A fire has been extinguished at the Zaporizhzhia nuclear power plant in Ukraine, Europe's largest, after it was shelled by Russian troops. The incident has raised concerns about the risk of a radiation leak or meltdown. The plant's design and safety features are being discussed in the context of the attack. The situation is being closely monitored, with some experts warning of the potential consequences of a breach of the reactor chamber or damage to the spent fuel stores.