Once atmospheric tests were banned, testing was transferred to underground locations at Chagan, Murzhik (in the west), and at the Degelen Mountain complex in the south, which is riddled with boreholes and drifts for both subcritical and supercritical tests.
Setelah uji atmosfer dilarang, pengujian dipindahkan ke lokasi bawah tanah di Chagan, Murzhik (di barat), dan di kompleks Degelen Mountain di selatan, yang penuh dengan lubang bor yang hanyut untuk tes subkritis dan superkritis.