The present volume in our annual review series reviews a wide range of developments, giving a broad interpretation to the "technology" of our title. Starting at the beginning, Science, we have the review of basic nuclear physics data of Walker and Weaver for reactor kinetics, particularly, there­ fore, delayed neutron data. In the search for better and better accuracy, it is being realized that this involves the closest scrutiny of fundamental data, given to us here from the Birmingham school. Associated with this review of data is the review from Italy by Professor Pacilio and his co­ workers of the theory of reactor kinetics in the stochastic form, and a valuable compilation of the theory underlying a wide range of practical techniques. Tending more to technology come the papers by Jervis, reviewing the application of digital computers to the control of large nuclear power stations as developed in both the united Kingdom and Canada, Pickman's review of the design of fuels for heavy water reactors, and the account by Ishi­ kawa and Inabe of the new Japanese Research Reactor Program, itself initially directed largely to fuel element studies. The balance of the volume is made up of more philoso­ phical contributions to the practicalities of nuclear power.