Those who were at the Fukushima No. 1 power plant two years ago probably remember their fears after towering tsunami knocked out the reactor cooling systems, triggering three core meltdowns that threatened to harm the entire nation.

Today the crippled reactors require close monitoring but are in a controllable state — at least compared with the chaos of 2011.

Looking at the bigger picture, however, Tokyo Electric Power Co. isn't making much progress decommissioning reactors 1, 2, 3 and 4 — a task expected to take at least three decades. This is because the very thing that saved the plant is now blocking the way: water.