This is the fourth part of a four-part guest post by Dr. Michael Dittmar. Dr. Dittmar is a researcher with the Institute of Particle Physics of ETH Zurich, and he also works at CERN in Geneva.

The accumulated knowledge and the prospects for commercial energy production from fission breeder and fusion reactors are analyzed in this report.

The publicly available data from past experimental breeder reactors indicate that a large number of unsolved technological problems exist and that the amount of "created" fissile material, either from the U238 → Pu239 or from the Th232 → U233 cycle, is still far below the breeder requirements and optimistic theoretical expectations. Thus huge efforts, including many basic research questions with an uncertain outcome, are needed before a large commercial breeder prototype can be designed. Even if such efforts are undertaken by the technologically most advanced countries, it will take several decades before such a prototype can be constructed. We conclude therefore, that ideas about near-future commercial fission breeder reactors are nothing but wishful thinking.

We further postulate that, no matter how far into the future we may look, nuclear fusion as an energy source is even less probable than large-scale breeder reactors, for the accumulated knowledge on this subject is already sufficient to say that commercial fusion power will never become a reality.

(Links to 1^st, 2^nd, and 3^rd parts)