Stopping Fukushima Leaks with a Giant Ice Wall

fukushima_icewallFor years, scientists and environmentalists have worried about the long-term fallout of the Fukushima Dai-Ichi nuclear accident. And after a month of radioactive water leaking from the plant, the Japanese government has announced the construction of a giant, $470 million ice wall to stop it from filtering into the surrounding environment and the sea. This announcement was made shortly after another leak was discovered over the August long weekend.

This came only two weeks after Tokyo Electric Power Co. (TEPCO) revealed that some 300 tons of radioactive water had disappeared from a steel tank at the site. Shunichi Tanaka, chairman of the Japanese Nuclear Regulation Authority then announced at a press conference the following Monday that a small leak had sprung from a connecting pipe between some of the emergency storage tanks constructed in the wake of the tsunami.

fukushima_leakTEPCO added that more radiation had been discovered near other storage tanks, pointing to the possibility of further leaks. Hence the decision to create a freeze wall, which would attempt to keep the leaks from getting into the groundwater and wreaking havoc all across the Pacific Ocean. According to the Associate Press:

The ice wall would freeze the ground to a depth of up to 30 meters (100 feet) through a system of pipes carrying a coolant as cold as minus 40 degrees Celsius (minus 40 Fahrenheit). That would block contaminated water from escaping from the facility’s immediate surroundings, as well as keep underground water from entering the reactor and turbine buildings, where much of the radioactive water has collected.

The project, which TEPCO and the government proposed in May, is being tested for feasibility by Japanese construction giant Kajima Corp. and is set for completion by March 2015.

Might sound a bit hokey, but this isn’t the first time that officials have tried using a giant frozen wall as a stopgap measure, or even the first time one was used to contain nuclear contaminants. In 1996, Tennessee’s Oak Ridge National Laboratory used an ice wall to keep radioactive waste from leaking into a creek.

fukushima_reactorIn England and Wales, freeze walls have been used in mining operations for almost half century, and are being used to isolate arsenic trioxide leftover from an abandoned gold-mining operation in Canada’s Northwest Territories. And Moretrench, a company that worked on Oak Ridge, is creating a freeze wall pilot for containing contamination from the Albertan tar sands.

This latter project has served as a model for the current Fukushima freeze wall project. Earlier this year, TEPCO engineers also visited Hanford, Washington, to learn about nuclear containment techniques. There, engineers are still at work decommissioning the original nuclear reactors used to create plutonium for the atom bomb dropped on Nagasaki in 1945, and the government has spent $16 billion to clean up the leaks that have since resulted.

fukushima_accidentHowever, according to the Associated Press, the decision to put a freeze wall in place also appears to be motivated by the imminent deadline for the Olympic Committee to choose a city for the 2020 games. Since Japan is looking to host, any ongoing environmental issues could sully their chances. However, as far as long term containment goes, this option may prove effective at averting a long-term ecological disaster.

What’s more, if the cooling system to keep the barrier of insulated ice intact fails, any leaks or cracks will freeze to the wall, stopping the possibility of the further contamination. In addition, as demonstrated by the Oak Ridge Wall, an ice wall has incredible longevity. Years after it was decommissioned and remediated, the government was still hauling solid ice out of the ground.

So it would not be unreasonable to expect that it will hold long after the reactor leak is contained and worries about contamination are no longer an issue.

Source: fastcoexist.com

Climate Crisis: The Pacific Ocean’s Cooling Effect

pacific1Climatologists and environmental scientists have been cataloging the global warming trend for decades, examining multiple fields of data that show fluctuations over a period of eons. And despite what appears to be a consistent trend warming that has been taking place since the 18th century – when levels of atmospheric CO2 began to climb steadily – there have been anomalies in the data.

One period was the three decades that fall between the 1940’s and 1970’s when no significant terrestrial warming took place, and the Pacific Ocean was anomalously cold. The Pacific is somewhat of a wild card when it comes to our climate, since it is responsible for the weather patterns known as El Niño and La Niña that can swing global average temperatures by as much as 0.3 degree Celsius.

Global_Temperature_Anomaly_1880-2012.svgFor the past decade or so the tropical Pacific has again gone cold and a new study suggests that it may once again be related to the recent “pause” in global warming of average temperatures. Although the past decade also qualifies as the hottest on record, the trend has been milder than expected, with average surface temperatures plateauing for many years.

This is in stark contrast to the end of the 20th century, when rising concentrations of greenhouse gases in the atmosphere accelerated warming to new heights. To explain this, climate scientists Shang-Ping Xie and Yu Kosaka of the Scripps Institution of Oceanography at the University of California looked to the Pacific Ocean, using observable data and an advanced computer model.

NASA_global_warming_predThe latter came from the US Department of Commerce’s Geophysical Fluid Dynamics Laboratory computer model of the oceans and atmosphere. By adding in sea-surface temperatures of an oceanic area covering roughly 8 percent of the globe, the researchers were able to mimic the recent hiatus in global warming as well as weather phenomena like the prolonged drought in the southern US.

The results were published in the Aug. 29th edition of Nature Magazine. In it, Xie observed that the “tropical Pacific is the engine that drives the global atmosphere and climate. There were epochs of accelerated and stalled warming in the past.” This included the pause in a global warming trend between the 1940s and 1970s, which has often been attributed to sunlight-blocking air pollution from Europe, the Soviet Union and the US.

Pollution over Mexico CityOther factors have also been considered – volcanoes, an unusually weak solar cycle, air pollution from China – when looking at restraining trends in global warming. Some of the observed climate effects may also stem from other ocean dynamics such as variations in the mixing of surface and deep ocean waters. And the meltdown of significant ice from Greenland or Antarctica might even cool oceans enough to offset the extra heat trapped by rising levels of greenhouse gases for a time.

What is less clear at this point is what is driving cycles of cooling and heating of tropical Pacific Ocean waters. But it is clear that the cool Pacific pattern cannot persist forever to cancel out the extra heat trapped by rising CO2 concentrations, Xie notes. As climate modeler Gavin Schmidt of the NASA Goddard Institute for Space Studies recently stated:

We need updates to the forcings and a proper exploration of all the different mechanisms together. This has taken time but will happen soon-ish.

global-warming-trends_lrgAnd despite any pause in the trend toward hotter temperatures, the first decade of the 21st century was still the hottest recorded decade since the 1880s, and it included record heat waves in Russia and the US as well as a precipitous meltdown of Arctic sea ice and surging sea level rise. Atmospheric concentrations of CO2 touched 400 parts per million on Mauna Loa in May, a first in the time line of human existence.

A cooler Pacific due to prolonged La Niña activity may have restrained global warming for the past decade or so, but it is unlikely to last. As Xie noted:

This effect of natural variability will be averaged out over a period of 100 years. and cannot argue away the threat of persistent anthropogenic warming that is occurring now.

These warnings are key since any changes or anomalous readings are often seized upon by Climate Change deniers as evidence that the problem does not exist, is not man-made, or is at least not as severe as otherwise predicted. But in the coming decades, even the most benign scenarios are still fraught with peril. If the worst is to be averted, extensive and positive changes need to be made now.

Source: news.cnet.com, nature.com