Hafnium isotope good for future Orion type Rocket (Score 1)

This new explosive seems like it would be great for making better rockets of the project Orion type. Cleaner than nuclear fission but still with energy density 1000 times higher than chemical. Scalable to smaller explosions (So a smaller scale rocket could be taken up to orbit). Seems like a very finely controlled hafnium injection system could be made with X-Ray ignition.