Thermobarics and Depleted Uranium: Pushing out the Conventional Envelope 


By Andy Oppenheimer

With Russia’s full-scale invasion of Ukraine extending well into its second year, Andy Oppenheimer reviews the deployment of weapons on the edge of being considered weapons of mass destruction (WMD).

Russia has used artillery shells, mortar rounds, rockets, missiles and aerial bombs in Ukraine as well as cluster munitions and, pushing out the conventional envelope, enhanced blast weapons, also known as thermobaric weapons.  

On April 3, 2023, a video posted online showed a Russian TOS-1A launcher lobbing powerful thermobaric rockets into the contested city of Bakhmut in eastern Ukraine’s Donbas region. 

Over a year earlier on February 28, 2022, the Ukrainian ambassador to the United States confirmed that Russia had used a ‘vacuum bomb’ – the other term for a thermobaric – killing 70 soldiers. Two days earlier, CNN reported that Russian TOS-1A rocket launchers, which can launch up to 30 rockets armed with thermobaric warheads, were mobilized in eastern Ukraine. Then, in late May 2022, footage emerged of Russian forces using thermobaric weapons against Ukrainian positions in the Donbas. 

The TOS-1A can fire unguided 220-mm rockets (30-barrel) or incendiary and thermobaric rockets (24-barrel) from a main battle tank chassis. High-accuracy firing calculation for unguided rockets enables them to cover a target densely at 6 seconds of full-salvo duration at a 6,000-m range. 

Thermobarics: the Back Story 

Both the U.S. and Russia have advanced these ‘bunkerbuster’ weapons as a conventional substitute for nuclear bombs to breach hardened overground and underground military targets. But like cluster munitions and barrel bombs, they have been used far more against civilians, who are likely to be vaporized by a thermobaric attack. 

The U.S. used thermobarics in Vietnam, and against al-Qaeda forces secreted in the Tora Bora caves in Afghanistan in 2001. In 2017, the U.S. deployed a 22,000-lb GBU-43 massive ordnance air blast (MOAB) – colloquially known as the ‘mother of all bombs’ – against ISIS. 

Russia’s MiG-27 attack aircraft also dropped ODAB-500S/P fuel-air bombs on the Mujahideen in Afghanistan, as well as in Chechnya in the 1990s and during the past decade in Syria. A barrage of handheld thermobaric weapons was used by Spetsnaz to retake the school in Beslan, Russia, that was taken hostage in 2004. These were reportedly the RPO-A, and either the TBG-7V thermobaric rocket from the RPG-7, or rockets from either the RShG-1 or the RShG-2. 

How They Work 

To date regarded as the biggest ‘conventional’ bomb, thermobarics are a type of volumetric weapon, which also include fuel air explosives (FAE). Thermobarics comprise a fuel container and two separate explosive charges. When dropped or launched, the first charge detonates to disperse the fuel particles.  

The second charge ignites the dispersed fuel and oxygen in the air. This produces a blast wave of extreme pressure and heat creating a partial vacuum that sucks up all surrounding oxygen in an enclosed space. This causes immense destruction at the target and, specifically, inside it: most notably buildings, trenches and bunkers. The blast area of a thermobaric can exceed 3,000m2 and a blast wave is evidence that a thermobaric was used.

“The mechanism of destruction [by explosion] against living targets is unique…What kills is the pressure wave, and more importantly, the ensuing rarefaction [vacuum], which ruptures the lungs…. If the fuel deflagrates but does not explode, the victims will be severely burned and will probably also inhale the burning fuel.”

U.S. Defense Intelligence Agency/Human Rights Watch, 1993 

These weapons always carry a high risk of mass civilian casualties. They are not banned by any treaty and their legacy of harm persists long after the cessation of hostilities. Since Russia’s full-scale invasion in February 2022, thousands of casualties, damage to power plants, hospitals and other major infrastructure have persisted because of their use of high-yield explosive weapons. Russia had previously conducted these attacks in Syria and Iraq for several years, where they were deployed by government forces against jihadist insurgents. 

Inspecting linked belts of Mark 149 Mod 2 20-mm depleted uranium ammunition before loading it into the magazine of a Mark 16 Phalanx close-in weapons system aboard the battleship USS Missouri in 1987,
©US DoD/Wikimedia

The Russian Arsenal 

The TOS-1A is a 1980s Soviet-era multiple rocket launcher system (MLRS) that combines the chassis of a modified T-71A tank and a rotary rocket launcher capable of firing thermobaric warheads. Dubbed ‘flamethrowers’ due to their ability to clear out fortifications, these ground-to-ground munitions have the requisite strike power to attack such fortified positions and destroy light armoured vehicles.  

The MLRS is equipped with two types of unguided munitions: the 173 kg MO.1.01.04 and the 217kg MO.1.01.04M. The TOS-1A can carry 24 thermobaric rockets, which can each be fired every six to 12 seconds. It can be combat-ready within 90 seconds with a range of 5.6 miles and can saturate an area of 40km2. In early August 2022 a video of a TOS-1A thermobaric MLRS strike on the town of Pisky in Ukraine’s eastern Donetsk region was posted online.  

Worthy of note is that the TOS-1A systems are deployed under Russia’s Nuclear, Biological and Chemical Protection Troops rather than its regular Army artillery units. 

An increasingly desperate and ruthless Vladimir Putin will not hesitate to unleash further mass-casualty attacks, and to step up attacks on vital infrastructure. Firing thermobarics into cities would cause immense destruction. Added to an already long list of war crimes will be his use of these borderline WMDs and their devastating, protracted effects on civilians, troops, property and infrastructure. 

Depleted uranium shells are harder than older tungsten shells, ©US DoD

Depleted Uranium Weapons 

Arguably equally controversial are depleted uranium (DU) weapons. In late March 2023, the UK Ministry of Defence confirmed it would provide Ukraine with armor-piercing shells. This reopened the controversy over DU, which is a customary ingredient of such rounds due to its high penetrative capacity. 

They are large explosive warheads using ‘dense metal’ unitary or advanced penetrators, and warheads and submunitions using shaped-charge technology. While having nothing whatsoever to do with nuclear weapons, DU is a byproduct of the enrichment process used to make reactor-grade uranium. It is 40% less radioactive than natural uranium but its high density – 70% greater than lead – makes it ideal as a high-speed, highly penetrative projectile. The weapon erupts in a burning cloud of vapour that settles as weakly radioactive but toxic dust. As the DU penetrates the tank, the flaking of burning fragments will shred whatever is inside it. 

The U.S. military first deployed DU weapons in Iraq during the First Gulf War in 1990, and again in the 2003 invasion. They were also used in the Balkan War in the early 1990s. Meanwhile, Russia has mass-produced the improved Svinets-1 and Svintes-2 DU ammunition for their which modernized T-80BVM tanks. DU is also a component of tank armor.

During the Gulf Wars, according to BellingCat more than 24 tons of DU was fired with no data made available on locations, often in urban areas against non-armoured targets, ©US Army via Wim Zwijnenburg/Twitter

Mired in Controversy 

Claims about the health impacts of DU are mired in controversy. U.S. government-funded research has denied its health risks to the Iraqi population, while a growing number of researchers claim that DU has caused increased rates of birth defects and cancers in Iraq.  

An example of a research report is from the British Medical Journal (BMJ). They found that available evidence suggested possible associations between exposure to DU and adverse health outcomes in the Iraqi population.  

The BMJ report was based on observational studies published between 1990 and 2020 that measured the association between exposure to weaponized uranium and cancer, birth defects, immune system function and mortality in Iraq. 

The 1999 NATO bombing of Yugoslavia has also been the subject of several studies on the alleged health risks of DU weapons. It is claimed that 400 Italian military personnel have died and 8,000 have fallen ill from conditions potentially linked to DU exposure.  

DU weapons are not banned, however. A 2022 UN Environment Programme (UNEP) report said that DU was an environmental concern in Ukraine, describing it as a “chemically and radiologically toxic heavy metal”. Much of the research has found that DU and its oxides pose a danger to human health primarily due to internal contamination, and to a much lesser extent due to radiation. Like other heavy metals such as mercury, it is toxic if it gets inside you. Finely dispersed aerosol particles of uranium oxides can enter the body by ingestion and inhalation, as well as through open wounds sustained in battle. 

Many recommend the decontamination of weapons and military equipment before leaving the contaminated zone. Campaigners against DU weapons warn that properties of the weapons make it impossible to completely decontaminate sites where they were fired, and that their use poses a long-term health threat for civilians and the military alike. 

A T-80BV of the Russian Army. In 2018, the official Russian agency Tass announced that these types of tanks can use 3BM60 Svinets-2 ammunition made with DU, ©Russian Ministry of Defence

The Cessation of Use of Near-WMDs is Nowhere on the Horizon  

However, experts are divided in their opinions on DU and its effects. According to Senior Policy Director at the Center for Arms Control and Non-Proliferation, John Erath: “What the depleted uranium rounds would add would be minimal. The environmental problems created by a war are so extreme that that should be what people are worried about and not the addition of a few depleted uranium projectiles.”

As a counterpoint, the United Nations Environment Programme has described such ammunition as “chemically and radiologically toxic heavy metal”. In terms of near-WMDs, only a worldwide verifiable ban – which is very rare – can halt or resist their use. And in Europe’s first full-scale conflict since World War II, the cessation of their use is nowhere on the horizon.

Andy Oppenheimer is author of IRA: The Bombs and the Bullets – A History of Deadly Ingenuity (2008) and a former editor of CBNW and Jane’s NBC Defense. He is a Member of the International Association of Bomb Technicians & Investigators and an Associate Member of the Institute of Explosives Engineers and has written and lectured on CBRNE weapons, countermeasures, and counterterrorism since 2002.

Related articles

Recent articles