Julin was an UNDERGROUND test. Normal people do not have the capability to perform UNDERGROUND testing. ATMOSPHERIC testing is the only option that an individual would be possibly capable of doing. The US has not performed atmospheric testing since 1962. Are you really trying to use underground testing as a reasonable possibility, when the discussion was specifically nuclear testing by an individual with US citizenship on US soil? You have lost focus of what the original question was and have been grasping at straws.
North Korea has claimed that they tested on back on 2009, which is not proven. The US has had zero nuclear testing that is publically acknowledged in over 20 years, partially due to the 1996 treaty that Clinton signed - that is hardly "all the time".
Read up, and learn. Nuclear weapons testing - Wikipedia, the free encyclopedia
Partial Nuclear Test Ban Treaty - Wikipedia, the free encyclopedia
Comprehensive Nuclear-Test-Ban Treaty - Wikipedia, the free encyclopedia