U.S. Selecting Hybrid Design for Warheads

By WILLIAM J. BROAD, DAVID E. SANGER and THOM SHANKER

Published: January 7, 2007

WASHINGTON, Jan. 6 — 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 new weapon would not add to but replace the nation’s existing arsenal of aging warheads, with a new generation meant to be sturdier, more reliable, safer from accidental detonation and more secure from theft by terrorists.