Cooper Nuclear Station (CNS) is a boiling water reactor (BWR) type nuclear power plant located on a 1,251-acre (506 ha) site near Brownville, Nebraska between Missouri River mile markers 532.9 and 532.5, on Nebraska's border with Missouri.

[4] In September 2008, NPPD applied to the U.S. Nuclear Regulatory Commission (NRC) for a renewal of the operating license for CNS, extending it for an additional twenty years.

[7] The Nuclear Regulatory Commission defines two emergency planning zones around nuclear power plants: a plume exposure pathway zone with a radius of 10 miles (16 km), concerned primarily with exposure to, and inhalation of, airborne radioactive contamination, and an ingestion pathway zone of about 50 miles (80 km), concerned primarily with ingestion of food and liquid contaminated by radioactivity.

[10][11] The Nuclear Regulatory Commission's estimate of the risk each year of an earthquake intense enough to cause core damage to the reactor at CNS was 1 in 142,857, according to an NRC study published in August 2010.

[12][13] At 0402 CDT on June 19, 2011 a Notification of Unusual Event (the lowest of NRC emergency classifications) was declared due to the elevation of the Missouri River reaching 899.1 feet above mean sea level.