I'm going to bed, now. I hope when I wake up everything is under control.Pressure and releases
Without enough power for cooling systems, decay heat from the reactor cores of units 1, 2 and 3 has gradually reduced coolant water levels through evaporation. The consequent increase in pressure in the coolant circuit can be managed via pressure release valves. However, this leads to an increase in pressure within the reactor building containment. Tepco has said that the pressure within the containment of Fukushima Daiichi 1 has reached around 840 kPa, compared to reference levels of 400 kPa.
The company has decided to manage this "for those units that cannot confirm certain levels of water injection" by means of a controlled release of air and water vapour to the atmosphere. Because this water has been through the reactor core, this would inevitably mean a certain release of radiation. The International Atomic Energy Agency said this would be filtered to retain radiation within the containment.
However, the company's monitoring of Fukushima Daiichi 1 has separately shown an increase in radiation levels detected emerging from the plant via routes such as the exhaust stack and the discharge canal.
Over the last several hours evacuation orders for local residents have been incrementally increased and now cover people living within ten kilometres of the power plant.
CONTINUED FROM: Battle to stabilise earthquake reactors