Complex sentence: The island of Amchitka was initially selected for these tests in 1950, but the site was later deemed unsuitable and the tests were moved the Nevada Test Site, where the first underground nuclear test was conducted on 29 November, 1951.
Split into simpler sentences: The island of Amchitka was initially selected for these tests in 1950, but the site was later deemed unsuitable and the tests were moved the Nevada Test Site. The first underground nuclear test was conducted on 29 November, 1951.