North Korea is apparently still cooperating with the IAEA inspectors and has allowed installation (or reactivation) of cameras and other monitoring devices in Yongbyon, and though this “radioactive contamination” (giving Richard Halloran “I told you so” rights) is being described as “quite minor” it has caused some delays:

U.N. monitors said on Wednesday they found higher than normal radioactive contamination at North Korea’s Yongbyon nuclear complex, causing an initial delay in verifying its shutdown, but the problem was now resolved.

[. . .]

“At the very beginning when we started the work (on July 14), the (radioactive) contamination was a bit higher than expected…, a bit more than normal,” Adel Tolba, head of the first monitoring group, said at Vienna airport on Wednesday.

“(So) there was a delay. It took a little time for us … until we cleaned everything up. But now everything is fixed,” he told reporters.

[. . .]

Tolba could not say why the radioactivity had been higher than normal. Yongbyon’s 5-megawatt reactor and its spent fuel reprocessing plant are based on an antiquated Soviet design. (emphasis added)

The spokesman “could not say” much about the contamination either because they’re not sure yet, or more likely because it’s too politically sensitive; publicly saying that North Korea’s reactor is a ruin or so poorly mismanaged that it’s leaking radiation wouldn’t do much to further the goals of IAEA inspectors.

A bit more from Kyodo:

The International Atomic Energy Agency has found small-scale radioactive contamination at North Korea’s key nuclear facilities in Yongbyon that is likely to delay work to set up equipment for monitoring their shutdown, informed sources said Wednesday.

The contamination, which one source described as “quite minor,” was discovered at two of the five facilities that a team of inspectors from the U.N. nuclear watchdog visited recently.

The sources did not give details about the contamination or when it was believed to have occurred, but there was no indication that it was large enough to impact the outside environment.

The sources said that “decontamination” steps are being taken at the facilities, including floors, to ensure the safety of IAEA personnel who are setting up monitoring cameras and carrying out work to seal the nuclear facilities. (emphasis added)

Unless the IAEA leaks the cause, it may be a few years before the true extent of the contamination is known, though I don’t see them letting their inspectors work in a dangerous environment.