SBTi definition of Renewable Energy

Hello, I apologise if I have missed this but I have been through the various SBTi documentation and searched through this forum but have been unable to locate a specific definition for ‘renewable energy’, this may sound daft but what is actually considered to be renewable for example nuclear can technically sit in both camps as a fuel source is required despite that not being fossil fuel based so if possible could anybody point me in the direction of a recognised definition.