Explained | What is a Dirty Bomb and What Damage Can Such a Device Cause?

Russia delivered a letter to the UN claiming that Ukraine is preparing to detonate a “dirty bomb” on its territory

Their primary objective is to create panic, confusion and anxiety.

(Photo: The Quint)

With the war in Ukraine entering its ninth month, Russia has delivered a letter to the United Nations claiming that Ukraine is preparing to detonate a dirty bomb on its territory. The allegations, however, have been denied by Kyiv.

But what is a dirty bomb? How harmful is it? And why has Russia claimed that Kyiv will be using the weapon on its own territory? The Quint answers these questions.

What is a Dirty Bomb?

A dirty bomb is a type of "radiological dispersal device (RDD)" that is created to contaminate a large area with radioactivity, making it harmful or uninhabitable for residents there, without using a nuclear explosion.

Their primary objective is to create panic, confusion and anxiety by hurling radioactive dust and smoke into the atmosphere and have therefore been long feared as a potential weapon of terrorists.

To put it simply, it is a basic, rudimentary device that is laced with explosives and radioactive material, nuclear expert Tom Plant, a senior associate fellow at the Royal United Services Institute, a defence and security think tank in London, told NBC News.

A blend of radioactive materials could be used, he said, including materials used in nuclear medicine and for industrial purposes. When it is deployed, the material does not do anything to make the explosion any bigger, he added.

What Has Russia Specifically Alleged?

In its letter to the UN, the Kremlin has alleged that Ukraine is preparing to detonate a dirty bomb in order to blame it on Russia and force an escalation to the war that has entered its ninth month.

The Kremlin circulated a 310-page document in the security council, repeating earlier debunked claims that Kyiv and its western backers had been working on a bioweapon.

Moscow's letter to the UN presented zero evidence for Russia's claim that Ukraine was preparing to detonate a dirty bomb.

Instead, it lists all the possible sources of radioactive isotopes to which Ukraine could conceivably have access, but makes several mistakes, suggesting whoever drafted the letter had no grasp of the science involved, experts said, according to The Guardian.

The head of Russia’s nuclear, biological and chemical protection troops, Lieutenant General Igor Kirillov, told a media briefing that, Ukraine’s aim for such an attack would be to blame Russia.

According to the newspaper, the letter to the UN also claimed that Ukraine intended the bomb to be a false-flag operation, in which the Ukrainians would claim it was a Russian low-yield nuclear weapon containing highly enriched uranium, which would be detected in the atmosphere. But the traces left by a dirty bomb would be vastly different from a real nuclear weapon, which would leave behind products of nuclear fission.

Has a Dirty Bomb Been Used In Wars or Conflicts in the Past?

Although no dirty bomb attack has ever been recorded, two failed attempts to detonate such a device were reported in the southern Russian province of Chechnya more than two decades ago, according to The Guardian.

What Impact Can Such a Weapon Have?

The number of casualties and the extent of damage from such a weapon depends on many variables, according to the United States Nuclear Regulatory Commission (USNRC).

A primary factor is the amount and type of conventional explosives that are used, which determine the magnitude of the blast.

The other factors affecting the possible fallout are the quantity and type of radioactive materials used as well as the weather conditions( and especially the wind) at the time of the blast.

Those closest to the RDD would be most likely to be hurt by the detonation of such a device. As radioactive material spreads, it becomes less concentrated and less harmful, according to the USNRC.

Immediate health effects from exposure to the low radiation levels expected from an RDD would likely be minimal.

The effects of radiation exposure would be determined by factors such the amount of radiation absorbed by the body, the type of radiation (gamma, beta, or alpha), the distance from the source of radiation to an individual, the means of exposure – external or internal (absorbed by the skin, inhaled or ingested); and, and the the length of time exposed.

The health effects of radiation tend to be directly proportional to radiation dose, which means that the higher the radiation dose, the higher the risk and severity of injury.

As Pavel Podig, a senior researcher at the UN Institute for Disarmament Research, said on Twitter, that a dirty bomb contamination area is likely to be no more than a few hundred yards in diameter. 

Retired nuclear scientist Cheryl Rofer pointed out on Twitter that "the point of a dirty bomb is to contaminate an area with radioactive material. People in the area will ingest some of that material and will need medical treatment, but few will ingest enough to produce radiation sickness".

How is a 'Dirty Bomb' Different From a Nuclear Bomb?

As the USNRC has put it, a dirty bomb is not a nuclear bomb. A nuclear bomb creates an explosion that is millions of times more powerful than a dirty bomb. A dirty bomb rather than being a "weapon of mass destruction" is a "weapon of mass disruption," where contamination and anxiety are the major objectives.

Dirty bombs are not for battlefield use, being deployed more obviously in urban areas, Scott Roecker, vice-president for the nuclear materials security program at the Nuclear Threat Initiative, a non-profit based in Washington, told The Guardian.

He added that dirty bombs are more of a psychological weapon. "When you’re trying to scare people, intimidate people, you’d use a weapon like this,” he added.

What Has Ukraine and the US Said?

The US and Kyiv’s other Western allies have unanimously rejected the claims as “transparently false,” saying this could be a way for Moscow to lay the groundwork for an escalation of its own as its military struggles to make progress on the battlefield. 

Ukrainian President Volodymyr Zelensky suggested Russia might be using the allegations as cover for plans for a similar attack of its own: “If Russia calls and says that Ukraine is allegedly preparing something, it means one thing: Russia has already prepared all this, " he said.