Consensus holds that Fukushima constitutes the greatest radiological release into the ocean ever to occur. According to Woods Hole Oceanographic Institution in Massachusetts, levels of radioactive cesium reached more than 100,000 becquerels per cubic meter in early April of 2011.[i] The World Nuclear Association suggests that 169 Petabecquerels of Iodine-131 equivalent were releases into the ocean from Cesium-137, Cesium-134, and Iodine-131from March 26 to September 30th.[ii] This figure does not include March releases into the atmosphere, which the World Nuclear Association calculates at 1020 petabecquerels from March 12 to March 31, 011. The French Institute for Radiological Protection and Nuclear Safety (IRSN) described Fukushima as the world’s worst nuclear contamination event ever for the ocean,[iii] reporting that from March 21st to mid-July 27, 27.1 petabecquerels of cesium-137 contaminated the ocean. One peta becquerel is equivalent to a million billion becquerels, or 10^15. [iv]
Atmospheric and direct ocean releases occurring as contaminated water spilled from reactors into the ocean caused radionuclide levels to spike offshore. Woods Hole scientist Ken Buessler revealed (12/12/2011) that Fukushima cesium-137 radiation in the sea near the plant peaked in April 2011 at 50 million times above normal levels (http://www.forbes.com/sites/jeffmcmahon/2011/12/12/fukushima-ocean-radiation-was-50-million-times-above-normal-but-no-threat-scientists/). In a separate interview with Straight on October 28, 2011, Ken Buesseler stated that Fukushima was by far the greatest accidental release of radiation into ocean waters, the magnitude of which in April 2011 was over one hundred times Chernobyl’s contamination of the Black Sea.[v]
These comments reflect concerns based on ocean emissions during the first few months of the disaster. Ocean contamination did not however end in the first months of the disaster. The releases of radioactive water from the plant into the ocean have been, in this writer’s opinion, ongoing because of the need for continuous cooling of melted reactor corium and the inability to effectively de-contaminate cooling water. Reactors 1 through 3 have been continuously cooled since March of 2011 with water injections. The World Nuclear Association reports that by the end of March 2011 all water storage tanks – the condenser units and condensate tanks – around units 1 through 4 were full of contaminated water pumped from the buildings.[vi] Tepco built a wastewater treatment facility to decontaminate the water but has struggled with decontamination and storage given the volume of water being pumped into the reactor buildings and the level of contamination. During the summer of 2011 Tepco installed concrete panels designed to seal water intakes of units 1 through 4 in order to prevent contaminated water from reaching the ocean. In October 2011, Tepco installed a steel water shield wall between the units and the ocean.[vii]
Yet, despite these efforts ocean contamination has continued because the site is literally saturated from the ongoing water injections. As of September of 2012, Tepco reported water injections as follows: five tons per hour at Unit 1reactor; seven tons per hour at unit 2; seven tons per hour at unit 3.[viii] No information was provided about any water injections into unit 4 or the common spent fuel pool. At 456 tons a day of water going into the units, we can expect substantial ongoing leakage into the ocean. In November of 2011,Tepco admitted that its filtration system at the plant dumped more 11,000 tons of water contaminated with cesium 134, 137, and Iodine 131 into the sea.[ix] Tepco stated that it had been spraying about 70 tons of water around the Daiichi compound a day since early October and that water in some trenches measured at 10,000 millisieverts an hour, which is 10 sieverts an hour, a fatal dose.[x]
Ken Buesseler speaking in March 2012, described the data from his international research cruise off Japan that took place in June 2011:
Despite the announcement in December that operators of the power plant had achieved cold shut down, we know they are still using tons of water to cool the reactors and that not all the water has been collected or treated. As a result, the ground around the site is like a dirty sponge, saturated with contaminated water that is leaking into the ocean.
He noted that other scientists had confirmed his 2011 findings of radiation levels 400 miles offshore Japan. He pointed out that little was known about radiation levels at seafloor levels but evidence exists that marine sediments are collecting radioactive contamination at higher concentrations than in the water. He said that little information was available about the radiation levels of groundwater. He tells the public that information about the extent of releases of contaminated water are lacking:
Other measurements show trends that are more worrisome. Levels of radioactivity found in fish are not decreasing and there appear to be hot spots on the seafloor that are not well mapped. There is also little agreement on exactly how much radioactivity was released or even whether the fires and explosions at the power plant resulted in more radioactive fallout to the ocean than did direct releases of radioactivity caused by dumping water on the reactors to keep them cool.[xi]
The Mainichi reported on April 3, 2012 that “Cesium up to 100 times levels before disaster found in plankton far off nuke plant” and that the “high concentration of cesium, which is believed to derive from the Fukushima No. 1 Nuclear Power Plant, suggests that radioactive substances that have leaked from the complex are spreading extensively in the sea.” http://mdn.mainichi.jp/mdnnews/news/20120403p2a00m0na009000c.html
Recent findings on cesium-134 deposits in marine snow gathered 2000 kilomters away from the plant at depths of 5000 meters measuring 1,200 Becquerels per kilogram indicate that radiation contamination from Fukushima has spread far and wide.
Lack of certainty about the extent of initial and ongoing atmospheric and ocean releases of radiation from the plant complicates extrapolations of effects. Tepco has provided no concrete information about the extent of damage to the nuclear fuel in the reactors and pools. Mr. Yastel Yamada, a retired engineer and founder of the volunteer Fukushima Skilled Veterans Corps commented that the fuel from the reactors may possibly be in powder form.[xii]
The radiation contamination of the Pacific will be an ongoing problem. One study that modeled dilution declines of Cesium-137 published in Environmental Research Letters predicted that after seven years the “total peak radioactivity levels would still be about twice the pre-Fukushima values” off the coastal waters of North America”[xiii] The risks from contaminated ocean water are not restricted to marine and coastal life. Long-lasting radioactive isotopes, such as cesium-137 and plutonium-239, will bio-accumulate in marine life in the same fashion that mercury bio-accumulates currently. Marine animals at the top of the food chain and birds that feed on marine life will become highly contaminated radioactively. The Canadian Museum of Nature notes that orcas are often considered toxic waste when they die based on their high toxicity.[xiv]
Furthermore, contaminants in the ocean do not necessarily stay in the ocean....
[i] Cited Hiroko Tabuchi. Fears Accompany Fishermen in Japanese Disaster Region The New York Times (2012, June 25): http://www.nytimes.com/2012/06/26/world/asia/fears-accompany-fishermen-in-japanese-disaster-region.html?nl=todaysheadlines&emc=edit_th_20120626
[ii] World Nuclear Association Fukushima Accident (2012, September last update), http://www.world-nuclear.org/info/fukushima_accident_inf129.html
[iii] Fukushima nuclear pollution in sea was world's worst: French institute. Japan Today Oct. 28, 2011 - http://www.japantoday.com/category/national/view/fukushima-nuclear-pollution-in-sea-was-worlds-worst-french-institute
[iv] “Fukushima Disaster Produces World’s Worst Nuclear Sea Pollution. The Maritime Excective (2011, October 28) http://www.maritime-executive.com/article/fukushima-disaster-produces-world-s-worst-nuclear-sea-pollution.
[v] Alex Roslin http://www.straight.com/article-491941/vancouver/what-are-officials-hiding-about-fukushima?page=0%2C2
[vi] World Nuclear Association Fukushima Accident (2012, September last update), http://www.world-nuclear.org/info/fukushima_accident_inf129.html
[vii] World Nuclear Association Fukushima Accident (2012, September last update), http://www.world-nuclear.org/info/fukushima_accident_inf129.html
[viii] Sep 1 2012 TEPCO reports drop in water injection rate at N-plant. Yomiuri (2012, Sep 1), http://www.yomiuri.co.jp/dy/national/T120831004812.htm
[ix] Robert Mackey and Ravi Somaiya (November 1, 2011) Japanese Official Drinks Water From Fukushima Reactor Buildings. The New York Times By ROBERT MACKEY and RAVI SOMAIYA http://thelede.blogs.nytimes.com/2011/11/01/japanese-official-drinks-water-from-fukushima-reactor-buildings/
[x] Robert Mackey and Ravi Somaiya (November 1, 2011) Japanese Official Drinks Water From Fukushima Reactor Buildings. The New York Times By ROBERT MACKEY and RAVI SOMAIYA http://thelede.blogs.nytimes.com/2011/11/01/japanese-official-drinks-water-from-fukushima-reactor-buildings/
[xi] Ken Buessler What Fukushima accident did to the ocean By Ken Buesseler, Special to CNN March 11, 2012 http://www.cnn.com/2012/03/10/opinion/buesseler-fukushima-ocean/index.html
[xii] “I Don’t Know What Would Happen”: Fuel from Fukushima reactors may be powder — If so, work almost impossible (AUDIO). Enenews (2012, ) http://enenews.com/dont-happen-future-fuel-fukushima-reactors-be-powder-work-almost-impossible-video/comment-page-1#comment-291586Mr. Yastel Yamada, a retired engineer and founder of the Fukushima Skilled Veterans Corps
Uploaded by: OccupyUkiah Filmed: July 30, 2012 Uploaded on: Sept. 27, 2012
Uploaded by: OccupyUkiah Filmed: July 30, 2012 Uploaded on: Sept. 27, 2012
[xiii] Erik Behrens1, Franziska U Schwarzkopf1, Joke F Lübbecke2 and Claus W Böning1 Model simulations on the long-term dispersal of 137Cs released into the Pacific Ocean off Fukushima Erik Behrens et al 2012 Environ. Res. Lett. 7 034004