High Level of Radioactive Strontium Found in Groundwater Near Fukishima Plant Tokyo Electric Power, the operator of the stricken nuclear power plant at Fukushima, said Wednesday that it had detected high levels of radioactive strontium in groundwater at the plant, raising concerns that its storage tanks are leaking contaminated water, possibly into the ocean. The operator said it had found strontium-90 at 30 times Japan's safety limit in groundwater near its No. 2 reactor, which suffered a fuel meltdown in 2011. The company has struggled to store growing amounts of contaminated runoff at the plant, but had previously denied that the site's groundwater was highly toxic. If ingested, strontium-90 can linger in bones, emitting radiation inside the body that can lead, in time, to cancer.