1. The National Ignition Facility [1] recently reported record amounts of energy produced by laser-based fusion, but it is more of a research facility than a power plant.

2. Do the betavoltaics [2] in some early pacemakers and the small reactor on spacecraft and the Mars Science Laboratory count as radioactive batteries? But I am assuming that, since betavoltaic pacemakers and nuclear spacecraft have been around since Asimov's time, they probably don't count.

[1] http://en.wikipedia.org/wiki/National_Ignition_Facility [2] http://en.wikipedia.org/wiki/Betavoltaics