"A paper reactor [new reactor concept] has the following characteristics: it is simple; it is small; it is cheap; it is lightweight; it can be built very quickly; very little development is required and it will use off the shelf components; it is in the study phase and not being built now. By contrast a real reactor has the following characteristics: it is complicated; it is large; it is heavy; it is being built now; it is behind schedule; it requires an immense amount of development on apparently trivial items; it takes a long time to build because of its engineering development problems."