Some of the abstracts will give insight into what the NSSS/reactor suppliers are considering.
See - Advances in Water Reactor Fuel Technology and Testing
This paper is a good summary - Codes & Methods Supporting AREVA Fuel Solutions for the Future - Development Strategy
Westinghouse has a New Reactor Core Engineering (NRCE) group, and AREVA has their EPR Project group.
GE is working with Hitachi with their ABWR and ESBWR.