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Tri-Valley Communities Against a Radioactive Environment
June 2, 2022
N. Korea Reveals Uranium-Enrichment Plant
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Peter Crail

North Korea unveiled a large uranium-enrichment pilot plant to a visiting team of former U.S. officials and academics Nov. 12, complicating efforts to denuclearize the Korean peninsula and potentially providing the country with another path to nuclear weapons.

During a Nov. 23 briefing, former Los Alamos National Laboratory Director Siegfried Hecker said that North Korean officials had showed him a facility containing about 2,000 gas centrifuges to enrich uranium. North Korean technicians claimed that the centrifuges were operating and producing low-enriched uranium (LEU) for a light-water reactor (LWR) Pyongyang revealed it was constructing earlier in the month, Hecker said.

Uranium enrichment can be used to produce LEU to power nuclear reactors but also to produce highly enriched uranium, which can be used for nuclear weapons.

North Korea has been suspected for many years of pursuing an enrichment capability, but the scale and sophistication of those efforts has been in question. (See ACT, April 2007.) Hecker said that “it was just stunning” to see “hundreds and hundreds” of centrifuges at the plant rather than the “couple of dozen” he was expecting. Pyongyang first publicly admitted to an enrichment program in June of last year, stating in September 2009 that the “experimental phase” of those efforts had been completed.

The decision to show Hecker the facility appears to have been made at the urging of former U.S. special envoy to North Korea Jack Pritchard, who visited the country in early November.

During a Nov. 23 briefing with Hecker at the Korea Economic Institute, Pritchard, who heads the institute, said that he was told about the existence of the enrichment plant during a visit to the Yongbyon complex. Upon Pritchard’s return to Pyongyang, North Korean Foreign Ministry officials expressed surprise that he was told about the facility, he said at the briefing. Pritchard said he told Pyongyang that because the international community would be skeptical of North Korea’s claims that it was pursuing enrichment for nonmilitary purposes, international inspectors, or at least Hecker, should be shown the new plant.

North Korea has invited Hecker to visit its nuclear facilities on several other occasions to provide confirmation of certain nuclear activities.

Hecker estimated that the facility is capable of producing two metric tons of LEU each year. That amount would be appropriate for fueling a reactor of the size North Korea intends to construct or for producing up to 40 kilograms of HEU, which is enough for one to two nuclear weapons.

Although Hecker indicated that he could not confirm that the centrifuges were in operation, he said the North Korean claim that they were operational was “not inconsistent” with what he saw. He also described the facility control room where he was taken as “astonishingly modern,” particularly compared to the other nuclear facilities located at the Yongbyon complex, which used decades-old instrumentation.

The centrifuges are located in a facility that formerly housed the metal fuel rod fabrication facility that North Korea used to fashion fuel for its five-megawatt reactor located at the same complex. When it was in operation, that reactor produced plutonium for Pyongyang’s nuclear weapons program. As part of a 2007 arrangement in which Pyongyang agreed to disable key facilities involved in that program, North Korea shut down its reactor and removed critical equipment from the fuel fabrication plant.

U.S. officials were present to confirm that those facilities remained disabled until April 2009, when North Korea backed out of multilateral talks in response to a UN Security Council rebuke of its rocket launch earlier that month and kicked out inspectors.

Hecker said North Korean technicians told him that they had begun constructing the enrichment plant in the former fuel-fabrication facility that same month.

Hecker, along with former U.S. officials familiar with North Korea’s nuclear program, has expressed surprise at the speed with which Pyongyang was able to install and possibly operate a facility of the scale revealed last month. During the Nov. 23 briefing, Hecker said that the centrifuges originally must have been installed in a plant in another location and moved to Yongbyon. He noted that North Korea could possibly have other enrichment facilities, adding that they would be difficult to detect.

The international community has expressed similar concerns over the difficulty of detecting covert enrichment plants in Iran, which was found to be constructing such a plant in secret last year. (See ACT, October 2009.) Tehran also uses gas centrifuge technology to enrich uranium, claiming that it is doing so to produce LEU for nuclear fuel.

The North Korean and Iranian gas centrifuge programs both received crucial assistance from the nuclear smuggling network run by Pakistani nuclear official Abdul Qadeer Khan, including centrifuge designs, components, and complete centrifuges.

In his 2006 memoir, former Pakistani President Gen. Pervez Musharraf said Khan provided North Korea with centrifuges and centrifuge components of the P-1 and the more advanced P-2 variety in 2000.

The centrifuges at the Yongbyon enrichment facility are believed to be based on the P-2 model whereas Iran’s centrifuge program has primarily relied on the P-1 machine. Former International Atomic Energy Agency (IAEA) Deputy Director-General for Safeguards Olli Heinonen said Nov. 22 that Iran does not appear to have progressed in its development of its own P-2 centrifuge variant.

The P-2 centrifuge can enrich uranium more than twice as fast as the P-1.

Hecker said he was concerned that North Korea was cooperating with Iran on centrifuge development, but he said that the facility he was shown indicates that North Korea’s enrichment program is more advanced than Iran’s. “I would not go to Iran if I were North Korea,” he said adding, “but it might in the future be the other way around.”

Centrifuge capabilities are generally measured in separative work units (SWU), or the effort needed to separate isotopes in the enrichment process. Iran’s industrial-scale Natanz facility is estimated to average less than 4,000 SWU per year while, according to Hecker, North Korea claims that the Yongbyon enrichment plant has an annual capacity of 8,000 SWU.

Hecker said North Korean technicians told him that their centrifuges were based on designs used by the European enrichment consortium Urenco, from which Khan stole the centrifuge designs during the 1970s, and Japan’s Rokkasho-mura enrichment plant.

The relation to the Rokkasho-mura plant is uncertain.

According to Hecker, North Korea admitted for the first time that it was capable of producing uranium hexafluoride (UF6), the feedstock for uranium enrichment. Although Pyongyang has denied possessing a UF6 plant in the past, suspicions mounted when international inspectors discovered UF6 in Libya that the United States believes originated in North Korea.

Libya also was pursuing an enrichment program with assistance from Khan’s network.

North Korea was known to have the capability to produce uranium tetrafluoride (UF4), the precursor for UF6, during the 1990s, but that facility was abandoned some time prior to 2002 due to corrosion and equipment failure.

Hecker said North Korean officials told him that they developed a less corrosive process that was used for UF4 production, which they used to produce UF6 as well.

Despite concerns that North Korea could have additional enrichment plants in other locations for military purposes, there is some question as to whether Pyongyang has sufficient materials to build such facilities.

“They are limited by the materials and the equipment,” Hecker said, noting that the requirements for construction of a centrifuge enrichment plant include high-strength steel and aluminum, ring magnets, bearings, and vacuum valves. Such materials and equipment fall under international controls over nuclear-related technology.

Going Alone on an LWR

Pyongyang claims that the enrichment facility viewed by Hecker is part of a fuel production process for an LWR it began constructing at the end of July. LWRs require enriched-uranium fuel.

Hecker said that the LWR is relatively small, providing about 25 to 30 megawatts of power. He said North Korean officials told him the reactor will provide power for local communities and that, given their lack of expertise in LWR technology, they would begin with a small-scale reactor.

North Korea declared last year that it would “actively consider” building such a reactor in response to the April 2009 Security Council condemnation of its rocket launch, among other steps to bolster its nuclear activities. Although North Korea is not believed to possess the expertise to construct a full-scale LWR, Hecker said the country’s plan to construct a 25- to 30-megawatt reactor “is credible.”

The LWR revelation comes about a month after satellite imagery revealed new construction at the Yongbyon site where the cooling tower for North Korea’s five-megawatt heavy-water reactor once stood. (See ACT, November 2010.) The cooling tower was demolished in 2008 as part of the multilateral denuclearization agreement and the site now is being used for the LWR.

Although two key facilities associated with North Korea’s now-dormant plutonium-production program are being used for North Korea’s enrichment plant and its LWR, Pyongyang could still reinstate plutonium production if it chose to do so.

Hecker said he did not think the new facilities would not significantly delay the reconstruction of the cooling tower, which would take about six months, and North Korea still has fuel rods for its existing reactor. Many of those fuel rods, however, would need to be machined before being loaded into the reactor, a process also estimated to take about six months.

According to Hecker, North Korea officials said that the five-megawatt reactor remains under repair and is “on standby.”

North Korea cannot produce any additional plutonium for weapons until it machines new fuel rods and constructs a new cooling system for the reactor.

Hecker suggested that North Korea’s fastest route to increasing its nuclear weapons capabilities would be for it to restore its plutonium-production facilities. “They’ve tested twice, they know how to build a plutonium bomb, that’s the way they would go,” he said.

He noted that because more-advanced weapons programs generally use plutonium, states that have developed nuclear weapons have switched from HEU-based to plutonium-based weapons, rather than the other way around.

Hecker and Pritchard said North Korean officials told them during their visits that the construction of the LWR, along with a number of major economic development activities, is slated for completion in 2012, when the country celebrates the 100th anniversary of the birth of its founder, Kim Il Sung. They both expressed doubt about that time frame.

The construction of an LWR has been a critical issue in negotiations over North Korea’s nuclear weapons efforts.

As part of a 1994 U.S.-North Korean denuclearization agreement, called the Agreed Framework, Washington agreed to facilitate the construction of two 1,000-megawatt LWRs in North Korea in return for a North Korean pledge to freeze and dismantle the facilities associated with its plutonium-based nuclear weapons program.

An international consortium poured concrete for the first reactor in 2002, but the project was suspended a year later following a breakdown of the Agreed Framework at the end of that year. The reactors, originally due to be completed in 2003, were never constructed. Pyongyang often complained about delays in the construction of the reactors.

The LWR issue was raised again in a 2005 agreement involving China, Japan, North Korea, Russia, South Korea, and the United States, in which the six parties “agreed to discuss, at an appropriate time, the subject of the provision” of an LWR to North Korea.

Hecker said North Korean officials told him that the possession of an LWR is important for energy production and for symbolic reasons and that Pyongyang maintains that it has a right to pursue nuclear energy.

North Korea still claims it is willing to honor the 2005 denuclearization agreement, a key U.S. condition to restart negotiations. (See ACT, October 2010.) It is unclear how the new enrichment facility would be addressed in any renewed talks.

The September 2005 joint statement commits North Korea to abandoning all nuclear weapons “and existing nuclear programs.” The two Koreas also pledged in that statement to abide by a 1992 joint declaration on denuclearization, which prohibits either country from developing enrichment or reprocessing technologies.

A decision to maintain an enrichment facility, even for peaceful purposes, would appear to be inconsistent with the 1992 declaration.

Pritchard said that, during his visit, North Korean officials talked about “a little bizarre reordering of priorities” with respect to the 2005 agreement, highlighting the U.S. commitment to discuss a formal peace treaty, normalization, and compensation for North Korean commitments, rather than the denuclearization process.

UN Report Details Proliferation

In the midst of revelations regarding North Korean nuclear activities in defiance of UN sanctions, a 75-page UN panel report released Nov. 10 detailed Pyongyang’s efforts to circumvent international controls and import and export prohibited goods.

The report was drafted by a seven-member panel established by UN Security Council Resolution 1874, adopted in response to North Korea’s May 2009 nuclear test. Diplomatic sources said that the release of the report, which was completed in May, has been delayed for several months by China.

The report says that North Korea “has established a highly sophisticated international network for the acquisition, marketing and sale of arms and military equipment,” noting that such exports are a key source of foreign currency for Pyongyang, amounting to about $100 million each year.

It indicates that Pyongyang is involved in nuclear- and ballistic missile-related activities in certain countries, including Iran, Myanmar (Burma), and Syria, and calls on states to prevent such transfers.

The panel concludes, however, that UN sanctions have “significantly constrained” Pyongyang’s illicit arms sales. To get around international sanctions, North Korea employs a “broad range of techniques to mask its financial transactions, including the use of overseas entities, shell companies, informal transfer mechanisms, cash couriers and barter arrangements.”

The report notes that North Korea relies on air cargo to transport high-value and sensitive arms exports. Resolution 1874 includes less-detailed enforcement measures for air cargo than for suspicious overseas freight.