The Bush administration is expected to announce next week a major step forward in the building of the country’s first new nuclear warhead in nearly two decades. It will propose combining elements of competing designs from two weapons laboratories in an approach that some experts argue is untested and risky. The announcement, to be made by the interagency Nuclear Weapons Council, avoids making a choice between two competing designs for a new weapon, called the Reliable Replacement Warhead, which at first would be mounted on submarine-launched missiles. The effort, if approved by President Bush and financed by Congress, would require a huge refurbishment of the nation’s complex for nuclear design and manufacturing, with the overall bill estimated at more than $100 billion. Full Story