Members of International Atomic Energy Agency inspect the Zaporizhzhia Nuclear Power Plant in Enerhodar, Ukraine on September 1. File Photo courtesy of IAEA Press Office/UPI | License Photo
Oct. 25 (UPI) -- Ukraine's nuclear energy company on Tuesday accused Russia of potentially planning to carry out "a terrorist act using nuclear materials" stored at the Zaporizhzhia Nuclear Power Plant where it said Kremlin forces were conducting secret, unauthorized construction work.
The allegation continues to raise sky-high concerns over the war in Ukraine escalating further, as the warring nations accuse one another with planning a false-flag attack that potentially involves nuclear material.
On Sunday, Russia's Defense Minister Sergei Shoigu held a series of phone calls with his U.S., British and French counterparts in which he alleged that Ukraine was potentially planning to use a dirty bomb within its own borders.
Britain's Defense Minister Ben Wallace said Shoigu told him that the Ukrainian provocation was being facilitated by Western nations with France's ministry of defense adding that the Kremlin military head feared Kyiv would hold Russia responsible for the attack.
A dirty bomb, according to the U.S. Centers for Disease Control and Prevention, uses conventional explosives with radioactive powder in pellets, which when detonated scatter the material throughout the surrounding area.
Ukraine, the United States and the other democratic nations have rejected Russia's allegations as false, while some have suggested the accusations may mean Moscow was planning such an attack of its own to blame on Kyiv.
On Tuesday, Energoatom said in a statement that Russian forces at the Zaporizhzhia site, which is Europe's largest nuclear plant, have for the past week been conducting unauthorized and secret construction work at the dry spent nuclear fuel storage facility, where 175 containers of spent nuclear fuel are located.
The Ukrainian officials said they are aware of Russia's unsubstantiated claims that Ukraine was preparing a dirty bomb with spent nuclear fuel and radioactive waste stored at Zaporizhzhia, and that they assume it indicates the Russians "are preparing a terrorist act" using the material from the storage facility.
It said neither its personnel nor workers for the United Nations' nuclear watchdog, the International Atomic Energy Agency, were allowed access to the site.
Energoatom called the ongoing construction illegal while warning that "the destruction of these containers as a result of detonation will lead to a radiation accident and radiation contamination of several hundred square kilometers of the surrounding area."
"Energoatom calls on the International Atomic Energy Agency to make assessment of the [R]ussians' provocative and threatening actions and statements as soon as possible," it said.
"The terrorist country -- [R]ussia -- must immediately stop any interference in the operation of Zaporizhzhia NPP, and the world community must make every effort to de-occupy and demilitarize ZNPP and transfer it under full control of the legal operator -- Energoatom!"
Russian forces have occupied the plant since early in the war, and it has been a frequent site of concern, as it has been repeatedly damaged in the fight with both sides trading accusations.
The accusation from Energoatom came as the U.N. Security Council held closed-door meetings on Tuesday to discuss the Kremlin's accusations.
Dmitry Polyanskiy, the first deputy permanent representative to Russia at the United Nations, told reporters during a press briefing that the alleged threat posed by Ukraine "is very serious."
Asked by reporters to substantiate the claims, Polyanskiy said it's "intelligence information."
"We know it and we shared it in our telephone conversations with counterparts who have the necessary level of clearance," he said. "So, those who wanted to understand that the threat was serious, they had all the possibilities to understand it. Those who want to reject it as Russian propaganda will do it anyway, so we are not very much worried about this."
He said Ukraine was developing the dirty bomb at the Kharkov Institute of Physics and Technology and the Institute for Nuclear Research of the National Academy of Sciences of Ukraine in Kyiv.
James Kariuki, Britain's permanent representative to the United Nations, told reporters that "we've seen and heard no new evidence" from Russia during the closed-door meeting, while reiterating that its allegations are "transparently false."
"Ukraine has been clear it has noting to hide," he said. "We should be clear: This is pure Russian misinformation of the kind we've seen many times before and it should stop."
After Russia made the allegations, Ukraine on Monday invited inspectors from the IAEA to examine the two sites, which its director-general, Rafael Grossi, accepted.
Polyanskiy said they can come but that he doubts "there is a possibility to be 100% iron-clad sure that there are no activities of this kind, even after this visit."
During a online press briefing with foreign media on Tuesday, Ukraine's Foreign Minister Dmytro Kuleba continued to refute Russia's accusations, which he called a disinformation campaign.
IAEA "experts are expected to arrive shortly. They will have full access and I am sure we will be able to swiftly refute all Russian falsehoods," he said.
Meanwhile, Russia has called for a second meeting at the U.N. Security Council to debate a resolution on Wednesday to set up a commission to investigate its claims that Washington and Kyiv were violating obligations under the Biological Weapons Convention at Ukrainian laboratories.
Russia has previously amid the war accused Ukraine, with aid from the United States, of pursuing biological weapons, which Washington and Kyiv have refuted.
Kariuki called the meetings called by Russia a waste of time.
"Its misinformation and it should stop," he said.
Meanwhile in Washington, U.S. President Joe Biden warned Russia that it would be making "an incredibly serious mistake" if it used a tactical nuclear weapon in the war.
"I'm not guaranteeing you that it's a false-flag operation yet; I don't know. But it would be a serious, serious mistake," he told reporters from the Eisenhower Executive Office Building.
Pentagon press secretary Air Force Brig. Gen. Pat Ryder also told reporters Tuesday that the allegations against Ukraine are false while stating the officials have not seen any indiction that Russia intends to employ nuclear arms.
"It's something that we'll continue to watching closely," he said. "And certainly, as others have said, there would be consequences for Russia, whether it uses a nuclear weapon or a dirty bomb."