A planned new generation of small nuclear reactors will create more waste than conventional reactors, while treatments to make some types of waste safe could be exploited by militants trying to obtain fissile materials, a study published on Tuesday said. The projects, called small modular reactors (SMR), are designed to be simpler and safer than conventional plants in the case of accident. They are also expected to be built in factories as opposed to today’s massive light-water reactors that are built on site and typically run billions of dollars over budget.