North Korea’s Yongbyon Nuclear Center: Rail Activity at the Radioisotope Production and Uranium Enrichment Plants

A 38 North exclusive with analysis by Peter Makowsky, Frank V. Pabian and Jack Liu

Recent commercial satellite imagery reveals minor activity within North Korea’s Yongbyon Nuclear Scientific Research Center complex with no indications of operations at the 5 MWe reactor or Experimental Light Water Reactor. There are four railroad flatcars present, each configured to carry four-to-five cylindrical containers. Their location and the lack of indicators at the Radiochemical Laboratory suggests that the railcars are carrying nonradioactive materials, likely chemicals related to uranium conversion operations at the Radioisotope Production Plant.

The Radioisotope Production Plant and Uranium Enrichment Plant Area

Satellite imagery from February 10 and 11 reveals the presence of four railroad flatcars specially configured to carry cylindrical containers in two separate locations. A group of three were observed to the north of the Uranium Enrichment Plant, on the rail line servicing the area. The first railcar (northern-most on Figure 2) has four canisters laid sideways or perpendicular to the length of the car. The cargo on the second is less clear but appears to have two donut-shaped objects laying at either end of the car. The third car has four cylindrical canisters laid sideways, with a probable fifth canister separating them, but aligned parallel to the length of the car. A similar set of three railcars has been observed in this area in the past, at least once on the rail spur located between and servicing both the Radioisotope Production and the Uranium Enrichment Plants, and most recently on November 14, 2019, at the Yongbyon Railyard.

A fourth flatcar carrying five canisters positioned sideways (the center one appearing smaller) is located east of the Uranium Enrichment Plant on the rail spur adjacent to the Radioisotope Production Plant.

The association of these specialized flatcars with these two plants suggests the content of the canisters is likely some chemical used in the uranium conversion process, producing feed material necessary for uranium enrichment. It would be unlikely that their content is radioactive, given that they’ve been twice sighted at unattended locations. Nonetheless, the movement of chemicals as a whole suggests one or both plants could be operating in some low-level capacity.

There is little evidence that the Uranium Enrichment Plant has been operating. No vehicles or personnel activities were observed inside the courtyard to the UEP. In the past, white tanker trailers (have been seen possibly involved in the delivery of liquid nitrogen) inside the courtyard, but none have been observed since early May last year. Moreover, no vapor has been observed from the six cooling units at the west end of the cascade halls during the coldest months.

Figure 1. Specialized flatcars present near the Radioisotope Production Plant and Uranium Enrichment Plant, February 10, 2020.

Image Pleiades © CNES 2019, Distribution Airbus DS. For media options, please contact [email protected]

Figure 2. Close-up of set of three railcars north of Uranium Enrichment Plant, February 11, 2020.

Satellite image © 2019 Maxar Technologies. All rights reserved. For media licensing options, please contact [email protected]

Figure 3. Specialized railcars most recently identified at Yongbyon Railyard on November 14, 2019.

Image Pleiades © CNES 2019, Distribution Airbus DS. For media options, please contact [email protected]

Figure 4. Close-up of railcar on rail spur adjacent to Radioisotope Production Plant, February 11, 2020.

Satellite image © 2019 Maxar Technologies. All rights reserved. For media licensing options, please contact [email protected]

The Radiochemical Laboratory

Imagery from February 11 provides a unique west-to-east view into the Fuel Reception Area of the Radiochemical Laboratory complex. The door to the reception building is open, revealing a set of rails emerging from the building continuing along the access roadway and across the crossing street toward the storage sheds. A mobile crane with its boom in the raised position is parked on the access roadway. Its purpose is unknown.

Figure 5. Rail tracks and mobile crane visible in close-up of Fuel Reception Area at Radiochemical Laboratory.

Satellite image © 2019 Maxar Technologies. All rights reserved. For media licensing options, please contact [email protected]

5 MWe Reactor

A red-cabbed tractor-trailer, a cargo truck, a utility vehicle and a sedan were observed near the 5 MWe reactor on February 7. All but the utility vehicle had departed by February 10, and no other vehicular activity was apparent. Ice continues to fill the channel serving the 5 MWe reactor-associated pump house, where we would expect to see ice melt if the reactor were operating.

ELWR

Vehicular activity in the vicinity of the ELWR or the adjacent engineering office building was limited with two probable vans present on February 7. As with the 5 MWe reactor, ice continues to fill the channel serving the ELWR-associated pump house, suggesting it is not operating.

Site Construction and Remodeling

Construction and renovation activities in the Main Research and Administrative Headquarters Area appears to have concluded. The multi-story building previously reported under construction and replacing a two-story structure razed in August 2019 now seems complete.

At the east side of that research complex, along the river’s edge, dredging and earthmoving continue. A dredge was observed continuing to build up the riverbank, which serves as a flood wall to protect the Yongbyon complex during the rainy season.

Figure 6. Overview of main research and administrative area and reactor complex, February 11, 2020.

Satellite image © 2019 Maxar Technologies. All rights reserved. For media licensing options, please contact [email protected]

Figure 7. No indications of operations at the 5 MWe Reactor or Experimental Light Water Reactor.

Satellite image © 2019 Maxar Technologies. All rights reserved. For media licensing options, please contact [email protected]

Figure 8. Construction activities concluded at Main Research and Administrative Headquarters area.

Satellite image © 2019 Maxar Technologies. All rights reserved. For media licensing options, please contact [email protected]
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