Seoul's deputy chief nuclear envoy Lim Sung-nam will join American, Chinese, Russian and Japanese envoys on a visit to North Korea's nuclear facilities.

From Pyongyang, they'll head to Yongbyon for three days starting Tuesday to see firsthand the disablement process under way there.

Up to now only experts from the nuclear states among the six parties -- the U.S., China and Russia -- were involved in such inspections due to intelligence security concerns.

Earlier this month U.S. nuclear experts began work at three key facilities at Yongybyon, making it difficult for them to be restarted.

Also a U.S. Department of Energy official is said to be staying in Pyongyang, serving as a liaison between the disablement team and Washington.

Eleven disablement measures are under way including the withdrawal of spent fuel rods, a task that may be hard to finish by the six-party-set deadline of Dec. 31.

But it is a crucial task since spent fuel rods can be reprocessed into weapons-grade plutonium, though a lingering issue is just what the six countries will do with the used-up fuel rods.

North Korea is also required to declare its atomic programs by year's end in return for diplomatic and economic concessions.

It has yet to submit a draft declaration and the question is whether and how the regime will declare its plutonium and alleged uranium enrichment program.

Arirang News