Russian manufacturers are dispatching several components to Turkey's first nuclear power plant, Akkuyu, which is currently the largest nuclear construction site in the world with 13,000 people working on a daily basis on the site that will house four large reactors.

Akkuyu 2's reactor pressure vessel in transit (Image: OMZ Group)

The first reactor at Akkuyu began construction in April 2018 and is scheduled to start up in 2023. It has already had major components for its reactor and primary coolant circuit installed.

Last week, Rosatom's main manufacturing subsidiary Atomenergomash announced it had made most of the components for one of Akkuyu 1's passive safety systems, the so-called SPZAZ tanks. These large metal tanks are installed above the reactor and steam generators. If the pressure in the reactor coolant system drops below a certain level, a solution of boric acid held in the SPZAZ tanks would flow automatically into the reactor core. Boric acid cuts reactivity and therefore heat generation in the reactor core by absorbing neutrons. The tanks are made to hold 120 cubic metres of boric acid solution each.

Atomenergomash said it has made seven of the eight SPZAZ tanks for Akkuyu 1, and the final one will be complete in time for shipment in December.

Akkuyu 2 is about one year behind unit 1 and should soon receive its reactor pressure vessel and main circulation pump. Its steam generators were shipped in August.

The reactor pressure vessel is thought of as the heart of the power system, housing the fuel assemblies and reactor internals, as well as being the central part of the water coolant and steam production system. The vessel for Akkuyu 2 has now begun its journey to the site, according to its manufacturer OMZ Group, which undertook the work for Atomenergomash at its Izhora plant.

OMZ said the cylindrical vessel is 12 metres long and 4.5 metres wide and made of steel some 20 centimetres thick. It weighs 334 tonnes. It was dispatched from Izhora on a barge to Saint Petersburg where it will be loaded on a ship for transport to Akkuyu, on Turkey's Mediterranean coast.

Meanwhile, at Atomenergomash's Petrozavodsk plant, the main circulation pump for Akkuyu 2 was assembled and checked. This component ensures the circulation of coolant through the reactor vessel and steam generators and therefore has an important safety role. Built to operate at temperatures of 300°C and withstand pressures of 16 MPa, the roughly spherical pump is 3.5 metres in diameter and weighs 48 tonnes when fully assembled. It will be given protective coatings and painted before shipment.

Manufacturing of Akkuyu 3's reactor pressure vessel continues at Atomenergomash's Volgodonsk plant.

Akkuyu is being built by Russia's state nuclear company Rosatom. The company's internal magazine, Strana Rosatom, said it is the world's largest nuclear construction site, with 13,000 people working on a daily basis towards four large reactors. Units 1, 2 and 3 are officially under construction, while unit 4 is at a preparatory stage and received authorisation to pour first concrete in October.

Researched and written by World Nuclear News