A section of the Chernobyl nuclear power plant in Ukraine has collapsed under the weight of snow but there were no injuries or any increase in radiation from the reactor that exploded in 1986, the country’s emergency agency said Wednesday. “The preliminary reason for the collapse was too much snow on the roof,” the agency said, adding that the radiation situation is “within the norm” and nobody was harmed in Tuesday’s incident. The roof was constructed after the 1986 disaster but is not part of the sarcophagus structure covering the reactor, it said. However the collapse underlines concerns about the condition of the now defunct nuclear plant over two-and-a-half-decades after the world’s worst nuclear disaster. Part of the roof and some of the walls at the plant’s machine room, close to the sarcophagus that seals the reactor number four which melted down in the 1986 accident, fell under the weight of the snow. The area of the accident is estimated about 600 square metres, (6,500 square feet), the emergency agency said. A statement on the website of the power station described the accident as the “partial failure of the wall slabs and light roof of the Unit 4 Turbine Hall”. It said that the damaged structure was not critical part of the protection structures at the power plant. “There are no changes in the radiation situation at the Chernobyl nuclear power plant industrial site and in the exclusion zone.