An earlier intergovernmental agreement envisages financing through a Russian loan of around EUR 5-6 billion. Their economic viability and investment attractiveness is determined by the prices of fuels (coal and natural gas) and electricity tariffs, which both depend mainly on politically sensitive tariff decisions. Investments in this sector thus remain a risky undertaking, despite the significant business potential for electricity exports to neighbouring countries, notably Belarus, Poland and Slovakia. New generation capacity has also been developed: the first unit of the Dnister pumped-storage hydroelectric power plant started operating by the end of 2009 and with additional units planned in coming years this plant might become one of the largest of its type in Europe. Other segments of the renewable sub-sector remain for the moment dominated by small-scale units, mostly privately-owned. Nuclear safety is probably the most successful field of Ukraine’s co-operation with the EU which provides and supports the country’s access to grants and loans.