Travel insurance covers non-refundable cancellation costs in specific circumstances, as long as you are travelling to a region where the virus has had a significant outbreak and that the UK government therefore advises against travelling to. Check your travel insurance policy for the scope of cover.
However, if you cancel your trip because of your own concern about coronavirus, but you are not travelling to a region which the UK government has advised specifically against travelling to, your travel insurance will not cover the cost.