TOKYO, Feb. 27, 2010 (Kyodo News International) -- North Korea provided about 45 tons of ''yellowcake'' uranium to Syria in September 2007 for production of fuel for an undeclared nuclear reactor, diplomatic and military sources knowledgeable on North Korean issues said Saturday.
But the shipment was followed shortly by an Israeli air strike targeting the reactor and the uranium involved is believed to have been transferred to Iran around last summer, according to a Western diplomatic source.
The move highlights North Korea's nuclear proliferation activities, leaving open the possibility that Iran would use the yellowcake for covert uranium enrichment. But a Middle East military source has said that Syria may have returned the yellowcake to North Korea in the wake of the air strike.
U.N. Security Council resolutions ban North Korea from exporting nuclear-related materials and prohibit all member countries from procuring such items from the reclusive communist country.
David Albright, president of the U.S.-based Institute for Science and International Security, said 89 to 130 kilograms of weapons-grade uranium could be produced if 45 tons of yellowcake is further processed into uranium hexafluoride and is enriched.
''In any case, 45 tons of yellowcake is enough for several nuclear bombs,'' Albright said in a written response to Kyodo News.
Such an amount of yellowcake is equivalent to making 5,500 nuclear fuel rods for the type of 5,000-kilowatt graphite-moderated experimental reactor in North Korea's Yongbyon nuclear complex, on which Syria is believed to be modeling its own reactor. Plutonium, another material used for nuclear weapons, can be extracted from spent fuel rods.
U.S. officials have said the Syrian reactor had been close to becoming operational when it was destroyed by the Israeli strike.
It remains unclear whether there was a facility designed to create nuclear fuel rods or a reprocessing plant in Syria. But U.S. government officials say the head of North Korea's nuclear reactor fuel manufacturing plant in Yongbyon had visited Syria.
The diplomatic source said that the cargo of the yellowcake left North Korea's Nampo and passed through China's Dalian and Shanghai before reaching the port of Tartus in Syria on Sept. 2, 2007.
Israel noticed the move beforehand -- a factor that led the country to launch the air strike on Syria on Sept. 6.
The diplomatic source said Iran provided financial support for the construction of the Syrian nuclear reactor. Iran asked Syria to hand over the yellowcake after the strike, and the source said it is highly likely that the material was transferred to Iran via Turkey.
Iran is believed to be close to exhausting its yellowcake stockpiles reserved for its nuclear program and is seeking supplies from abroad.
North Korea, meanwhile, has abundant natural uranium resources which can be processed into nuclear fuel rods. It is also believed to be capable of making uranium hexafluoride for enrichment.
The United States and a number of European countries are wary that the North's resources and technologies may be used for secret nuclear development programs in Iran and other countries for the purpose of earning foreign currency.
In September last year, it was revealed that Iran was secretly constructing a second uranium enrichment plant.
''Iran might want a secret source of uranium or uranium hexafluoride for a parallel enrichment program, since the uranium hexafluoride produced at Esfahan is safeguarded by the International Atomic Energy Agency,'' Albright said, referring to a uranium conversion facility in the central city.
Some experts think that North Korea may refrain from exporting nuclear-related materials as it is seeking dialogue with the United States, which aims to prevent North Korea from engaging in nuclear-proliferation activities.
However, Pyongyang was once supporting Syria in its nuclear reactor construction program when the six-party talks aimed at denuclearizing the North were being held. Given such a track record, a high-level South Korean official said, ''There are no taboos for the North.''