[en] Nuclear power generation is a reliable source of energy for Romania and an important contributor to the national electricity supply. Romania has one nuclear power plant, Cernavoda, which operates one CANDU 6 reactor, 707 MWe, designed by Atomic Energy of Canada Ltd (AECL). It provides about 10% of the total country electricity generation. The state-owned company responsible for the production and supply of energy from Cernavoda NPP, as well as for its development, is Societatea Nationala 'Nuclearelectrica'. The plant was designed to have five similar units. The studies performed for the plant, prior to the construction's start, established feasible technical solutions for all problems related to a 5- units plant, including the environmental impact, which was determined to be entirely acceptable. Construction of the first unit started in 1980, and units 2-5 in 1982. The pressing problems encountered during construction of Unit 1 (import restrictions, delays etc.) restrained the progress at Unit 2. Starting in 1990, the work on Cernavoda site was focused on Unit 1. Construction at the other units was suspended; during many years; only preservation works were carried-out. The re-start of work at Unit 2 began in 1995, under the management of the AECLANSALDO Consortium. Some work to further construction progress was carried-out (e.g. installation of the fuel channels) and a thorough assessment was performed of the condition of the equipment procured for Unit 2 and stored on site, or already installed. The absence of a clear contractual framework and the lack of resources hindered significant advances in the construction of Unit 2. Recently, estimates in Romania are that annual electricity production will become insufficient unless Unit 2 of Cernavoda NPP is commissioned. In this environment and considering the relatively low cost of the electricity produced at Unit 1 of Cernavoda NPP versus the energy cost in the conventional thermal stations, the Romanian Government started to provide greater support for the completion of the Cernavoda Unit 2 project. In the year 2000, the Government decided that completion of Cernavoda Unit 2 was a high priority and supplied part of the financing for it. In May 2001, 'Nuclearelectrica' signed a new contract with its traditional partners, AECL and ANSALDO, for the joint management of the construction and commissioning work on Unit 2 Cernavoda NPP. The unit achieved initial criticality in early 2007. The reference design for Unit 2 is the 'as built condition' of Unit 1, with a certain number of improvements. A number of changes are aimed to meet new regulations by providing increased safety margins or improving the reliability of operation in accordance with the development of nuclear technology. Other changes, of a minor nature, will improve system or station performance, or will replace obsolete equipment