The head of Ukraine’s Zaporizhzhia nuclear plant was abducted and later released by Russian forces, the United Nations’ nuclear watchdog has said — a move that comes in the wake of a forced referendum that claims to grant control of the plant’s home region to Moscow.

The land-grab of Ukrainian territory orchestrated by the Kremlin — and condemned in Kyiv and the West as illegal — annexes the Zaporizhzhia region, as well as those of Donetsk, Luhansk and Kherson, making them, from Moscow’s point of view, a part of Russia territory.

In a fiery speech on Friday, Russian President Vladimir Putin claimed that residents of these eastern and southern regions had voted in favor of unifying with Russia and threatened to defend them by “all available means” — a dark nod to the Kremlin’s nuclear capabilities.  The United States and its NATO allies have called the vote — in which many Ukrainian residents in the war-torn areas were forced to participate by gun-wielding Russian soldiers — a sham.

The illegitimate vote heightens questions about what country is now responsible for running and maintaining Europe’s largest nuclear power plant at Zaporizhzhia, which has been held by Russian troops since the early weeks of war, but continues to be operated by Ukrainian technicians.

The abduction of Ihor Murashov, the Zaporizhzia complex’s general director, seems designed to resolve that question in Russia’s favor.

According to Energoatom, Ukraine’s nuclear operator, Murashov was blindfolded and bundled into a car on his way home from the plant by a Russian military patrol on Friday.  He was released Monday, the IAEA confirmed — but the agency provided no information on why Murashov was detained or what condition he was in when he was released.

Yevhenii Tsymbaliuk, Ukraine’s ambassador to the IAEA told the agency last week that Rosatom, Russia’s state nuclear corporation, has sent more of its representatives to the Zaporizhzhia site to enforce its changeover to Russian hands following the referendums.

Ukrainian staff already at the plant will be forced to reapply to Rosatom should they wish to continue working their jobs, Tsymbaliuk told the UN agency, according to Bloomberg.

But transferring the Zaporizhzhia plant to Russian control may not be as easy simply declaring that the six-reactor complex is now Russian , numerous experts told the Russian business daily Kommersant.

Instead, what would amount to the theft of several billion dollars’ worth of Ukrainian infrastructure could become a bureaucratic, diplomatic, and technical migraine.

For one, Rosatom —one of Europe’s most important nuclear fuel and technology exporters — has thus far evaded the Western sanctions that have hit other Russian energy producers.

But that would likely change should the corporation absorb the Zaporizhzhia complex ,making it Russia’s 12^th nuclear power plant, Anton Imennov, a senior partner with Pen & Paper, a prominent Moscow-based law firm, told Kommersant.

The rest of the world likely would refuse to recognize Zaporizhzhia as a Russian possession, noted Dmitry Gorchakov, a Russian nuclear industry expert with Bellona.

“Transferring the [Zaporizhzhia nuclear plant] to another jurisdiction would not be recognized outside of Russia and might stretch on for years,” he told the newspaper. “The Russian operator and nuclear regulator would need to issue new licenses, certify personnel, and check equipment, much of which is not certified for use in the Russian Federation.”

And though the Zaporizhzhia complex’s VVER-1000 reactors are Soviet-built and familiar to Russian technicians, they have been operated for three decades in a different country with different technical rules and have undergone various modifications, Gorchakov noted.

Moreover, several of the reactors at the plant have been loaded with nuclear fuel manufactured by the American nuclear corporation Westinghouse, to which Ukraine turned in an effort to wean itself off Russian-produced fuel. If the Russians were to assume operations at Zaporizhzhia, they would doubtless discontinue that practice —but switching back to Russian-produced fuel would be time consuming, said Gorchakov.

“As a result, a situation could arise in which the plant will have no legal ground for operation,” said Gorchakov. “Ukraine’s nuclear regulator, which won’t recognize the plant as Russian, may revoke its license, and Russia might not have time to issue its own.”

The licensing process on the Russian side may face even more protracted delays, Gorchakov noted. Rosenergoatom, the Rosatom-affiliated nuclear operator, and Russia’s nuclear regulator Rostekhnadzor would essentially be taking responsibility for a nuclear power plant located in an active war zone — something that has never been done before and for which no regulatory blueprint exists.

IAEA oversight of the plant is also bound to grow more convoluted should the plant be taken over by Russia. At present, there are two IAEA inspectors onsite at the Zaporizhzhia plant. They remained behind following the agency’s September mission to the complex and serve as neutral observers to the deteriorating conditions at the site, which is still surrounded by intense fighting.

But it’s worth remembering that those inspectors are there at Ukraine’s invitation, Andrei Baklitsky of the United Nations Institute for Disarmament Research told Kommersant.

The mission that brough them arrived via Ukrainian-held territory, and Russia agreed to their arrival, thereby acknowledging that the Zaporizhzhia plant was under Ukrainian jurisdiction.

If that jurisdiction were to change, noted Baklitsky, it’s difficult to see how the observers would be able to remain.

Since it’s safety and inspection mission, the IAEA has implored both sides of the conflict to agree to a demilitarized zone around Zaporizhzia plant without success. Since September 11, all six of the plant’s reactors have been cycled down to cold shutdown mode for safety reasons.