gbrumfiel writes "In May of 2010, North Korea made the bizarre claim that it had achieved nuclear fusion. Many, many commentators (including faithful Slashdot readers) mocked the dear leader for his outlandish boast, but could there have been a kernel of truth in the claim? Apparently some odd radioactivity was spotted by detectors surrounding the North just days after the announcement. Now, a new analysis by a Swedish scientist suggests that the radiation may have leaked from covert experiments into boosting fission warheads. The evidence is tentative at best, and many are skeptical, but it does seem that something odd was up on the Korean peninsula that spring."