PLUTONIUM SEEN LASTING LONGER
By WALL STREET JOURNAL Staff Reporter
November 30, 2006

New studies by the Department of Energy show that plutonium, the most 
critical element used in the nation's nuclear-weapons arsenal, may 
last longer than previously thought, easing some safety and budget 
concerns about aging warheads.

The studies, done by Lawrence Livermore and Los Alamos national 
laboratories, indicate that plutonium may remain unchanged for 85 
years or longer. They show that degradation of the heavy, explosive 
metal "will not affect warhead reliability for decades," according to 
Linton F. Brooks, administrator of the National Nuclear Security 
Administration.

His agency uses a multibillion-dollar "stockpile stewardship program" 
to check nuclear weapons as they age. Unofficial estimates put the 
number of plutonium-based weapons in U.S. stockpiles at about 10,000. 
He noted that other factors, including the decay of conventional 
explosives and other materials used in warheads, will continue to 
require monitoring and replacement programs.

Because plutonium was first produced in significant quantities in the 
1940s for the nation's nuclear-weapons programs, relatively little 
was known about how the metal might change with age during World War 
II and the ensuing Cold War buildup of nuclear weapons.