Any spy who listened to the directors of the three national nuclear laboratories testify before the Senate Armed Services and Foreign Relations committees could have gotten an advanced primer on the U.S. nuclear weapons complex and the stockpile of missile warheads and bombs.

The directors' prepared testimony and the National Nuclear Security Administration's Stockpile Stewardship and Management Plan for fiscal 2011 were also made available.

For example, the B-61 bomb, the basic U.S. nuclear weapon stored in Europe for use by NATO forces, probably will not remain "as a vital weapon system through the decade" without completion of its life-extension program, according to Paul J. Hommert, director of the Sandia National Laboratories.

The original B-61 entered the stockpile in 1968 as a tactical nuclear bomb. In those days, and for almost two decades, they were hung from F-4 fighter bombers on forward bases in Greece, Italy and Turkey -- on the perimeter of the Soviet Union -- with both U.S. and foreign pilots on 15-minute alert.

Those early B-61s had dials that could make them low-, medium- or high-yield weapons, with explosive power that could be less than, or far greater than, the Hiroshima atomic bomb. Beginning in 1985, a newer B-61-7 replaced the old ones. This strategic version has yields that range from 10 kilotons to more than 300 kilotons, the equivalent of 300,000 tons of TNT. Hiroshima was 12.5 kilotons.

An even more modern version, B-61-11, ended production in 2008, with a raised yield and a hardened nose cone to make it more effective against deeply buried targets. More than 150 of the B-61s -- the 7s and 11s -- are now stored in Western European countries.

Sandia has the lead in the life-extension program of the older versions of the B-61-7s, which has been underway since 2009. As currently planned, the design and cost analysis for the extension is to take place next year. Development and engineering will run through 2017, and production, of probably 100 or less, will occur from 2018 to 2023. That offers an example of just how long the life-extension process takes.

Hommert told the senators that critical non-nuclear components "are exhibiting age-related performance degradation." He cited specifically that the earlier B-61 radar, which begins the fusing process of the weapon as it descends toward the target, includes vacuum tubes that now will be replaced by computer chips. Plans also call for replacing the battery component and the neutron generator in each bomb, the latter device being the one that initiates the fission process leading to the nuclear explosion.

The nuclear package of the B-61 was developed at the Los Alamos National Laboratory, and its director, Michael R. Anastasio, told the committees that his staff was turning to the nuclear bomb, having finished work on the extension program for W-76, the warhead carried by the submarine-launched Trident intercontinental ballistic missile. Los Alamos will refurbish a new detonator cable assembly for the B-61 as well as foams and polymers that have shown decay and are needed to protect the nuclear package.

Anastasio also added that the extension program will see installation of "safety and security features," which probably means devices that would allow disarming the bomb if someone stole it.

One additional driver for hastening the B-61 schedule, Hommert told the panels, is the schedule for the F-35 Joint Strike Fighter, which the Sandia director said "requires a new digital interface" to enable it to carry the nuclear bomb. With costs of that fighter-bomber rising, making it nuclear-capable has become a contentious issue. Given the potentially limited future use of nuclear weapons, and the existence of long-range strategic bombers such as the B-52 and B-2 that are equipped to carry the B-61 bomb, questions have been raised as to why to make the short-range F-35 nuclear-capable. The answer: While some NATO countries want the United States to remove its B-61 nuclear bombs from Europe, others want the bombs to remain and therefore want fighter-bombers stationed alongside that can deliver those weapons.

Cost estimates for the B-61-7 extension program, as Hommert put it, "are subject to change until the design definition and requirements are finalized next year."

But according to the National Nuclear Security Administration's recently publicized fiscal 2011 Stockpile Stewardship and Management Summary, the costs for the total B-61-7 life-extension program -- which began in 2003 and are expected to run through 2023 -- could total $4 billion.

By the way, on Wednesday, the Senate Foreign Relations Committee had a closed hearing on the National Intelligence Estimate on START.

To date, no word has leaked out about its contents on how the intelligence community views its ability to monitor and verify Russian observance of the treaty's provisions.

At the Senate Armed Services hearing the next day, however, Lawrence Livermore National Laboratory Director George Miller told the panel he concurred with the NIE's key judgment on the monitoring of the treaty.

That is a pretty firm indication that the intelligence crowd's key judgment holds that the treaty's inspection provisions and other available U.S. national technical means, such as satellites, mean compliance can be verified.

http://www.washingtonpost.com/wp-dyn/content/article/2010/07/19/AR2010071905187_pf.html

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