Why Fukushima's Water Is Growing More Radioactive

The Atlantic on Why Fukushima's Water Is Growing More Radioactive

"Let us go straight to the primary source of all this radioactive material: the heat-producing nuclear fuel. Preventing overheating, which could lead to another huge environmental release of radioactive material, is the highest priority. So far it’s been successful, primarily due to the makeshift cooling system, which has effectively kept the melted fuel rods (as well as those in the spent fuel pools) cool and stable since the fall of 2011. Time and the laws of physics have also lent a hand—the fuel generates less and less heat with each passing day. Indeed, its potential for overheating is significantly less than it was two years ago and will continue to diminish at a known rate.

This makeshift cooling system is a conceptually simple cycle. Water is constantly pumped to the stricken reactor vessels containing the damaged fuel. Because the integrity of internal various containment units was compromised, the water not only becomes contaminated by its pass over the damaged core but also finds its way into the buildings’ basements. The water is then pumped back out of the building, processed, and pumped through the building again. 

In practice, however, the system is not a neat, closed cycle; and it is here that major problems begin to appear. The entire site bristles with conduits, tunnels, and trenches, which, unfortunately, allow some of the untainted groundwater on its way to the sea to leak into these basements. This net inflow of about 400 tons of water per day, amounting to the carrying capacity of about 13 large gasoline truck, adds continuously to the volume of contaminated water that must be processed and contained. The solution so far has been to keep building more storage tanks and reservoirs on site.

Uphill of the stricken reactors is land covered with almost 1,000 of these water storage units. After two and a half years, they already hold enough water to fill 120 Olympic-size swimming pools, and their burden continues to grow. This colossal effort is unsustainable. Not surprisingly, leaks have begun to appear. "

There's a bunch more in the article.