At the South-Ukraine energy complex in the Mykolaiv region, summer started with a pleasant and long-awaited event – the launch of two new spray ponds built to improve the nuclear power plant cooling system.

Large-scale, costly and extremely urgent upgrades are needed not only for the operation of NPP but also for improvement of the environmental situation in the region at large. Moreover, upon the final implementation of the program «Reconstruction of the service water system at the Tashlyk reservoir and spray ponds of SUNPP» the volumes of electricity production by the power plant will increase by 40% in the summer. By the end of the year, the third hydro unit is planned to be launched at the Tashlyk hydro pumped storage power plant, which is currently 90% ready. However, the innovations and transformations planned for the unique for Ukraine complex combining nuclear and hydro generation are not limited to this.

Guarantor of the national power system stability in the south of the country

The favorable location of the South-Ukraine energy complex on the Southern Buh River made it possible to combine three generating capacities in one place – South-Ukraine nuclear power plant, Oleksandrivska hydroelectric power plant, and Tashlyk hydro pumped storage power plant. The complex generates about 10% of the total electricity production in Ukraine (17-20 billion kWh per year) and meets the five million population and industry needs of Mykolayiv, Odesa, Kherson, and Kirovohrad regions.

South-Ukraine NPP operates with three 1000 MW power units

The peculiarity of the South-Ukraine energy complex is in its capacities and functionality. South-Ukraine NPP operating with three 1000 MW power units forms the basis, HPP with two hydraulic units with a total capacity of 11.5 MW serves essentially as a dam while HPSPP (capacity of 302 MW) during peak hours and night reduction of energy consumption regulates the load in the south-western part of the Unified Power System (UPS) of Ukraine.

Hydroelectric power plant with two hydraulic units with a total capacity of 11.5 MW serves essentially as a dam

Tashlyk HPSPP, which is the second-largest component of the energy complex, was designed as a kind of water accumulator. At night, when consumption is significantly reduced, the plant's hydraulic units raise water from the lower (Olexandrivska) reservoir to the upper one. Whereas in the morning and evening, when energy consumption increases rapidly, water from the upper reservoir enters the hydraulic units, producing the necessary «peak» electricity.

Tashlyk hydro pumped storage power plant is the second-largest component of the energy complex

Currently, the power plant operates on two units out of six possible. With the completion of the THPSPP, the stability of the domestic UPS will increase, an operational reserve will be formed to regulate the frequency of electric current, and thus the conditions for the export of electricity. In a long run, increasing the capacity of the power plant will allow it to enter the market of ancillary services to make it profitable.

It should be taken into account that Mykolayiv region where the complex is located is considered an arid zone. By monitoring the state of the formerly water-abundant Southern Buh, experts state that from year to year the water content of the river decreases. This is due to the geographical features of the region: the vast majority of surface water is formed here by small rivers flowing as tributaries into a large river. However, off-flow from small rivers of Mykolayiv region is insignificant and it is impossible to use it for water supply without creation of reservoirs for flow control.

Mykolayiv region, where the South-Ukraine energy complex is located, is considered an arid zone. Reservoirs are needed for the normal supply of water to the region and flow control

Recently, the actual water content is 36-65% lower than the average rate of many previous years. At the same time, the region's water needs are growing – both to provide people with drinking water and for agriculture and business, so it was clear that the energy complex needs large-scale reconstruction to address water issues in the region and globally upgrade the cooling system of South-Ukraine NPP.

The largest fountain in Mykolayiv region

The nominal capacity of South-Ukraine nuclear power plant is 3,000 MW, but in the heat due to a significant water temperature increase in the Tashlyk cooling pond, electricity production has to be halved to 1,500 MW. To address this issue, a «Reconstruction of the service water system at the Tashlyk reservoir and spray ponds of SUNPP» started five years ago. The large-scale project, envisaging the construction of five spray ponds at the power plant, was approved by the Cabinet of Ministers back in 2016, but the first stage of construction was finalized only during the last year – under the new top management of Energoatom.

Reconstruction envisages the construction of five spray ponds at the power plant

Just a few figures to understand the scale of construction. The size of one spray pond is 145 by 395 meters, that is 7 Olympic (i.e. the largest) football fields. Moreover, the total area of ​​all five ponds provided by the project is 286 thousand 375 m². Just imagine!

The project cost is UAH 3.4 billion, of which works for UAH 2.3 billion has been executed so far.

Upon the completion of all ponds, the water temperature in the Tashlyk reservoir should decrease by 7-8 degrees, which will not only improve the environmental situation around the NPP but also lift restrictions on electricity production in the warm season and the nuclear power plant will be able to increase electricity production to 2549 million kWh according to the maximum estimate.

«This year, the third and fourth ponds out of five planned and the third hydro units of the Tashlyk hydro pumped storage power plant will also be commissioned, whereas the reconstruction and launch of the pond №5 are scheduled for 2022,» – the NNEGC Energoatom head Petro Kotin said during the formal launch of the first stage of the ponds..

Upon the completion of all ponds, the water temperature in the Tashlyk reservoir should decrease by 7-8 degrees

Furthermore, in the waters of the Tashlyk reservoir, a baffle plate is being installed while a complex of structures is being erected nearby to fill and feed the cooling reservoir.

For modern Ukraine, such large projects have long been a rarity, because they are catastrophically short of funds. It was not easy for Energoatom to complete two new spray ponds with a powerful pumping station in time and to adjust the necessary equipment, especially given the fact that the debts to the Company for timely generated and available to the general public electricity have already reached tens of billions of hryvnias.

Launch of a new pumping station at SUNPP 

«Due to the difficult financial standing of our company, we overran the schedule of payments to contractors, which led to a slowdown in construction,»  said the Director for projects and investment programs of NNEGC «Energoatom» Tetiana Amosova. «However, since this project has become one of our priorities for our top management, every effort has been made, and after Energoatom was partially repaid the debt for electricity sold, we were able to make basic payments for our facilities, including spray ponds and Tashlyk HPSPP.»

The head of Energoatom Petro Kotin solemnly launches the first stage of spray ponds at South-Ukraine nuclear power plant 

Thus, two ponds are already in operation. After solemn pressing the central button «Start» on the control panel of the new powerful pump station, one of its employees proudly said: «n 40 seconds, the largest fountain of Mykolayiv region will start working!».

Completion of Tashlyk HPSPP

This is not the end of the renovation of the South-Ukraine energy complex – many more projects are planned. However, their completion encounters obstacles. Thus, the announced completion of the Tashlyk Hydro pumped storage power plant (THPSPP) provoked a backlash from eco-warriors, even though it is provided by the state «Hydropower Development Program until 2026», approved by the Cabinet of Ministers (№ 552-p of July 13, 2016) and Energy strategy of Ukraine until 2035.

Completion of THPSPP construction is provided by the government program and includes gradual commissioning of six hydraulic units with a total capacity of 906 MW

The project was also approved by the Ministry of Energy (№ 01/33-2327 of March 7, 2019) and the Ministry of Environment (№ 5/4-7/12569-18 of November 20, 2018), provided that all documents are based on many years of research, observation and feasibility studies carried out by leading expert organizations – PJSC «Ukrhydroprojekt», NAS of Ukraine, CS «Ukrinvestexpertyza».

Completion of THPSPP construction includes gradual commissioning of six hydro units with a total capacity of 906 MW. The cost of the reconstruction project is UAH 14.25 billion, as of May 1, 2021, UAH 3.3 billion has been financed.

Turbine Hall of Tashlyk HPSPP and «top» of hydraulic unit N1. It is planned to launch the unit N3 by the end of 2021.

Currently, the plant has two hydraulic units with a total operating capacity of 302 MW. The third unit capable of operating at the current water level in the Olexandrivska reservoir is planned to be put into operation by the end of 2021. By the way, water from this reservoir is also used for irrigation and water supply.

Further development of the plant envisages the commissioning of units № 4–6 (not earlier than 2024–2026), and it is included in the government program for the development of nuclear and hydropower. In fact, the completion of THPSPP will ensure the smooth operation of the power plant and help address urgent «water issues» of the arid steppe Mykolayiv region while the issues are severe.

Environmental health costs of the Olexandrivska reservoir for the economic needs of the region (irrigation and drinking water) in the warmest season of the year for more than a decade do not reach the current regulating release – 17 m3/s. In 2007, this period lasted 53 days, in 2015 – 100 days, in 2020 – 114. Thus, the low streamflow period (when the river has the lowest water levels while its costs are less than environmental health ones) is growing steadily.

«Completion of the reconstruction of the pumped-storage unit under the project will increase the volume of the reservoir to 72 million cubic meters, of which 46 million will be used for the needs of the national economy,» said Pavlo Virych, head of the capital construction department of South-Ukraine NPP. Currently the reservoir has 14 million cubic meters. Upon the reconstruction, we will be able to provide regulating release below the Olexandrivka node in summer season. Then we will have water intakes in Voznesensk and Nova Odesa and there will be a stream flow. We will have water!»

Completion of Tashlyk HPSPP under the project will provide the region with water

Any project solution necessarily requires comprehensive scientific support, including environmental monitoring. Therefore, for the construction and operation of Tashlyk HPSPP since 1998 and until now, the Institute of Environmental Geochemistry of NASU carries out comprehensive environmental monitoring at the power plant, reservoir and adjacent area.

Observations have shown that with the filling of the Olexandrivska reservoir to the mark of 16 m in 2010, the values ​​of physical and chemical indicators of water quality have not changed while the local flora and fauna can adapt to changing living conditions. The filling of reservoir to the level of 20.7 m envisaged by the project will take place only at the peak of spring floods, when the river is «full» and it is possible to accumulate water, which would otherwise simply float into the sea.

South-Ukraine energy complex ensures the stability of the domestic UPS 

Public discussions of the Environmental Impact Assessment Report for the completion of the Tashlyk HPSPP are currently underway. Based on their results, the relevant ministry will prepare conclusions and a report, an integral part of which are, in particular, the minutes of public hearings, all received written comments and suggestions from the public, as well as a table with information on full, partial consideration or reasonable rejection of comments and suggestions which will be published in the Unified Register of Environmental Impact Assessment.

By the way, the project of completion of Tashlyk HPSPP for the first time in Ukraine provides for simultaneous financing of the construction of an industrial facility and a social and environmental program, which is directed to 10% of the allocated funds. Measures to preserve flora and fauna of the regional landscape park «Granite-steppe Pobuzhzhya» are financed separately. UAH 156 million has already been used for the social and environmental development program of the region while a total of UAH 910.6 million has been allocated.

At the request of the National Science and Natural History Museum of the NAS of Ukraine, rehabilitation measures are being implemented to reduce the impact on the populations of rare plant species under international, national and regional protection.

SUNPP 

Therefore, the construction of the Tashlyk hydro pumped storage power plant is carried out under the project, which has undergone all the necessary examinations and is approved in the manner prescribed by law. Energoatom's priority is primarily the interests of the people – ensuring their needs for electricity and heat, purity of environment as well as restoring the natural balance of the areas they live in.