Summary:

• **What Happened**: Japan turned back on the world's biggest nuclear power plant after it had been shut down for 15 years following the Fukushima disaster in 2011. A nuclear power plant is a facility that uses nuclear energy to create electricity for homes and businesses.

• **Why It Matters**: Nuclear power plants can produce lots of clean energy without creating air pollution, but they need to be very safe because nuclear energy can be dangerous if something goes wrong. Japan decided to restart this plant because they need more energy and believe they can now operate it safely with better safety systems.