State nuclear corporation Rosatom said the component, with a weight of 322 tonnes and a height of 12 metres, took about 12 hours to lift into place.
The internal containment will consist of 12 parts when completed. Workers will now begin welding the first and second tiers together.
After installation of all tiers is complete, concrete will be poured on top and the containment will be tested for leaks.
Rosatom said the reactor buildings of the Akkuyu nuclear units will be equipped with two-layer containments.
The $20bn Akkuyu, the first commercial nuclear power station in Turkey, is being built by Russian state-owned nuclear corporation Rosatom under a contract signed in 2010.
The station will have four Generation III+ VVER-1200 units, with the first expected to come online in 2023 and a further unit starting every year afterwards.