Road to Rubicon

North Korean concern for security dates back to the Korean War when the U. S. threatened to use nuclear weapons to end the war.

ON October 16, a week after the North Korean claim of a successful underground nuclear test, the United States Office of the Director of National Intelligence (ODNI) issued the following statement: "Analysis of air samples collected on October 11, 2006, detected radioactive debris which confirms that North Korea conducted an underground nuclear explosion in the vicinity of P'unggye on October 9, 2006. The explosion yield was less than a kiloton."

This puts to rest speculation that the North Korean test was a fake, that conventional explosives were set off and that there was no nuclear explosion at all. Of course, the statement does not tell us whether the test was based on plutonium (Pu) or enriched uranium (U). Also, whether it was a successful test or a fizzle to result in such a low yield or a sophisticated compact design intended to be a missile-capable warhead.

Analysis of vented radioactivity over the explosion site and air sampling of radionuclides should throw light on these, but that data seem to have been held back by the ODNI. However, quoting unnamed officials who had reviewed the results of air sampling, Thomas Shanker and David Sanger wrote in The New York Times of October 17 that U.S. intelligence determined that the test used a plutonium bomb.

This is significant because, while the U.S. believes that North Korea has a uranium enrichment programme based on technology and centrifuges supplied by A.Q. Khan, the former chief of the Pakistan nuclear programme, it implies that only the Pu route has been exploited. This also indicates that the North Koreans have mastered the implosion technique because the gun-type design, which can be used for a uranium weapon, cannot be used with plutonium. If the sub-kT yield was indeed from a successful explosion, it would mean they have achieved sophistication in implosion so as to be able to subject small amounts of plutonium to a high degree of compression, resulting in a compact design suitable for a missile warhead.

"This [determination] is good news because we have a reasonably good idea of how much plutonium they have made," Siegfried S. Hecker, former chief of the Los Alamos National Laboratory and now a visiting Professor at Stanford University, told The New York Times. Hecker is one of the few from the West to have visited the North Korean nuclear establishment. He also said his guess was that they tried to test a reasonably sophisticated device but had trouble imploding it properly, implying that the test probably failed and the sub-kT yield was less than the desired value for the design.

Speculation about the exact nature of the device and the test arose because the seismic signal - body wave magnitude of around 4 on the (logarithmic) Richter Scale - was much weaker than what is expected from the underground explosion of a typical Hiroshima-Nagasaki-like first-generation device with a yield of around 15 kT. Different agencies have given different values for the seismic magnitude and corresponding evaluations of the site location and the explosive yield.

The data put out by the U.S. Geological Survey (USGS), which can be taken as a reliable estimate, placed the magnitude at 4.2 and the location at about 70 km from Kimch'aek. Some reports stated that the U.S. official estimate of the yield was 800 tonnes. Most of the other data also seemed to suggest that the yield was about 1 kT or lower.

Irrespective of what the true yield was, what was only inferred from nuclear-related events in North Korea over the years is now a demonstrated fact: that Pyongyang has nuclear-weapons material and it has the capability to fashion them into weapons. In traversing this tumultuous road over the last two decades to cross the Rubicon, North Korea would seem to have repeatedly not complied with its international commitments since it became a member of the Nuclear Non-Proliferation Treaty (NPT).

Shen Dingli, a scholar at Fudan University in China, in an analysis immediately after the North Korean announcement argued why it would go ahead with the test. "The DPRK," he wrote, "considers its national interests to be greater than its relations with China. It will not give up the independent guarantee of national security gained through nuclear tests just because of China's concerns and the possibility of China applying pressure on it. Therefore, the DPRK is bound to hold that the advantages of conducting a nuclear test outweigh disadvantages; hence it will proceed with the nuclear test."

This North Korean concern for national security arising from nuclear politics dates back to the Korean War when the U.S. threatened to use nuclear weapons to end the war. In 1958, the U.S. deployed nuclear weapons in South Korea and the weapons remained there until President George Bush Sr. withdrew them in 1991. However, in North Korea's perception about 1,000 warheads continue to be stationed in the South and the nuclear threat from the U. S. remains.

North Korea established the Atomic Energy Research Institute in 1952 but the nuclear programme could take off only after a cooperation agreement for the peaceful use of nuclear energy with the Soviet Union in 1959. This included the setting up of a nuclear research reactor complex in Yongbyon-kun, North Pyongan Province, by the Soviets. With extensive technical assistance from the Soviet Union, North Korea built the Yongbyon nuclear research centre in the early 1960s. It included a Soviet IRT-2000 research reactor, which continues to be used to produce radioisotopes and to train people.

It is believed that Kim Il Sung sought weapons technology from China after its 1964 test, but Chairman Mao Zedong refused. By the early 1970s, North Korea had developed sufficient indigenous expertise to expand the IRT-2000 facility and it sought to acquire reprocessing technology from the Soviet Union. In July 1977, North Korea signed a trilateral safeguards agreement with the International Atomic Energy Agency (IAEA) and the Soviet Union, which brought the IRT-2000 reactor and a critical assembly in Yongbyon-kun under safeguards. The Soviet Union was party because it had supplied the fuel.

Significant indigenous expansion began in 1979, which included uranium milling facilities, a fuel rod fabrication complex and a 5 MWe natural uranium gas cooled, graphite-moderated research reactor. The 1980s marked the beginning of high-explosives tests that are required to trigger a nuclear weapon. By the time the 5 MWe reactor became operational in 1986, construction of the first of the two large graphite-moderated Magnox-type power reactors, a 50 MWe reactor due for completion in 1995, began in Yongbyon. Such reactors were built in the United Kingdom in the 1950s to produce plutonium for its warheads. Around 1987 the construction of a radiochemical laboratory with a sizable reprocessing capacity started.

Faced with energy shortage, North Korea explored the possibility of acquiring light water power reactor technology during the 1980s. In exchange for Soviet assistance in the construction of four light water reactors, the Soviet Union apparently insisted that North Korea sign the NPT. Pyongyang did so on December 12, 1985. Article III.4 of the NPT states that a non-nuclear weapon state (NNWS) must bring into force a comprehensive Safeguards Agreement with the IAEA not later than 18 months after its accession to the Treaty.

However, the initial set of documents that North Korea submitted were found to be wrong and it was given 18 more months to complete the agreement. Pyongyang not only failed to meet the extended deadline but also demanded that the U.S. withdraw its nuclear weapons from South Korea and that Washington and Seoul terminate their joint military exercises.

In September 1991 Bush Sr. withdrew the nuclear weapons and on December 18, 1991, President Roh Tae Woo declared that South Korea was free of nuclear weapons. North and South Korea then signed the `Joint Declaration on the Denuclearisation of the Korean Peninsula', whereby both sides agreed "not to test, manufacture, produce, receive, possess, store, deploy or use nuclear weapons".

The agreement also forbade the two sides from acquiring "nuclear reprocessing and uranium enrichment facilities". The agreement also included a bilateral inspections regime but a mutually agreeable implementation mechanism could not be worked out.

Following these initiatives, North Korea signed the Safeguards Agreement on January 30, 1992, and it was ratified on April 9, 1992. North Korea's "initial declaration" of its nuclear facilities and materials included a small amount of plutonium (less than 100 gm), which was claimed to have been separated during a single reprocessing operation in 1990 of a damaged fuel rod in the 5 MWe research reactor.

However, the IAEA's analysis found that there had been three campaigns: in 1989, 1990 and 1991. To determine the completeness and correctness of the initial declaration, when the Agency requested access to two nuclear waste sites, North Korea refused access stating that they were "military sites".

Thereupon, the IAEA Director-General invoked, in February 1992, the special inspection procedure provided for in the Safeguards Agreement. North Korea refused and on March 12, 1993, announced its intention to withdraw from the NPT. Under the terms of the Treaty, a 90-day notice period is required before withdrawal. On June 11, 1993, one day before withdrawal was due to take effect, the U.S. persuaded North Korea to suspend the "effectuation" of its withdrawal and accept normal IAEA inspections of the seven sites declared initially.

Even as talks with the U.S. on North Korea's return to the NPT were on, the 5 MWe reactor continued to operate. In spring 1994, when the irradiated fuel was being discharged, the IAEA proposed that this be done in a manner that would enable it to reconstruct the history of the reactor core and thereby verify North Korea's declaration of plutonium, but North Korea rejected the proposal. On May 14, 1994, the fuel rods were removed and placed in the temporary storage pond randomly, which made a historical reconstruction of the core impossible.

On June 10, 1994, the IAEA Board of Governors decided to suspend all technical assistance to North Korea. The latter responded on June 13 by giving notice for withdrawal from the Agency. On June 16, the U.S. moved the United Nations Security Council for imposition of economic sanctions on North Korea, to which North Korea declared that sanctions would mean "an act of war".

The crisis was defused when former U.S. President Jimmy Carter stepped in, met Kim Il Sung and initiated a reconciliatory dialogue process between the two countries. The framework that Carter outlined had to wait until October 1994 to be formalised as the North Korean leader died within days. Under this "Agreed Framework", North Korea agreed to freeze and ultimately dismantle its graphite-moderated reactors and related facilities at Yongbyon, and allow IAEA inspectors to monitor the freeze. Pyongyong also agreed to "consistently take steps to implement the North-South Joint Declaration on Denuclearisation" and remain a party to the NPT.

In exchange, the U.S. agreed to lead an international consortium to arrange financing for the construction of two 1,000 MWe light water power reactors and provide 50,000 tonnes of heavy oil a year for North Korea's energy needs until the first reactor became operational by the target date of 2003. The U.S. would also provide "formal assurances against the threat of use of nuclear weapons" by it. This resulted in the setting up, in 1995, of the Korean Peninsula Energy Development Organisation (KEDO).

Significantly, the Agreed Framework stipulated that North Korea would come into full compliance with the Safeguards Agreement when a significant portion of the light water project was completed but "before the delivery of key components". This was clearly an unhappy situation for the IAEA as it meant a delay of at least five to seven years before it could ensure full implementation of the Safeguards Agreement and, in particular, before it could inspect the two waste deposit sites and verify North Korea's initial declaration.

Equally dissatisfied were the U.S. and North Korea with the implementation of the Agreement. The U.S. was dissatisfied with the postponement of verification of North Korea's past activities and North Korea was unhappy with the delay in the construction of the power reactors. As a result, progress on the Agreed Framework came to a halt though North Korea's plutonium production had been frozen.

The Bush administration, after assuming office in 2001, reviewed the North Korea policy. The revised policy sought "improved implementation of the Agreed Framework, verifiable constraints on North Korea's missile programme, a ban on missile exports and a less threatening North Korean military posture". In October 2002 the U.S.-North Korea talks finally resumed when the then U.S. Assistant Secretary of State for Asia and Pacific Affairs, James Kelly, visited Pyongyang. During the visit Kelly apparently provided the North Koreans with evidence of their secret programme to produce highly enriched uranium (HEU) based on technology supplied by Pakistan in 1996-97 in exchange for intermediate range Nodong ballistic missiles. On October 16, 2002, the Bush administration declared that presented with the evidence North Korea admitted to such a programme, though the North Koreans denied it.

In December 2002 the U.S. responded by suspending heavy oil shipments, which led North Korea to lift the freeze on its nuclear installations. On December 31 it expelled IAEA inspectors from North Korean territory. Till date, therefore, the IAEA has not been able to verify the completeness and correctness of North Korea's initial declaration and cannot determine whether fissile material has been diverted for military use or not. On January 10, 2003, North Korea declared its withdrawal from the NPT, stating that the withdrawal was effective from the next day as 89 days had transpired in 1993 itself. In late February 2003, North Korea restarted the 5 MWe reactor. In May 2003 it declared that the North-South Joint Declaration was no longer valid because of "violations by the U.S." In September 2003 the North Korean Foreign Ministry declared that the reprocessing of 8,000 fuel rods from the reactor had been completed "to increase its nuclear deterrent force".

To defuse the ensuing North Korean nuclear crisis and to end its weapons programme, a multilateral dialogue at China's initiative began in Beijing in April 2003. Initially, it was a trilateral forum comprising China, the U.S. and North Korea. It expanded into six-party talks with the inclusion of Russia, South Korea and Japan in August 2003. Four rounds of six-party talks have subsequently taken place: in February 2004, June 2004, July 26-August 7, 2005, September 2005, and November 2005.

The implementation of what appeared to be a highly promising Statement of Principles signed by the six members in September 2005 ran into immediate obstacles. A renewed effort to restart the talks in April 2006 proved futile. The major obstacles were Pyongyang's insistence on its right to use peaceful nuclear technology, namely all aspects of the fuel cycle, and Washington's bid to stop North Korea's illicit activities such as counterfeiting, narcotics trafficking and proliferation of weapons of mass destruction and missiles by imposing sanctions.

On February 10, 2005, the Foreign Ministry announced that North Korea had manufactured nuclear weapons, presumably using the reprocessed plutonium from the earlier discharged 8,000 fuel rods, which should have yielded 25-30 kg. In April 2005, once again the 5 MWe reactor, which had been in operation since February 2003, was shut down and should have produced enough plutonium for two or three bombs. This reprocessing campaign was apparently completed by late August 2005.

According to Hecker, who visited nuclear installations in Yongbyon and had discussions with the head of the Yongbyon complex during January 6-10, 2004, North Korean reprocessed plutonium metal is of high weapons-grade quality. His estimate of the total separated plutonium stocks with North Korea is about 45 kg; give or take 10 kg, the equivalent of six or seven weapons.

The arithmetic is as follows: North Korea should have separated eight or nine kilograms from the operation of IRT-2000 and the 5 MWe reactor prior to the freeze following the Agreed Framework. After the defreeze, the campaign to reprocess fuel rods from the 5 MWe reactor in 2003 should have yielded about 25 kg. The 2005 campaign should have yielded 10 kg to 14 kg. In addition, the operation of the 5 MWe reactor post-2005 should produce 5 kg to 7 kg a year.

North Korea, as the first "breakout" country from the NPT, presents a very unique case in the application of international law and treaty obligations. The IAEA Safeguards Agreement is not valid once the treaty membership is terminated. Of course, this would mean that only new material and facilities would not come under safeguards. But what it implies for the material already under safeguards is not quite clear. In principle, the perpetuity of safeguards should apply. In this case, the first discharge of fuel rods from the 5 MWe reactor should continue to be under safeguards. But it is open to interpretation by North Korea and a possible resolution of this imbroglio is far from apparent.

Given that North Korea has already reprocessed it in a manner that would prevent the IAEA from being able to do proper accounting of the safeguarded material, it would be interpreted as a violation of the Safeguards Agreement. As such North Korea has been in non-compliance of its safeguards commitments by not allowing complete verification of its declared material and facilities. It should, therefore, be assumed that all the reprocessed plutonium is effectively out of safeguards and available for weapons. And there goes the NPT.

The blame for that rests squarly with the nuclear-weapon states, who continue to legitimise the possession of nuclear weapons and show no propensity to wind down their arsenals in compliance with Article VI of the NPT. It would, therefore, hardly be a surprise if more countries follow the North Korean example and emerge as "breakout" states and acquire weapons.