When Sweden Got Wind of an Apocalypse: the Man Who Raised the Chornobyl Alarm

Sweden was the first country to raise the alarm but initially thought the accident had occurred in one of Sweden’s power plants. Meteorologist Christer Persson, who was there, tells his story. Make us preferred on Google Share Facebook X (Twitter) LinkedIn Bluesky Email Copy Copied Meteorologist Christer Persson, May 2022. (Photo by Gunilla Lundström). Content Share Facebook X (Twitter) LinkedIn Bluesky Email Copy Copied Flip Make us preferred on Google Sweden, April 28, 1986. It was Monday. In Chornobyl, a nuclear accident had occurred two days earlier on the night between Friday and Saturday, but no one knew about it. At SMHI (Swedish Meteorological and Hydrological Institute) in Norrköping, meteorologist Christer Persson heard the news that high levels of radioactivity had been measured around the Forsmark nuclear power plant. No one knew what caused them. Follow our coverage of the war on the @Kyivpost_official . He worked as a metrologist, but had previously done research on meteorological models and calculations. Christer Persson told Kyiv Post how he, as a meteorologist, alerted Swedish authorities about the Chornobyl radioactivity. On that Monday, reports of radioactivity had begun at the Forsmark nuclear power plant in Sweden. It was just before 7 a.m. and employees at the nuclear power plant were starting to arrive for work. The first person to arrive passed the radiation meter at the Forsmark nuclear power plant, a normal routine. Then the alarm went off as the system detected elevated levels of radioactivity. The next person went through the check, and the alarm went off again. The alarm on the radiation monitor blared continuously for every employee who came to work. At Forsmark, it was assumed that the radiation came from their own power plant. The head of information for the Forsmark nuclear power plant, Karl-Erik Sandstedt, was interviewed on Swedish Radio (SR) , the same day about the situation at the nuclear power plant and said they were mapping out how far the radioactivity had spread in the sealed-off area. Other Topics of Interest Police Detain Gunman Following Shooting Incident on Bucha Street A 42-year-old man was arrested after firing chaotically in a residential area on Saturday; no casualties were reported as investigators launch a criminal probe. “As far as we know, there is no radioactive release taking place, but there has probably been a radioactive release, otherwise we cannot explain this radioactivity,” he said In a tormented voice he said: “I must admit that we don’t know how the radioactivity could have come out but hope to be able to answer that within an hour.” A minister in the government at the time, Lena Hjelm-Wallén, told SVT on this 40th anniversary of the accident, what she remembers of that day. “Authorities began reporting rising levels of radioactivity, but it was difficult for the government to inform the public when they knew so little. That was a big problem.” At the nuclear power plant, it was soon understood that contaminated shoes had triggered the scanning frame when the employees came to work. Through further measurements of the rainwater that had collected in the hull of a boat parked on land 2-3 kilometers from the power plant, they found more iodine in the boat’s rainwater than in the entire reactor. The concentrations appeared to be similar in several directions, but the source was still unknown. At lunchtime, Christer Persson, a meteorologist at SMHI, understood from the news reporting that high levels of radioactivity had been measured at the Forsmark nuclear power plant. Meteorologist Christer Persson, May 2022. (Photo by Gunilla Lundström). “I then began to investigate on my own what was behind it and started a trajectory calculation to calculate, by tracing the air’s transport path backwards, where the air came from on its way to Forsmark,” he said. A trajectory model is a mathematical, computer-based tool that calculates the path an air parcel or plume travels through the atmosphere over time. Based on a large amount oыf information about wind direction, speed, and other factors, the calculations suggested that the radioactivity came from afar, specifically somewhere around the southwestern Soviet Union. “I immediately tried to call the Swedish Radiation Protection Institute (SSI), but it was impossible to get through,” Persson said. “The news had spread and everything was chaos. I finally reached them by fax.” Persson used a research model that had recently been installed at SMHI. “The model was not part of my normal duties as an air environment meteorologist; it was something I did on the side,” he said. “Moreover, due to the emergency situation, I had contacted SSI without informing my superiors.” Initially, Christer felt confident about the calculation, but when the Soviet Union did not confirm, doubts arose. “What if I did something wrong? What if I contributed to a serious political crisis for Sweden? The superpower Soviet Union was not to be trifled with during the Cold War.” At the same time, a researcher at the Swedish Defence Research Agency (FOA) who monitored values for nuclear weapons tests had analyzed the calculations Persson had submitted and concluded that it was a nuclear power plant release. The Embassy of Sweden in Moscow then contacted the Soviet authorities and said that a severe nuclear accident had likely occurred in the southwestern part of the country. But the Soviet Union denied it. The procedure was repeated during the afternoon without the Soviet Union confirming any accident. This made Persson again shaky and scared. “What if I was wrong and caused a serious political crisis? And I hadn’t even informed my bosses what I was doing. It was incredibly unpleasant for me personally.” In the evening, Persson learned that the Soviet Union had announced that a reactor in Chornobyl, Ukraine, had already exploded around midnight on April 25-26, almost three days earlier. Persson was right. The Soviets kept their own citizens and the world in the dark for the longest time, but Sweden contributed to the fact that the Soviets finally felt compelled to inform about it.