LIFE EXTENSION PROGRAMS FOR U.S. NUCLEAR WEAPONS

Test Launch Of Minuteman III ICBM.  Credit:  U.S. DOD. 

FROM: U.S. DEPARTMENT OF STATE

U.S. Nuclear Weapons Stockpile Life Extension Programs
Fact Sheet
Bureau of Arms Control, Verification and Compliance
January 3, 2013

Key Point: The end of nuclear explosive testing has resulted in the development and application of advanced processes for extending the service life of the warheads in the United States’ nuclear weapons stockpile. Extending the life of existing warheads helps to eliminate the need to build and test new weapons.

The National Nuclear Security Administration (NNSA), a semi-autonomous agency within the Department of Energy that has "cradle to grave" responsibility for the nuclear weapons stockpile, performs alterations and modifications to the stockpile in order to sustain the warheads that underpin the U.S. nuclear deterrent. It also conducts routine nuclear weapon maintenance operations. Over the last decade, the NNSA, through the Stockpile Stewardship Program (SSP), accomplished changes to the stockpile through Life Extension Programs (LEPs), with the goal of extending the service life of the current weapons in the stockpile. The NNSA will continue to conduct LEPs as outlined in the April 2010 Nuclear Posture Review, in order to maintain the existing stockpile. LEPs will use only nuclear components based on previously tested designs and will not support new military missions or provide for new military capabilities. The United States will not develop new nuclear warheads.

Prior to 1993, it was a routine practice for changes to warheads to be evaluated with underground nuclear explosive tests, in order to verify the relative effectiveness of these changes. Over the last two decades, the NNSA has completed several changes to nuclear warheads without performing underground nuclear explosive testing, due to improvements in computer simulation capabilities. Examples of NNSA’s success in maintaining the stockpile without nuclear explosive testing include the LEPs for the W87 Intercontinental Ballistic Missile (ICBM) warhead and B61‑7/11 strategic bomb, and the current W76-1 Submarine-Launched Ballistic Missile (SLBM) warhead LEP.

The continued success of future changes to the stockpile (i.e., B61-12 strategic bomb and W78‑1 ICBM warhead) relies on continued support for the SSP. SSP tools and investments in the future form the basis for our ability to maintain a safe, secure and effective U.S. nuclear weapons stockpile without nuclear explosive testing.

BRIEF HISTORY OF ARMS CONTROL SINCE THE COLD WAR

FROM:  U.S STATE DEPARMENT
History of the CTBT
Fact Sheet
Bureau of Arms Control, Verification and Compliance
April 9, 2012
Key Point: The effort to end nuclear explosive testing has spanned five decades with efforts culminating in theComprehensive Nuclear Test-Ban Treaty (CTBT), which was opened for signature in 1996.

The first nuclear explosive test was conducted by the United States on July 16, 1945. The Soviet Union followed with its first nuclear test on August 29, 1949. By the mid-1950s, the United States and the Soviet Union were both conducting high-yield thermonuclear weapon tests in the atmosphere. The radioactive fallout from those tests drew criticism from around the globe. The international community’s concern about the effects on health and the environment continued to grow. In 1954, Indian Prime Minister Jawaharlal Nehru proposed a ban on all nuclear testing. The increasing public concern over explosive tests led to the negotiation and entry into force of the 1963 Limited Nuclear Test-Ban Treaty(LTBT). This Treaty banned nuclear testing in the atmosphere, outer space, and under water, but underground tests were still permitted.

When the Nuclear Non-Proliferation Treaty was being negotiated in 1968, a comprehensive test ban was discussed, but the international community failed to reach agreement on the issue. Advocates for a ban on explosive testing persisted.
In 1974, the United States and the Soviet Union signed the Treaty on the Limitation of Underground Nuclear Weapon Tests, also known as the Threshold Test Ban Treaty (TTBT). It established a nuclear "threshold" by prohibiting the United States and the Soviet Union from conducting tests that would produce a yield exceeding 150 kilotons (equivalent to 150,000 tons of TNT). The mutual restraint imposed by the Treaty reduced the explosive force of new nuclear warheads and bombs, which could otherwise be tested for weapons systems. The TTBT was not intended as a substitute for a comprehensive test ban. Article I of the Treaty states that, “the Parties shall continue their negotiations with a view toward achieving a solution to the problem of the cessation of all underground nuclear weapon tests.”

In 1976, scientists from different countries formed the Group of Scientific Experts (GSE) and began conducting joint research into monitoring technologies and data analysis methods for the verification of a comprehensive test ban.

Almost two decades later, the Cold War ended, bringing with it increased possibilities for progress on disarmament and self-imposed testing moratoriums from the United States and the former Soviet Union. Capitalizing on this momentum, the United Nations’ disarmament body, the Conference on Disarmament (CD) in Geneva, began formal negotiations on the Comprehensive Nuclear Test-Ban Treaty (CTBT) in 1994. Capitalizing on the GSE’s research, the CD was able to reach consensus on the verification regime. Other parts of the negotiations proved more difficult, but members of the CD were able to find common ground and move forward. Australia submitted the Treaty to the U.N. General Assembly, where it was adopted on September 10, 1996 and opened for signature on September 24, 1996.

Since then, 183 nations have signed the Treaty, and 156 have ratified it. Of the 44 nations whose ratifications are specifically required by the Treaty for it to enter into force, 41 have signed and 36 have ratified.