The Petrozavodsk branch of AEM-Technologies JSC (part of Rosatom’s mechanical engineering division Atomenergomash) said on 8 July it had carried out cargo tests of two casings for the main circulation pumping units (MCPU) for unit 2 of the Akkuyu NPP being built in Turkey. The purpose of the cargo tests is to control the strength of the welded seams between the trunnions and the reactor coolant pipeline (RCP) body.
The pump body is lifted by a crane using three trunnions; additional loads weighing 40 tons are attached to the bottom of the traverse. Taking into account the mass of the body itself, the total load on the trunnions reaches 72 tons. The structure is raised above the floor to a height of about 10 cm and held for 10 minutes. After removing the load, a visual-measuring control is carried out to ensure the absence of damage to the welded seams. The RCP housings then go for machining and further checks in accordance with the product passport, including a control assembly with a spacer, as well as hydraulic tests.
The main circulation pump is circulates the coolant from the reactor to the steam generators and operates under a coolant pressure of about 160 atmospheres and at a temperature of 300 degrees. The mass of one body is more than 31 tons with a height of 3.5 metres and a width of over 3 metres. A suspension element is attached to the body, the so-called spacer, together with it, the weight of the product reaches 48 tons.
The Akkuyu NPP construction project is being implemented by Akkuyu Nuclear following an intergovernmental agreement signed between Russian and Turkey in 2010. The Akkuyu NPP, with four VVER-1200 units, is being constructed on a build-own-operate basis by Rosatom, with commissioning of the first unit planned for 2023.