A Ukrainian nuclear regulator is accusing Russia of bombing a research facility containing a reactor and fuel cells, an action it considers “an act of nuclear terrorism.”

The Thursday rocket attack against the Kharkiv Institute of Physics and Technology, which occurred around 8:20 p.m. local time, marks at least the third time that Russian forces have attacked Ukraine’s nuclear sites. Observers worry that such attacks could hint at Russia’s willingness to use nuclear retaliation to gain an upper hand in its invasion.

“Once again, the Russian Federation has committed an act of nuclear terrorism!!!” the State Inspectorate for Nuclear Regulation of Ukraine announced in a March 10 press release, according to Google Translate.

The regulator said that it is still surveying the full damage from the attack, which resulted in a fire. Prior to Russia’s invasion, the reactor’s core was loaded with fresh nuclear fuel cells, the regulator added in a report.

However, even though locals fear a potential “large-scale ecological disaster” from the attack, according to The Independent, a large nuclear accident at the institute is unlikely because the institute’s reactor lacks the neutrons needed to activate the fuel cells as well as any highly enriched uranium onsite, nuclear analyst Matthew Bunn told Physics Today.

The Ukrainian regulator added that a March 6 Russian attack on the institute damaged its air conditioner cooling systems and left surface damage on the institute’s main installation as well as its pump and cooling tower building.

The International Atomic Energy Agency (IAEA) confirmed that the March 6 attack resulted in no increased radiation levels though, Newsweek reported.

On March 3, Russia attacked the Zaporizhzhia Nuclear Power Plant, Europe’s largest nuclear power plant. The attack hit a building adjacent to six reactors, resulting in a fire that was soon extinguished. None of the plant’s security or safety systems were compromised, and no reactors were hit.

Soon after the attack, Russian forces surrounded the plant, and the plant eventually resumed normal functioning. Russia later blamed Ukrainian saboteurs for starting the fire at the plant.

READ ALSO:

• Lagos-Ibadan train runs out of diesel, stops midway, passengers complain
• Many killed in tanker explosion around MFM on Lagos-Ibadan Expressway
• MC Oluomo pulls out of NURTW national body

Ukrainian President Volodymyr Zelensky said that Russia resorted to “nuclear terror” in attacking the plant. Ukraine’s Minister of Foreign Affairs Dmytro Kuleba tweeted that if the plant blew up, it would be 10 times worse than the 1986 Chernobyl nuclear disaster. He urged the Russian military to cease fire immediately.

However, one nuclear researcher was doubtful that a fire at a nuclear plant could set off a radioactive disaster.

“A single fire located somewhere on the same site as a nuclear power plant cannot feasibly trigger a meltdown,” Edward Obbard, a senior lecturer and nuclear engineering program coordinator at The University of New South Wales in Australia, told the Australian Science Media Centre.

Obbard and other nuclear experts said that a greater risk would be a direct explosion upon a reactor or spent fuel pool by explosive ordnance, which could release radioactive material.

Similarly, damage to a nuclear plant’s cooling systems could result in the nuclear reactor fuel getting so hot that it burns through its containment chamber, causing a nuclear meltdown and a widespread release of radiation, Newsweek reported.

Though U.S. Energy Secretary Jennifer Granholm said there was no indication of elevated radiation levels at the plant, the U.S. Department of State announced that it was “assessing” whether the attack constituted a war crime. The United Nations also convened an emergency meeting after the Zaporizhzhia attack to discuss its implications.

After its invasion, Russian forces also took control of Chernobyl, the site of the 1986 nuclear disaster that killed 31 people and left radioactive pollution in the region.

Near the beginning of the invasion, Russian President Vladimir Putin also commanded his military to raise the readiness level of his nation’s nuclear forces. The vague command alarmed international observers, but others have doubted that Russia will risk any sort of nuclear attack.

Olga Oliker—the European program director for the International Crisis Group, a think tank on global crises—believes that Russia would only use a nuclear weapon if it found itself in a direct war with NATO forces. Oliker said it was “unlikely” that Russia would use one against Ukraine.

Other experts have doubted that Putin would deploy nuclear weapons because of their toxic effect on the region.

U.S. President Joe Biden has said that Americans shouldn’t worry about the possibility of a nuclear war with Russia. Both the U.S. and the North Atlantic Treaty Organization (NATO) have said there is no need to change their own nuclear alert levels, despite Putin’s command.

However, in 2018, the Pentagon warned in its nuclear posture review that Russia could use a battlefield nuclear weapon to “‘de-escalate’ a conflict on terms favorable to Russia.” That is, it could feasibly use a small-range nuclear weapon to get its enemy to stop fighting back.

Putin could also launch a nuclear weapon if his military received a false alarm about another nation deploying a nuclear assault, Jeffrey Lewis, a senior scholar at the Middlebury Institute of International Studies at Monterey, told NPR.

Newsweek contacted the IAEA for comment.

Newsweek