Via The New York Times: Worst Spill in 6 Months at Stricken Japanese Nuclear Plant. Excerpt:
About 100 tons of highly radioactive water leaked from one of the hundreds of storage tanks at the devastated Fukushima nuclear plant, its operator said on Thursday, calling it the worst spill at the plant in six months.
The operator, the Tokyo Electric Power Company, said the leak, discovered on Wednesday and stopped on Thursday, happened far enough from the plant’s waterfront that none of the radioactive water was likely to reach the Pacific Ocean, as has happened during some previous spills.
Still, the incident was an uncomfortable reminder of the many mishaps that have plagued the containment and cleanup efforts at the plant, as well as the hundreds of tons of contaminated groundwater that still flows unchecked into the Pacific every day.
The company, known as Tepco, said it had traced the latest leak to a pair of valves that were left open by mistake.
The leaked water was among the most severely contaminated that Tepco has reported at the Fukushima Daiichi plant since March 2011, when damage caused by an earthquake and a tsunami led to meltdowns in three of the plant’s reactors. Each liter of the water contained, on average, 230 million becquerels of particles giving off beta radiation, the company said.
About half of the particles were likely to be strontium-90, which is readily taken up by the human body in the same way as calcium, and can cause bone cancer and leukemia.