New SANE Project Leader

The global consequences of the accident had no borders. The radioactive cloud contaminated parts of Ukraine, Belarus, Russia, and reached much of western Europe. An estimated 8 tons of radioactive material were released into the atmosphere, with the radioactive output 500 times larger than that of the Hiroshima bomb.

Over 600,000 liquidators were mobilised to conduct firefighting, decontamination works, and construction of the “sarcophagus”. Many of them were exposed to high radiation doses. 28 firefighters died in a short period due to acute radiation sickness. Long-term estimates of related deaths range from 4,000 to more than 90,000, depending on the methodology. Over the years, thousands of people suffered from radiation-related illnesses.

The emergency evacuation operations were tremendous. Within 36 hours, 50,000 residents of Pripyat, where the ChNPP employees lived with their families, were evacuated. In 1986, an estimated 116,000 people were evacuated from the 30-km Chernobyl Exclusion Zone established around the ChNPP site. In the late post-accident period, above 220,000 people were relocated from contaminated areas.

The initial concrete “sarcophagus” - Object Shelter - was constructed within 206 days to enclose destroyed Reactor 4. Over time, its structures were impacted by ageing, becoming potentially unstable with a risk of destruction. In 2016, due to powerful international support, the New Safe Confinement (NSC) was placed over the sarcophagus - a steel arch of 108 meters height and 36,000 tons weight, and estimated lifetime of 100 years. NSC houses the damaged reactor and allows for safe dismantling and waste management operations, being the largest movable land-based structure in the world.

Regarding the accident's financial consequences, the Soviet Union spent approximately. USD 18 billion on initial cleanup and containment in the late 1980s. Ukraine, since its independence in 1991, has contributed over USD 1.5 billion to the ongoing management of the Exclusion Zone, maintenance of the Shelter, and social programmes. Through international funds - the Chernobyl Shelter Fund and the Nuclear Safety Account - the EBRD raised approx. USD 2.4 billion from over 45 donor countries and institutions. These funds were used to finance the design and construction of the New Safe Confinement, maintenance and upgrades to spent fuel storage facilities, radioactive waste management systems, ongoing safety monitoring and research.

New nuclear risks and threats have emerged since the full-scale invasion of Ukraine by Russian troops on 24 February 2022. During the occupation of the Chernobyl Exclusion Zone, which lasted until 31 March 2022, the military forces of the Russian Federation held the NPP staff under duress for over three weeks, with serious risks to operational control and nuclear safety monitoring. The IAEA later confirmed that the occupation posed significant nuclear security and radiation risks.

On 14 February 2025, the Russian drone attacked the Chernobyl site, damaging the outer wall of the New Safe Confinement. It took three weeks to eliminate the consequent fire. The incident revealed the unprecedented vulnerability of nuclear legacy infrastructure during military conflict.

The drone strike on the NSC and the lasting military occupation of the Zaporizhzya NPP must be clearly defined as violations of international law. The demand for the demilitarisation of ZNPP needs strong international support. The use of nuclear facilities as instruments or shields of warfare during armed conflict should explicitly be prohibited. The efforts at the national and international scale are required to raise awareness about the weaponisation of nuclear infrastructure as a geopolitical threat to global nuclear security. Investigations at both Chernobyl and ZNPP, including the damage and risk assessment by an independent international scientific mission, are deemed necessary. Their findings will contribute to shaping future IAEA policy and emergency response protocols.  

Fire on NSC after the drone attack on 14-02-2025. Photo by State Emergency Service of Ukraine 

The nuclear research community of Ukraine needs support and collaboration on international research projects, among others, focused on the post-conflict site remediation, radiological monitoring under military threats, cybersecurity and physical protection upgrades in war zones. As a positive example of such cooperation, the ongoing EURATOM-funded project SANE examines, among other things, communication strategies under threats due to hostilities in Ukraine, utilising lessons learned from the Russian occupation of the Chernobyl site.

Chernobyl is more than a historical tragedy - it is a continuing case study in nuclear safety, risk governance, international cooperation, and now, nuclear infrastructure resilience in conflict zones. As the world expands nuclear energy to address climate and energy challenges, Chernobyl reminds us that safety, accountability, and preparedness are fundamental.

On the day we mark another year since the Chernobyl disaster, we honour the victims, the heroes, and the hard lessons it left behind. This is a moment to remind the world that nuclear energy was created with promises of peace and prosperity, not as a tool for aggression.