Hairline in clear cap

I fused a large circle, 11", with the design against the kiln shelf and a clear cap on top. The clear cap developed a Hairline fracture that self-healed, but remains visible. I'm thinking this happened because, in my frugality, I added a second shelf to my small kiln, thinking that since it was a full fuse, it would be ok. I'm now thinking it was too hot at the top of the kiln. I was using a pre-set schedule. If I were to refire the piece at the bottom of the kiln, is there any hope of the Hairline fracture repairing itself, or is this now a giant piece of scrap?