The late 1960s and early 1970s saw a rapid growth in the development of nuclear power in the United States. By 1976, however, many nuclear plant proposals were no longer viable due to a slower rate of growth in electricity demand, significant cost and time overruns, and more complex regulatory requirements. Also, there was considerable public opposition to nuclear power in the US by this time, which contributed to delays in licensing planned nuclear power stations, and further increased costs.