23 Novembre 2016
November 22, 2016
The Shinzo Abe government’s plan to restart nuclear power in Japan was shaken to its core with a 7.4 magnitude earthquake that struck on November 21, 2016 (the date here in the U.S.) just off the coast of the destroyed Fukushima Daiichi atomic reactors. Fukushima Daiichi is also the site of a huge radioactive waste tank farm that continues to expand from an on-again off-again radioactive cooling water treatment system for the three still unrecovered melted reactor cores. Little is presently known about how the hastily built tank farm has fared during the earthquake.
The four-unit Fukushima Daini nuclear power complex just seven miles south of Fukushima Daiichi temporarily lost cooling to Daini’s Unit 3 spent fuel pool raising concerns for the overheating of high-level nuclear waste configured as 2400 used fuel rods being stored underwater. Fukushima Daini remains shutdown and barred from power operations along with 38 operable units in Japan following the March 11, 2011 8.9M earthquake and catastrophic tsunami. Only two of the nation’s nuclear reactors have successfully returned to power operations amid intense public and political opposition that continues to grow.
Tuesday morning’s 7.4M earthquake struck around 6 am (JST) 31 miles off the east coast. The large earthquake set off coastal tsunami warnings for several hours, eventually measuring up to a sea level rise of 55 inches. A second 5.5M earthquake struck shortly after with its epicenter on land just 7 miles from Fukushima Daini with another tsunami warning. Aftershocks continue to jolt the area with officials concerned that another major quake can be expected within the week.
During times of natural disaster and national security threats, nuclear power is more a dangerous societal liability than an asset. All of the reactors’ safety systems and their nuclear waste cooling systems are 100% reliant upon offsite electrical grid power during normal operations. If the electric grid is disturbed by disaster or sabotage, nuclear power plants automatically shut down and emergency electrical power systems kick in to service a subset of priority reactor safety and cooling systems. If those systems fail or are disabled, nuclear power stations typically have 4 to 8 hours of back-up battery power to prevent a meltdown. Cooling capability to thousands of tons of high-level nuclear waste (irradiated fuel rods) initially rely upon the same off-site electrical power. Since the 9/11 World Trade Center aircraft attacks and the 3/11 Fukushima nuclear disaster, reactor spent fuel pools with high-density storage of nuclear waste are being equipped with make-up water systems should a loss of power threaten to boil off the water filled pools. Each pool containing up to 700 to 1000 tons of thermally hot and highly radioactive nuclear waste can overheat, boil off and catch fire without cooling.
The Beyond Nuclear Facebook page posted live stream coverage broadcasted from Japan during the tsunami warning.