In the Soviet union during the cold war, the main defects found tank is limited, the fuel tank, no matter how carefully designed the cross-country distance is impossible, and more than 1,000 kilometers in armor and fire protection on pay a heavy price. Unable to satisfy the need to compete with the Soviet union. In this context, the United States in 1965, secretly developing nuclear tanks, developed in the reactor volume and cost and pollution problems, no success.
Although r&d difficulties. But in 1969. Researchers successfully resolved the reactor radiation shielding, miniaturization, powerful small shell, long life and tracked. In 1970, produce the world first nuclear-powered tanks.