2230 CET: 0617 local time — Chief Cabinet Secretary Edano says that reactor No.2 remains unstable. As of 0300 local time on Tuesday, pressure inside the reactor container had dropped and it was believed seawater had been pumped in succesfully, Tepco said, according to the Kyodo news agency. However, Tepco admitted that it had not yet been able to confirm that water levels inside the reactor had risen. The fuel rods were fully exposed at 2300 local time on Monday night.
2000 CET: Japanese media are concentrating on human stories and playing down the nuclear danger. Foreign media seem to be competing to see who can be most alarmist. The truth is probably somewhere in between.
It is now 4 am on Tuesday in Fukushima and Kyodo News reported at 0346 local time that sea water cooling of reactor no.2 has restarted. It has been about 4 hours since the announcement of exposed fuel rods and about 3 hours since the faulty valve was reported fixed. Since it is unclear how long it will take to get the fuel rods fully immersed again, this second exposure of the fuel rods could be significantly longer than the 2.5 hours of the first exposure. Once again with very hot fuel rods the cooling water will first evaporate and pressure could rise. With every venting of steam there will be some radiation leakage.
1700 CET: It seems the faulty valve on reactor no.2 for steam venting and which prevented the pumping in of cooling water has been accessed and fixed.
TEPCO reported that when reactor no.2 at Fukushima Dai-ichi nuclear plant released steam earlier on Monday radiation levels were found to be twice the maximum levels previously detected, but the levels dropped sharply. The radiation levels at the front gate of the power plant were found to be 760 μS at 9:35 p.m.; 3,130 μS two minutes later; and 400 μS by 10:15 p.m.
1600 CET: FLASH from Kyodo NEWS. Fuel rods at reactor No.2 fully exposed again.
From NHK – A confused report in translation but it may be that ingress of sea water is being stopped by a valve which has closed and is preventing the evacuation of air. Is the pressure too high inside the reactor?? A fear is that the water has evaporated in which case it could be a steam pressure building up.
Putin and Medvedev have stated that Russia has a moral responsibility to assist Japan. Oil and Gas supplies and upto 6,000 MW of electricity are being spoken of. It is now midnight in Sendai and temperatures are down to about 2 °C and will be dropping to freezing in a couple of hours.
1500 CET: Reactors Nos. 1, 2 &3 at Fukushima Dai-ichi are all cooling. But fuel rods at reactor no. 2 were fully exposed for 2.5 hours. Coolant levels are now rising. Some radiation leakage did occur and the fully exposed fuel rods must have partially melted. Reactor buildings 1 & 3 suffered hydrogen explosions which removed the roofs and part of the building walls.
Russian monitoring stations in the east of the country (Vladivostok) have not so far measured any increases of radiation.
There are no adverse reports concerning Reactors 4, 5 & 6.
Kyodo News:
Fuel rods at the quake-hit Fukushima No. 1 nuclear power plant’s No. 2 reactor were fully exposed at one point after its cooling functions failed, the plant operator said Monday, indicating the critical situation of the reactor’s core beginning to melt due to overheating.
The rods were exposed as a fire pump to pour seawater into the reactor to cool it down ran out of fuel, Tokyo Electric Power Co. said. The firm had reported the loss of cooling functions as an emergency to the government.
TEPCO said water levels later recovered to cover 30 centimeters in the lower parts of the fuel rods.
Later in the evening water levels had risen to cover 2m of the fuel rods.
The k2p blog 