The Reactor 1 of the failed Fukushima Daichi plant might be recritical as Radioactive Chlorine has been detected suggesting chain reactions continued after the reactor shut down.This is quite alarming and has made Japan thing about pouring concrete into its crippled Fukushima atomic plant IEAE warned that a potential uncontrolled chain reaction could cause further radiation leaks.The risk to workers might be greater than previously thought because melted fuel in the No. 1 reactor building may be causing isolated, uncontrolled nuclear chain reactions.Dumping concrete on the plant would serve a second purpose: it would trap contaminated water, said Tony Roulstone, an atomic engineer who directs the University of Cambridge’s masters program in nuclear energy.