Lake Karachay The lake accumulated some 4.44 exabecquerels (EBq) of radioactivity over less than one square mile of water, including 3.6 EBq of caesium-137 and 0.74 EBq of strontium-90. For comparison, the Chernobyl disaster released 0.085 EBq of caesium-137, a much smaller amount and over thousands of square miles. (The total Chernobyl release is estimated between 5 to 12 EBq of radioactivity, however essentially only caesium-134/137 [and to a lesser extent, strontium-90] contribute to land contamination because the rest is too short-lived). The sediment of the lake bed is estimated to be composed almost entirely of high level radioactive waste deposits to
Radiation effects from the Fukushima Daiichi nuclear disaster tests. As the isotope signature of the plutonium is closer to that of power-reactor plutonium, TEPCO suggested that "two samples out of five may be the direct result of the recent incident." The more important thing to look at is the curium level in the soil; the soil does contain a short-lived isotope (curium-242) which shows that some alpha emitters have been released in small amounts by the accident. The release of the beta/gamma emitters such as caesium-137 has been far greater. In the short and medium term the effects of the iodine and the caesium release will dominate the