Experts have pointed out that one after another, “the probability of Units 2 and 3 leads to core damage is about 10%” and “core melt avoid water injection to Unit 2 as early as four hours” at Fukushima nuclear accident.Unit 1 of the older equipment aside, Units 2 and 3 to was brought to accident It was a incompetence of TEPCO.Percentage of Unit 2 is occupied by the release of radioactive material is large, wide-area pollution had been reduced considerably if not alone explosion March 15 Unit 2.
I have reported the analysis Takeshi Matsuoka Utsunomiya Visiting Professor (Systems Engineering) was conducted based on the criteria of the Atomic Energy Society of Japan with “: analysis of the probability of core damage … if work properly Fukushima Daiichi nuclear power plant” Mainichi Shimbun.Were analyzed by considering the failure rate of equipment and “equipment.I assumed as well as affected the actual situation, the total supply of Units 1 to 3 is lost in the tsunami of 15 meters height, part of the emergency battery to activate the emergency core cooling system is unavailable in the submerged.As a result of the analysis, the probability of leading to core damage to up to 7 days after all power loss, Unit 1 70.8%, Units 2 and 3 is 11.8%, respectively ”
“It was equipped with a cooling system of another called” Isolation cooling system and (RCIC) “in Units 2 and 3, but in actual incidents, there is any interruption or delay in operation of cooling by invoking the RCIC”.Badness of these procedures is stacked in an accident early correspondence, accident was expanded to Units 2 and 3 originally, it was supposed to need a safe.
In addition, the NHK news “Japan Atomic Energy Agency has examined whether there was no means to Reproduce computer the state of the reactor of Unit 2, to prevent a meltdown” is “melting avoidance as early as four hours”.If you turn on the water by lowering the pressure in 4:30 after “In the afternoon, the temperature will drop once, but the temperature began to rise because the water level in the reactor is substantially reduced already, it reaches the meltdown of the 14th You.However, if you start the injection of water to up to 4 o’clock pm for the first time earlier work to lower the pressure, the surface temperature of the fuel could begin, been prevented a meltdown falling before reaching the 1200-degree cladding tube is broken We notify them that “there.
TEPCO seems to come vindication, “We work hard in an environment radiation dose is high,” but the battery that was driving the cooling system isolation at the time of the expiration of the To loose up to 14 days to obvious to everyone Because I was afford to stand still, there is no convincing.you should consider that it has spent the time idly by being dragged to a bad decision, “water is up to half of the fuel rods in the reactor core” and as pointed out that “Units 2 and 3 was Rescue if radioactive tellurium next day discovery” in .