Fresh leak at Fukushima No. 1 highlights Tepco’s struggle to decommission plant


Sensors at the Fukushima No. 1 nuclear plant have detected a fresh leak of highly radioactive water to the sea, the plant’s operator announced Sunday, highlighting continued difficulties in decommissioning the crippled atomic station.

Tokyo Electric Power Co. said the sensors, which were rigged to a gutter that drains rain and groundwater at the plant into a nearby bay, detected contamination levels up to 70 times greater than the already-high radioactive status seen on the plant grounds.

Tepco said its emergency inspections of tanks storing nuclear wastewater did not find any additional abnormalities, but the firm said it closed the gutter to prevent radioactive water from flowing into the Pacific Ocean.

The higher-than-normal levels of contamination were detected at around 10 a.m., with sensors showing radiation levels 50 to 70 times greater than usual, Tepco said.

The levels of beta ray-emitting substances, such as strontium-90, measured 5,050 to 7,230 becquerels per liter of water between 10:20 a.m. and 10:50 a.m. Tepco requires radioactivity levels of groundwater at the plant discharged into the sea to remain below 5 becquerels.

Though contamination levels had steadily fallen throughout the day, the same sensors were still showing contamination levels about 10 to 20 times more than usual, a company spokesman said later in the day.

It was not immediately clear what caused the original spike and its gradual fall, he added.

“With emergency surveys of the plant and monitoring of other sensors, we have no reason to believe tanks storing radioactive wastewater have leaked,” he said.

“We have shut the gutter (from draining water to the bay). We are currently monitoring the sensors at the gutter and seeing the trend,” he said.

The latest incident, one of several that have plagued the plant in recent months, reflects the difficulty in controlling and decommissioning the plant, which suffered a triple-meltdown and explosions after being battered by a giant quake and tsunami in March 2011, sparking the world’s worst nuclear disaster in a generation.

Tepco has been unable to effectively deal with an increasing amount of contaminated water, which is used to cool the crippled reactors and molten fuel inside them and is kept in large storage tanks on the plant’s vast spread.

Adding to Tepco’s headaches has been the persistent flow of groundwater from nearby mountains traveling under the contaminated plant before flowing into the Pacific Ocean.

The International Atomic Energy Agency recently said Tepco has made “significant progress” in cleaning up the plant, but suggested that Japan should consider ways to discharge treated wastewater into the sea as a relatively safer way to deal with the radioactive water crisis.

Since the drainage ditches are connected to the port of the No. 1 plant, the NRA has instructed Tepco to shut the gates there, officials said.

Tepco confirmed that no leaks from tanks containing radioactive water were found, but said it was investing further.

  • Leslie Corrice

    The are more than 60 Beta-emitting isotopes in the F. Daiichi wastewaters. You make it seem as if Sr-90 is the only one causing the spike. It is grossly misleading and needs to be corrected.

  • Vivienne Perkins

    The fact is that the accident at Fukushima-daiichi represents the gravestone to the human enterprise on this planet. Like Chernobyl, it will never be cleaned up. Every government with nuclear reactors or weapons lies about their safety; I’ve lived through the entire nuclear era and have heard all of them. Whether or not we want to face up to the facts, we have poisoned our planet (radioactive fallout, highly contaminated weapons mfg. sites like Hanford, Savannah River and the rest, emissions from power reactors, detonating H-bombs in the Van Allen radiation belt, mountains of r/a waste and spent fuel rods no one knows how to dispose of–and which won’t be disposed of). We also know very little about the health consequences of radioactive exposures for the simple reason that our govt. took care not to keep adequate records. We might as well give up the fatuous notion that human beings are capable of reason; anyone who knew the facts and could use his brain would know that we must abolish them utterly. They are now in the inexorable process of abolishing us.

  • boonteetan

    Almost 4 years after the explosion, Fukushima is still deadly as ever. This terribly ugly episode of nuclear reactor disaster should remind people that even in a highly advanced technology country like Japan, there is no guarantee of safe reactors.

  • pete0097

    I assume that you have a very nice cave (with geothermal heat), eat your food both fresh and un-cooked. Don’t wear anything that was made from petrochemicals and walk or ride a bike to get around. If not, you may be a hypocrit.

  • vlady47

    NRC Magwood:
    It is very difficult to overstate how difficult the work is going to be at that site. There will need to be new technologies and new methodologies created to be able to enable them to clean the site up and some of these technologies don’t exist yet, so there’s a long way to go with that …. There’s a long, long way to go.

  • Enkidu

    Hi vlady,

    The article you linked to has nothing to do with Fukushima. Maybe you could tell us which “lessons learned from Chernobyl prove [Fukushima] can’t be clean [sic] up”?

    Also, Tim Mousseau, who is highly quoted in the article, is a crank. For example, this statement, from near the end of the article is profoundly stupid: “There will be areas that will be contaminated for thousands, if not millions, of years.” This is meaningless. Those areas were “contaminated” before the accident at Chernobyl, and they will be “contaminated” forever regardless of whether the accident ever happened. Any person with even a basic understanding of environmental health understands that.