IPFM International Panel on Fissile Materials

Progress Toward Nuclear Disarmament

There were about 60,000 nuclear weapons worldwide at the end of the Cold War. It is estimated that more than 30,000 nuclear weapons remain, including weapons that have been partially dismantled into components. Of these, more than 10,000 are believed to be operational in the arsenals of the United States, Russia, the United Kingdom, France, China, Israel, India, Pakistan, and perhaps North Korea. The United States and Russia have over 90 percent of all deployed nuclear weapons. The other seven nuclear weapon states are estimated to possess a combined total of less than 1000 operational warheads. The unexpectedly slow pace of nuclear reductions has led many to question the commitment of the nuclear armed states to the goal of eliminating these weapons.

This section looks at the current arsenals of the United States and Russia and their plans for reducing them. It describes proposals for cutting these arsenals to 1000 warheads or fewer, as a next step in arms reduction—and then for deep cuts which would bring them down to 200 warheads or fewer. Such reductions would permit very large quantities of fissile materials to be declared excess to military requirements and made available for disposition under international safeguards.

A key constraint on the pace of irreversible nuclear disarmament is the slow rate of warhead dismantlement, currently running at a fraction of the rate that prevailed during the 1990s. This rate could be significantly increased in the United States by focusing resources on warhead dismantlement at the Pantex warhead assembly and disassembly plant in Texas.

Nuclear Disarmament

International support. The international community recognized very early on the need for eliminating nuclear weapons. The very first U.N. General Assembly Resolution called for “the elimination from national armaments of atomic weapons and of all other major weapons adaptable to mass destruction.”223 The United States was the only country with nuclear weapons at that time. The Soviet Union tested its first weapons in 1949, however, and the arms race ensued. Simple fission weapons with yields of 10-20 kilotons gave way to thermonuclear weapons, with megaton yields. Within two decades, Britain, France and China had also acquired and tested nuclear weapons.


Country	Date of 1st Nuclear Test	Date of 1st Thermonuclear Test
United States	July 16, 1945	November 1, 1952
Russia	August 29, 1949	August 12, 1953
United Kingdom	October 3, 1952	November 8, 1957
France	February 13, 1960	August 24, 1968
China	October 16, 1964	June 17, 1967
India	May 18, 1974	May 11, 1998
Pakistan	May 28, 1998
North Korea	October 9, 2006

First nuclear and thermonuclear tests, 1945-2006.

The goals of nuclear disarmament and non-proliferation were formally linked in the 1970 Nuclear Non-proliferation Treaty (NPT). The intent of the Treaty is laid out in the preamble, which states that the signatories are:

"Desiring to further the easing of international tension and the strengthening of trust between States in order to facilitate the cessation of the manufacture of nuclear weapons, the liquidation of all their existing stockpiles, and the elimination from national arsenals of nuclear weapons and the means of their delivery."

Article VI of the NPT specifically calls on nuclear-weapon states party to the treaty "to pursue negotiations in good faith on effective measures relating to cessation of the nuclear arms race at an early date and to nuclear disarmament." The United States, Russia and the United Kingdom joined the NPT at its inception, but China did not become a party to the treaty till 1991 and France till 1992.

In 1996, the International Court of Justice, ruling on a case brought by the United Nations General Assembly, gave a unanimous advisory opinion interpreting Article VI as "an obligation to pursue in good faith and bring to a conclusion negotiations leading to nuclear disarmament in all its aspects" [emphasis added]. Subsequently, at the April 2000 NPT Review Conference, the nuclear weapon states that are parties to the NPT (the United States, Russia, the United Kingdom, France, and China) offered an "unequivocal undertaking ... to accomplish the total elimination of their nuclear arsenals."

Israel, India, Pakistan and North Korea, the countries outside the NPT that possess nuclear weapons, also have committed to the goal of nuclear disarmament. Israel has supported a U.N. resolution calling for a Nuclear Weapons Free Zone in the Middle East, on the condition that "the Middle East ... should also be free of Chemical [and] Biological weapons as well as ballistic missiles." The Prime Ministers of India and Pakistan, in their 1999 Lahore Declaration, announced that both countries were "committed to the objective of universal nuclear disarmament and non-proliferation." Similarly, in the September 2005 six-party talks, North Korea agreed that it was "committed to abandoning all nuclear weapons and existing nuclear programs and returning, at an early date, to the Treaty on the Non-Proliferation of Nuclear Weapons and to IAEA safeguards."

U.S.-Soviet/Russian nuclear-warhead reduction agreements. Starting in 1969 with the Strategic Arms Limitation talks, the focus of nuclear limits and reductions negotiated by the United States and the Soviet Union and then Russia has been on deployed warheads and delivery vehicles—with the decision on elimination of warheads removed from deployment left to the owning country. The 1987 Intermediate Nuclear Forces (INF) Treaty eliminated all Soviet and U.S. ground-launched ballistic and cruise missiles with ranges between 500 km and 5500 km, along with their launchers and support and training equipment. A total of almost 2700 missile systems were eliminated. The 1991 START treaty limited the United States and Russia to 1600 strategic nuclear weapon delivery systems (i.e., long-range missiles and bombers) each and capped the number of warheads that they could carry.

The 1991 U.S. and Soviet Presidential Nuclear Initiatives for the first time effected the destruction of entire classes of U.S. and Soviet nuclear battlefield warheads as well as removal of other classes of weapons from deployment. President G. H. W. Bush announced first that the United States would destroy all nuclear artillery and nuclear warheads for short-range ballistic missiles and also no longer deploy nuclear weapons on surface ships or land-based naval planes. The Soviet Union reciprocated by announcing it would eliminate its nuclear artillery, nuclear mines, and land-based tactical nuclear warheads. Tactical naval nuclear weapons would be placed in storage in Russia, and some would be destroyed.

These were reciprocal unilateral initiatives and, in contrast to the treaties limiting strategic and intermediate-range forces, involved no verification. Independent analysts estimate that Russia has 2000-3000 operational tactical nuclear warheads today. The United States may possess a total of about 1300. The U.S. total includes an estimated 350 nuclear bombs stored in Belgium, Germany, Italy, the Netherlands, Turkey, and the United Kingdom. While the United States has formal control of all of these weapons, an estimated 140 are earmarked for use by the air forces of Belgium, Germany, the Netherlands, Italy and Turkey. These are currently the only land-based nuclear weapons that are stationed outside of their owning country.

U.S. nuclear weapons and storage vaults in Europe. The United States maintains about 350 nuclear weapons at military bases in Western Europe, and a number of nuclear weapon storage vaults from which the weapons have been removed, but that could be brought back into use.

The most recent U.S.-Russia strategic arms control treaty, the Strategic Offensive Reduction Treaty (SORT) entered into force in June 2003. Under SORT, the United States and Russia agreed that by December 31, 2012 each will not deploy more than 2200 strategic nuclear warheads. SORT does not have its own verification arrangements and depends on the verification system established by the START Treaty. The START Treaty will expire in 2009, however. SORT also is easily reversible, in that it does not require the elimination of either delivery vehicles or warheads, and it expires at the end of 2012, at the end of the day on which its limits come into force.

President Putin, in 2006, called for a "renewed dialogue on the main disarmament issues." In March 2007, the U.S. ambassador to Moscow announced, "It is also important today to look ahead to the challenges and possibilities that lie beyond the expiration of the START Treaty in 2009 and the Moscow Treaty in 2012. At the direction of our Presidents, we have begun a strategic security dialogue to consider what we want in place when the START Treaty expires, what further steps to pursue, and what sort of transparency and confidence-building regime makes the most sense."

Current Nuclear Arsenals and Planned Reductions

Despite four decades of nuclear arms control negotiations and agreements, the United States and Russia continue to retain very large nuclear arsenals. They each have about 15,000 nuclear warheads and equivalent sets of reserve components, about one-third of which are currently deployed.


	ICBMs	SLBMs	Bombers	Nonstrategic	TOTAL
United States	900	1728	1917	500	5045
Russia	1788	636	872	2330	5614

Estimates of U.S. and Russian deployed nuclear warheads. Data from "World Nuclear Forces, 2007," SIPRI Yearbook 2007, Oxford University Press, 2007, p. 514.

Among the nine nuclear weapon states, only the United States and Russia maintain thousands of warheads on hair-trigger alert--ready to be launched within 15-30 minutes. Only these states plus the United Kingdom, France and China keep nuclear weapons routinely deployed with their armed forces. Although Israel, India, Pakistan and North Korea do not currently have any of their warheads permanently deployed, they probably can deploy them at short notice.

As part of its SORT reductions, the United States plans by 2012 to reduce the number of warheads carried by its Intercontinental Ballistic Missiles (ICBMs) to 500 warheads on 450 missiles, with perhaps 300 additional warheads in reserve for possible upload. The U.S. Navy will retain 14 out of its 18 ballistic-missile submarines, each equipped with 24 Trident II missiles, but the missiles probably will be downloaded from an average of six today, to four warheads each by 2012. The Air Force plans to retire its 400 Advanced Cruise Missiles but will retain many older dual-capable (armed with either nuclear or conventional warheads) Air Launched Cruise Missiles for its long-range bombers.

In addition to its almost 5000 deployed nuclear weapons, the United States had, as of the end of 2006, a "responsive" force of about 2000 warheads, and another 3000 awaiting dismantlement--for a total stockpile of about 10,000 intact warheads. Five thousand pits are designated as a strategic reserve.

Nuclear weapons storage bunkers, Pantex Plant, Amarillo, Texas. Some staging bunkers, or "igloos," contain nuclear weapons to be dismantled, or which have just been assembled and await shipment. Others contain plutonium pits from dismantled warheads. There are 60 of these earth-mounded bunkers in an area designated Zone 4. As of June 2007, 14,000 plutonium pits were stored at Pantex.

There is greater uncertainty about the Russian arsenal. It is estimated to have over 5000 operational weapons with perhaps 10,000 additional intact warheads in reserve or awaiting dismantlement.

Although the SORT treaty does not require the elimination of warheads removed from deployment, the United States is substantially reducing its stockpiles. In mid-2004, the U.S. Government announced that it would shift almost half of the current U.S. nuclear-warhead stockpile into the dismantlement queue by 2012. Non-governmental estimates project a reduction to about 5000 total warheads. Assuming that there are 4 kg of plutonium in the average Russian or U.S. warhead, each country would require about 25 tons of weapon-grade plutonium and 150 tons of weapon-grade uranium to support 5000 warheads, assuming roughly 20 percent for R&D and process inventories. A comparison of this number to the estimated plutonium inventories in Table 5.3 shows that Russia and the United States could today declare excess, over half, and about one third, respectively, of their stockpiles of plutonium reserved for weapons.

Down to 1000 or Less

A 1999 study, The Nuclear Turning Point: A Blue Print for Deep Cuts and De-Alerting of Nuclear Weapons, proposed that the United States and Russia reduce their operational warheads to 2000 each by the end of 2007, and to a ceiling of 1000 weapons each by 2012. All of the remaining weapons would be dismantled as part of a bilaterally verified process, with the fissile materials placed in internationally monitored storage pending final disposal. The United States and Russia would also insist that all the nuclear-armed states, including those outside the NPT, end their production of fissile materials for nuclear weapons.

As an illustration of a 1000-warhead arsenal, it was suggested that the United States could eliminate its ICBMs and move to a force that relied on 640 warheads on ten ballistic-missile submarines and 320 air-launched cruise missiles. At any time, at least four submarines carrying about 250 warheads could be survivably deployed at sea. Similarly, Russia could reduce to a force of 160 single-warhead ICBMs in silos and on mobile launchers; 432 warheads on submarines; and 404 air-launched cruise missiles. From these, about 150 warheads could be survivably deployed on submarines at sea and mobile missiles in the field. A more recent proposal for a possible U.S. 1000-warhead nuclear force envisages 500 operationally deployed nuclear warheads and another 500 in a responsive force.

The fissile material inventory required to sustain a 1000-warhead arsenal would be about 5 tons of weapon-grade plutonium and 30 tons of HEU, including material for nuclear-weapon R&D and in working inventories.

Deeper Cuts in Nuclear Forces

Before the United States and Russia reduce below 1000 total weapons each, the other weapon states will probably have to join the nuclear disarmament process. At the 1995 NPT Review and Extension Conference, Britain indicated its willingness to join the disarmament process once "U.S. and Russian stockpiles were in the hundreds." France and China also have indicated a willingness to join such negotiations, once the United States and Russia have reduced to much smaller warhead stockpiles. The Nuclear Turning Point proposed that the United States and Russia each reduce their nuclear arsenals to 200 warheads by 2020, that China cap at this level, and that the United Kingdom and France reduce to a combined 200-warhead force. The 200-warhead forces would be fully de-alerted, i.e., not ready to launch at short notice, but would have a fraction of the warheads survivably deployed.

For an arsenal of about 200 warheads, the fissile material requirement--including material for R&D and a working inventory--would be 1 ton of plutonium and 5 tons of HEU.

The United Kingdom, in a 2006 Defense White Paper announced that it intended to reduce its warhead stockpile to less than 160 operationally available nuclear warheads, with only one submarine armed with 48 warheads on patrol at any time and at "several days notice to fire." The United Kingdom has 22 tons of HEU and 3.2 tons of weapon-grade plutonium in its military stockpile, far more than is required for the arsenal it now has. The U.K. military HEU stockpile--like that of Russia and the United States--is for naval reactor fuel as well as for weapons. But it has not declared excess the plutonium from its recent warhead reductions.

Israel, India and Pakistan would also have to join the disarmament process, and the reductions would have to be accompanied by parallel actions, including entry into force of the Comprehensive Test Ban Treaty and a Fissile Material Cut-Off Treaty.

Warhead Dismantlement

A key element in deep cuts in the nuclear arsenals will be to ensure that they are irreversible. Excess warheads that are removed from deployment will need to be dismantled rather than simply stored, and their fissile materials will have to be eliminated. The rates of warhead dismantlement have slowed dramatically in recent years, in both the United States and Russia, however, leaving a large stock of weapons that potentially could be returned to service.

In the early 1990s, warhead dismantlement rates in Russia were estimated at about 2000 per year. One independent estimate of the current dismantlement rate in Russia is 400-500 warheads a year, with about 200 dismantled warheads being replaced with remanufactured warheads. The net reduction rate in the Russian stockpile therefore would be 200-300 per year. Russia currently has two operating nuclear weapon assembly/disassembly plants: one in Lesnoy (formerly Sverdlovsk-45) and the other in Trekhgorny (Zlatoust-36).

Assuming an average of 25 kg of HEU per warhead, Russia’s current dismantlement rate would yield much less HEU than the 30 tons per year that it is blending down to LEU for sale to the United States. Russia would have to be making up the difference from a large stock of HEU components from earlier dismantlements.

In the United States, between 1980 and 1992, a total of 13,223 warheads were retired and dismantled at DOE’s Pantex warhead assembly and disassembly plant in Texas. For the period of fiscal years 1990-98, over 11,500 warheads were dismantled at an average rate of about 1300 per year. More recent dismantlement rates have been classified. It has been reported, however, that the U.S. warhead dismantlement rate may have fallen to about 130 weapons per year in 2003, and continued at about the same rate through 2006.

Warhead dismantlement cells, Pantex plant, Amarillo, Texas. The circular concrete structures, "gravel gerties," cover cells where warhead components containing conventional high explosives are assembled and disassembled. Pantex has 13 such disassembly cells and 60 bays that can be used for assembly/disassembly operations involving insensitive high explosives. 31 of these 73 cells and bays are not currently in operational use.

As of June 2007, 14,000 plutonium pits from dismantled warheads were stored at the Pantex plant. Thermonuclear components, which contain HEU, are stored and dismantled at the Y-12 Plant in Oak Ridge, Tennessee.

The Natural Resources Defense Council and Federation of American Scientists estimate that the U.S. stockpile of "active" warheads will decline from almost 10,000 warheads today, to approximately 5,000 warheads by the end of 2012. The DOE estimates that dismantlement of previously retired warheads, and those that are added to the queue because of the 2004 decision, will not be completed until 2023. Dismantling 5000 warheads between 2006 and 2023 would require the average dismantlement rate to increase to about 300 warheads per year.

NRDC/FAS estimate of the rate of U.S. nuclear weapons dismantlement, 1945-2023.

In its proposed National Defense Authorization Act for fiscal year 2008, the U.S. House of Representatives included a requirement that the Department of Energy’s National Nuclear Security Administration submit, by February 1, 2008, a report that includes "the current plan and schedule for retirement and dismantlement of those warheads that have not yet been retired and dismantled but are not part of the nation’s enduring stockpile;" and an assessment of the capacity of the Pantex and Y-12 plants to respectively accommodate accelerated warhead and HEU component dismantlement schedules.

One way to increase the U.S. warhead dismantlement rate would be to reduce the rate at which warheads are going through the Life Extension Program at Pantex. This program refurbishes and modernizes warheads in order to extend their operational lives and capabilities. Much of the U.S. stockpile is currently going through this process. Approximately 550 W-87 ICBM warheads went through this program between 1994 and 2004. Refurbishment of about 480 B-61 mod-7 and mod-11 gravity bombs is to be completed by 2009. Life extension of the W-80 cruise-missile warheads was deferred in 2006. The Life Extension Program for the W-76 Trident missile warheads is expected to produce its first refurbished warhead in 2007-8 and is to be completed by 2022 at an estimated cost of almost $3 billion. There are currently about 3000 W-76 warheads in the stockpile. It is expected that in the first phase about one-quarter of them will be refurbished by 2012. This alone would require processing about 125 warheads per year at Pantex, which is about the estimated current total dismantlement rate.

Reducing this high rate of remanufacture could allow a higher rate of warhead dismantlement. Such a reduced rate should be considered. A 1999 Jason report remarked that:

"We have seen on many bar charts the 'design life' of a nuclear weapon stated as 20 years, or perhaps 25 years, and one still sees a peak in planned remanufacture at precisely 20 years or 25 years after a weapon was manufactured. However, there is no such thing as a 'design life.' The designers were not asked or permitted to design a nuclear weapon that would go bad after 20 years."

The study concluded that "there is certainly no reason to expect all of the nuclear weapons of a given type to become unusable after 20 or 25 years." A subsequent Jason study concluded that rather than 20-25 years, "the primaries of most weapons systems types in the stockpile have credible minimum lifetimes in excess of 100 years." The problems of safe storage and disposition of the large number of plutonium pits and HEU secondaries that have already been produced by warhead dismantlement to date, and of disposition of the plutonium and HEU that they contain, are addressed in other chapters of this report.

Conclusion

De-alerting and deep cuts in U.S. and Russian nuclear arsenals to 200 nuclear weapons each, with the other nuclear weapon states cutting to similar levels, would mark a big step towards the elimination of nuclear weapons. To be irreversible, these reductions in deployed weapons and the subsequent warhead dismantlement process would need to be transparent and verifiable with the excess fissile materials placed under international monitoring and disposed of as quickly as possible. After such reductions it should be easier to take the final steps toward the elimination of nuclear weapons.