The Tokyo Electric Power Company (TEPCO) revealed last Thursday that one of the 1,000 makeshift tanks used to hold radioactive water at its Fukushima nuclear plant had leaked more than 100 tonnes of highly contaminated water over the previous day. The leakage—the largest since August 2013—occurs two weeks after revelations that TEPCO deliberately suppressed, for six months, its own findings of extremely high radiation levels in groundwater near the sea.
TEPCO spokesman Masayuki Ono said the company was sorry for “worrying the public with such a leak,” and claimed it was “unlikely” that the radioactive water had reached the ocean, which is just 700 metres away. The water had a radioactivity of 230 million becquerels per litre, 23 million times greater than the legal limit for drinking water.
The company has immediately sought to present the leakage—which occurred because the tank overfilled—as a result of human error. The company claims that valves controlling the flow of water along a pipe that fills the tank were mistakenly left open by an employee. However, TEPCO has admitted that one of the three valves was closed and is investigating why this did not prevent the tank from filling.
The leakage is a direct result of the short-term measures put in place by the company to address previous problems. The radioactive water breached a concrete perimeter around the tank by passing along a rainwater gutter. The gutters were installed in November to prevent rainwater from building up inside the barrier. Heavy rains the previous month flooded the storage area and allowed radioactive water to breach the concrete walls. Ono admitted that “this incident revealed [the gutter’s] weak point. We have to redesign it.”
The March 2011 earthquake and tsunami resulted in a failure of power supplies at the Fukushima plant, a partial meltdown, several hydrogen explosions and damage to the spent fuel rod pool at a fourth reactor. The failure of the reactors’ cooling systems meant that water had to be continuously injected into the cores, producing huge quantities of highly radioactive water. The company is now storing hundreds of thousands of tonnes of contaminated water in more than 1,000 tanks at the plant and the quantity continues to grow.
At every stage, TEPCO has sought to cut costs, creating further dangers. Yoshitatsu Uechi, an auto mechanic at the plant from December 2011 to June 2012, told the Asahi Shimbun in January that duct tape was commonly used to seal holes in storage tanks, and that wire nets rather than reinforcing steel bars were used in the storage tank foundations. Waterproof sheets were placed along the joints of the metal tanks to save on sealing agent. Uechi told the Japanese newspaper: “I couldn’t believe that such slipshod work was being done, even if it was part of stopgap measures.”
No faith can be placed in any of the claims of TEPCO or the government’s Nuclear Regulation Authority (NRA) about the extent of water leakage or the amount of radioactive waste that has reached the environment. TEPCO has a long and documented history of cover-ups and falsifying safety reports, with the collusion of the government’s nuclear supervisory organisations.
On February 7, TEPCO released its own findings on radioactivity levels in groundwater in the area around the plant—only 25 metres from the sea. The samples were taken in July and analysed by September 2013. Groundwater passes through the plant due to the natural weather cycle, becoming contaminated in the process. Between 300-400 tonnes of radioactive groundwater passes every day into the ocean.
TEPCO revealed that the groundwater at one of its monitoring wells contained five million becquerels per litre of Strontium-90, which is highly poisonous as it can replace calcium, accumulate in the food chain and build up in the bones of humans. This is more than five times the 900,000 becquerels per litre that the company reported at the time for all isotopes emitting beta radiation, including Strontium-90.
The company has given no explanation for the delay in releasing the data. NRA official Shinji Kinjo told Reuters on February 13: “We did not hear about this figure when they detected it last September. We have been repeatedly pushing TEPCO to release strontium data since November. It should not take them this long to release this information.”
The NRA was set up as a merger of two previous organisations, in a bid to dispel mass opposition to the Fukushima disaster and the collusion of regulatory bodies with giant energy companies such as TEPCO. Despite its history of deception and cost cutting, TEPCO has been left in charge of the massive task of dismantling the Fukushima reactors and cleaning up the site.
The latest storage tank leak is the largest since last August, when it was revealed that approximately 300 tonnes of radioactive water had leaked from a tank. Leaks are occurring regularly, however, and it is unclear how much of the water has already reached the ocean. Also on February 7, TEPCO announced that video footage taken by a robot used to clear debris from the damaged number three reactor showed highly radioactive water—containing large amounts of cesium and cobalt—leaking to the reactor’s drainage ditch.
The Japanese government of Prime Minister Shinzo Abe, like its predecessors, is completely beholden to the interests of the big energy corporations. Last month, the government approved—in the face of popular opposition to nuclear power in Japan—TEPCO’s plan to restart its biggest nuclear station, Kashiwazaki Kariwa, this summer.
The government has vested interests in suppressing evidence of the catastrophe caused by the Fukushima disaster. Abe is determined to ensure that Japan maintains its capacity to produce nuclear energy and, if ordered by the government, nuclear weapons. At the same time, Abe has downplayed the threat to the population posed by nuclear leaks at Fukushima as part of his bid for the 2020 Olympic Games.