www.cbc.ca/news/world/fukushima-s-crippled-reactors-the-risky-plan-to-move-fuel-rods-1.2431190
"TEPCO spokesperson Tatsuhiro Yamagishi told CBC News that along with cesium-137 and cesium-134, the radioactive isotopes contained in the fuel include strontium-90, radium-226, uranium-235, and plutonium-239, which has a half-life of approximately 24,000 years."
