North Korea’s Yongbyon reactor was ostensibly built to generate electricity but is reportedly not connected to any power lines.
Instead, experts say, it has produced enough plutonium from its fuel rods for possibly up to a dozen nuclear weapons over its 20-year history.
The US State Department said Saturday it had been told that the reactor and other facilities at Yongbyon had been shut down, as part of a six-nation nuclear disarmament deal agreed in February.
UN nuclear inspectors and a first shipment of fuel oil, promised in return for the shutdown, arrived in the communist state earlier in the day.
The reactor, 96 kilometres (60 miles) north of Pyongyang, has a capacity of five megawatts and began operating in 1987. Two larger reactors are at the same site but are not yet thought to be operational, along with a functioning plutonium reprocessing plant several stories high.
About 2,000 to 3,000 people work at the complex.
The five-megawatt reactor is too small to make much difference to the nation’s acute power shortage and a US Congressional Research Service (CRS) report in January said it reportedly had no power lines attached to it.
Nevertheless, the North demanded steep compensation for lost energy when it shut down Yongbyon under a 1994 “Agreed Framework” deal with the United States.
An international consortium started work on two proliferation-resistant light water reactors and the US provided an interim 500,000 tonnes a year of heavy fuel oil.
The deal collapsed in 2002, when Washington accused the North of running a covert highly enriched uranium programme, and fuel shipments were suspended.
North Korea denied the charge but restarted Yongbyon after an eight-year shutdown, expelled UN atomic inspectors and announced it was leaving the nuclear Non-Proliferation Treaty.
When the reactor is operational, the CRS report said, it can produce about six kilograms (13 pounds) of plutonium annually, enough for one small bomb.
US intelligence officials believe that the North removed fuel rods for reprocessing into plutonium during a 70-day shutdown in 1989.
During a shutdown in May 1994 about 8,000 fuel rods were removed. The North said it removed a further 8,000 rods during another closure that began in April 2005.
The 1994 defuelling triggered the first nuclear crisis with the US. The Pentagon drew up detailed plans to bomb the facility and the North went on a war footing.
Diplomacy involving former US president Jimmy Carter and others averted a clash and led to the eight-year shutdown.
The latest shutdown, if confirmed, stops the North producing any more plutonium to swell its stockpile — estimated by the Washington-based Institute for Science and International Security at 46-64 kilos (101-141 pounds).
Some 28-50 kilos of this is estimated to have been separated, enough for about five to 12 nuclear weapons, the institute said in February.
The North conducted its first nuclear test last October, an underground explosion. Experts differ on whether it has the technical ability to miniaturise a bomb so it could be carried on a missile warhead.
Güncelleme Tarihi: 15 Temmuz 2007, 11:04