The foundations of the future power plant were laid in 1987 after the design of Atomenergoproekt Kyiv from the USSR and Energoproekt Sofia. The design suggested the construction of four VVER-1000/320 units. Between 1988 and 1990 40% of the construction work on Unit 1 was finished and 80% of the equipment was supplied. The project was abandoned in 1990 due to the fall of communism in Bulgaria and only conservation work was done thereafter. Since then, measures have been continuously undertaken to preserve the supplied equipment, the construction site and the buildings; various investigations and assessments have been carried out with respect to the site suitability and the equipment status, all of which yielded positive conclusions. New investigations have been performed in relation to site safety and its compliance with international requirements. There has been particularly extensive research on the seismic safety of the chosen site. A number of missions were carried out by the International Atomic Energy Agency (IAEA) and other bodies of authority. All these came up with positive conclusions and confirmations that the Belene site is suitable for the construction of a nuclear power plant.