In 2011, 3 reactors at the Fukushima Daiichi Nuclear Power Plant suffered meltdowns. The operator plans to decommission the plant within 40 years. But the people involved in the process face a critical challenge: locating and removing tons of hardened nuclear debris. Engineers are trying to develop special robots and experimenting with life-size replicas of the reactors. In this program, we report from the frontline of efforts to deal with the fuel debris.