TMI とチェルノブイリ事故の教訓と対策
Lessons Learned from the TMI-2 Accident and Chernobyl Nuclear Disaster for Nuclear SafetyInnovation
著者:
杉山 憲一郎 Kenichiro SUGIYAMA 奈良林 直 Tadashi NARABAYASHI
発刊日:
公開日:
Chernobyl Nuclear DisasterFukushima-Daiichi Nuclear Power PlantsTMI-2 accident
概要
The 2011 off the Pacific coast of Tohoku Pacific Earthquake and the Tsunami gave the serious damage to the Fukushima-Daiichi Nuclear Power Plants (NPPs). The accidents occurred in Unit 1, 2, 3 and 4. It is said that the height of tsunami attacked Fukushima NPP was more than 14m. After 50 minutes from the automatic shut-down, tsunami a ttacked the NPPs in Fukushima Daiichi NPPs. For example, the Unit 1 lost A/C power caused the loss of water injection function; it made the core meltdown and unusual increase of PCV pressure in the midnight of March 11th to 12th morning. Though the Unit one has the Isolation Condenser Core Cooling system, it was stopped by the operator to keep the cooling rate of 55°C/h. Finally, the isolation signal was transmitted from the control room to the motor driven isolation valves when the control room's battery discharged. It was the initiation of the core meltdown. The lessons from the TMI-2 accident, human error and instrumentation & control system trouble cased the core damage. Though the NPPs in European counties have filtered venting system after the Chernobyl Nuclear disaster, there are no filtered venting system connected the containment vessel in Japanese NPPs. If the Fukushima Daiichi NPPs have filtered venting system, the venting could be much earlier and no nuclear disaster would be occurred.
