Almost 48 hours since the re-rated magnitude 8.8 earthquake and following tsunami ravaged a large area of Honshu Island NE of Tokyo the weasel words from its nuclear industry have given way to some appalling realities.
The Tokyo electric company has lost control of a total of seven reactors, four in the Fukushima Daini plant, and three in the Fukushima Daiichi plant, one of which exploded yesterday.
It is the second plant at Daiichi which has been the focus of most attention given the blast that removed an outer wall from its No 1 unit yesterday afternoon, and admissions within recent hours that its No 3 unit is ‘probably’ experiencing partial meltdown because of the failure of its fail safe emergency cooling system, putting it in the same parlous state as that assigned to the No 2 Daiichi unit yesterday.
However this afternoon Tokyo Electric said that it was trying to ‘gain control’ over the four reactors at its physically separate Fukushima Daini site. A water condensate system used to supplement the cooling system at Fukushima Daini Unit 1 stopped working when temperatures reached 100 degrees Celsius early in the crisis, the company has finally disclosed.
Tokyo Electric also announced that it would carry out controlled releases to ease pressure in the containments of all four units at Fukushima Daini. This is the same process that was being used at Daiichi 1 before the outer wall of its reactor block was destroyed by a violent explosion attributed officially to a build up of hydrogen gas. It is the same process now underway at the other two Daiichi reactors as well as the four at Daini.
Extensive evacuations of more than 200,000 people living in the immediate vicinity of both plants are underway, and potassium iodide tablets are being distributed to inhibit the uptake of radioiodine nuclear contaminants by the thyroid gland.
The authorities at Fukushima have revealed that at least 160 people are being treated for radiation exposure in hospital according to one media report, all of them believed to be employees at the Daiichi plant. Other reports put the number of radiation exposure patients as much lower, at 19, and a third report now says one not two power company employees have been killed at the Daini plant in a crane accident.
The Japanese authorities, who lied unashamedly about the nature of the emergency until mid morning yesterday, claiming that there was no evidence of melt downs in the reactors nor unmanageable consequences, have now confirmed the detection of caesium and radioiodine nuclear contaminants outside of the Daiichi complex. This confirmation came in two stages, the caesium being acknowledged yesterday afternoon before the Daiichi 1 explosion and the radioiodine today. Both would have been detected at the same time.
It has been apparent to independent nuclear scientists since yesterday afternoon that the presence of caesium particles outside that bank of reactors and low key official announcements of the ‘harmless’ release of ‘slightly radioactive’ steam from the Daiichi 1 unit were unambiguous signs that coolant levels in the core of the reactor had fallen and exposed part of the fuel rods, leading to a partial melt down as they began to burn in contact with air instead of being fully immersed in coolant.
On Saturday nuclear industry apologists in the western media said that the situation in Japan would only be serious if such desperate measures as flooding the reactor cores with sea water occurred.
Sea water drowning of the No 1 Daiichi reactor has been confirmed, and there are references by Tokyo Electric this afternoon to sea water being used in other reactors as the water injection systems which use high pressure water used for fire fighting emergencies is for some reason no longer available or effective.
The drowning of the reactors, as well as references to introducing boric acid to the cores mean that the power company no longer expects to use them in the future given the damage that will be done to them. In fact the Daiichi plant’s 40 year licences are due to expire in May this year. The media in Japan says it is unknown if there was an intention or application pending for the Daiichi licences to be renewed, of if the plant was intended to be decommissioned.
The submerging of reactor cores with sea water means that no further attempt to use control rods as part of the normal process of moderating reactor activity will be made. It also explains the relevance of references yesterday to unspecified damage to the fuel rods, as fuel rod breakages or deformation would prevent the use of control rods.
Those reactors in which Tokyo Electric is trying to prevent further meltdown or atmospheric combustion of the fuel rods by dousing them under sea water are by definition, in a state of uncontrolled nuclear activity that will require massive physical intervention to end, or to securely entomb.