40 Years After Chornobyl: The Risk Remains
On April 26, Ukraine marks 40 years since the Chornobyl nuclear disaster, which killed thousands and contaminated 145,000 square kilometers across multiple countries. Soviet authorities concealed the catastrophe and its devastating conseque
This article was written by Mr. Viktor Semenov, Chargé d'Affaires a.i. of Ukraine to the Kingdom of Thailand, on the occasion of the 40th anniversary of the Chornobyl Nuclear Power Plant disaster.
On 26 April 2026, we mark the 40th anniversary of the accident at the Chornobyl Nuclear Power Plant, one of the largest man-made disasters in human history. The catastrophe that unfolded in 1986 was the result of a reactor experiment carried out under Moscow's orders, in blatant violation of basic safety protocols.
The scale of the tragedy was not caused only by the explosion itself. The criminal negligence, combined with the Soviet authorities' attempts to conceal the truth about the accident and its consequences, meant that the world remained unaware of the explosion for at least two full days, while Soviet citizens were kept unaware for weeks. In those critical early days, silence was enforced, and truth was suppressed.
Despite the fact that radiation was already in the air, on 1 May the Soviet authorities forced people to participate in a demonstration in the center of Kyiv. This decision reflected a system where image and control mattered more than human life.
The consequences quickly spread far beyond Ukraine. Contamination was recorded in Belarus, Sweden, Norway, Poland, Austria, Switzerland, Germany, Finland, and the United Kingdom. The scale of the disaster is difficult to comprehend. 20,000 roentgens was the level of radiation in the destroyed reactor. For comparison, only 500 roentgens for five hours is a lethal dose. The total radiation from the released isotopes was 30 times greater than that from the bomb dropped on Hiroshima. Over 145,000 square kilometers of land were contaminated with radionuclides, and 8.5 million people were exposed to radiation.
Around 5,000 settlements across present-day Ukraine, Belarus, and Russia were affected – 2,218 of them in Ukraine, home to approximately 2.4 million people. Over 300,000 people had to leave their homes forever. The exclusion zone remains today.
The Soviet authorities hid the fact of the accident and its effects, falsifying diagnoses of radiation exposure. Data on contamination were classified until 1989. It is clear that the Chornobyl tragedy was not just a technological failure, but also the result of a Soviet system built on secrecy, the absence of freedom of speech, and disregard for human life. The Soviet authorities concealed the scale of the disaster and delayed action, turning an accident into a global tragedy.
Ukraine has drawn important lessons, choosing transparency, responsibility, and international cooperation as the basis of its approach to nuclear safety. After 1991, during all years of Ukraine's independence, my state maintained the highest standards of safety at its nuclear facilities.
Since 2022, however, Ukrainian nuclear industry has been under constant threat from the Russian army's actions.
