福島第一原子力発電所事故の考証

(1)炉心溶融と放射能大量放出はどのように起こったか

抄録

Fukushima Daiichi NPP Accident caused core melts and hydrogen explosions on their reactors and a large amount of radioactive gas release in environment, forcing many people refuge. The core melts were not induced by decay heat only as many nuclear scientists believe but initiated by heat of chemical reaction between hot cladding material Zry and water. Hydrogen gas generated by the reaction flew up into operating floor above containment to explode it. Two type of radioactive gas release were recorded at the accident by radiation monitor provided near the site gate, showing the large amount of the radioactive gas release was caused by failure of opening vent system of No.2 reactor, as well as indicating that decontamination effect of BWR wet vent through suppression chamber is so large enough to extingish the need of refuge from radiation exposure, even at core melt accident.