Here’s the latest of our news bulletins from the ongoing crisis at Japan’s Fukushima Daiichi nuclear power plant.
State of the Fukushima Reactors
In its most serious move since the March 2011 triple meltdown at the Fukushima Daiichi nuclear power plant, Japan’s Nuclear Regulation Authority (NRA) has declared TEPCO’s radioactive water crisis a level 3 (“serious incident”) on the International Nuclear and Radiological Event Scale (INES). The rating is contingent upon review by the International Atomic Energy Agency (IAEA). The NRA made its decision after TEPCO announced on August 19 that 300 tons of highly radioactive water was leaking from a storage tank near reactor #4, and that the water had probably flowed directly into the Pacific Ocean, located 500 meters away. Even utility officials admitted that the debacle has become a “crisis situation.” Zengo Aizawa, one of TEPCO’s executive vice presidents, acknowledged, “The problem of contaminated water is the largest crisis facing the management, and we will place priority on dealing with the issue.”
Initially, TEPCO officials said that 120 liters had leaked, and the NRA determined that the incident measured 1 on the INES scale. However, they were forced to backtrack when it was later discovered that 300 tons of the highly radioactive water had poured out. The NRA tentatively changed its assessment to a level 3 on the INES scale, pending confirmation from IAEA officials. Nevertheless, that could still change; Toyoshi Fuketa, an NRA commissioner, notes, “The INES evaluation is based on the 300 ton leak, but I wonder if we can trust data provided by TEPCO. I really wonder if we should judge based on TEPCO’s data.” The INES scale goes from level 0 to 7, where level zero is too low to even be rated, and level 7 is considered a “major accident.” The 2011 Fukushima disaster and the 1985 Chernobyl nuclear disaster were both rated a 7.
Currently, TEPCO has no sense of where the leak occurred or how to stop it. Workers noticed two puddles of radioactive water near the container, and then realized that the tank, which is designed to hold 1,000 tons of water, only contained 700 tons. The other 300 tons (enough to fill 1,500 barrels, or a 25-meter swimming pool) had seeped out. Radiation levels near the puddles measured 100 millisieverts per hour, which is 100 times the government’s legal limit for the general public over the course of an entire year. Masayuki Ono, TEPCO’s General Manager, explained, “One hundred millisieverts per hour is equivalent to the limit for accumulated exposure over five years for nuclear workers, so it can be said that we found a radiation level strong enough to give someone a five-year dose of radiation within one hour.” A low-level concrete wall, which is designed to prevent water from leaking into the ocean, surrounds the tanks there, but TEPCO workers had opened its valves in order to release rainwater that was pooling and preventing them from identifying leaks. Instead, it allowed the contaminated water to flow out. The company reports that those valves have now been closed. The area was also surrounded by a “failsafe” boundary of sandbags, but that too failed, and the contaminated water breached it. The water within the tanks contained 80 million Bq/liter of radioactive materials, which means that the total amount leaked contained 24 trillion Becquerels. It contained strontium-90 and cesium-137, both of which have been linked to cancer, as well as radioactive tritium. That’s eight million times greater than the amount of radiation that the government considers safe for drinking water.
Workers do not know how much leaked into the sea, because some has been absorbed by soil. So far, they have only been able to recover four tons. Additional sandbags have been placed around the tank, in an effort to prevent the problem from worsening—but because workers do not know from where the water is originating, they assume the leak is ongoing. Some members of an NRA working group suggested that the concrete base of the tank might be cracked, although TEPCO has rejected that claim. Workers have removed the radioactive water from the tank, but because radiation levels there are so high, they cannot enter it to examine the structure until next week. NRA Chair Shunichi Tanaka has raised concerns that this may just be the tip of the iceberg. “We should assume that what has happened once can happen are, and prepare for more. We are in a situation in which there is no time to waste,” he said.
The leak occurred in a tank that was built by bolting sheets of stainless steel together; the tank is lined with resin. Officials believe that water may have leaked through areas where the bolts were improperly joined or had loosened. So far, four other smaller leaks have occurred in tanks of this type. Welded tanks are considered stronger and more stable, but they take longer to build, and TEPCO has been frantically looking for ways to store contaminated water. Even in the best-case scenario, the life expectancy for the bolted tanks is only five years, because the highly radioactive water is corrosive. Meanwhile, each day, approximately 400 tons of groundwater flow into the cracked basements of reactor buildings, which were heavily damaged by the 2011 earthquake and tsunami; that water mixes with other contaminated water, and thus also needs to be stored.
Initially, TEPCO dug seven belowground storage pits, which were capable of holding 58,000 tons of water, but after they too began to leak in April, 20,000 tons of radioactive water was transferred to aboveground tanks. The company had planned to filter much of that water through its Advanced Liquid Processing System (ALPS), but was forced to put the plan on hold in June, after one of the system’s tanks also began to leak. Officials are not expecting it to be fixed until December, although the NRA has urged TEPCO to work faster. As of August 20, there were 430,000 tons of radioactive water being stored at the compound. Eighty percent of the available tanks have been filled, not taking into account leaking ones that may need to be taken out of service. TEPCO is building more tanks, and hopes to be able to store 700,000 tons of water by 2015 and 800,000 tons by 2016. However, those tanks will only last for five years and will eventually need to be replaced.
NRA Chairman Tanaka has warned that the situation is spiraling downward, and eventually, TEPCO may intentionally dump radioactive water into the ocean because it has no where else to put it. “We fear a situation in which we have no control unless the water is dumped into the ocean, as the number of tanks keeps increasing rapidly,” he said. The chairman of a committee on water treatment issues agreed with the severity of that assessment, saying, “Unless government measures are taken promptly, the Fukushima Daiichi nuclear power plant will collapse at some point.” Not surprisingly, local fisheries cooperatives as well as other countries, including China and South Korea, both of which share the ocean with Japan, are not happy with that option, and have demanded more information. Tanaka also raised concerns about what would happen if another tsunami strikes the area and destroys the more than 1,000 tanks that are currently peppering the plant compound.
Currently, 350 of TEPCO’s approximately 1000 aboveground tanks are the bolted type, and the NRA has ordered the utility to immediately examine them to see if they, too, are leaking. Because most of them do not contain water measurement meters to determine if water levels have dropped, workers are simply conducting visual checks, and measuring for increased radiation levels nearby. Analysts say that the tanks were checked for leaks before they were ever used, but the process was conducted in the rain, making it difficult to assess whether or not they were actually watertight.
On Thursday, officials admitted that they had found two more radioactive hotspots at the bottom of two bolted tanks, but said that no water appeared to leaking from them, and water levels inside were stable. Radiation readings measured 70 and 100 millisieverts per hour, respectively. Radiation levels of nearby air measured 96 millisieverts per hour. The NRA has ordered TEPCO to step up its search for leaks, install water gauges on all tanks, and create a new water storage plan. Commissioners will conduct an onsite inspection today.
TEPCO has had a long series of mishaps at the plant, including numerous leaks, power outages (two of which were caused by rodents that chewed through electrical wires and shut down the entire cooling system for the plant’s spent fuel pools), and equipment malfunctions. But these most recent incidents are having a significant financial effect on both TEPCO and Japan at large. Asiana Airlines, the second largest carrier in South Korea, announced this week that it will cease flights to Fukushima Prefecture once its current contracts end in September, as a result of radiation concerns of its customers. “Passengers are clearly anxious, and we are paying attention to all reports on nuclear pollution levels at Fukushima,” said a company spokesperson. Fisheries cooperatives for Iwaki and Soma-Futaba have voluntarily halted test fishing indefinitely, recognizing that the public has lost faith in the safety of their seafood. And, Mitsuhei Murata, former Japanese ambassador to Switzerland, has called for the withdrawal of Tokyo’s bid to host the winter Olympic games.
Anger from residents of Fukushima Prefecture continues to build. Nearly two and a half years after the nuclear disaster first began, approximately 150,000 residents still are unable to return to their homes, and many believe that they will not be able to recreate their lives or earn a living there if the restrictions are lifted. Suspicion towards TEPCO remains high and is growing. “It’s just one problem after another,” said one resident. “All your countermeasures look like nothing but makeshift expedients,” complained a fisherman. And Yuhei Sato, the Governor of Fukushima, was blunt: “We want these problems dealt with for what they are, a national emergency. We’ve repeatedly demanded that TEPCO improve its safety management, and this latest incident is very frustrating,” he said, urging the central government to step in.
In the meantime, the utility announced that water flowing from trenches connected to reactors #2 and #3 has flowed into the Pacific, and at this point, an estimated 30 trillion Becquerels of highly radioactive water (10 trillion Becquerels of strontium-90 and 20 trillion Becquerels of cesium-137) has now entered the ocean since May 2011. That’s more than 100 times the amount of contamination that TEPCO normally allows to flow into the sea in the course of a year, and does not take into consideration radiation that spewed into the water in March and April of 2011, when the disaster was first unfolding and contamination levels were at their highest. TEPCO said on August 2 that 40 trillion Becquerels of radioactive tritium has probably flowed into the sea.
Ken Buessler, a marine biologist at Woods Hole Oceanographic Institution, raised concerns about the oceanic contamination. “It is not over yet by a long shot. Chernobyl was in many ways a one-week fire explosive event, but nothing with the potential of this, right on the ocean. We’ve been saying since 2011 that the reactor site is still leaking, whether that’s the buildings and the groundwater, or these new tank releases. There’s no way to really contain all of this radioactive water on site. Once it gets to the groundwater, it’s like a river flowing to the sea—you can’t really stop a groundwater flow. You can pump out water, but how many tanks can you keep putting on site? Our biggest concern is if…isotopes such as strontium-90…get through these sediments in the groundwater. They are entering the oceans at levels that then will accumulate in seafood, and will cause new health concerns.”
Mycle Schneider, a nuclear consultant who has served as lead author of the World Nuclear Industry status reports, said, “The quantities of water [TEPCO is] dealing with are absolutely gigantic. What is worse is that the water leakage is everywhere else—it’s not just [coming] from the tanks. It is leaking out from the basements, it is leaking from the cracks all over the place. Nobody can measure that. It is much worse than we have been led to believe, much worse.”