Submarine propulsion research was suspended in October 1952 so they did not interfere with plutonium production for nuclear weapons .
By 1954 the Royal Navy had concluded that it would not be possible until the 1960s .
Submarine propulsion research was suspended in October 1952 so they did not interfere with plutonium production for nuclear weapons , and by 1954 the Royal Navy had concluded that it would not be possible until the 1960s .