Scientists have been using UV light to kill bacteria, viruses and other single cell organisms like algae for decades. It’s a process called “Ultraviolet germicidal irradiation“, it works by breaking down the molecular bonds that hold their DNA together which prevents the virus from multiplying and breaking their life cycle. Instead of multiplying as normal they are unable to do this and simply die at the end of their life. Coronavirus can be controlled in the exact same way.