Nuclear power reactors spilt atoms to release energy used to generate electricity. Many of the byproducts formed when atoms split are unstable (radioactive) and release particles or gamma rays in search of stability. These radioactive emissions produce energy. Whether in the core of an operating reactor, in the core of a shutdown reactor, in the spent fuel pool after discharge from a reactor core, or in dry storage after offloading from a spent fuel pool, the energy released from nuclear reactor fuel must be removed before it damages the fuel from overheating. This commentary describes the energy levels associated with nuclear fuel in various locations at various times to illustrate the factors that affect the associated hazard levels. Read more >
March 26, 2018 6:00 AM EDT
On March 11, 2011, a large earthquake with an epicenter a few miles off the northeastern shores of Japan spawned a tsunami that inundated the Fukushima Daiichi nuclear plant. The earthquake disconnected the plant from the offsite power grid. The tsunami disabled the onsite emergency diesel generators. Deprived of electricity for emergency systems, the reactor cores for Units 1, 2 and 3 overheated and melted down.
On March 12, 2012, the Nuclear Regulatory Committee (NRC) ordered owners of US nuclear power plants to develop and implement mitigation strategies to reduce the vulnerabilities of their facilities to extreme earthquakes and floods. While the specific measures varied from plant to plant, the mitigating strategies generally involved portable pumps, portable generators, cables, hoses, and hauling equipment (called FLEX equipment) and associated procedures for workers to use should permanently installed equipment become disabled.
While the NRC’s order and the industry’s FLEX equipment were intended to reduce vulnerabilities to hazards over and above those deemed credible when the nuclear plants were designed and licensed, Dominion Energy has figured out how to use the new equipment to lessen old risks at its Surry nuclear plant, thus reaping a nuclear safety dividend from its Fukushima investment.
May 25, 2017 2:48 PM EDT
In a Policy Forum article published in this week’s Science magazine, I argue, along with my co-authors Frank von Hippel and Michael Schoeppner, that the U.S. Nuclear Regulatory Commission (NRC) needs to take prompt action to reduce the alarmingly high potential for fires in spent fuel pools at U.S. nuclear plants. Read more >
April 19, 2016 6:00 AM EDT
Disaster by Design/Safety by Intent #28
Disaster by Design
This commentary describes a progression leading to overheating damage of fuel in a spent fuel pool. Next week’s post will describe how fuel in a spent fuel pool could experience a reactivity excursion. Read more >