I took another look at North Korea’s uranium refinery in Pyongsan county, North Hwanghae province, using various satellite images. I utilized thermal IR and nighttime light photography, along with high-resolution satellite imagery, to assess the facility’s recent condition, activity and nighttime operations from multiple angles. Satellite thermal IR images detect temperatures or heat on the Earth’s surface and record the intensity in numbers. They are often used to detect and analyze facility operations by measuring the heat generated when plants are in operation. Nighttime light photography is often used to analyze downtown economic activity by detecting lights on the surface using satellite photos taken worldwide at 1:30 a.m.
Analysis of the photos shows that as North Korea strengthens its nuclear arsenal by boosting nuclear weapon production, production at the Pyongsan refinery has recently increased, and the release of wastewater into the facility’s settling pond has grown since last year.
The Pyongsan uranium complex comprises three zones. There is a mine where uranium is extracted, a refinery where the uranium is processed, and a settling pond where wastewater is collected. On the right side of the satellite photo, one can make out an anti-aircraft battery on a hill across the Yesong River, about 300 meters from the facility. Nine anti-aircraft guns are deployed in an oval at the battery — the guns are tasked with protecting the uranium plant against air strikes. The place is one of North Korea’s strategically important facilities. However, it is doubtful that a single anti-air battery could protect the facility against airstrikes.
The Pyongsan plant is North Korea’s only uranium refinery. If an airstrike put Pyongsan out of commission, North Korea’s plan to boost its nuclear arsenal would run into significant difficulties. The country used to have another uranium refinery in Pakchon county, North Pyongan province. The Pakchon facility has reportedly closed. According to some, the shuttered and abandoned Pakchon refinery is currently undergoing repairs and modernization, and could return to operation once the repairs are complete.
I also used IR images and nighttime light photography to examine operations at Pyongsan. The plant is presumed to have engaged in production-related activities recently, with even occasional nighttime operations.
The IR imagery was taken by the American Earth observation satellite Landsat 9 at 10:30 a.m. on June 5. To analyze the photo, the data was modified using specific processes to convert the ground temperature into Celsius and indicate the temperature distribution in ranges of 1 or 2 degrees, using different colors. Based on the color temperature distribution map, I examined recent operations at the uranium plant. Analysis of the IR images showed that the average temperature at Pyongsan on June 5 was 26 degrees, with a low of 19 degrees and a high of 33 degrees.
Areas of high temperature are represented in red, while areas of low temperature are shown in blue. In the satellite image, several facilities, such as the thermal power plant, radiate high heat (light red and red), indicating productive activity. The power plant is producing and supplying electricity, while nearby facilities appear to be operating briskly. The water processing facility, cooling tower and uranium refinery are radiating high heat, suggesting that “yellowcake” production is at its height. Other buildings, including closed ones, have a lower temperature, indicated by a violet color. These structures appear to have little activity.
For the analysis of nighttime light photography, I examined nighttime lights at the uranium facility by analyzing Visible Infrared Imaging Radiometer Suite (VIIRS) images taken at 1:30 a.m. by the U.S. National Oceanic and Atmospheric Administration’s JPSS satellite. As shown at the bottom of the photo above, faint lights have been detected recently at night in the area around the uranium plant. I can detect some nighttime activity at the Pyongsan factory from the lights visible in the satellite photo. Activity to produce nuclear materials presumably continues into the night. This place is ordinarily pitch-black at night, with not a light to be seen, but suspicious lights have been spotted frequently lately. This cautiously suggests that nighttime activity to produce nuclear materials has increased.
Recent release of water into the settling pool
I examined the recent release of wastewater into the settling pond using high-resolution satellite imagery taken in late May. Compared to photos taken last December, the amount of wastewater released has increased. I can clearly see wastewater released into the settling pond flowing along the 2-meter drainage in black. The rainy season in Korea is fast approaching. One worries that the amount of wastewater released will increase even more in line with the frequent rains.
Mysterious disease in Pyongsan
According to articles in the Daily NK (Jan. 21, 2022) and Monthly Chosun (July 23, 2018), disquieting rumors have spread in the Pyongsan area. “Soldiers and workers at the uranium mine and local residents have short lives, give birth to deformed children and die from a mysterious disease of unknown origin,” a source said. “The social atmosphere is ugly, fear and discontent are rife, and loyalty and morale are low.”
To determine the veracity of those rumors, efforts to collect a wide range of testimony and materials from people from Pyongsan, soldiers or workers who served in the area, or defectors familiar with the area would be necessary. And if possible, collecting intelligence on the area’s current condition through local collaborators would greatly help in determining the situation. I also recommended conducting a comprehensive joint study — in collaboration with the U.N. and South Korean and international environmental and human rights groups — to determine the pollution level in the Pyongsan area and the veracity of the so-called “mysterious illness” spreading in the area.
