Workers are finally done installing a shelter over the damaged reactor of the Chernobyl nuclear plant in Ukraine on Tuesday, Nov. 29.

One Of The Most Ambitious Engineering Projects In The World

Installing the massive shelter shaped like a half cylinder over the remains of the damaged reactor is considered as among the most ambitious engineering projects in the world. The structure was placed on top of the plant's reactor No. 2.

The European Bank for Reconstruction and Development said that the new shelter, which costs about 1.5 billion euros, measures 843 feet wide and 354 feet tall. The construction received funding from more than 40 governments and required 10,000 workers.

Closing A Nuclear Wound

The feat marks an important step toward containing the impact of the worst nuclear accident the world has seen. One expert has said that the installation of the massive shelter closed a "nuclear wound."

"Moving together two halves of the huge arch and sliding the gigantic shelter in the position over the historic reactor is like closing a wound, a nuclear wound that belongs to all of us," said Hans Blix, Chernobyl Shelter Fund chairman.

Workers will now start work to dismantle the old and unstable parts of the sarcophagus, the original cover that was placed over the damaged reactor after the nuclear accident to contain harmful radiation.

The Chernobyl Disaster

On April 26, 1986, a sudden jolt of power destroyed Unit 4 of the Chernobyl nuclear power plant. Following the explosion and fire that occurred afterward, massive amounts of radioactive materials were released into the surroundings, prompting the evacuation of thousands of people.

Workers aboard helicopters poured sand on the remnants of the reactor to stop the fire and radiation emissions. The crew also also poured boron to prevent more nuclear reactions and eventually managed to fully contain the area with a temporary concrete structure known as the sarcophagus. Authorities also cut down and buried a pine forest and closed the area near the Chernobyl plant.

Chernobyl After 30 Years

As a result of the incident, thousands of people were evacuated. Residents never returned but the area was gradually populated by wildlife such as elk, wolves, wild boars and deer. Radiation, however, remains a threat to these animals.

The health impact of the nuclear disaster also remains a concern. A substantial rise in cases of thyroid cancer was observed after childhood exposure to the radiation.