For years, security services have worried about terrorists unleashing a ‘dirty bomb’ – where a conventional explosive is used to spread radioactive material over a large area. Russian forces now stand accused of threatening a similar form of warfare in Ukraine: attacking a nuclear power station with conventional weapons. Shelling of the Zaporizhzhia nuclear power station on the Dneiper River in the south of the country over the weekend is not believed to have released any radiation, although it did damage some equipment and one worker has been reported injured.