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The National Nuclear Security Administration finished building the secondary stage for the first war-ready B61-12 nuclear gravity bomb on Dec. 6, the semi-autonomous Department of Energy agency said late last week. The canned subassembly is the uranium-fueled stage of the future gravity bomb, which as part of a 20-year life-extension program will homogenize four previous versions of the venerable weapon. The subassembly is only part of the first war-ready weapon, which the semiautonomous Department of Energy nuclear-weapon steward says it will build…
