However, while the employees prepared to leave, the tsunami warning came. Many of them fled to the top floor of a building near the site and waited to be rescued. The reason for official reluctance to admit that the earthquake did direct structural damage to reactor one is obvious. They are using a number of antiquated reactors that have the same systematic problems, the same wear and tear on the piping.
He sent the Japanese government a letter, dated June 28, , warning them of the problems there. It took the Japanese government more than two years to act on that warning. Sugaoka has also said he saw yakuza tattoos on many of the cleanup crew staff. Most of the critical work: construction work, inspection work, and welding were entrusted to sub-contracted employees with little technical background or knowledge of nuclear radiation.
One told him that often piping would not match up the way it should according to the blueprints. In that case, the only solution was to use heavy machinery to pull the pipes close enough together to weld them shut. Inspection of piping was often cursory and the backs of the pipes, which were hard to reach, were often ignored.
Since the inspections themselves were generally cursory and done by visual checks, it was easy to ignore them. Repair jobs were rushed; no one wanted to be exposed to nuclear radiation longer than necessary.
Pipes on the wall, on the ceiling, on the ground. It was like a maze of pipes inside. To pump seawater into the core is to destroy the reactor.
Problems with the fractured, deteriorating, poorly repaired pipes and the cooling system had been pointed out for years. In , whistle-blower allegations that TEPCO had deliberately falsified safety records came to light and the company was forced to shut down all of its reactors and inspect them, including the Fukushima Daiichi Power Plant.
Not only did the government of Japan take more than two years to address the problem and collude on covering it up, they gave the name of the whistleblower to TEPCO.
In September of , TEPCO admitted to covering up data concerning cracks in critical circulation pipes in addition to previously revealed falsifications. So there is a great deal of concern that if the core does melt, the containment will not be able to survive. And if the containment doesn't survive, we have a worst-case situation.
And just what is that worst-case scenario? But if a core melts, it will slump to the bottom of the reactor vessel, probably melt through the reactor vessel onto the containment floor. It's likely to spread as a molten pool—like lava—to the edge of the steel shell and melt through. That would result in a containment failure in a matter of less than a day. It's good that it's got a better containment system than Chernobyl, but it's not as strong as most of the reactors in this country.
Finally, Bergeron summed up the events so far: "Based on what we understand, the reactor has been shut down, in the sense that all of the control rods have been inserted—which means there's no longer a nuclear reaction. But what you have to worry about is the decay heat that's still in the core—that will last for many days. And the conventional sources of water, the electricity that provides the power for pumps, have failed.
So they are using some very unusual methods of getting water into the core, they're using steam-driven turbines—they're operating off of the steam generated by the reactor itself. And the batteries aren't designed to last this long, so they have failed by now.
So we don't know exactly how they're getting water to the core or if they're getting enough water to the core. We believe, because of the release of cesium, that the core has been exposed above the water level, at least for a portion of time, and has overheated.
What we really need to know is how long can they keep that water flowing. And it needs to be days to keep the core from melting. But if the core does melt, that insult will probably not be sustained and the containment vessel will fail.
Proper equipment has now replaced ragged plastic hoses held together with tape and an outdoor power switchboard infested by rats, which caused blackouts. Radiation levels have declined, allowing workers and visitors to wear regular clothes and surgical masks in most areas.
But deep inside the plant, danger still lurks. Journalists from The Associated Press recently visited the plant to document progress in its cleanup on the 10th anniversary of the meltdowns and the challenges that lie ahead. After a magnitude 9. About tons of melted nuclear fuel remain inside the three damaged reactors, and its removal is a daunting task that officials say will take years. Separate efforts to remove spent fuel from cooling pools inside the reactor buildings were hampered by high radiation and debris and have been delayed for up to five years.
The melted cores in Units 1, 2 and 3 mostly fell to the bottom of their primary containment vessels, some penetrating and mixing with the concrete foundation, making removal extremely difficult. The water is pumped up and treated. Part is recycled as cooling water, with the remainder stored in 1, huge tanks crowding the plant.
Early in the crisis, highly contaminated water that leaked from damaged basements and maintenance ditches escaped into the ocean, but the main leakage points have been closed, TEPCO says. Tons of contaminated sandbags filled with a material used to reduce cesium in the highly radioactive water early in the disaster remain in two basements.
Tiny amounts of radiation have continued leaking into the sea and elsewhere through underground passages, though the amount today is small and fish caught off the coast are safe to eat, scientists say. The 1, tanks filled with treated but still radioactive water tower over workers and visitors at the plant.
TEPCO says the tanks' 1. A government panel's recommendation that the water be released into the sea is facing fierce opposition from local residents, especially fishermen concerned about further damage to the area's reputation. A decision on that recommendation is pending. TEPCO and government officials say tritium, which is not harmful in small amounts, cannot be removed from the water, but all other radionuclides selected for treatment can be reduced to safe levels for release. Even so, they remain in the water, some scientists say, raises a concern about their impact on marine life from a long-term release.
TEPCO has managed to cut the amount of contaminated water to one-third of what it used to be through a series of measures.
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