Nuclear Leaks 29: Billions of Bequerels of Radiocesium Per Litre at Fukushima

"Workers in the rain install underground walls to prevent contaminated groundwater from flowing into the ocean on July 22 [2013]." Image Source: Asahi Shimbun.

A trench along the seawall at Fukushima with 5,000 cubic metres of water may be leaking - or be on the verge of leaking - into groundwater and into the Pacific. The water, which appears to be coming from, or did come from, under Fukushima Daiichi reactor #2, contains astonishing levels of radioactive material. After a 26 July test, TEPCO's published results from 27 July 2013 are translated from Japanese at EX-SKF here. Workers are building a wall of liquid glass between the trench and the sea to prevent extreme contamination of the Pacific Ocean.

The situation had already begun attracting growing external criticism in April. Pity the brave workers, who are struggling with this monster:

“The water keeps increasing every minute, no matter whether we eat, sleep or work,” said Masayuki Ono, a general manager with Tepco who acts as a company spokesman. “It feels like we are constantly being chased, but we are doing our best to stay a step in front.”...

The situation is worrisome enough that Shunichi Tanaka, a longtime nuclear power proponent who is the chairman of the newly created watchdog Nuclear Regulation Authority, told reporters after the announcement of the leaking pits that “there is concern that we cannot prevent another accident.” ...

A growing number of government officials and advisers now say that by entrusting the cleanup to the company that ran the plant before the meltdowns, Japanese leaders paved the way for a return to the insider-dominated status quo that prevailed before the disaster. 

Even many scientists who acknowledge the complexity of cleaning up the worst nuclear disaster since Chernobyl fear that the water crisis is just the latest sign that Tepco is lurching from one problem to the next without a coherent strategy. 

“Tepco is clearly just hanging on day by day, with no time to think about tomorrow, much less next year,” said Tadashi Inoue, an expert in nuclear power who served on a committee that drew up the road map for cleaning up the plant.

Today's reports:

• WSJ:  "Radiation of 750 million becquerels a liter of cesium-134 and 1.6 billion becquerels a liter of cesium-137 was recorded, Tepco said. The normal limits for the two potentially harmful isotopes are 60 and 90 becquerels, respectively. In April 2011 a combined 1.8 billion becquerels was recorded. 'The level of radioactivity is potentially serious but the impact would depend on where it is found,' a Tepco official said. The sample came from a trench near the No. 2 reactor turbine building, the utility said. Water with much lower radiation—around 9,000-18,000 becquerels a liter--has leaked into the sea from groundwater, Tepco said earlier this week after the Nuclear Regulation Authority said it suspected seepage. This radiation was at 'far lower levels' than found in the trench samples, the Tepco official said. Tepco is searching for the water source. It is probably from one of the damaged reactor cores. It is trying to stop the water leaking into the sea, it said." 
• EXSKF: "5,000 cubic meters, or 5,000 tonnes of this water is in the trench. Note: 5,000 cubic meters of water is equal to 5 million liters. One liter was found to contain 2.35 billion becquerels of cesium. If this concentration is consistent, the total amount would be nearly 12 quadrillion becquerels of cesium in this one trench."
• Japan Times (hat tip: ENE): "Tokyo Electric Power Co. said Saturday that the trench problem at the crippled Fukushima No. 1 nuclear plant has cropped up again and is sending highly radioactive water into the sea. The water in the underground passage, which runs under the turbine building of reactor 2, contains 2.35 billion becquerels of cesium per liter, roughly the same as that measured right after the crisis began in spring 2011. The latest sample, taken Friday from a trench, contained 750 million becquerels of cesium-134, 1.6 billion becquerels of cesium-137 and 750 million becquerels of other radioactive substances, the utility said. A sample from April 2011 contained 1.8 billion becquerels of both cesium-134 and cesium-137 per liter. Cesium has a half-life of about 30 years. The trench is believed to be the source of the groundwater problem that’s been baffling Tepco’s experts for months. Their current theory is that the highly radioactive water found and left in the trench in 2011 is now leaking directly into the groundwater, which is seeping into the sea.Tepco finally admitted Monday that contaminated water was getting into the Pacific. The admission came after the Nuclear Regulation Authority pointed out that highly radioactive water was 'strongly suspected' to be seeping into the ground under the site and making its way to the sea." 
• Asahi Shimbun: "According to TEPCO, 2.35 billion becquerels of radioactive cesium were detected per liter of water that was sampled July 26 from a cable pit on the ocean side of the No. 2 reactor. The breakdown was 750 million becquerels of cesium-134 and 1.6 billion becquerels of cesium-137. A liter of the water was also found to contain 750 million becquerels of radioactive substances that emit beta rays, such as strontium. Those concentration levels are almost the same as measurements taken during the early phases of the disaster, TEPCO said. 'We believe the highly radioactive water is staying within the pit,' a TEPCO official said, adding that the utility will nevertheless check carefully for possible leaks into surrounding soil and seal the ground to block such leaks from reaching the sea. ... The utility hopes to halt the problem by building a wall out of liquid glass between the reactors and the sea and removing the contaminated water from the underground passage."