Science Replaces Nuclear Tests

Volume 2, Issue 14, November 2, 2011

A front-page story in today’s Washington Post (“Supercomputers Offer Tools for Nuclear Testing--and Solving Nuclear Mysteries) illustrates how far the U.S. Stockpile Stewardship Program has come since nuclear explosive tests ended in 1992. Scientists at the three U.S. national laboratories now have a deeper understanding of nuclear weapons than ever before.

“We have a more fundamental understanding of how these weapons work today than we ever imagined when we were blowing them up,” Bruce T. Goodwin, principal associate director for weapons at Livermore National Laboratory, told the Post. Goodwin is in agreement with National Nuclear Security Administration (NNSA) administrator Thomas D'Agostino, who in 2008 said, "We know more about the complex issues of nuclear weapons performance today than we ever did during the period of nuclear testing."

It’s time for U.S. national policies to catch up with the science. The Senate voted against the Comprehensive Test Ban Treaty (CTBT) in 1999, in large part because the stewardship program was as yet unproven. Now, with two decades of experience, the Senate can ratify the CTBT with full confidence that the stewardship program can keep the U.S. arsenal safe and reliable.

Countries with nuclear weapons, such as China, India and Pakistan, cannot create advanced nukes without further nuclear test explosions. Without nuclear tests, Iran could not confidently build warheads for delivery by ballistic missiles. The CTBT would also improve America’s ability to detect, deter, and confront any nation that attempts to break the global taboo against nuclear testing. 

Stockpile Stewardship Passes the Test, Again

Almost 20 years after the last U.S. nuclear test explosion, it is clear that the existing arsenal can be maintained indefinitely, without nuclear test explosions and without pursuing new warhead designs.

Since 1994, each warhead type in the U.S. nuclear arsenal has been determined to be safe and reliable through a rigorous annual certification process. The Stockpile Stewardship Program includes nuclear weapons surveillance and maintenance, non-nuclear and subcritical nuclear experiments, and increasingly sophisticated supercomputer modeling.  Life extension programs have successfully refurbished existing types of nuclear warheads and can continue to do so indefinitely.

A 2009 study by JASON, a high-level independent technical review panel, concluded that the "lifetimes of today's nuclear warheads could be extended for decades, with no anticipated loss in confidence."

And as the National Academy of Sciences concluded in 2002, the stewardship program “provides the technical capabilities that are necessary to maintain confidence in the safety and reliability of the existing seven types of nuclear warheads in the active stockpile, provided that adequate resources are made available...and are properly focused on this task."

Stewardship Program Adequately Funded

Since fiscal year 2010, the Obama administration has requested, and the Congress has granted, significant increases for NNSA nuclear weapons activities, upping the budget by 10% to $7.0 billion from the previous year. Longer term, the administration has laid out an unprecedented $88 billion, ten-year plan for the nuclear weapons complex from 2012 to 2021. Then-Defense Secretary Robert Gates noted in 2010 that, "These investments, and the... strategy for warhead life extension, represent a credible modernization plan necessary to sustain the nuclear infrastructure and support our nation's deterrent."

On December 1, 2010, the then-directors of the three U.S. nuclear weapons laboratories wrote that they were "very pleased" with the administration's budget plan. Lawrence Livermore director Dr. George Miller, Los Alamos director Dr. Michael Anastasio, and Sandia director Dr. Paul Hommert said that the increased funding plan provides "adequate support" to sustain the U.S. nuclear arsenal.

For fiscal year 2012, the Obama administration is requesting $7.63 billion for NNSA weapons activities. Congress is likely to increase NNSA funding again, but not as much as the administration wants. The Republican-led House appropriations committee increased funding for NNSA weapons activities to $7.13 billion, and the Senate approved a similar increase to $7.19 billion.

However, these minor reductions in the President’s proposed NNSA budget will not prevent NNSA from completing its primary mission.  As House Energy and Water Subcommittee Chair Rep. Rodney Frelinghuysen (R-N.J.) said in June:

“Yes, ‘Weapons Activities’ is below the President’s request, but this request included hundreds of millions of dollars for construction projects that are not ready to move forward, capabilities that are secondary to the primary mission of keeping our stockpile ready, and, yes, slush funds that the administration has historically used to address its needs…The recommendation before you eliminates these weaknesses and it is responsible.”

Life Extensions: Be Conservative

Beyond funding questions, NNSA needs to ensure that the national labs are focused on the highest priority stockpile stewardship tasks. For example, the labs should only pursue cost-effective, technically conservative warhead life extension strategies that minimize unnecessary changes to already well-understood and proven warhead designs.

From fiscal year 2011 to 2031, NNSA plans to spend almost $16 billion on Life Extension Programs (LEPs) to extend the service life and in some cases modify almost every warhead in the enduring stockpile. This includes an estimated $3.7 billion on the W88 warhead, $3.9 billion on the B61 bomb, $4.2 billion on the W78 warhead, $1.7 billion on the W76 warhead, and $2.3 billion on the W80-1 warhead.

Some enhancements for safety and security may be warranted, but there is a risk. For years, stockpile managers and designers have preached design-change “discipline,” noting that an accumulation of unnecessary design and materials modifications could undermine confidence in warhead reliability.

For example, the Senate Energy and Water Appropriations Subcommittee warned in September that efforts to modify the B61 bomb with “untried technologies” should “not come at the expense of long-term weapon reliability. New safety and security features should be incorporated in weapon systems when feasible, but the primary goal of a life extension program should be to increase confidence in warhead performance without underground nuclear testing.”

As a result, the Senate reduced the B61 LEP budget request by more than $43 million. Former weapons designer Bob Peurifoy, a retired Sandia National Laboratory vice president, said that NNSA’s plans to change the B61 are “risking a very reliable system.”

The NNSA and Congress need to review the current life extension program to ensure that enthusiasm associated with extensively modifying warheads does not get out of hand. Marginal improvements in weapons security and safety should not come at the expense of long-term weapon reliability.  —Daryl G. Kimball and Tom Z. Collina