The new 330 kV overhead cable line connects the 330 kV outdoor switchgear at LNPP 1 with the 330 kV gas-insulated switchgear and control gear at LNPP 2. This is necessary to ensure exchange of the generated power between the first and the second plants.

The overall length of the line is about 5 kilometres. Its overhead part consists of 14 unique reinforced supports whose dimensions comply with the standards for and are adjusted to components of 500 kV power transmission lines. Each support weights approximately 70 tonnes and is made of more than 2,000 parts. The structures were assembled locally with cranes. Supports are designed and executed with the prospect of suspension of the second circuit during construction of Power Units 3 and 4 of the LNPP 2. The construction part (foundations of supports) was performed in advance in summer. Construction of the overhead line took 3 months.

Today, the SEM team is implementing the second stage of the installation of the power output system. This includes construction of a 330 kV cable line between the 330 kV gas-insulated switchgear at the LNPP 2 and the 750 kV outdoor switchgear at the LNPP 1. The horizontal directional drilling and the construction part of sleeve sections have been completed. At presently, they route cables and install coupling sleeves into the sleeve wells.

The third stage will include connection of the cable line to the 750 kV outdoor switchgear of the LNPP 1. For this purpose, 750 kV coupling autotransformers and 750 kV shunt reactors, seven 750 kV cells of high-voltage circuit breakers, relay protection and automatic controls, the 35 kV switchgear and control gear, and the power supply system for auxiliary loads of the substation shall be installed on the 750 kV outdoor switchgear.

The standard time period for such works is 1.5 years, but because the 24-hour operation has been timely arranged and additional special equipment was engaged (cranes with load capacity of 200 tonnes, heavy dump trucks, Casagrande drill rigs), the entire cycle of construction and installation shall not take more than 9 months.


The TITAN-2 holding is a Russian group of companies that builds nuclear facilities. Organisations of the holding perform the whole cycle of works, from development of basic design documentation to facility commissioning.

The TITAN-2 holding is the general contractor for construction of the new power units of the Leningrad NPP. At the construction site, the organisations of the holding perform all civil construction, installation, and electric installation works.

The holding is the main contractor at the construction of the Hanhikivi 1 NPP in Finland and of the Akkuyu NPP in Turkey.