The learning cycle is too long. It takes ~10 years to build a reactor, so if you spot a way to improve on costs or safety it will take another 10 years for the

The learning cycle is too long. It takes ~10 years to build a reactor, so if you spot a way to improve on costs or safety it will take another 10 years for the innovation to see the light. At the contrary in renewables the learning cycle is in months so costs fall exponentially. That's the real reason of high costs in fission, not red tape or public sentiment.