The oldest nuclear bomb in the U.S. arsenal is being modernized with a precision-guidance kit and more modern safety features, Pentagon and Energy Department officials told Congress on Monday.
Air Force Gen. C. Robert Kehler, commander of the U.S. Strategic Command, testified during a hearing of the House Armed Services subcommittee on strategic forces that upgrading the B-61 bomb is a key military necessity for nuclear deterrence and defending allies in Asia and Europe.
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"Our requirement to deter nuclear attack is a military mission," Kehler said when asked why the bomb upgrade is needed. "This B-61 weapon arms the B-2. It will arm the future long-range strike platform. It arms the dual-capable aircraft that are forward stationed in Europe as well as those of our NATO allies."
"It’s about deterring; it’s about assuring our allies of our extended deterrent commitment to them and from a military standpoint it’s about being able to offer the president a series of options that include nuclear options in extreme circumstances," he said.
Four variants of 1960s-era B-61 gravity bombs are being combined into a single bomb that will be outfitted with a motorized tail kit to replace its parachute, used to slow descent, Kehler and three other officials said during the hearing.
The tail kit is similar to the guidance packages outfitted on conventional bombs that convert them into precision-guided munitions capable of highly accurate attacks.
The bomb upgrade will cost $8.1 billion through 2024 and is part of the Obama administration’s program to modernize aging nuclear weapons called "3 plus 2."
That program will update the current 12 warhead types used on land- and sea-based nuclear missiles into three interoperable missile warheads. Two aircraft bombs will be upgraded and carried on B-2 bombers, as well as F-16 and future F-35 tactical nuclear bombers.
Equipping current and future nuclear bombers is a "necessary and crucial component of the triad and arming that force is a top priority," Kehler said.
Democrats on the subcommittee questioned the officials during the hearing about whether the expensive B-61 modernization is needed.
In response, all four officials said the upgrade program is required to maintain U.S. nuclear deterrence and assure U.S. allies.
The testimony by the officials in favor of the B-61 life-extension program is a setback for anti-nuclear activists in Congress and arms control groups that are opposing the bomb modernization.
The liberal Ploughshares Fund stated in July, "The U.S. does not need and cannot afford this nuclear budget buster."
Kehler said the new B-61 upgrade program would assist future warhead life-extension programs.
Another nuclear weapon, the W-77/W-88 interoperable missile warhead, will be the next modernization effort after the B-61, and will be the first of the three exchangeable missile warheads for the 3 plus 2 strategy.
Donald L. Cook, deputy administrator for Energy’s National Nuclear Security Administration (NNSA), said the B-61 Mod 12 life-extension program has made "great progress" and is currently in its second year of development at a cots of about $1.2 billion.
"The B-61 [life-extension program] represents not only a critical modernization activity to sustain the health of the nuclear deterrent and a viable triad, but from the NNSA perspective it also exercises the talents and pushes the technical skills of the nuclear security enterprise—both the labs and plants," Cook said. "Overall, it is one of the most important programs in which the NNSA is currently engaged."
The modernization will permit the reduction in the total number of nuclear gravity bombs by a factor of two, Cook said.
About 400 B-61s, including nearly 200 deployed in Europe, are currently deployed. The Mod 12 will consolidate four variants, Mod 3, Mod 4, Mod 7, and Mod 10.
The bomb currently has varying yields of between .3 kilotons and 300 kilotons. A kiloton is the equivalent of 1,000 tons of TNT. Officials said Monday that the Mod 12 would have a yield at the lower end of the current variants.
The weapons also are the key element of U.S. "extended deterrence" used to bolster alliances in Asia and Europe, the officials said.
President Barack Obama announced in Berlin in June that the Pentagon would seek to further reduce U.S. nuclear arms below the 1,500 deployed strategic warheads allowed under the 2010 New START arms treaty with Russia.
However, Russia’s government has rejected U.S. efforts to engage in further arms cuts. China’s government also has refused to engage in any strategic arms talks with the Obama administration. Beijing is currently engaged in a significant buildup of strategic nuclear forces.
Madelyn Creedon, assistant defense secretary for global strategic affairs, testified at the hearing that the bomb modernization is urgently needed.
"I cannot emphasize this point enough: The B-61-12 is critical to U.S. nuclear deterrence and is viewed by the administration and others as the cornerstone of our extended deterrence commitment to allies around the globe," Creedon said.
Under questioning from subcommittee chairman Rep. Mike Rogers (R., Ala.), Creedon disagreed with a New York Times editorial from May that called the B-61 upgrade "nonsensical" and inconsistent with Obama’s call to eliminate all nuclear arms.
"We’ve seen massively uninformed editorials and articles out there on the B-61," Rogers said.
Creedon said the bomb modernization bolsters the president’s nuclear policies that say nuclear weapons are needed as long as other states maintain nuclear arsenals.
Ranking Democrat Rep. John Garamendi asked why the newer B-83 nuclear bomb should be used instead of modernizing the B-61.
The officials said the B-83, which is a huge bomb with a yield of 1.2 megatons or the equivalent of 1.2 million tons of TNT, is too big for tactical nuclear use and cannot be carried on NATO or U.S. dual-use conventional nuclear jets like the F-16 and F-35.
Eventually, the upgraded B-61 will replace the B-83, the officials said.
Creedon said the B-61 modernization tail kit is a key element of the bomb upgrade.
"The improved accuracy [with the tail kit] will allow the B61-12 to achieve the same military effects of today’s highest-yield versions, while incorporating the smallest yield design available," Creedon said.
The role of the B-61 bomb upgrade "in providing nuclear deterrence throughout the globe is extremely important," she added.
Creedon said NATO last year affirmed its need for nuclear arms in a deterrence and posture review. The review confirmed nuclear arms as a "core component" of NATO defense.
Paul J. Hommert, director of Energy’s Sandia National Laboratories, that is involved in B-61 modernization, said he has expressed formal concerns about the aging bomb in recent years.
"While the B-61 is currently safe and secure, these concerns continue to increase," Hommert said.
Among the problems are degradation in electronics, polymer components and high explosives used to trigger a nuclear blast.
The modernization will also replace obsolete technology, Hommert said.
Vacuum tubes used in the bombs are outdated and difficult to test, and a new radar used inside the bomb will employ radio-frequency integrated circuits.
Also, encryption used on the codes that prevent unauthorized use of the bombs also are becoming outdated. "So key features associated with use control and denial must be upgraded," Hommert said.
Also, electronic signals sent from delivery aircraft to the bombs need updating from analog to digital technology for use with the new F-35 joint strike fighter, he said.
The House voted down legislation in July that would have cut $23.7 million from the B-61 modernization program.
Officials at the hearing said defense-spending cuts made under sequestration had already delayed the needed B-61 modernization program by six months.
U.S. nuclear modernization options are limited by the Obama administration’s policy of not producing new nuclear weapons. As a result, old weapons, some built in the 1960s, must undergo life-extension programs.
The 2010 Nuclear Posture Review also stated that upgrade program will only use previously tested designs and will not expand military missions or provide new military capabilities.
For example, under the restrictive policy, the Pentagon was prohibited from converting the B-83 into a penetrating warhead that can reach deep underground structures, a growing problem for strategic war planners and officials in charge of countering terrorists’ potential use of nuclear, chemical and biological weapons.
By contrast, Russia and China are developing new, more modern and more lethal nuclear warheads and bombs as part of their respective strategic modernization programs.