Could even high conversion PWRs be inherently safe

For the LWHCR (light water high converter reactor) concept involving the use of Pu02/U02-fueled tight lattice cores in PWRs, the effective void coefficient is expected to be significantly less negative than in current-day LWRs. In certain regions of the equilibrium core the local void coefficient may, in fact, be positive. An analogy is drawn with standard PWRs with exceptionally high boron concentrations in the moderator. The application of a 3-D dynamics code in such a case shows that results based on a single zone, i.e. points kinetics, treatment of the whole reactor can be much too conservative. A detailed analysis of transients for alternative LWHCR designs is called for if the inherent safety criterion for such a reactor is to be realistically assessed