REPUBLIKA.CO.ID, KIEV -- Ukraine prepared on Tuesday to mark the 30th anniversary of the Chernobyl nuclear disaster, which permanently poisoned swathes of eastern Europe and highlighted the shortcomings of the secretive Soviet system.

In the early hours of April 26, 1986, a botched test at the nuclear plant in then-Soviet Ukraine triggered a meltdown that spewed deadly clouds of atomic material into the atmosphere, forcing tens of thousands of people from their homes.

The latest anniversary of the world's worst nuclear accident has garnered extra attention due to the imminent completion of a giant 1.5 billion euros ($1.7 billion) steel-clad arch that will enclose the stricken reactor site and prevent further leaks for the next 100 years.

The project was funded with donations from more than 40 governments. Ukrainian Prime Minister Volodymyr Groysman said lessons learned from Chernobyl should be heeded all over the world.