Spent fuel pools pose catastrophic risks should cooling be interrupted. A 2003 study of the hazards of spent fuel pools describes risks:
R. Alvarez, J. Beyea, K. Janberg, J. Kang, E. Lyman, A. Macfarlane, G. Thompson, and F. von Hippel (2003) ‘Reducing the Hazards from Stored Spent Power-Reactor Fuel in the United States’, Science and Global Security, 11.1, 1–51.These dangers were also documented in a 2005 report by the National Academy of Sciences.[see here]. The radioactive contamination from fuel pools is so threatening because of the volume of fuel and the lack of containment. Given these known dangers, concerns were expressed early in the Fukushima crisis that a fire in the spent fuel pools would release even more radiation than melted fuel in the actual reactors.
Spent fuel recently discharged from a reactor could heat up relatively rapidly to temperatures at which the zircaloy fuel cladding could catch fire and the fuel’s volatile fission products, including 30-year half-life 137Cs, would be released. The fire could well spread to older spent fuel. The long-term land-contamination consequences of such an event could be significantly worse than those from Chernobyl.
Recent research re-affirms the dangers of spent fuel pools:
Patrick Malone. May 20, 2016. Scientists say nuclear fuel pools around the country pose safety and health risks, Center for Public Integrity, https://www.publicintegrity.org/2016/05/20/19712/scientists-say-nuclear-fuel-pools-around-country-pose-safety-and-health-risks
The Fukushima nuclear catastrophe could have been far worse, it turns out, and experts say neither the nuclear industry nor its regulators are doing enough to prevent a calamitous nuclear fuel fire in America. Ninety-six aboveground, aquamarine pools around the country that hold the nuclear industry’s spent reactor fuel may not be as safe as U.S. regulators and the nuclear industry have publicly asserted, a study released May 20 by the National Academies of Sciences, Engineering, and Medicine warned.Citing a little-noticed study by the Nuclear Regulatory Commission, the Academies said that if an accident or an act of terrorism at a densely-filled pool caused a leak that drains the water away from the rods, a cataclysmic release of long-lasting radiation could force the extended evacuation of nearly 3.5 million people from territory larger than the state of New Jersey. It could also cause thousands of cancer deaths from excess radiation exposure, and as much as $700 billion dollars in costs to the national economy.
LINK TO THE THE STUDY Committee on Lessons Learned from the Fukushima Nuclear Accident for Improving Safety and Security of US Nuclear Plants. Nuclear and Radiation Studies Board Division on Earth and Life Studies. Lessons Learned from the Fukushima Nuclear Accident for Improving Safety and Security of US Nuclear Plants, Pase 2. http://www.nap.edu/read/21874/chapter/1
I find the study committee members to be quite interesting. I wonder if they represent a variety of stakeholders or whether they have been selectively included?
Regardless, the National Academies has identified problems in current risk management practices at US nuclear power plants. Greenpeace offers additional evidence of risk management problems, with 166 near misses or accident precursors:
Jim Riccio. May, 2016. Nuclear Near Misses: A Decade of Accident Precursors at U.S. Nuclear Plants, http://www.greenpeace.org/usa/research/nuclear-energy-power-plant-accidents-united-states/Greenpeace has documented 166 near misses or accident precursors at U.S. nuclear power plants. Sixty one events and more than one hundred conditions were identified by the U.S. Nuclear Regulatory Commission’s (NRC) risk analysts over the last decade that could have lead to a meltdown. Ten of these near misses are considered important precursors to a melt down.
Apparently the US military nuclear arsenal also faces risk management issues deriving from reliance on outdated technology, preferred for security (anti-hacking) purposes:
Brian Fung. May 26, 2016. The real reason America controls its nukes with ancient floppy disks. The Washington Post, https://www.washingtonpost.com/news/the-switch/wp/2016/05/26/the-real-reason-america-controls-its-nukes-with-ancient-floppy-disks/?wpmm=1&wpisrc=nl_headlinesAmerica’s nuclear arsenal depends on a surprising relic of the 1970s that few of us may recall: the humble floppy disk. It’s hard to believe these magnetic, 8-inch data storage devices are what’s propping up the most fearsome weapons humanity has ever created. But the Department of Defense is still relying on this technology to coordinate key strategic forces such as nuclear bombers and intercontinental ballistic missiles, according to a new government report.
The floppy disks help run what’s known as the Strategic Automated Command and Control System, an important communications network that the Pentagon uses to issue launch orders to commanders and to share intelligence. And in order to use the floppy disks, the military must also maintain a collection of IBM Series/1 computers that to most people would look more at home in a museum than in a missile silo.