B61-11 Concerns and Background
 

 

February 10, 1997

Researching this issue has been a cooperative effort.  This summary could not have been written without the help of Bruce Hall at Greenpeace and Stan Norris and Chris Paine of the Natural Resources Defense Council.
For further information contact:  Greg Mello 505-982-7747


Summary


The U.S. is now fielding a new tactical and strategic nuclear military capability that has already been used to threaten a non-nuclear country.  This new capability was certified without nuclear testing, using an existing surrogate testing facility with capabilities much less than those under construction and planned.  The weapon was developed and deployed in secret, without public and congressional debate, contrary to domestic and international assurances that no new nuclear weapons were being developed.  Other new or "modified" nuclear weapons, earth-penetrating and otherwise, are planned.


Concerns

  • The B61-11's unique earth-penetrating characteristics, not to mention its wide range of yields, allow it to threaten otherwise indestructible targets from the air and are its raison d'etre.  The new weapon is uniquely useful from a military perspective -- and hence provocative from an arms control and nonproliferation perspective.
  • A central and expressed purpose of the Comprehensive Test Ban Treaty (CTBT) has always been to stop the further evolution of the world's nuclear arsenals.  This modified weapon -- certified without nuclear testing and deployed after signing the CTBT -- undercuts that treaty and could provide political cover to countries who have their own unsatisfied nuclear ambitions.
  • Earth-penetrating weapons, deployed by Clinton in the post-Cold-War era, were rejected for deployment by Carter, Reagan, and Bush.  What is the new reason to deploy these weapons?  What are the new targets?  What is known about the B61-11 strongly suggests that its rushed development has been motivated by a desire to target one or more non-nuclear-weapon states. 
  • On July 8, 1996, the International Court of Justice ruled that any use or threat of use of nuclear weapons, other than possibly in the case where the very survival of a nation was threatened, was against international law.  After this landmark decision, it is difficult to legally support the deployment, let alone the new development, of any tactical nuclear weapon -- especially one whose development appears to have been motivated by a desire to target non-nuclear weapon states.
  • In order to gain support for indefinite extension of the NPT, the United States repeatedly assured the world in April and May of 1995 that it would not continue "vertical proliferation."  During these same months the Department of Energy was seeking, and obtaining, approval for a weapon modification with significant new military utility.
  • Development of this weapon was approved outside the regular budget process and without congressional debate, by means of secret letters to key committee chairmen, raising constitutional questions.
  • In their efforts to gain acceptance for the advanced surrogate testing of the "science-based stockpile stewardship" program, Clinton Administration officials and laboratory spokespersons have for years assured a skeptical public that no new nuclear weapons would be developed or built.  At the very same time, secret development of this provocative weapon was being requested by the Pentagon and carried out by the DOE in complete secrecy.
  • The DOE claims that this weapon, with its unique new military characteristics, is not a new weapon but rather a minor modification of an existing weapon.  Lab spokespersons admit that other "modifications" are now in the works or planned for the future. What are these?
  • The current B61 modification allegedly involves only the nonnuclear components of the bomb (notwithstanding months of effort at Los Alamos).  Yet the labs maintain that in the future, modifications to the nuclear components will definitely be made and certified as well, using computer simulations and surrogate tests.  Since none of the modifications can be explosively proof-tested, why won't "confidence" in the reliability of U.S. nuclear weapons decrease under these plans?  Unfortunately, allowing such changes to be made will likely result, over time, in calls for the resumption of nuclear testing.
  • Continued modification of the U.S. stockpile is expensive.  While this particular project may or may not be expensive in itself, the DOE's $3 billion construction plans to build new nuclear test simulators, plus its planned Cold-War-level nuclear weapons program funding, is largely driven by the proclaimed "need" to maintain the capability to develop new warheads and bombs.  These DOE expenses, it must be said, are just a fraction of the $34 billion spent annually by the U.S. to field and maintain its nuclear arsenal.
  • For these reasons and others, new or "modified" nuclear weapons like the B61-11 are not in the security interests of the United States.  On the contrary, it is in our manifest interest to get rid of such weapons as fast as possible and to quit their further legitimization, as former STRATCOM commander Lee Butler and others have recently said. (1) 


Development, Testing, and Deployment


The B61-11 story came to light in slow installments. 

In early September 1995, the U.S. Department of Energy (DOE) and its three nuclear weapons labs released a revised version of a report about their nuclear stockpile surveillance program.  This report contained a footnote on page 11:
A modification of the B61 is expected to replace the B53 by the year 2000.  Since this modification of the B61 is not currently in the stockpile, there is no Stockpile Evaluation data for it.  The B61-7 data can be used to represent this weapon.  (2)
  Dr. Don Wolkerstorfer, Above-Ground Experiments I (AGEX I) Program Manager, Nuclear Weapons Technology Program, Los Alamos National Laboratory (LANL), had shed light on this modification in a broadcast debate: 
The services are looking at redeploying an existing weapon in such an earth penetrating warhead to address hardened targets, that's exactly right.  The hope is to replace the high yield B53, which has some safety problems...  (3)
 For reference, the B53 is a 9-megaton gravity bomb first placed in service in 1960.  Retirement of early versions began in 1967, but later versions of this bomb remained in the arsenal until 1987, when retirements were halted and retired (but still assembled) bombs were brought back into the active stockpile.  The B53 can be a surface-burst but not an earth-penetrating weapon.  (4)  It lacks complete electrical safety.  There are thought to be 50 of these weapons in the stockpile. (5)

The B61-7 is a more recent strategic bomb in the stockpile.  It has a selectable yield of 10 to about 340 kilotons.  The original B61-1 first entered the stockpile in 1968; the "mod 7" was first placed in service in 1985.  The B61-7 can be fuzed for air or surface burst and has "a hardened ground-penetrator nose" with a retarded contact burst fuzing option.  It can be dropped with or without a parachute.  There are thought to be 750 of these bombs in the active stockpile, along with about 600 B61-3, -4, and -10 tactical bombs. (6) The B61 family of weapons can be configured with a wide variety of yields, including 0.3, 1.5, 5, 10, 45, 60, 60, 80, 170, and 340 kilotons. (7)

In recent years, many military strategists have advocated the deployment and use of very small tactical nuclear weapons against Third-World adversaries, especially in earth-penetrating roles. (8) The two lowest yields of the B61 family lie well within this so-called "mininuke" range.  The percent of blast energy converted into shock waves in the earth is extremely sensitive to the depth of the blast.  Thus even a small increase in earth penetrating capability can greatly affect the military utility of a nuclear weapon to hold deeply buried and hardened targets at risk.  Hardening of the B61 to allow very high altitude release, with consequent high velocity ground impact, apparently provides such an increase in capability. 

In September 1995, when the B61-11 story broke, Lab spokespersons said the development of the modified warhead would take two years, and would be done primarily at Sandia.  Development, but allegedly not deployment, had been approved at that time. (9)  DOE's classified request to reprogram $3.3 million in funds within its Atomic Energy Defense Weapons Activities account was dated April 18, 1995 and was sent to the following committees: 
  • House Energy and Water Development Appropriations Subcommittee (approval from Tom Bevill and John Myers, 5/15/95);
  • House National Security Committee (approval from Floyd Spence and Ronald Dellums, 6/29/95);
  • Senate Armed Services Committee (approval from Strom Thurmond, 7/19/95); and
  • Senate Energy and Water Development Appropriations Subcommittee (approval from Pete Domenici, 6/12/95). (10) 
Not long after the existence of the weapon became public, Dr. Harold Smith, then Assistant to the Secretary of Defense for Atomic Energy, requested at the Nuclear Weapons Council Standing Safety Committee meeting of November 15, 1995, that the above schedule be accelerated, with the First Production Unit (FPU) of the B61-11 be delivered "as soon as possible, with a goal of December 31, 1996." (11)

The response from the nuclear labs, here from Los Alamos, was positive:
The B61-11 modification project...was originally scheduled for completion by August 1997; however, DoD requested that we advance the completion date to December 1996.  NWT [the Nuclear Weapons Technology program] is committed to meeting the aggressive schedule, and a significant reprogramming of resources has allowed us to accelerate our progress...Full-scale testing, led by Manny Martinez, is in progress, and three successful test drops took place in Alaska on February 28... (12)
In August 1996, LANL provided an update on the project, along with some additional details.
The essence of the modification is a field changeout of the weapon's case to provide an earth-penetration capability.  The B61's inherent ability to perform this mission was demonstrated in Nevada almost a decade ago...The engineering and nuclear certification activities are in high gear.  Hydrotest Shot 3574 in September [at LANL's newly-upgraded PHERMEX surrogate testing facility] will be the basis for assuring that the underground environment does not adversely affect nuclear performance.  Full-scale penetration tests of real and high-fidelity mock hardware are being conducted at the Tonopah Test Range in Nevada...We are committed to delivering the First Production Unit kits by the end of the calendar year. [emphasis added] (13)
Note that the "nuclear certification" mentioned is being done on the basis of hydrodynamic testing and computer modeling, without underground nuclear testing.  The reference to earlier B61 earth-penetration tests is discussed below.  Two months later, Steven Younger, Program Director of NWT, encouraged his troops with this message:
As I see it, our highest priority over the next several months is the B61 Mod 11, and the Air Force is anxiously awaiting this system....The project is proceeding at a very fast pace, and almost every division associated with our Program is contributing to this important work. (14)
 These goals have now been achieved.
The last in a series of B61-11 full-scale drop tests, prior to the Major Assembly Release (MAR), was conducted at the Tonopah Test Range on November 20, 1996.  More than 60 people from throughout the complex were on hand to observe the early morning drops.  Three units were dropped from a B2-A aircraft, two units from about 6900 feet above ground level (AGL) and a third from about 25,700 feet AGL.  Prior to November's tests, we had demonstrated compatibility with the F-16 and the B-1A aircraft...All objectives with the exception of recording the strain measurements were met...Another attempt to record strain measurements will be made in the upcoming test, now scheduled for early April [1997] in Alaska. [emphasis added] (15)

 Note that the new weapon has been tested for delivery with a variety of aircraft, including the F-16, a tactical delivery system, marking a considerable shift in application from the B53. 

Inquiries with DOE have confirmed that deployment is indeed now underway.  The "front" components of the new weapon are being or were made at the Y-12 Plant on the Oak Ridge Reservation in Tennessee, with "tail" (read:  arming and fuzing?) components made at the Kansas City Plant in Missouri.  The decision to retire the B53 is now "pending." The location(s) where the modifications are being done is classified, as well as the number of weapons being converted.  (16)   You can also find this paper at the Brookings Institute Website.

Even before Deployment, the B61-11 Caused Collateral Damage

  • The B61-11's unique earth-penetrating characteristics, not to mention its wide range of yields, allow it to threaten otherwise indestructible targets from the air and are its raison d'etre.  The new weapon is uniquely useful from a military perspective -- and hence provocative from an arms control and nonproliferation perspective.
  • A central and expressed purpose of the Comprehensive Test Ban Treaty (CTBT) has always been to stop the further evolution of the world's nuclear arsenals.  This modified weapon -- certified without nuclear testing and deployed after signing the CTBT -- undercuts that treaty and could provide political cover to countries who have their own unsatisfied nuclear ambitions.
  • Earth-penetrating weapons, deployed by Clinton in the post-Cold-War era, were rejected for deployment by Carter, Reagan, and Bush.  What is the new reason to deploy these weapons?  What are the new targets?  What is known about the B61-11 strongly suggests that its rushed development has been motivated by a desire to target one or more non-nuclear-weapon states. 
  • On July 8, 1996, the International Court of Justice ruled that any use or threat of use of nuclear weapons, other than possibly in the case where the very survival of a nation was threatened, was against international law.  After this landmark decision, it is difficult to legally support the deployment, let alone the new development, of any tactical nuclear weapon -- especially one whose development appears to have been motivated by a desire to target non-nuclear weapon states.
  • In order to gain support for indefinite extension of the NPT, the United States repeatedly assured the world in April and May of 1995 that it would not continue "vertical proliferation."  During these same months the Department of Energy was seeking, and obtaining, approval for a weapon modification with significant new military utility.
  • Development of this weapon was approved outside the regular budget process and without congressional debate, by means of secret letters to key committee chairmen, raising constitutional questions.
  • In their efforts to gain acceptance for the advanced surrogate testing of the "science-based stockpile stewardship" program, Clinton Administration officials and laboratory spokespersons have for years assured a skeptical public that no new nuclear weapons would be developed or built.  At the very same time, secret development of this provocative weapon was being requested by the Pentagon and carried out by the DOE in complete secrecy.
  • The DOE claims that this weapon, with its unique new military characteristics, is not a new weapon but rather a minor modification of an existing weapon.  Lab spokespersons admit that other "modifications" are now in the works or planned for the future. What are these?
  • The current B61 modification allegedly involves only the nonnuclear components of the bomb (notwithstanding months of effort at Los Alamos).  Yet the labs maintain that in the future, modifications to the nuclear components will definitely be made and certified as well, using computer simulations and surrogate tests.  Since none of the modifications can be explosively proof-tested, why won't "confidence" in the reliability of U.S. nuclear weapons decrease under these plans?  Unfortunately, allowing such changes to be made will likely result, over time, in calls for the resumption of nuclear testing.
  • Continued modification of the U.S. stockpile is expensive.  While this particular project may or may not be expensive in itself, the DOE's $3 billion construction plans to build new nuclear test simulators, plus its planned Cold-War-level nuclear weapons program funding, is largely driven by the proclaimed "need" to maintain the capability to develop new warheads and bombs.  These DOE expenses, it must be said, are just a fraction of the $34 billion spent annually by the U.S. to field and maintain its nuclear arsenal.
  • For these reasons and others, new or "modified" nuclear weapons like the B61-11 are not in the security interests of the United States.  On the contrary, it is in our manifest interest to get rid of such weapons as fast as possible and to quit their further legitimization, as former STRATCOM commander Lee Butler and others have recently said. (1) 


Development, Testing, and Deployment

The B61-11 story came to light in slow installments. 

In early September 1995, the U.S. Department of Energy (DOE) and its three nuclear weapons labs released a revised version of a report about their nuclear stockpile surveillance program.  This report contained a footnote on page 11:
A modification of the B61 is expected to replace the B53 by the year 2000.  Since this modification of the B61 is not currently in the stockpile, there is no Stockpile Evaluation data for it.  The B61-7 data can be used to represent this weapon.  (2)
  Dr. Don Wolkerstorfer, Above-Ground Experiments I (AGEX I) Program Manager, Nuclear Weapons Technology Program, Los Alamos National Laboratory (LANL), had shed light on this modification in a broadcast debate: 
The services are looking at redeploying an existing weapon in such an earth penetrating warhead to address hardened targets, that's exactly right.  The hope is to replace the high yield B53, which has some safety problems...  (3)
 For reference, the B53 is a 9-megaton gravity bomb first placed in service in 1960.  Retirement of early versions began in 1967, but later versions of this bomb remained in the arsenal until 1987, when retirements were halted and retired (but still assembled) bombs were brought back into the active stockpile.  The B53 can be a surface-burst but not an earth-penetrating weapon.  (4)  It lacks complete electrical safety.  There are thought to be 50 of these weapons in the stockpile. (5)

The B61-7 is a more recent strategic bomb in the stockpile.  It has a selectable yield of 10 to about 340 kilotons.  The original B61-1 first entered the stockpile in 1968; the "mod 7" was first placed in service in 1985.  The B61-7 can be fuzed for air or surface burst and has "a hardened ground-penetrator nose" with a retarded contact burst fuzing option.  It can be dropped with or without a parachute.  There are thought to be 750 of these bombs in the active stockpile, along with about 600 B61-3, -4, and -10 tactical bombs. (6) The B61 family of weapons can be configured with a wide variety of yields, including 0.3, 1.5, 5, 10, 45, 60, 60, 80, 170, and 340 kilotons. (7)

In recent years, many military strategists have advocated the deployment and use of very small tactical nuclear weapons against Third-World adversaries, especially in earth-penetrating roles. (8) The two lowest yields of the B61 family lie well within this so-called "mininuke" range.  The percent of blast energy converted into shock waves in the earth is extremely sensitive to the depth of the blast.  Thus even a small increase in earth penetrating capability can greatly affect the military utility of a nuclear weapon to hold deeply buried and hardened targets at risk.  Hardening of the B61 to allow very high altitude release, with consequent high velocity ground impact, apparently provides such an increase in capability. 

In September 1995, when the B61-11 story broke, Lab spokespersons said the development of the modified warhead would take two years, and would be done primarily at Sandia.  Development, but allegedly not deployment, had been approved at that time. (9)  DOE's classified request to reprogram $3.3 million in funds within its Atomic Energy Defense Weapons Activities account was dated April 18, 1995 and was sent to the following committees: 
  • House Energy and Water Development Appropriations Subcommittee (approval from Tom Bevill and John Myers, 5/15/95);
  • House National Security Committee (approval from Floyd Spence and Ronald Dellums, 6/29/95);
  • Senate Armed Services Committee (approval from Strom Thurmond, 7/19/95); and
  • Senate Energy and Water Development Appropriations Subcommittee (approval from Pete Domenici, 6/12/95). (10) 
Not long after the existence of the weapon became public, Dr. Harold Smith, then Assistant to the Secretary of Defense for Atomic Energy, requested at the Nuclear Weapons Council Standing Safety Committee meeting of November 15, 1995, that the above schedule be accelerated, with the First Production Unit (FPU) of the B61-11 be delivered "as soon as possible, with a goal of December 31, 1996." (11)

The response from the nuclear labs, here from Los Alamos, was positive:
The B61-11 modification project...was originally scheduled for completion by August 1997; however, DoD requested that we advance the completion date to December 1996.  NWT [the Nuclear Weapons Technology program] is committed to meeting the aggressive schedule, and a significant reprogramming of resources has allowed us to accelerate our progress...Full-scale testing, led by Manny Martinez, is in progress, and three successful test drops took place in Alaska on February 28... (12)
In August 1996, LANL provided an update on the project, along with some additional details.
The essence of the modification is a field changeout of the weapon's case to provide an earth-penetration capability.  The B61's inherent ability to perform this mission was demonstrated in Nevada almost a decade ago...The engineering and nuclear certification activities are in high gear.  Hydrotest Shot 3574 in September [at LANL's newly-upgraded PHERMEX surrogate testing facility] will be the basis for assuring that the underground environment does not adversely affect nuclear performance.  Full-scale penetration tests of real and high-fidelity mock hardware are being conducted at the Tonopah Test Range in Nevada...We are committed to delivering the First Production Unit kits by the end of the calendar year. [emphasis added] (13)
Note that the "nuclear certification" mentioned is being done on the basis of hydrodynamic testing and computer modeling, without underground nuclear testing.  The reference to earlier B61 earth-penetration tests is discussed below.  Two months later, Steven Younger, Program Director of NWT, encouraged his troops with this message:
As I see it, our highest priority over the next several months is the B61 Mod 11, and the Air Force is anxiously awaiting this system....The project is proceeding at a very fast pace, and almost every division associated with our Program is contributing to this important work. (14)
 These goals have now been achieved.
The last in a series of B61-11 full-scale drop tests, prior to the Major Assembly Release (MAR), was conducted at the Tonopah Test Range on November 20, 1996.  More than 60 people from throughout the complex were on hand to observe the early morning drops.  Three units were dropped from a B2-A aircraft, two units from about 6900 feet above ground level (AGL) and a third from about 25,700 feet AGL.  Prior to November's tests, we had demonstrated compatibility with the F-16 and the B-1A aircraft...All objectives with the exception of recording the strain measurements were met...Another attempt to record strain measurements will be made in the upcoming test, now scheduled for early April [1997] in Alaska. [emphasis added] (15)
 Note that the new weapon has been tested for delivery with a variety of aircraft, including the F-16, a tactical delivery system, marking a considerable shift in application from the B53. 

Inquiries with DOE have confirmed that deployment is indeed now underway.  The "front" components of the new weapon are being or were made at the Y-12 Plant on the Oak Ridge Reservation in Tennessee, with "tail" (read:  arming and fuzing?) components made at the Kansas City Plant in Missouri.  The decision to retire the B53 is now "pending." The location(s) where the modifications are being done is classified, as well as the number of weapons being converted.  (16)  

You can also find this paper at the Brookings Institute Website.


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