Reports that plutonium had been detected at five locations inside the grounds of the stricken Fukushima nuclear power plant set off a flurry of activity on blogs and twitter accounts today. But the truth is that plutonium around the facility was to be expected–and the levels found do not pose a threat to human health.
Indeed, TEPCO officials believe that three of the five samples found on March 21 and 22 were actually deposited on the site many years ago following the testing of nuclear weapons by various countries in the atmosphere, which left trace amounts of plutonium in the soil of locations around the world. The other two traces of plutonium came from fuel of reactor No. 3, a MOX fuel that, as we’ve explained here and here, contains roughly 5% plutonium. These samples of escaped plutonium were of similar concentrations to the decades-old plutonium, and therefore do not pose an immediate threat to human health, the company said. However, because plutonium stays around for thousands of years, it will complicate the clean-up operation at the plant.
Of more urgent concern on Monday was revelations that highly contaminated water had escaped from Reactor No. 2, further complicating clean-up operations by posing a threat to emergency workers, and also threatening to leak into the ocean. This means that radioactivity could contaminate fish, but Japanese officials said no fishing would be allowed within the 12-mile exclusion zone of the plant.
The water, which had leaked into an overflow tunnel that leads to an opening 180 ft. from the sea, contained radiation measuring 1,000 millisieverts per hour, according to a report in the New York Times. At that level, workers would be at risk of acute radiation poisoning. Dr. Ferenc Dalnoki-Veress, a Research Scientist at the Monterey Institute of International Studies, told Ecocentric that the clean-up operation of radioactive water would pose a variety of safety concerns for the emergency workers. “Can you imagine spraying around highly radioactive water? What a nightmare.”