TOKYO (AP) — A draft investigation report into the 2011 Fukushima nuclear meltdown says it has detected dangerously high levels of radioactive contamination at two of the three reactors, adding to concerns about decommissioning challenges. The interim report says data collected by investigators showed that the sealing plugs sitting atop the No. 2 and 3 reactor containment vessels are as fatally contaminated as nuclear fuel debris that had melted and fell to the bottom of the reactors following the March 2011 tsunami and earthquake. The experts measured radiation levels at multiple locations inside the three reactor buildings and examined how radioactive materials moved and safety equipment functioned during the accident. The Nuclear Regulation Commission called the findings extremely serious.