit’s six steam generators and pipelines withstood 10 minutes of pressure of up to 19.12MPa, almost 190 times the normal atmospheric pressure.

“We filled the primary circuit system with water and gradually pressurised it to the required level. The test included 208 valves, whose hermetic seal enabled us to reach such a high testing pressure,” explained John Clark, Mochovce 3&4 project director.

“We demonstrated that the system and components can safely hold 1.5 times normal operating pressure, inspected all relevant equipment and successfully tested remote operations from the control room,” Clark added.

SE said it will now continue to prepare Mochovce 3 components and systems for cold hydrostatic testing, which aims to verify the integrity of weld points and interfaces associated with the equipment and pipes of all those pressure-containing components ( pressure vessels, piping, pumps, and valves) relating to the reactor coolant system.

Mochovce 3 is almost 94% percent complete, while Mochovce 4 is at 80%, according to SE. The units are expected to start up in 2018.