Headrace Tunnel Repair Completed at the Borisoglebskaya HPP of TGC-1


TGC-1 has completed main and auxiliary equipment repairs at the Borisoglebskaya HPP, the world’s most northerly underground hydroelectric power plant. Among other tasks, the company’s specialists drained and repaired the headrace tunnel, which was really unique.

“The diversion tunnel is 817 meters long. To ensure compliance with applicable regulations, it is drained on a regular basis so that specialists could examine the tunnel and check its condition, remove muck, rock debris and trash, check the condition and antirust protection of the caisson door and overhaul the trash rack structures,” said Andrey Nikitin, manager of the Borisoglebskaya HPP in the Paz HPPs Cascade of TGC-1. “It took us 15 days to drain the tunnel and complete the repair of the auxiliary equipment, such as valves, pipes, boulder rack structures, which cannot be worked with when the tunnel is full. It should be noted that no such work has been done for nine years.”

Simultaneously with the drainage work, hydroelectric unit 1 was put under maintenance, while the second unit was down. By now, the tunnel has been filled with water, which means that it again can be converted into electricity by the Borisoglebskaya HPP’s hydroelectric units.