By Tom Balmforth
ZAPORIZHZHIA REGION, Ukraine (Reuters) -The head of the U.N.'s atomic watchdog, ignoring gunfire he said had come uncomfortably close, visited the Russian-occupied Zaporizhzhia nuclear plant in Ukraine on Thursday and said his experts would stay at the facility.
Rafael Grossi, who spent several hours at the plant, said he would continue to worry until the situation at Zaporizhzhia had stabilised. Both Russia and Ukraine say they fear a possible radiation disaster as a result of shelling that the two sides blame on each other.
Grossi said he had been able to tour the entire site, seeing key areas such as the emergency systems and control rooms. His team would now need to do a lot of work to finish its analysis of worrisome technical aspects.
"We are not going anywhere. The IAEA is now there, it is at the plant and it is not moving - it's going to stay there," a tired-looking Grossi said after what he called a long day.
"We're going to have a continued presence there at the plant with some of my experts," he told reporters once he had crossed back into Ukrainian-held territory.
Those experts, he said, would provide what he called an impartial neutral technically sound assessment of what was happening on the ground. They would dig deeper into conditions and deliver a report.
"It is obvious that the plant and the physical integrity of the plant has been violated, several times ... this is something that cannot continue to happen," he said.
The IAEA team, which crossed the frontline into Russian-held territory, was delayed several hours by shelling near the site of the plant.
"This morning the situation was pretty difficult but ... having come this far, I was not going to stop," said Grossi.
"There were moments where fire was obvious, heavy machine gun, artillery mortars, at two or three times (it was) really very concerning I would say for all of us."
(Reporting by Tom Balmforth in the Zaporizhzhia region, Ukraine; Writing by David Ljunggren; Editing by Chizu Nomiyama, Matthew Lewis and Jonathan Oatis)