Nuclear reactor accidents in the United States reactors and research facilities. This led to the introduction of the Price-Anderson Act in 1957, which was "an implicit admission that nuclear power provided risks that producers were unwilling to assume without federal backing". Nuclear reactor accidents continued into the 1960s with a small test reactor exploding at the Stationary Low-Power Reactor Number One in Idaho Falls in January 1961 resulting in three deaths which were the first fatalities in the history of U.S. nuclear reactor operations. There was also a partial meltdown at the Enrico Fermi Nuclear Generating Station in Michigan in 1966. The large size of nuclear reactors
Nuclear reactor burnoff (power) transient". Control rods must be further inserted to replace the neutron absorption of the lost xenon-135. Failure to properly follow such a procedure was a key step in the Chernobyl disaster. Reactors used in nuclear marine propulsion (especially nuclear submarines) often cannot be run at continuous power around the clock in the same way that land-based power reactors are normally run, and in addition often need to have a very long core life without refueling. For this reason many designs use highly enriched uranium but incorporate burnable neutron poison in the fuel rods. This allows the reactor to