STORY: In a video realeased on social media on Thursday (September 1) Grossi was standing outside the power plant and was speaking after spending several hours at the plant on Thursday, braving gunfire he said had come "uncomfortably close."
He and his team of U.N. experts were returning on Friday (September 2) across the frontlines to assess physical damage to Europe's biggest nuclear energy plant.
The site was captured by Russian forces soon after they invaded Ukraine in late February and has become a focus of deep concern over the possibility that shelling in the vicinity could cause a nuclear disaster.
Moscow and Kyiv blame each other for the shelling. Kyiv accuses Moscow of using the facility to shield its forces, a charge Moscow denies while rejecting calls to withdraw its troops. The plant is still run by Ukrainian staff.
Grossi said on his return to Ukrainian-held territory: "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 his experts would stay at the facility and he would continue to worry until the situation had stabilized.
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 technical aspects, he said.