Colby Cosh complained yesterday about the low quality of information being provided by the Tokyo Electric Power Company (TEPCO), and that has not really improved since yesterday. At The Register, Lewis Page updates the situation as best he can:
The story of the three quake- and tsunami-hit reactors at Japan’s Fukushima plant continues, with indications that one of the three worst-hit reactors has sustained further damage. A fire also broke out at another reactor, shut down at the time of the quake and not previously thought to be a problem, but this has now been put out. None of this suggests that the reactors’ crucial containment vessels could be breached, however.
World Nuclear News reported in the early hours (UK time) that a “loud noise” had been heard at the site of the No 2 reactor at Fukushima and pressure readings had fallen in the doughnut-shaped “suppression chamber” situated beneath the core. The suppression chamber holds a large quantity of water and steam from the core, released into it to be condensed, so reducing pressure in the core without the need to vent to atmosphere in some situations: though reactors 1, 2 and 3 have all been repeatedly vented to atmosphere since the quake nevertheless.
Following the apparent release from inside the suppression chamber, radiation levels at the site briefly rose to 8217 microsieverts per hour — such that an unprotected person outside would receive several years’ normal background radiation dose in a single hour. Radiation then dropped to less than 2,500 microsievert/hr. (UPDATED TO ADD: The IAEA reports that as of 6am UK time this had fallen to 600 microsievert/hr). WNN reports that a statement from TEPCO, the plant operators, stated that there had been “no significant change” to the status of the vital containment vessel surrounding the reactor core.
