North Korean leader Kim Jong-il is using nuclear weapons development to maintain his firm grip on power, but a compilation of North Korean state media reports the Unification Ministry has gathered since June 2000, the reclusive leader has never visited the main Yongbyon nuclear complex.

Experts say this is unusual given that Kim has undertaken more than 100 of his so-called on-the-spot guidance tours this year alone, to anything from shoe factories to military units. One theory is that the site is simply too dangerous. Yongbyon "is such a 'sensitive' location that he may have made secret visits, but there is a good chance that he avoided visiting the site due to fears of radiation," an intelligence official said. Sensitive locations do not normally put Kim off. Some years ago he made two visits to a long-range missile base and a nuclear testing site in North Hamgyong Province.

At present, the Yongbyon nuclear complex contains a 5MW graphite-moderated reactor, plutonium extraction facilities, a nuclear fuel processing plant, a half-built 50 MW reactor, two unreported storage facilities for spent nuclear fuel, one storage facility that has been reported, and a light-water reactor that may or may not be completed by 2012.

The plutonium extraction facility is the main reason for the radioactive contamination. "Radioactive materials such as neptunium, americium and curium are released in the process of extracting plutonium by melting spent nuclear fuel rods with nitric acid," said Hwang Il-soon, a nuclear scientist at Seoul National University. "The problem is that these materials have half-lives of hundreds of thousands of years." That means the radioactive contamination possibly caused by the Yongbyon nuclear facility is a problem that will not go away.

There are also facilities in Yongbyon that store the nitric acid and other liquid waste generated from melting spent nuclear fuel rods, but they were covered with dirt, while new buildings have been built over them to cover them up. Other landfills storing solid radioactive waste, including spent nuclear fuel rods, have been covered with soil and trees. Since North Korea expelled IAEA inspectors in 2002, nobody knows for sure what is going on in Yongbyon.

One intelligence official said, "A bigger problem is the light-water reactor slated for completion in 2012. We don't think North Korea is capable of building it, but if the North compromises safety by hastily finishing it, we might witness a nuclear disaster."