SEOUL (BLOOMBERG) - North Korea appears to have taken steps to conceal upgrades to an uranium-enrichment plant from spy satellites as it reopens communications with South Korean President Moon Jae-in, who is pro-engagement.
Satellite imagery shows that previously reported construction in an area at the Yongbyon uranium-enrichment plant has been covered to hide details of the building's layout, the US-based 38 North website said in a post.
It added that although there may be several reasons for the expansion, one option could be to increase production of fissile material.
"One option, assuming that North Korea is producing low-enriched uranium at two enrichment halls, is that the extension could also be used to enrich low-enriched uranium to weapons-grade (high-enriched uranium) as it becomes available from those two cascade halls," it said.
The renovations could indicate that North Korea plans to increase production by as much as 25 per cent, weapons expert Jeffrey Lewis wrote on his Arms Control Wonk website in mid-September.
38 North had earlier said the satellite imagery indicated that cooling units were removed from the facility between Aug 25 and Sept 1, and the reason for the move was "unclear".
The upgrade at the uranium-enrichment facility at Yongbyon comes after the International Atomic Energy Agency said North Korea had also resumed plutonium production operations at its main nuclear complex for the first time in about three years.
The moves show that leader Kim Jong Un is ramping up production of material for nuclear bombs, which he kept churning out during disarmament talks with former US president Donald Trump.
Mr Kim has piled pressure on President Joe Biden and Mr Moon through tests in September of three new weapons systems designed to deliver nuclear weapons to all of South Korea and most of Japan - two countries that host the bulk of US troops in the region.
Mr Kim offered an olive branch to Mr Moon this week by restoring inter-Korea hotlines that Pyongyang let go silent for about two months and dangled the prospects of another face-to-face meeting before the South Korean leader leaves office next year.
The change in tone likely has a lot to do with the political calendar in Seoul. South Korea elects a new president in March and time is running out for Mr Moon to make good on one of his core pledges to bring the two Koreas closer to peace.
North Korea likely sees the election as a chance to win concessions from Mr Moon and get him to press the United States to do the same.
Mr Andrew Kim, the former head of a Central Intelligence Agency centre in charge of countering threats from North Korea, said he expects a video summit to take place before Mr Moon leaves office, military newspaper Stars and Stripes reported on Wednesday (Oct 6).
North Korea produces about enough fissile material for five to six nuclear bombs a year, according to estimates by weapons experts, and has a stockpile large enough for about 30 to 60 weapons.
The Yongbyon nuclear complex, which has served as the crown jewel of North Korea's atomic programme, is an ageing facility about 100km north of Pyongyang that once was the only source of its fissile material.
It churned out roughly enough plutonium each year for one atomic bomb. Since then, North Korea has used uranium enrichment as the main source of fissile material for weapons.