Fukushima Reactors Still Acting Up
The discovery of fissile materials that have a half life of 9 hours indicates that fission is still occurring in parts of the damaged reactors. One such discovery required infusing the damaged reactor with boron to quash any potential runaway reactions.
The unexpected bursts — something akin to flare-ups after a major fire — are extremely unlikely to presage a large-scale nuclear reaction with the resulting large-scale production of heat and radiation. But they threaten to increase the amount of dangerous radioactive elements leaking from the complex and complicate cleanup efforts, raising startling questions about how much remains uncertain at the plant, the site of the world’s worst nuclear disaster since Chernobyl. The Japanese government has said that it aims to bring the reactors to a stable state known as a ‘cold shutdown’ by the end of the year.
On Wednesday, the plant’s operator, the Tokyo Electric Power Company, said that measurements of gas from inside Reactor No. 2 indicated the presence of radioactive xenon and other substances that could be the byproduct of nuclear fission. The presence of xenon 135 in particular, which has a half-life of just nine hours, seemed to indicate that fission took place very recently.
Trade Minister Yukuo Edano censured Japan’s nuclear regulator, the Nuclear and Industrial Safety Agency, for failing to report the discovery to the prime minister’s office for hours, according to local media reports.