Yesterday, much of the world watched astonished, appalled, and terrified as Russian ground forces attacked the Zaporizhzhya Nuclear Power Plant (ZNPP) in southern Ukraine, setting a building onsite ablaze. We had thought the armed occupation of the Chernobyl Nuclear Power Plant (ChNPP) a week prior on February 24th, and holding the plant’s operation crew hostage, was the height of recklessness. But the attack on Zaporizhzhya revealed that the Russian military possesses the capacity for unprecedented depravity. The damage this time was relatively minor, with no radioactive releases detected. But now we must expect that Russian leaders are willing to risk nuclear disaster without hesitation in order to achieve short-term military objectives.

Surveillance camera footage shows a flare landing at the Zaporizhzhia nuclear power plant during shelling in on March 4, 2022.

When the invasion began on Feb. 24, we watched anxiously and thought of the risks our many friends and colleagues there were facing. As word emerged that the Chernobyl exclusion zone and powerplant had been occupied by force, we contacted our networks in Ukraine and other countries and began to discuss the needs for radiation monitoring that would emerge. News sources had reported radiation spikes at sensors near the Chernobyl NPP as it was being occupied, and we began to receive inquiries from experts and media who wanted to know if we could provide current readings. Unfortunately, Safecast has no realtime sensor installations in Ukraine. The Fukushima Daichi NPP is now ringed by network of 7 of our Solarcast Nano sensor units placed about 2 km from the plant, and an equal number further away. We have nothing like that at Chernobyl, but we have quite a lot of mobile monitoring data from the area, going back several years. We expect this will be of use for comparison when independent monitoring is able to be resumed in the future.

The Chernobyl region on the Safecast radiation map. The power plant is center right, and the town of Pripyat upper left.

As in earlier instances when reports of radiation releases in Japan, Europe, or elsewhere have caused alarm, our team hunkered down to find information about the radiation spikes at Chernobyl so we could provide public information. We’re still a bit puzzled by these spikes, as are other experts we know, but the consensus is that the most probable cause was that heavy Russian military vehicles traveling through the area resuspended radioactive dust. The theory that RF interference from Russian military radio transmitters or radars could be the cause has also been plausibly suggested. To put it in context, though, it was a very transient event; levels rose a lot in some locations a but were still similar to other places in Chernobyl; and, there was no real risk to the public, especially compared to the mortal danger of the war. Nevertheless, it would be good to understand what the cause was.

Ukrainian gov’t sensor at ChNPP displayed on the SaveEcoBotMap. The large spike that occured the night of Feb. 24 can clearly be seen (units are nSv/hr)

As we noted in our Twitter thread about the incident, part of our puzzlement is because the primary sensor network covering the area, operated by the State Agency of Ukraine on Exclusion Zone Management (SNRIU) went offline shortly after the spikes occurred, around 1am on Feb. 25. We now believe the two are not causally related. People very familiar with that network think the outage was likely due to server overload on the government system. The sensors came back online briefly on March 1, but the system has been unstable and intermittent since then.

We were happy to get to know the outstanding people behind SaveEcoBot, a great Ukrainian project which aggregates data for radiation and air quality from a number of platforms, including the Ukrainian government. They have provided the most accessible and useful radiation data throughout the conflict, though it’s affected by the intermittency of the government sensor data. SaveEcoBot has kept their website running despite the war and personal hardship and deserve everyone’s support.

Although we weren’t pointed to it until a few days later, a 10-unit sensor system inside ChNPP has remained online without interruption. So far everything there has looked normal. This system showed no spikes on Feb. 25, which adds to our puzzlement.

The European Union has a very extensive online radiation map system, including sensors in Ukraine. This system has remained stable throughout the invasion.

The soot-blackened training building at ZNPP several hours after it was fired on by Russian troops.

Plan of ZNPP by Tom Bielefield. The building that was hit and caught fire is at #15. The camera viewed live on YouTube is at #9.

When the Zaporizhzhia attack occurred on March 4, we again found ourselves trying to find nearby radiation sensors online, and vetting information about the rapidly unfolding events. Safecast chat rooms were lit up, and we were rapidly sharing information with other experts around the world as well. Where is the fire? How serious? How close to the reactor containment structures? What kind of weapons are they shooting? What are they shooting at? Where is the webcam, and from what angle is the image being taken? In situations like this, there is even more bad information than usual, both intentional and unintentional, and experts and media around the globe were hard-pressed to establish the facts. After Russian shelling caused the fire broke out, a Ukrainian government source said that radiation levels had risen onsite. This proved difficult to either verify or deny. The government radiation monitoring system was offline, but an EU sensor about 15km away had showed no change. Finally, we were able to access the powerplant’s online status report, which showed radiation levels onsite to be normal. (That webpage dropped offline a few hours later and we have been unable to access it since then). We quickly Tweeted out our report.

Trust is everything. As we explained to the Japan Times a few days ago, “When it comes to the information, we look at what’s confirmed, we say how things have been confirmed, and if there’s something that seems plausible but we haven’t confirmed it yet, we will say so.”

Many colleagues have spoken to the media about the events at Zaporizhzhia (see the selected list below), stressing that there was never a risk of nuclear detonation, and that the robust construction of the reactor containments is designed to withstand impacts as destructive as aircraft collisions. What we and the expert community are most concerned about is the real risk that shells or missiles could destroy less-protected components of the reactor cooling systems, or destroy the offsite power transmission systems needed to operate them. This could lead to a station blackout, meltdowns, and massive radioactive releases like those that happened at Fukushima.

SNRIU (State Nuclear Regulatory Inspectorate of Ukraine ) released results today of simulations showing what would happen if such an accident occurred at Zaporizhzhia. With current wind conditions, most of the radioactive plume would blanket southern Russia. We hope the Russian leadership thinks that sort of scenario is worth avoiding.

We strongly condemn Russia’s unprovoked and brutal invasion of Ukraine and the ongoing massacre of its citizens. Organizations such as Bellingcat have documented many instances of the intentional targeting of civilians, and the OSINT community has already amassed a large quantity of documentation and verification of probable war crimes, attacks on nuclear power plants included. We join them in this effort. Russia’s wanton recklessness at Ukrainian nuclear facilities is ongoing, as they hold the plants’ operating crews hostage and forced to work in unacceptably hazardous conditions. Our hearts, our minds, and our efforts are aligned in support of the Ukrainian people.


Images from the SNRIU Telegram channel showing simulations of possible results of a serious reactor accident at ZNPP.


Here are some good explainers about the Zaporizhzhia attack and its aftermath:

Zaporizhzhia Nuclear Power Station Attacked by Russian Forces   Posted on March 4, 2022 by Dan Yurman (@djysrv) — (Excellent summary, very authoritative, complete, and detailed)

Why Didn’t the Zaporizhzhia Nuclear Power Plant Fire End in Disaster?   Vice, Mar 5, 2022

A Ukrainian Nuclear Plant Is Now A War Zone. Here’s What That Means.   Buzfeed News, Mar 5, 2022

Ukraine nuclear power plant attack: scientists assess the risks  Nature, March 4, 2022


EU JRC EURDEP REMon  (map currently live)

SaveEcoBot  (map currently live)

State Agency of Ukraine on Exclusion Zone Management  (map currently offline)

EcoCenter (Chernobyl Exclusion Zone)  (map currently offline)

OPYT (map online but not updated since March 1, 2022)

Chernobyl Power Plant (Map currently offline)

Zaporizhzhya Nuclear Power Plant status page (currently offline)

Yuzhnoukrainsk (South Ukraine) Nuclear Power Station  (currently offline)



Ministry of Energy

State Nuclear Regulatory Inspectorate of Ukraine (SNRIU)


Updated information about Zaporizhzhia NPP (08:00) Mar 4

Energoatom (National Nuclear Energy Generating Company of Ukraine)