Chernobyl disaster: Giant shield begins move towards reactor
Work has begun at Chernobyl in Ukraine to move a giant shield over the site of the world's worst nuclear accident. The concrete and steel arch will eventually cover the remains of the reactor which lost its roof in a catastrophic explosion in 1986. The blast sent a plume of radioactive material into the air, triggering a public health emergency across Europe. The shield is designed to prevent further radioactive material leaking out over the next century.