TEPCO is also facing severe problems filtering and storing the contaminated water it does pump out from the ground and ruined buildings.
In May of 2013 The Asahi Shimbun reported the TEPCO was going to begin dumping groundwater at the Daiichi site because its storage capacities for contaminated water were nearly exhausted. There was considerable resistance from local fisherman because TEPCO lacked the capacity to remove Strontium-90 from captured water.
At that time, TEPCO reported that filtered water measured 710 million Becquerels per liter while unfiltered water was reported as twice as radioactive,[i] from tritium and strontium, the latter of which could not be filtered until the fall of 2014.[ii]
In 2015 the NRA approved a plan to allow TEPCO to dump decontaminated groundwater into the sea if the water registered less than 1 becquerel per liter of cesium, less than 3 becquerels per liter of beta emitters such as Strontium-90, and 1,500 becquerels per liter of tritium (NRA signs off on TEPCO plan to release decontaminated groundwater into sea January 22, 2015 http://ajw.asahi.com/article/0311disaster/fukushima/AJ201501220054).
Despite the low limits of contamination allowed by law in 2015, it appears likely from news accounts and TEPCO press releases that contaminated water has been deliberately and accidently released into the ocean since 2013, if not earlier, because the reported volume of water in storage has declined, despite daily production of hundreds of tons of water that exceed decontamination capacities:
May of 2013, TEPCO reported it held approximately 280,000 tons of radioactive water in storage, while an additional 100,000 tons were believed to reside in the basements of units 1 through 4, as well as in the turbine buildings.[iii]
August 2013 TEPCO reported that approximately 300,000 tons of contaminated water leaked from one of the storage tanks and promised to treat all the contaminated water in storage by March 2015 (http://www3.nhk.or.jp/nhkworld/english/news/20150123_30.html).
January 2014 TEPCO announces at press conference that contaminated water in storage tanks is producing Bremsstrahlung radiation, which contributes to rising atmospheric radiation levels at the Daiichi site (Mochuzuki, 2014). The Nuclear Regulation Authority ordered TEPCO to lower radiation levels derived from tanks storing contaminated water to below 1 millisievert by the end of March 2015. Nagano
February 2014 TEPCO reports a high of 360,000 tons of contaminated water in storage (Varma, 2014).Water measuring 230 million Becquerels per liter was reported leaking from storage containers at Daiichi in February 2014 (“TEPCO Finds,” 2014).
September 18 2014: TEPCO reports 365,000 tons of highly contaminated water in storage tanks as of Sep 16 2014. (TEPCO begins test runs of new ALPS system at stricken plant. September 18, 2014). The Asahi Shimbun because the system in place since March 2013 has been prone to problems “So far, the existing trouble-prone ALPS equipment has processed 138,000 tons of contaminated water.”
November 2014 TEPCO reports 500,000 tons of radioactive water is being stored in 1,000 large tanks, which include costlier new ones less likely to leak AP. Nuclear cleanup at Fukushima plant stymied by water woes November 13, 2014 http://ajw.asahi.com/article/0311disaster/fukushima/AJ201411130092
January 15 2015 TEPCO reported it had 280,000 tons in storage and would not be able to meet its promised 2015 deadline (“TEPCO Racing Against Time, 2015)TSUYOSHI NAGANO TEPCO racing against time to process 280,000 tons of tainted water at Fukushima plant. (January 19, 2015)The Asahi Shimbun, http://ajw.asahi.com/article/0311disaster/fukushima/AJ201501190050
I think it appears highly likely that highly contaminated water has been deliberately dumped for years. TEPCO cannot filter tritium and has only recently began filtering strontium yet the amount of water in storage has remained strangely constant.
TEPCO has struggled with its ALPS water filtration system from the beginning: the system could not beta-emitters effectively (e.g., strontium and tritium) and was prone to breakdowns.
The new filtration system adopted in the fall of 2014 was an improvement because it removed Strontium but TEPCO announced it would regard water filtered by that system decontaminated, despite its failure to reduce other radionuclides:
Nagano, Tsuyoshi.TEPCO racing against time to process 280,000 tons of tainted water at Fukushima plant January 19, 2015 http://ajw.asahi.com/article/0311disaster/fukushima/AJ201501190050
The company introduced additional ALPS systems last autumn [fall 2014] to treat up to 1,960 tons of radioactive water a day. The maximum processing capability was still insufficient to complete procedures by the end of March 2015, so TEPCO introduced equipment that only removes strontium, which accounts for a large portion of all radioactive substances in the water.
TEPCO has since been working to meet the target date by regarding strontium-free water as being “processed,” even if other radioactive substances remain.
Water filtered for strontium alone is now being designated as “processed,” although TEPCO hopes to get both the new and the old filtering system running together sometime in the spring of 2015. It seems clear from these news report that water contaminated with beta emitters has very likely been dumped into the Pacific since the Fukushima crisis began.
How long will contaminated water continue to be dumped or flow uncontained into the Pacific Ocean? Lack of ongoing sampling on land and in fresh and ocean water may lead scientists to underestimate the long-term effects of the disaster on the environment, particularly the ocean.
[i] S. Kimura (6 April 2013) ‘120 Tons of Contaminated Water Leaks at Fukushima Nuclear Plant’, The Asahi Shimbun, http://ajw.asahi.com/article/0311disaster/fukushima/AJ201304060038, date accessed 7 April 2013.
[ii] Yoshida ‘Fukushima No. 1 Can’t Keep its Head Above Tainted Water’.
[iii] ‘TEPCO to Dump Groundwater to Ease Crisis at Fukushima Nuclear Plant’.