Due to difficulties with filling the Chornobyl Shelter Fund, work within the second start-up complex of the New Safe Confinement (NSC) has been postponed indefinitely, which threatens the collapse of unstable structures of the Shelter, said Oleh Korikov, head of the State Nuclear Regulatory Inspectorate of Ukraine. "Further delays in the implementation of the project to dismantle unstable structures of the Shelter under the NSC shell increase the risks of their collapse," he said.