Depending on what news media you read, the latest radiation readings at the earthquake-damaged Fukushima nuclear power plant are frightening, or still manageable and only a big problem in the vicinity of the plant. Both points of view are understandable.
You know radiation levels are intense when they will “kill” a robot in less than two hours. “The searing radiation level,” to use Japan Times’ alarming phrase, has reached 530 sieverts per hour, while 4 sieverts per hour is enough to outright kill one out of every two people. One sievert has serious health impacts, and anything above 1/10th of a sievert increases the risk of cancer, according to the Times.
All this is scary, but the insides of failed reactor vessels are bound to be highly toxic. The news isn’t so much that radiation levels have increased — they probably have been sky-high ever since the 2011 earthquake-related disaster. The real significance of the news appears to be that responders now are managing to get closer to the melted cores, an essential step along the way to ensuring they remain safely cooped up.
Fukushima’s melted cores are believed to still be pooled within reactor containment vessels. Jonathan O’Callaghan, writing on the essential online news site IFLScience, notes, “While a higher level of radiation has been found inside the plant, levels around it are continuing to fall. This suggests no radiation is escaping from Fukushima into the surrounding environment.” This finding is verified by many people around Japan using radiation detectors to ensure their own safety.
“Measurements in new locations means that we can pinpoint hot-spots and understand the nature of the radioactive materials within the reactor complex and to better inform us on suitable strategies for long-term decommissioning and cleanup,” a nuclear engineering expert told IFLScience.
There is no doubt the cleanup remains a nearly unimaginably expensive and complex task. It currently is expected to cost $188 billion and take until around the year 2060. If U.S. experiences at the Hanford Nuclear Reservation are any guide, eventual costs and time are likely to be far higher.
Any Fukushima news ratchets up concerns on the U.S. West Coast about how contaminated ocean water might impact marine life, shellfish and human health on this side of the Pacific. For now, such concerns remain unwarranted. However, we clearly must closely monitor the situation. A proven failure of the containment vessels would mark the start of a much bigger emergency, but there is no current reason to think such a catastrophe is imminent.
All this must continue to inform our own national decisions about nuclear power. It remains an intriguing option for generating electricity without producing greenhouse gases. But anything resembling the reactor designs at Fukushima ought to be off limits forever.