The monument in “memory of the victims of the Chernobyl nuclear disaster” in front of Chernobyl’s New 108 metres (355 feet) Safe Confinement covering the 4th block (reactor 4) of Chernobyl Nuclear power plant. (Sergei SUPINSKY/AFP via Getty Images)

The name “Chernobyl” is synonymous with nuclear disaster, so when Russian troops cut off power to the Ukrainian reactor in the process of seizing it last week, red flags went up around the world. Worry only grew as two other nuclear reactors were seized by Russian forces. But in a new analysis Jack Kelly, a nuclear expert with the German Marshall Fund, explains why he believes these concerns are overblown.

Close to the three-week mark of Russia’s war in Ukraine, one question remains an overarching worry, asked and answered in think tank analyses and experts’ tea leaf readings alike: “Will Russian leader Vladimir Putin use nuclear weapons?”

My colleagues inside the Beltway and the Brussels bubble have discussed this question at length, and I understand its appeal and the genuine concern underpinning it. Being fearful is normal during a large-scale war, even more so when nuclear weapons enter the picture.

At the same time, it is important for that concern to be tempered by reality, and the good news among the nuclear details is that the situation is not as scary as it sounds.

At the beginning of the war, Russia captured the Chernobyl nuclear power plant; late last week, Russia captured the Zaporizhzhia nuclear power plant. The Kharkiv Physics and Technical Institute, housing a small nuclear research reactor used for experimentation, also suffered heavy shelling from Russian forces in the past few days, and the International Atomic Energy Agency (IAEA) now reports that the neutron generator at that location has been destroyed. In the abstract, this sounds scary, but while all three facilities faced significant damage, none saw nuclear material release.

RELATED: For more on Russia’s invasion of Ukraine, click here.

After the shelling of Kharkiv and the capture of Zaporizhzhia, the Russian Ministry of Foreign Affairs accused Ukraine of staging an attack, as part of an accusation that Ukraine is seeking to set off its nuclear reactors to strike at Russia; Moscow even accused Ukraine of creating a dirty bomb, a statement with no merit. This news sent worries about Russia purposefully using radiological dispersal devices — otherwise known as “dirty bombs”— in false flag incidents to justify its invasion of Ukraine, or simply as a weapon with plausible deniability against the Ukrainian population.

In warfare, fear is as much a weapon as a rocket, and when it comes to nuclear weapons and radiological incidents, any mention of exposure is enough to send populations into panic — such as the runs on iodine tablets in Belgium, Italy, and Denmark seen in the last several days. However, we must understand the reality of a situation and respond accordingly. The reality here is a lot less scary than full-blown nuclear warfare.

Dirty bombs, known as radiological dispersal devices (RDDs), are not nuclear weapons. These devices do not explode due to a nuclear chain reaction, they do not cause nuclear fission or fusion, and they do not require certain elements like uranium or plutonium to be created. They combine conventional explosives, such as dynamite, with available radiological elements, such as nuclear waste, to explode and disperse radiological material. If a nuclear reactor was hit in a military engagement, the reaction would be akin to a dirty bomb going off.

RDDs are not weapons of mass destruction. If a reactor was hit by a missile, the blast from the conventional explosives would likely do more damage and kill more people than the attached radioactive material. The dispersion of the radioactive material would depend on how strong the blast was, along with wind conditions, but it is likely that an RDD explosion would only contaminate blocks, not hundreds of miles.

The military power of an RDD lies in its ability as an “area denial” tool. Use of an RDD would cause expensive cleaning and radiation studies which would deny access to an area for a prolonged time. While there have been many events that could have ended as dirty bomb events, no RDD has ever been exploded.

Let us talk specifics about the Ukrainian facilities.

The reactor at the Kharkiv Physics and Technical Institute is a small, relatively new reactor which has only been operated occasionally and uses tiny amounts of fuel. This means that waste generation and storage may be low; though the possibility for medical isotopes, such as Iodine-131 and Strontium, in the facility does exist, reports indicate safety measures were taken to put the reactor into a “subcritical” (safe) state as the war began. This facility was also built with modern safety standards.

A strike on this facility that was to explode some level of radioactive material would create more of a radiological dispersal “incident”, and the size of the incident depends on many variables. Even in the event of complete destruction, this would likely become a localized event and deny entry to the area of Kharkiv until remediation efforts were able to measure and clean the extent of radioactive material release. While area denial may play into Putin’s intentions, it is unlikely this would pose a continent-level danger.

While the name Chernobyl is synonymous with nuclear disaster, another epic meltdown at the location does not appear in the cards. Reports indicate that the plant and cooling pools lost power due to a damaged power cable. Chernobyl’s cooling pools store around 20,000 spent pieces of fuel which need to be cooled by water. Without water being refreshed or cooled, the water can evaporate. However, the site has diesel backup generators which can run for two days, and the due to the age of the fuel, the water in the pools will continue to cool efficiently even without power. During the outage, power was maintained with generators and has since been restored. Luckily, IAEA reports no significant increase in radioactive release at any of these sites. Assuming the Russians now in control of the site continue to monitor the facility, it should be no more dangerous than it was the morning that Russia decided to invade.

As Western countries live through the first modern war in Europe, being fearful is normal. Fear is even more normal when nuclear weapons enter the picture. Understanding the current scenario and the weapons being discussed can help soothe panic. Nuclear weapons are expensive, complex military weapons which take many steps to create and have only been used offensively twice in history. Radiological dispersal devices are comparatively simpler, but their effects are localized and they have never been used. What concerns me more in the nuclear picture of Ukraine is ensuring that nuclear reactors, which need cooling and power, are kept safe. The IAEA has outlined seven steps which must be taken, and we must ensure these are brought to fruition.

There will be many trying days ahead as the war continues, but nuclear war worry should be kept realistic.

Jack Kelly is a Fulbright Schuman Scholar and Visiting Fellow at the German Marshall Fund of the United States currently based in the Brussels, Belgium office. Kelly researches nuclear weapons, nuclear material black markets, smuggling and weapon creation, and transatlantic cooperation and policy response to illicit weapon detection and response.