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Ust-Khantayskaya powerplant recommissioned after upgrade

An inauguration ceremony was held on 18 October to mark the return to full operation of Russia’s most northerly hydropower plant. Nikolay Shulginov, Russian Minister of Energy, and Alexander Uss, Governor of Krasnoyarsk Krai, attended the recommissioning ceremony by video conference.

Russian metals group MMC Norilsk Nickel (Nornickel) has completed the recommissioning of the Ust-Khantayskaya hydropower plant in northern Siberia, following a total modernization.

“With the upgrade comes higher capacity and performance efficiency for the station, as well as better reliability of the plant and the region’s power grid,” said Shulginov, who launched the restart of the final unit. “The replacement of units at Ust-Khantayskaya will make a strong contribution to providing settlements in the north of the Kras­noyarsk Territory and the company’s major assets with reliable and environmentally friendly power,” said Evgeny Fyodorov, Nornickel’s Vice Presi­dent for Energy.

Nornickel, the world’s largest producer of palladium and high-grade nickel, and a major producer of platinum and copper, replaced all seven adjustable blade turbines with new radial-axis Francis turbines at the storage plant in Taymyr Peninsula over a seven-year period, as part of an Rb 7.5 billion (US$ 105 million) modernization project. The upgrading of the station, undertaken as part of Nornickel’s wider investment programme to revamp energy infrastructure and produce carbon-neutral metals, increased the capacity of each unit from 63 to 73 MW and its combined installed capacity to 511 from 441 MW. It also increased the maximum efficiency factor of each turbine from 88 to 95 per cent, increased its average annual output to 2.4 TWh, and extended the plant’s service life by around 40 years. In addition, the plant’s upgrade will reduce CO2 emissions by 174 000 t/year with increased output offsetting production by local coal-fired thermal plants.

The modernization works were carried out by the general contractor OJSC Tyazhmash. Under a contract signed in November 2012, OJSC Tyazhmash, the original equipment manufacturer, undertook the design, manufacture and supply of all the equipment and carried out construction, installation and commissioning of the units on a turnkey basis. Subcontractor LLC Elektro­tya­zh­mash-Privod manufactured the vertical synchronous generators.

Design work began in early 2013 with more than 10 options for turbine runners considered, according to Nornickel. Those selected underwent model tests with six configurations of blades, and guidevanes being tested, before the optimal solution was found. Starting from 2015, one unit was replaced each year. The works were carried out in such a way as to accommodate the existing constraints on the overhaul of the hydroelectric units and spatial restrictions, as the rockside location of the plant’s main generator hall made it impossible to work on two units simultaneously. The new turbines provided several advantages, according to Nornickel. These in­cluded enhanced reliability of the new turbines with a radial axis runner, lower operating and maintenance expenses, better environmental safety and the ability of the turbines not to be materially restricted in terms of water pressure whatever the combination of headwater and tailwater levels. The modernization project also involved the reconstruction of the generator hall, construction of a new compressor station operating as a synchronous compensator, and installation of an automated dispatch control system.

Ust-Khantayskaya, which was the first of Nornickel’s hydropower plants in the Taymyr Peninsula and the first in the Arctic, was built to supply power to the company’s mining and metallurgical operation in Norilsk, as well as to residential consumers in Norilsk, Igarka and Dudinka. The dam and powerplant were built on the Khantayka river along the Bolshoi Khantayskiy rapid between 1963 and 1975. The plant was originally equipped with seven units with adjustable blade turbines of 63 MW each, which operate at a design hydraulic head of 45.8 m, generating as of early 2012 average annual output of around 2055 GWh. Its 72 m-high rock- and earthfill em­bankment dam with a 5.34 km-long crest forms the Khantayskoye reservoir, which covers an area of 2230 km2 and has a maximum storage capacity of 22.55 km3 and live storage of 14.03 km3. Construction of the plant, which was designed by experts from the Krasnoyarsk and Leningrad branches of the Hydro­project Ins­titute, was a major undertaking given the harsh Arctic climate and permafrost, with temperatures as low as -64°, snow cover continuing for 240 to 265 days a year, and the frost-free season lasting just 78 days.

Construction work began in May 1963 and the plant began into full commercial service on 25 Sep­tember 1975.

It is one of two hydro plants owned and operated by the metals group with a combined capacity of 1041 MW. The Kureiskaya hydro plant on the river Kureyka, which is a tributary of the Yenisei, close to Svet­logorsk, is equipped with five radial axis units with a capacity of 120 MW each. They operate under a head of 57 m. The plant’s earthfill embankment dam with a 1.6 km long crest and a maximum height of 79 m forms the Kureyskoye reservoir, with live storage capacity of 7 km3. This plant was fully commissioned in 1994. The acceptance certificate marking the full commissioning of the plant was signed in 2003.

The two hydropower plants, to­gether with three thermal powerplants, power grid assets, and heat and water supply networks, form the Norilsk Industrial District energy system, which is operated by Nor­nickel’s Energy Division. The energy system is isolated from the national grid (Unified Energy Sys­tem of Russia), which means stricter requirements apply regarding its reliability and useful life. The Ust-Khantayskaya and Kureyskaya plants generate 55 per cent of the system’s electricity production.