DUSHANBE, September 13, 2010, Asia-Plus  -- Installation work at Unit 8 of the Norak hydroelectric power plant (HPP) has been completed, Asia-Plus has learned from the source at Barqi Tojik power holding (Tajik electricity supplier).

“Balancing and commissioning will start after repair of the unit’s rotary valve,” he said, noting that spare parts for the rotary valve were delivered from Turboatom (Ukraine).

We will recall that reintroduction of Unit 8 of the Norak hydroelectric power plant (HPP) into operation scheduled for late August has been for an uncertain term.

Modernization will allow increasing the unit’s capacity to 350 megawatts.  In 2009, the rotor of Unit 3 was replaced and modernization allowed increasing its capacity to 335 megawatts.

Barqi Tojik and Ukraine’s Turboatom signed a contract on modernization of Norak HPP''s units in Dushanbe in October 2009.  Modernization will increase the station’s capacity by 10 percent.

The Norak Dam is an earth fill embankment dam on the Vakhsh River in Tajikistan. At 300 meters it is currently the tallest dam in the world.  Construction of the dam began in 1961 and was completed in 1979, when Tajikistan was still a republic within the Soviet Union.  The Norak Dam is uniquely constructed, with a central core of cement forming an impermeable barrier within a 300 meter-high rock and earth fill construction. The volume of the mound is 54 million m³. The dam includes nine hydroelectric generating units, the first commissioned in 1972 and the last in 1979.

A total of nine hydroelectric turbines are installed in the Norak Dam.  Originally having a generating capacity of 300 megawatts each (2,700 megawatts total), they have since been redesigned and retrofitted such that they now combine to produce 3,000 megawatts.  Units 1,2,3,4,6,7,8, and 9 now have capacity of 335 megawatts each and Unit 5 now has capacity of 320 megawatts.