In response to a request from Congress, the Nuclear Regulatory Commission and the Department of Homeland Security sponsored a National Academies study to assessthe safety and security risks of spent nuclear fuel stored in cooling pools and drycasks at commercial nuclear power plants. The information provided in this bookexamines the risks of terrorist attacks using these materials for a radiological dispersaldevice. Safety and Security of Commercial Spent Nuclear Fuel is an unclassified publicsummary of a more detailed classified book. The book finds that successful terroristattacks on spent fuel pools, though difficult, are possible. A propagating fire in apool could release large amounts of radioactive material, but rearranging spent fuelin the pool during storage and providing emergency water spray systems wouldreduce the likelihood of a propagating fire even under severe damage conditions. The book suggests that additional studies are needed to better understand theserisks. Although dry casks have advantages over cooling pools, pools are necessary atall operating nuclear power plants to store at least the recently discharged fuel. Thebook explains it would be difficult for terrorists to steal enough spent fuel to constructa significant radiological dispersal device.