By Alix Kroeger
BBC correspondent in Prague
The Temelin nuclear power plant in the Czech Republic is now one step away from commercial use.
This plant is now producing electricity at full capacity
On Friday, it began an 18-month trial period, producing electricity at full capacity.
Trials of the first phase began last year; if both phases complete successfully, the plant will be in full-scale commercial production by the end of 2004.
But Temelin has been dogged by shutdowns and safety scares since it began tests two and a half years ago.
The plant is based on a Russian design, upgraded with US technology.
It is located just 60 kilometres from the Austrian border, and its presence has strained relations between the two countries.
Austria, which opposes the use of nuclear energy, has argued that the plant is unsafe and should be closed down.
Last year 900,000 people signed a petition, demanding the Austrian Government veto the Czech Republic's application to join the European Union, unless Temelin were closed.
The government refused. A new package of safety measures was agreed, and the Czech Republic will join the EU next year.
Nonetheless, Temelin will be under scrutiny as it completes this final stage of its tests.