After several days of wrangling with Russian official, experts from the UN’s International Atomic Energy Agency on Monday were given access to the sixth and final reactor unit at the embattled Zaporizhzhia nuclear power plant in Ukraine.

Situated on the front lines of fighting as Ukraine struggles to repel Moscow’s invasion, the plant has been held by Russian troops since the early days of the war, now reaching its second year.

The IAEA experts on the site of the plant — which is the largest nuclear power station in both Ukraine and Europe —regularly cross the frontlines of the war to maintain a presence at the facility.

In about mid-December, according to an IAEA, the experts had requested access to the reactor halls of Units 1, 2 and 6. But Renat Kharchaa, a Ukraine-based official with Rosatom, Russia’s state nuclear corporation, denied access, saying the reactors were “sealed.”

This explanation, however, strained credulity, given that the team has visited reactor Unit 3, which was likewise hermetically sealed, as recently as December 15, according to an earlier IAEA statement

In a subsequent statement, IAEA Director General Rafael Grossi noted that the denial of access to the Unit 6 reactor hall constituted the first time Russian officials had been rebuffed in their attempts to inspect any unit that, like Unit 6, was in cold shutdown.

On Monday, the IAEA released a statement saying that their “experts were yesterday granted access to the reactor hall of unit 6 of Ukraine’s Zaporizhzhia Nuclear Power Plant after previously having not been given access.”

“While in the reactor hall, the team observed main components of the reactor, confirming the cold shutdown state of the reactor,” the statement added.

The statement continued, however, to note that the Agency’s inspectors were denied a view of some segments of the sixth unit’s turbine halls, adding that their visits to the halls have been prevented since October of last year.

“For the first time, under far-fetched pretexts, IAEA inspectors were rebuffed from entry into the reactor halls of power units in a state of cold shutdown — and in the end, with a delay of a couple of weeks, they were allowed into only one of them.,” says Dmitry Gorchakov, a nuclear expert with Bellona.

“But the problem is much deeper,” he continues. “After all, such delays and restrictions in access are systemic problem. IAEA inspectors are not allowed or are allowed with huge delays into requested Zaporizhzhia NPP locations while almost the entire time they are present at the plant. As Rafael Grossi said on his very first visit to the plant on September 1, 2022, ‘If we are not allowed somewhere, we will say  so.’ And since then, regularly in numerous IAEA information messages on Zaporizhzhia NPP you can see that inspectors are waiting until they are allowed access to numerous plant facilities and they have been waiting for this for months. And no meetings between the head of Rosatom Likhachev and Grossi, as a matter of principle, can solve this problem. This is an obvious obstruction of the IAEA’s work at the site. Under one pretext or another.”

Grossi has warned numerous times that, should outside power be cut to the plant, cooling apparatus could be interrupted, risking a nuclear accident.

The IAEA teams at the Zaporizhzhia site also inspect for the presence of weapons and troops onsite, which would further put the six-reactor plant at risk of bombardment and attack.

All of the plant’s reactors have been in some state of shutdown since September of last year, a measure that would lessen the radioactive consequences should they get caught in the crossfire of warring troops.

The IAEA has lobbied both Moscow and Kyiv to implement a non-military zone around the plant to prevent it from coming under fire, but those efforts have proven unsuccessful.

Bellona has closely monitored events at the plant and last year published an exhaustive report on the dangers the plant — and the world — face as a result of its seizure. For the first time ever, the report notes, a nuclear plant has been made hostage to a raging military conflict.

At present, IAEA experts at the plant are still waiting on access to the roofs of the reactors — an inspection that was scheduled for December 19, but which was scotched by Russian officials over what they described as security concerns, the Ukrainian national newswire Ukrainska Pravda reported.

The IAEA team likewise has yet to receive 2024 reactor maintenance schedules from the Russian occupiers, Ukrainska Pravda said.