North Korea's Missile and Nuclear Programmes
19 Apr, 2009 11:21 am
The nuclear programme of North Korea is again in the news. Selig S. Harrison, a specialist on South Asia and East Asia and a senior scholar of the Woodrow Wilson International Center for Scholars, recently visited North Korea and talked with four North Korean officials, including Li Gun of the Foreign Ministry. Li Gun told Harrison that the North Koreans had ?weaponised 30.8 kilograms (68 pounds) of plutonium" enough he said to make four or five nuclear weapons.
The first tests of the Taepodong-2 were conducted in 2006 but they were failures. The 5 April launch arguably violated a UN Security Council Resolution 1718, approved after the 2006 tests, under which North Korea must "not conduct any further nuclear test or launch of a ballistic missile", "suspend all activities related to its ballistic missile programme" and "abandon all nuclear weapons and existing nuclear programmes in a complete, verifiable and irreversible manner”. Whether or not North Korea can mount a nuclear warhead on a ballistic missile is not known.
US Secretary of State Hillary Clinton said on 25 March 2009 that the launch by North Korea of a multi-stage missile would be a “provocative act that would have consequences for Pyongyang”.
It is expected that President Barack Obama and Hilary Clinton will continue and enhance the Bush Administration’s efforts to persuade Pyongyang to stop its nuclear-weapon programme in the Chinese-sponsored six-nation talks, involving the regional powers (2). The talks have been stalemated since the end of 2008.
David Albright, a physicist and nuclear weapons expert who heads the Washington-based Institute for Science and International Security, has stated that North Korea is "likely able to build a crude nuclear warhead" for its midrange missiles that target Japan” (3). But most experts agree that it is likely to be years before North Korea is able to put nuclear warheads on ballistic missiles having sufficient range to target the United States. It will probably need this time to miniaturize its warheads to fit them to long-range ballistic missiles.
North Korea's test of a nuclear device on 9 October 2006 produced a small nuclear explosion and was probably only a partial success. If this is so, the step to a miniaturized nuclear warhead will be a long one.
North Korea is an unusually closed and secretive country. Reliable publicly available information about its nuclear programme has always been hard to find. Most is released by American intelligence agencies. To assess North Korea’s nuclear-weapon capability, the world has relied on remote monitoring, information from defectors, and inspections conducted by the IAEA between 1992 and 2003 when North Korea was a Party to the NPT.
The 2006 nuclear test showed beyond doubt that North Korea has a nuclear weapon capability. But the explosive yield of the test was surprisingly low – the equivalent of the explosion of between 500 tonnes of TNT and 1,000 tonnes of TNT. Expectations were that the yield would be in the kiloton range – up to 20 kilotons.
The low yield led many experts to suggest that the explosion was a ’fizzle’ in which the detonation was inefficient, resulting in less than a full chain reaction and the release of less explosive power than predicted (4). But perhaps too little plutonium was used in the device. Or the weapon was exploded in a large underground cavity that would have decoupled it from the surrounding rock, producing smaller seismic signals. The plutonium may have been too contaminated with plutonium isotopes other that plutonium-239, particularly plutonium-240.
Another possibility is that the shock wave produced by the conventional high explosives may not have been sufficiently symmetrical – perhaps one of the detonators misfired or the electronic circuit used to produce the voltage pulse to fire the detonators was inadequate. Or perhaps the high explosive was chemically impure. Or the implosion may have been too slow and a stray neutron could have produced a premature nuclear explosion. If a neutron gun was used to initiate the nuclear explosion at the precise moment of maximum criticality, it may have been fired at the wrong time.
North Korea began its nuclear activities in 1956. Regional security concerns in the early 1960s led it to increase its efforts to acquire the technology to produce nuclear weapons. A 5 megawatts-electrical experimental reactor, the Yongbyon-1, reportedly went critical on 14 August 1985 and became operational in January 1986. Yongbyon-1 is a gas-cooled (using carbon dioxide gas) and graphite-moderated reactor, fuelled with natural uranium (relatively abundant in North Korea).
The reactor is designed to hold a total of about 8,000 fuel rods, containing about 50 tonnes of uranium, in its core. This type of reactor produces plutonium of the type preferred for the fabrication of nuclear weapons (weapon-grade plutonium) very effectively. It is similar to the Magnox reactors, developed in the 1950s and used by the British, for example, for the production of plutonium for Britain’s first nuclear weapons.
Yongbyon-1 is able to produce up to about 6 or 7 kilograms of weapon-grade plutonium per year of full operation. It was shut down in July 2007 as agreed at the Six Party talks and the reactor’s cooling tower was destroyed a year later. In return, the US agreed to begin the process of removing North Korea from the list if terrorist sponsoring states and it was agreed that the US and North Korea will begin bilateral talks to resolve outstanding issues and move towards full diplomatic relations. The agreement has yet to be fully implemented.
In September 2008, however, North Korea announced that the reactor would be restarted because of American ‘hostility’. Some suspect that North Korea has clandestine, underground, nuclear-weapons facilities. Many believe that North Korea will not give up its nuclear weapons in the foreseeable future.
The existence of a reprocessing plant at Yongbyon to separate plutonium from the fuel elements removed from the Yongbyon-1 reactor was reported in 1989. It is thought that work began on the reprocessing plant, or ‘Radiochemistry Laboratory’ as it is known, in 1986 and was completed in the mid-1990s.
According to David Albright and Paul Brannan, North Korea had a total stock of plutonium of 46-64 kilograms, of which 28-50 kilograms was separated from spent reactor fuel elements and usable in nuclear weapons (5).
Pyongyang’s defiant launch of a Taepodong-2 missile on 5 April cast a cloud over Obama’s speech in Prague in which he announced a package of measures aimed at stopping the spread of nuclear weapons to countries that do not now have them and having the production of fissile materials for nuclear weapons prohibited.
Obama also pledged to negotiate bilateral cuts in nuclear arsenals with Russia and multilateral cuts with all the other nuclear-weapon powers. He also pledged to encourage the US Senate to ratify the Comprehensive Test Ban Treaty, banning all nuclear-weapon testing.
His stated intention of direct diplomacy and engagement with the North Koreans may lead to the fulfillment of the 2007 agreement at the Six Party talks. A sufficiently attractive economic offer may persuade North Korea to give up its nuclear-weapons. This would be a major fillip for Obama’s nuclear non-proliferation policy.
On 14 April 2009, North Korea threatened to withdraw from the Six-Party Talks in response to the UN rebuke on North Korea’s missile launch and start making weapons-grade plutonium again (6). Whether or not, the other parties to the talks, particularly China, can persuade North Korea to change its mind remains to be seen.
1. Justin McCurry and Ed Pilkington, Missile launch revives fears on US west coast, The Guardian, 6 April 2009, p.7.
2. The six nations are: the USA, China, Russia, Japan, South Korea and North Korea.
3. Blaine Harden, North Korean Missile Test a Growing Possibility, Washington Post Foreign Service,
March 27, 2009; Page A01.
4. Stockholm International Peace Research Institute (SIPRI), Armaments, Disarmament and International Security, SIPRI Yearbook 2008, Oxford University Press, 2008, p.397.
5. Albright, D and Brannan, P. The North Korean plutonium stock, February 2007, Institute for Science and International Security (ISIS), 20 February 2007.
6. John M. Glionna and Ju-min Park, North Korea threatens to exit nuclear weapons talks, The Los Angeles Times, 14 April 2009