I don't understand what you mean by that

Do you mean the Pacific Ocean is your backyard? Cuz there's 6000km between Papeete and Sydney That's a very big Backyard

Otherwise the tests in the Australian Outback by the British between 1956 and 1963 clearly fit your definition of nuclear test in your Backyard. (Granted that the UK only did 7 athmospheric tests of much lower yields than the ~47/50 of the French atmospheric tests but the 550 sub-critical tests by the Brits produced more radioactive contamination than the 7 atmospheric tests).

Reading about the british tests shown me that the australian public perception of the nuclear test on their soil changed in the late 1970's. In December 1976 questions were asked to the then Minister of Defense Jim Killen in the Parliament about the ever so secret nuclear tests at Maralinga. With Avon Hudson disclosure of the way the brits handled tests and subsequent clean-up and journalists publishing a leaked secret document from an aus. government commision titled "Plutonium Buried Near Maralinga Airfield"