Friday, May 20, 2011

Just another typical day in Dai-ichi - Head-scratching, uncertainty predominate

Just in time to offset the Tepco Execs 'cold shutdown in 6 months' drivel, it was recently discovered that the water level in a tunnel linked to the Number 3 reactor has been rising several centimeters a day for the past week. The water is expected to rise to about one meter below the ground level soon.  It works out great.  At that rate, the highly radioactive water should completely fill the basement and reach ground level at about the same time cold shutdown is achieved.

Perhaps Tepco has a problem grasping the law of conservation of matter.  Water goes in, water must come out.  For how long now; massive, drought-inducing, crop-shriveling amounts  have been pumped into reactors with known leaks. Tepco has to expect water to pop up at different locations, however remote that possibility may appear (see next paragraph), but they always seem surprised when it happens.

Tepco is also confirming that radioactive water levels are also rising - if you can believe it - in the Number 5 and 6 turbine buildings. Also, TEPCO says an estimated 67,500 tons of contaminated water are now in the Number 1, 2 and 3 reactors alone, "hampering efforts to restore the reactors' cooling systems".

In a stroke of luck, workers entering the unit 2 building for the first time since the explosion discovered lower amounts of radiation than expected, at 10 to 50 milliSieverts/hr.  This will enable each worker to spend 20 minutes a day instead of just 10 minutes a day in the unit.  What they will be able to accomplish in that greatly expanded time frame is hard to say - maybe installation of some air purification system that reduces radiation by 96%, but in actuality, only reduces it 5-10%. 

And no wonder they've been putting cows down outside the exclusion zone.  It's in the grass - 1,530 becquerels of radioactive cesium per kilogram were found in a sample collected last Wednesday from a farm in southern town of Marumori in Miyagi Prefecture. That is 5 times the legal limit of 300 becquerels.

350 becquerels of cesium were also detected in a sample from a prefectural farm in the northern city of Osaki.

No comments :

Post a Comment