The plutonium in nuclear warheads will be reliable for as long as 100 years, twice as long as previously thought, according to a study released Wednesday, raising questions by some critics over the need to replace aging weapons.
WASHINGTON The plutonium in nuclear warheads will be reliable for as long as 100 years, twice as long as previously thought, according to a study released Wednesday, raising questions by some critics over the need to replace aging weapons.
The five-year government study involving all of the warheads in the nuclear stockpile, concluded that the plutonium pits -- softball size devices used to trigger a nuclear explosion -- degrade at a much slower rate than previously believed.
The research was conducted by nuclear scientists at the Los Alamos and Lawrence Livermore weapons laboratories and reviewed by an outside panel of nuclear physicists and weapons experts known as the JASON panel.
"These studies show that the degradation of plutonium in our nuclear weapons will not affect warhead reliability for decades," said Linton Brooks, head of the National Nuclear Security Administration, the Energy Department agency that oversees the nuclear weapons stockpile.
The government has long assumed that plutonium would deteriorate to the point that it no longer could be relied upon in 45 to 60 years. The new study put the minimum lifetime for plutonium pits at 85 to 100 years.
Some nuclear weapons watchdogs said the new finding undermines the Bush administration's plan to build a factory to make new plutonium pits and its program to replace current warheads with more robust designs for longer reliability.
"The U.S. has a huge surplus of plutonium pits and now DOE's own independent expert scientists confirm that they last 100 years," said Susan Gordon, director of the Alliance for Nuclear Accountability.
She said the DOE argument for a new pit factory and new warheads has largely rested on a pit lifetime expectancy of 45 years, so they now are "completely unnecessary."
The alliance represents a network of citizen groups near federal nuclear weapons facilities.
But National Nuclear Security Administration officials said plutonium aging is only one variable that can affect overall system reliability and that the report does not change the need to manufacture more plutonium pits or design sturdier warheads. The country currently has no pit manufacturing plant, using pits taken out of dismantled warheads.
"What this (finding) does do is it informs us that pit age isn't the primary thing that concerns us," said Tom D'Agostino, the nuclear agency's deputy administrator for defense programs.
He said the research gives the government more time to establish a new supply of plutonium pits for the weapons stockpile. He said the agency still wants to have a new pit production facility by 2022 to ensure future supplies.
"Although plutonium aging contributes, other factors control the overall life expectancy of nuclear weapons systems" making no less important the development of sturdier long-lasting warheads, said Brooks.
These factors include the aging of high explosives and other organic components in the weapons and corrosion of weapons parts.
Source: Associated Press