Thirty years after the world's worst nuclear catastrophe, the Chernobyl nuclear reactor is now due for a new sarcophagus, or protective shell.

When the nuclear power plant explosion happened on April 26, 1986 -- three decades ago -- in the Ukrainian town of Chernobyl, workers hurriedly built a sarcophagus to prevent further radiation leak. A sarcophagus is defined by Merriam-Webster as "a stone coffin from ancient times." But Chernobyl's own sarcophagus was a tomb made of concrete and steel, quickly erected to house the remains of the power plant's blown up Unit 4.

But the original sarcophagus was only meant to last for 30 years. This 2016, its time is already up.

This new protective shell, funded mostly by the G7 through the Chernobyl Shelter Fund, is meant to last longer, specifically for 100 years.

Called the New Safe Confinement (NSC), this massive architectural and engineering project started in 2010 and is nearing its completion. By November, the structure will be slowly slid over the reactor and its present sarcophagus. Since it will be done at a snail's pace, the Tetris-like endeavor is projected to completely cover the target area by 2017.

This feat makes the NSC the largest man-made moveable structure on land, as per the European Bank and Reconstruction Development, which oversees the project.

According to their statement, the new confinement will prevent the further leak of contaminated material. It will also protect the structure from external phenomena, such as weather disturbances or natural disasters like tornadoes, earthquakes and even Ukraine's extreme cold.

The magnificence and massiveness of the structure are nothing like anyone has ever seen -- or built. It spans 260 meters, twice the size of a football pitch. Its length is 160 meters and its height is 110 meters -- six times the height of the Eiffel Tower in Paris.

Nicolas Caille, project director, said their work has not been done anywhere else.

"For an engineer, it's Mecca," he told National Geographic. "I mean, I hope we will not have to rebuild such an arch elsewhere -- it's because of a catastrophe that we are here -- but for an engineer, it is perfect."

The structure weighs over 30,000 tons and is being constructed away from the site to minimize the workers' exposure to radiation.

The nuclear accident, which caused radiation isotopes to be released in the environment, has made the word "Chernobyl" synonymous to Ground Zero. However, recent studies show that wildlife is beginning to thrive again in the area and that communities are still living within its boundaries.

However, despite the disaster, Ukraine continues to rely on nuclear energy, with as many as 15 reactors providing 60 percent of the country's electricity, as reported by Deutsche Welle.

The global impact of Chernobyl may already be gone from some people's minds, but for those who continue to worry about the effects of radiation thirty years after, hopefully, the New Safe Confinement for Unit 4 provides some peace of mind.