Speaking of Korean

2013년 3월 16일 토요일

Yonomori line

Where is 05 located, and what is 12 called?
The 66kV lines are leftovers from the plant construction phases.

Lines into units 5 and 6 were hot at the F1 plant substation.
From METI Causes and Coutermeasures, March 2012, here, p39.

Note that all the Ohkuma lines tripped (the White X's), either at the plant substation or at the transmission substation. Protection equipment activated to protect the equipment from electrical damage. Physical damage is still a possibility, and some happened (the Red X's). The same types of physical damage could happen at either end of the wire. The equipment at each end is about the same, and both ends received some physical damage from the shaking, the plant more.

Bad design. Easy to say.

What in the world do you make of the little note on the left that says that a transmission line was good-to-go by 7pm that night. Does that refer to the small power line that runs parallel to the first base line, just south west of unit 4? Tower behind home plate.

2013년 3월 15일 금요일

Grid failure at Fukushima 1

The wires and the towers were fine. (Yes, one tower, tower 27 went down on the 66kV line. Not important.That line isn't even on the picture.) The "grid problem", such as it was, was caused by damage (how much was it, by the way?) at the ShinFukushima Transmission Substation. At least one, and probably more, other transmission lines "into" ShinFukushima were energized. We can be sure because F2 (Fukushima Daini) was receiving power from ShinFukushima by midnight.

There were problems on the 275kV side of the substation. The 500kV side saved F2 a melt down, and could have powered F1's units 5-6 by midnight, if their yard substation was not ruined in the flooding. Bad design, eh?

Yes the F1 yard had some damage from the earthquake, broken breakers, but that's easier to fix, and still not a grid problem, so more bad plant design.