Fukushima No. 4 reactor's coolant may be boiling, evaporating 16 Mar 2011 Fukushima’s imperiled nuclear plant is now facing another crisis, with authorities there stating a fourth reactor’s nuclear waste is overheating, which could lead to more spent fuel becoming unstable, compounding an already dire situation. After explosions at the No. 1 and No. 3 reactors at Fukushima’s Dai Ichi nuclear facility in Japan destroyed containment buildings, latest reports reveal the growing crisis now includes an unstable situation at its No. 4 reactor.