When the 9.0-magnitude earthquake struck off the east coast of Japan, at 2:46 p.m. on 11 March, the ground beneath the power plant shook and alarms blared. In quivering control rooms, ceiling panels fell open and dust floated down onto instrument panels like snow. Within 5 seconds, control rods thrust upward into the three operational reactors and stopped the fission reactions. It was a flawless automatic shutdown, but the radioactive by-products in the reactors’ fuel rods continued to generate tremendous amounts of heat.
Without adequate cooling, those rods would become hot enough to melt through the steel pressure vessel, and then through the steel containment vessel. That would result in the dreaded core-meltdown scenario, which could lead to the release of clouds of radioactivity that would be carried by winds to sicken or kill masses of people.
But the heat wouldn’t be a problem so long as Fukushima Dai-ichi had power to run the pumps that circulate water from the reactor cores through heat-removal systems. …
Tag Archives: Radioactivity
Sievert, gray, rem, and rad: Why are there so many different ways to measure radiation exposure? | Slate Magazine
Japan’s unfolding nuclear disaster has introduced Americans to the confusing practice of measuring radiation exposure. According to some stories, the water nearby to the No. 2 Fukushima reactor has a radioactivity level of 1,000 millisieverts per hour. But other articles describe radiation levels in terms of millirem per year. And a few sources have referred to exposure in terms of millirad or nanogray per hour. Why don’t all radiation experts just use the same unit?
As Japan edged forward in its battle to contain the damage at its ravaged nuclear power plants on Saturday, the government said it had found higher than normal levels of radioactivity in spinach and milk at farms up to 90 miles away from the plants, the first confirmation that the unfolding nuclear crisis has affected the nation’s food supply.
Japan tsunami: Fallout from Japan nuclear disaster could reach U.S., but no danger expected – chicagotribune.com
Fallout from Japan’s crippled nuclear reactors could reach the West Coast within a couple of weeks, depending on weather conditions. But scientists who track pollution blowing across the Pacific Ocean say the amount of radioactivity should pose no danger to the United States.
Like other forms of pollution, radioactivity attaches to dust and fine particles that are carried by wind, rain and snow and can be breathed in or ingested. As the disaster in Japan unfolds, the U.S. Environmental Protection Agency is sending extra staff to the West Coast to monitor radiation levels in air, cow’s milk and rain. Other agencies, including the Nuclear Regulatory Commission, the National Oceanic and Atmospheric Administration and the Department of Energy, are tracking weather patterns and using computer models to predict how radioactivity from Japan might spread.
A Quarter Century after Chernobyl: Radioactive Boar on the Rise in Germany – SPIEGEL ONLINE – News – International
As Germany’s wild boar population has skyrocketed in recent years, so too has the number of animals contaminated by radioactivity left over from the Chernobyl nuclear meltdown. Government payments compensating hunters for lost income due to radioactive boar have quadrupled since 2007.
In the 1950s and early 1960s, the buzz word in American homes was “fallout shelter.”
A fallout shelter was a civil defense initiative intended to reduce casualties in a nuclear war. It was designed to allow occupants to avoid exposure to harmful radioactive fallout from a nuclear blast and its likely aftermath of radiation until radioactivity dropped to a safer level.
The Chernobyl disaster happened over two decades ago, but its effects continue to be as present as ever. German photographer Rüdiger Lubricht spent months documenting what has been left behind in the exclusion zone which now surrounds the stricken reactor. In an interview with seen.by, he talks about his experiences.