"Sedan" is code name for Sudan;

U.S., realizing the risks of nuclear tests in the United States West,
conducts the most deadly ones in a poor, developing country, Sudan.

http://www.sudani.com/dir/s.asp?l=29454

Realising that Movie star John Wayne had been diagnoised with cancer,
contracted by working in radioactive sections of the Nevada desert,
U.S Officials, acting under the auspicese of John Foster Dulles,
Bribed Sudanese officials with Liquor and Prostitutes,
then set up a secret nuclear test site in the Sudanese desert.
U.S. Nuclear tests were then conducted in Sudan between 1962 and 1970,
when Richard Nixon, alerted by the Soviet Union of the goings on in
Sudan,
ended this test program.
The entire program is still classified as top secret