11 May 2021 Share Ukrainian nuclear power plant operator Energoatom and the country's transmission system operator Ukrenergo completed tests last week at unit 1 of the Zaporozhe nuclear power plant for the provision of ancillary frequency maintenance reserve services at +/-20 MW. The tests should confirm the compliance of the unit with the requirements of the Transmission System Code in order to obtain a certificate entitling Energoatom to introduce the power unit to the ancillary services market. Zaporozhe nuclear power plant (Image: Energoatom) Ancillary services may be purchased or used for a day, week, month, quarter or years. To provide ancillary services a market participant should be registered by the transmission system operator as a supplier.