LCWRA and one-off work

Hi everyone
Currently claiming LCWRA on UC and thinking of applying for an arts grant from my local council, it's for a photo project about my experiences of living with a disability. The grant is £2500, I'm hoping to get a family member to help me with the bits I can't manage due to my health issues. The council say they have access support costs available too. How will this work out with UC as it's not regular work? I'm conscious I may have to declare it through HMRC perhaps, but I don't want UC to get the wrong impression and think I'm self-employed. I'll just be spending say an hour a day on it over the course of a few months. thanks.