Radioactivity levels in water increased dramatically at Fukushima reactor units 1 and 2. Moreover, Cs-134 and I-129 levels 15km offshore now exceed safety standards. TEPCO pumped contaminated water out of the tunnel of reactor unit 2 into a reactor condenser but TEPCO has run out of places to store radioactive water from other reactors. The lack of storage tanks for radioactive water is stopping TEPCO from restoring the cooling systems of the damaged reactors. TEPCO is trying to finish building makeshift storage tanks by the end of May.
Moreover, new measurements show that the spent fuel pool water of unit 4 contains high levels of radioactive cesium and iodine, indicating that the spent fuel's cladding has been damaged. This will complicate removal of spent fuel from the damaged facility.
The good news is that environmental monitoring shows that airborne releases of radioactivity have greatly decreased. Efforts to cool the reactors has successfully kept airborne radionuclide releases down while producing increasing amounts of radioactive waste water.
TEPCO collected wastewater samples from the No.1 and No.2 reactors on Wednesday, and found that radioactivity levels had increased dramatically during the past week.
According to TEPCO, 400 becquerels of iodine-131 and 53 becquerels of cesium-134 per cubic centimeter were detected in the wastewater of the No.1 reactor. These levels are 6 times and 38 times higher than a week ago respectively. In the No.2 reactor, 610 becquerels of iodine-131 and 7.9 becquerels of cesium-134 per cubic centimeter were detected. These levels are 17 times and 8 times higher than a week ago respectively.
However, radioactive contamination has grown worse 10 miles offshore.
Safety standards are exceeded for I-131 and CS-134 15km offshore.
TEPCO data show that spent fuel pool water at unit 4 is contaminated with dangerous levels of radioactive cesium and iodine. This means that spent fuel rods were damaged when water levels dropped and fires were observed in the vicinity of the spent fuel pool.
NOAA's NCOM model shows that an eddy has formed near the Fukushima reactor site, transporting the contaminated water offshore towards the rapid moving current called the Kuroshio extension, Japan's Gulf Stream.
TEPCO's inability to restore the cooling systems of the damaged reactors and spent fuel ponds will leave them vulnerable to aftershocks and other problems that might arise. The marine environment will continue to be threatened until TEPCO can properly store contaminated water.