Russia has stepped up its nuclear propaganda and delivered a letter to the United Nations claiming that Ukraine is preparing to detonate a “dirty bomb” on its territory, an allegation dismissed by Kyiv, western governments and weapons experts as absurd and an attempt at distraction or pretext for Moscow’s own escalation.
The letter was addressed to the UN secretary general and the Gabonese ambassador, who currently holds the rotating presidency of the security council, and follows calls by Russia’s defence minister to foreign ministers in recent days making similar unfounded allegations.
At the same time, Russia circulated a 310-page document in the security council, repeating earlier debunked claims that Ukraine and its western backers had been working on a bioweapon.
Asked about the Russian claims on Tuesday, US president Joe Biden said: “I spent a lot of time today talking about that.”
The letter was delivered at a time when Russia is still suffering battlefield losses in Ukraine and anxious to reverse the momentum. Nato has entered its second week of annual drills rehearsing for nuclear war, and Russia is expected to launch its own annual exercises this week.
The Russian UN letter presented no evidence for Moscow’s claim that Ukraine was preparing to detonate a dirty bomb, an explosive device designed to disperse radioactive materials over an area to render it at least temporarily uninhabitable.
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.
Ukraine’s uranium mines are listed as one possible source for material for a dirty bomb, but natural uranium ore would be useless for such a purpose.
“You can’t make a dirty bomb with uranium ore. It’s a bunch of rock that contains tiny inclusions of uranium 99% of which only a tiny bit is radioactive. Only long-term sustained exposure can result in harm to humans,” said Mariana Budjeryn, a senior research associate at the project on managing the atom at the Harvard Kennedy school’s Belfer Center.
Other sources of radioactive material the letter mentioned were spent fuel at the Chornobyl nuclear plant, but that has been cooling for decades and would not do much harm. Other sites it listed with potentially more toxic material are sealed and monitored by the International Atomic Energy Agency (IAEA), so any diversion would be spotted and flagged.
The letter also claimed Kyiv 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 completely different from a real nuclear weapon, which would leave behind products of nuclear fission.
“There is no world in which dispersed spent nuclear fuel or some kind of radioactive material from research facilities could be mistaken for, or misrepresented as, byproducts of a nuclear fission reaction,” Budjeryn said. “It is just elementary physics.”
The Russian letter also pointed to another “heinous scenario” supposedly plotted by Kyiv, to sabotage a nuclear power plant under its control or shell the Zaporizhzhia plant under Russian occupation. But again it offered no evidence why Ukraine would carry out an act of such significant self-harm.
The flimsiness of the claims led some diplomats and experts to suspect it was not intended to convince anyone but to send a message, but it is unclear what that message may be. One possibility is that it is meant to look like a cover for Russia’s own plans to use such a device in the latest of a long series of efforts to deter Ukraine’s backers from continuing their support.
Another option is that it is simply a distraction from Russia’s continuing military setbacks in Ukraine, intended principally for domestic consumption.
“I guess because they need something to sell to Russian media when they are pushed out of Kherson,” one western diplomat at the UN suggested.
The Ukrainian president, Volodymyr Zelenskiy, has said Russia’s accusation was a sign that Moscow – which has threatened to use a tactical nuclear weapon in Ukraine – was planning such an attack and preparing to shift the blame to Ukraine.
In Washington on Tuesday Biden said: “Russia would be making an incredible, serious mistake if it were to use a tactical nuclear weapon.”
Asked about the Russian dirty bomb claims, he replied: “I’m not guaranteeing that it’s a false flag operation yet. Don’t know, but it would be a serious mistake, a very serious mistake.”
The Kyiv government has asked the IAEA to verify that no radioactive materials in Ukraine have gone missing, and the UN nuclear watchdog said it was preparing to send inspectors to two unidentified Ukrainian sites, both already subject to frequent inspections.
At the same time, the Ukrainian nuclear power authority, Energoatom, reported that Russian occupying forces were carrying out secret construction work within the Zaporizhzhia nuclear plant.
Energoatom said it believed the Russians “are preparing a terrorist act using nuclear materials and radioactive waste” stored at the plant compound.
The Russian allegations come amid reports suggesting Russian forces and Wagner mercenaries had suffered heavy losses in recent days in fighting in the key Donbas city of Bakhmut, which has been the focus of four months of ferocious Russian efforts to advance there with little to show for the effort.
The flurry of Russian accusations has been met with deep scepticism in the west with analysts pointing to Moscow’s history of false allegations – including its characterisation of Ukraine as a “neo-Nazi” regime – to justify its own aggression.
France, Britain and the US said the allegations were “transparently false” and Washington warned Russia there would be “severe consequences” if Russia used any nuclear material, while saying there were no signs of that yet.
“There would be consequences for Russia whether it uses a dirty bomb or a nuclear bomb,” said the state department spokesperson, Ned Price.
Perhaps significantly, the Russian allegation has prompted rare communication with the west, with Moscow’s armed forces chief of staff, Valery Gerasimov, speaking on Monday to his US counterpart, Mark Milley, for the first time since May.
Early on Tuesday, Ukraine’s army chief, Valeriy Zaluzhnyi, said he too had spoken to Milley.
Most analysts believe there is little chance a false-flag dirty bomb attack could really be used as a pretext for a nuclear detonation.
“If this was a false-flag event, we would know it instantly, nobody would blame Ukraine,” said William Alberque, an arms control expert at the London-based International Institute for Strategic Studies.
“Radiological weapons are so identifiable, so scrutinised. You can make a chemical weapon from scratch,” but “nuclear material has a fingerprint” based on the facilities used to create it, he told AFP.
