Contaminated water leak from the Reverse Osmosis apparatus found yesterday was probably caused by over-tightening the cap of the flow meter attached to the apparatus, TEPCO says.
I think the lack of skilled workers at Fukushima I Nuclear Power Plant has started to show more conspicuously in the past few months.
According to TEPCO, they disassembled the flow meter on June 20 to clean the window of the meter. When they reassembled it, they over-tightened the cap, causing it to deform and crack. But the leak didn't happen immediately because of the rubber gasket.
TEPCO's solution is to replace the entire flow meter the next time the window gets dirty, and not bother trying to clean the window.
From TEPCO's handout 6/21/2013 (Japanese only for now; English labels by me):