How dangerous is the situation at the Zaporizhzhia nuclear plant?

Ukraine’s reactor has been damaged by Russian shelling and the UN has asked to be given access to the site

People receive food at a humanitarian aid distribution point in Zaporizhzhia, Ukraine. Picture: AP Photo/Andriy Andriyenko

The UN has called for international inspectors to be given access to the nuclear power plant in Zaporizhzhia, Ukraine, after it was shelled at the weekend. 

But how dangerous is the situation and what is likely to happen next?