Tokyo Electric Power (Tepco), the operator of the crippled nuclear plant in Fukushima, continues to report spikes in the amounts of radioactive cesium, tritium and strontium detected in groundwater at the plant.
That information continues to add a level of urgency to the task of sealing any leaks. Radioactive cesium and strontium, especially, can raise the risk of cancer in humans.
Shunichi Tanaka, the head of the Nuclear Regulation Authority, said in a New York Times report neither his staff nor the plant’s operator knew exactly where the leaks were coming from, or how to stop them.
Tanaka’s comments just goes to show the severe difficulty with the cleanup at the Fukushima Dai-ichi Nuclear Power Plant, where core meltdowns occurred at three of the six reactors after an earthquake and ensuing tsunami struck the plant over two years ago. A critical problem has been the groundwater that has been pouring into the basements of the damaged reactor buildings and becoming contaminated. Workers have been pumping the water out to store it in dozens of tanks at the plant, but have not stopped the inflow.
Tepco up until recently flatly denied any of that water was leaking into the ocean, even though various independent studies of radiation levels in the nearby ocean have suggested otherwise. But now Tepco said it was not sure whether there was a leak into the ocean.
“We’ve seen for a fact that levels of radioactivity in the seawater remain high, and contamination continues — I don’t think anyone can deny that,” he said Wednesday at a briefing after a meeting of the authority’s top regulators. “We must take action as soon as possible.
“That said, considering the state of the plant, it’s difficult to find a solution today or tomorrow,” he added. “That’s probably not satisfactory to many of you. But that’s the reality we face after an accident like this.”
Tanaka confirmed fears held by experts the plant continued to leak radiation into the ocean long after the huge initial releases seen in the disaster’s early days.
A study released earlier this year by Jota Kanda, an oceanographer at the Tokyo University of Marine Science and Technology, examined Tepco’s own readings of radiation levels in the waters near the plant’s oceanfront site. The study concluded it was highly likely the plant was leaking.
“If there was no leak, we would see far lower levels of radioactive cesium in waters off the plant,” Professor Kanda said last month. He said that natural tidal flushing of the water in the plant’s harbor should have dispersed the initially released radioactivity by now, with a far more rapid drop in radiation levels than had been detected.
“This suggests that water might be leaking out from the plant through damaged pipes or drains, or other routes Tepco doesn’t know about,” he said. “We need to find out where exactly these leaks are, and plug them.”