Soaring radiation spikes in water at and around Fukushima Daiichi hindering progress to cool reactors

ingressimage_control_room_reactor_2.jpg Photo: Kyodo

Engineers have been battling to control the six-reactor Fukushima Daiichi complex since it was damaged by a March 11 earthquake and tsunami that also left more than 27,000 people dead or missing across Japan’s devastated northeast. Some 200,000 people have been evacuated from the 30 kilometer radius surrounding the plant, and radiation levels that have been released are reported by many groups to be equal to or closing in on those that were released at Chernobyl, the Russian environmental group Ecodefence reported.

Rain containing trace amounts of radioactivity from Fukushima Daiichi was reported in Boston today. Levels were said not to be harmful to human health, but it is a telling development in the crisis, which has literally reached across the globe.

Radiation at the nuclear plant has soared in recent days. Latest readings on Sunday showed contamination 100,000 times normal in water normally found at a nuclear power plant in reactor No. 2 and 1,850 times normal in the nearby sea.

Highly contaminated water is also escaping the damaged reactor No 2 and could soon leak into the ocean, the country’s nuclear regulator warned on Monday. Japan’s Nuclear and Industrial Safety Agency said workers were redoubling efforts to remove the water, which stands in the way of them making critical repairs to cooling systems in the defunct reactors.

In another grim new discovery, plutonium was detected in soil at five locations at the plant, Tokyo Electric Power Co (TEPCO), which runs the complex, said. The company asserted that the plutonium, found in samples taken a week ago, posed no threat to public health.

Whether that assertion is true was heavily questioned by an ex-government official in an email interview with Bellona Web.

“TEPCO Vice President [Sakae] Muto is dodging the question like a politician, repeating that the measured amount is within the amount which was measured in the past in Japan,” wrote the ex-official of the televised TEPCO press conference earlier today when the discovery was made public. “The meaning of this is not clear and I cannot understand what he wants to say.” 

The source said that samples of plutonium were taken on March 20th and 21st from five locations within the Fukushima Daiichi plant. Two of the five samples likely came from fuel rods at Fukushima Daiichi’s reactor No 3, which burns plutonium and uranium mixed oxide, or MOX, fuel.

TEPCO said that the concentration of plutonium 238 in the samples was more than three times the average concentration found in Japan. Plutonium 239 and 240 where also found in the samples, said TEPCO.

The ex-government official pointed to a glaring conflict of interest within the agencies overseeing nuclear power in Japan and those promoting the use of dangerous MOX fuel. Japan’s nuclear safety watchdog, the Nuclear and Industrial Safety Agency, and the Agency for Natural Resources and Energy, which stumps for MOX use, both answer to the Ministry of Economy, Trade Industry.

“This puts things at cross purposes,” said the source.

That plutonium is turning up in the environment confirms a number of suspicions held by Bellona nuclear physicist Nils Bøhmer – that a core breach at the No 3 reactor, which burns MOX, did indeed occur during an explosion in the reactor building on March14; and that spent nuclear fuel, which contains plutonium, released large quantities of radioactivity as reactor No 4’s spent nuclear fuel storage pond burned last week and the week before.  

All of this could mean crews seeking to determine damage and fix the problems at the plant may not be able to approach some of the most troubled parts of the complex until the water can be safely removed.

Tetsuo Iguchi, a professor in the department of quantum engineering at Nagoya University, told the New York Times that at these sharply elevated radiation, workers would be able to remain on the site for only about 15 minutes before health considerations required them to leave. That could compromise attempts to bring the crisis under control.

Alarm over the radiation levels first intensified Thursday when three workers rushed to hospital after receiving radiation burns in reactor No 2 when water poured into their boots. Two workers remain hospitalized, while the third avoided burns because he was wearing higher boots.

Late Saturday, a worker trying to measure radiation levels of the water at another reactor, No. 2, saw the reading on his dosimeter jump beyond 1,000 millisieverts per hour, the highest reading on the device. The worker left the scene immediately, said Takeo Iwamoto, a spokesman for TEPCO, Kyodo News reported.

Michiaki Furukawa, a nuclear chemist and a board member of the Citizens’ Nuclear Information Center, a Tokyo-based watchdog group, told the New York Times that exposure to 1,000 millisieverts of radiation per hour would induce nausea and vomiting, while exposure to triple that amount could be lethal.

The contaminated water threatening the ocean has radiation measuring 1,000 millisieverts per hour and is in an overflow tunnel outside the plant’s reactor No. 2, Japan’s nuclear regulator said at a news conference. The maximum dose allowed for workers at the plant is 250 millisieverts in a year.

TEPCO said that since the crisis began, 19 workers had been exposed to radiation levels of 100 millisieverts.

The tunnel holding the irradiated water leads from reactor No 2’s turbine building, where contaminated water was discovered on Saturday, to an opening just 180 feet from the sea, Hidehiko Nishiyama, deputy director-general for NISA, told reporters.  The water level is now at almost a meter and rising, he said.

Contaminated water was also found at tunnels leading from the No 1 and No 3 reactors, though with much lower levels of radiation.

NISA also reported that radioactive iodine 131 was detected Sunday at a concentration 1,150 times the maximum allowable level in a seawater sample taken about a mile north of the drainage outlets of reactor units 1 through 4. It also said that the amount of cesium 137 found in water about 300 meters from plant was 20 times the normal level, roughly equal to readings taken a week ago.

The irradiated water inside the reactors is hindering worker access to reactor control rooms, which is critical to putting restored electrical power to use in the cooling systems, which have been down since hours after the quake hit.

Rescuers also attenuated spraying the exposed fuel rods at reactor No 2 and at other reactors to hinder the overflow, which is hindering efforts to cool them off. 

“I think maybe the situation is much more serious than we were led to believe,” said one expert, Najmedin Meshkati, of the University of Southern California, adding it may take weeks to stabilize the situation and the United Nations should step in.

“This is far beyond what one nation can handle – it needs to be bumped up to the U.N. Security Council,” he said.

TEPCO has conceded it faces a protracted and uncertain operation to contain overheating fuel rods and avert a meltdown.

“Regrettably, we don’t have a concrete schedule at the moment to enable us to say in how many months or years (the crisis will be over),” TEPCO vice-president Sakae Muto said in the latest of round-the-clock briefings the company holds.

Charles Digges