nuclear-news

Controlled Nuclear Fusion Not Reached   https://ladailypost.com/letter-to-the-editor-controlled-nuclear-fusion-still-not-reached/  Carol A. Clark

Los Alamos

This is a comment on your recent piece on nuclear fusion. It was misleading in one respect. Both in the title and in the text, it stated that this research was an important step toward the practical use of controlled nuclear fusion.

In fact, we are no closer to that goal then we were 60 years ago. The article reported on an important study of plasma physics, but the study made no impact on reaching the goal of electrical energy from fusion. The reason is that fusion has to occur at millions of degrees and the temperature to produce electrical power is many orders of magnitude less.

First look at the fairly rapid development of nuclear power from fission. In less than 20 years after the discovery of nuclear fission there were operating nuclear reactors. Soon after we began to have nuclear power reactors.

That was primarily because fission occurs at room temperature and by controlling the chain reaction it was simple to take temperatures up enough to generate electricity. In contrast for fusion reaction you have to start with millions of degrees, sustain the reaction to a steady state, contain the extremely hot plasma, and then extract the heat at moderate temperatures. While no technical and engineering problems are insoluble these are very difficult.

Containment involves what the scientists call PFM.  It stands for Plasma Facing Materials. These containment materials have to stand the intense heat from the plasma. All the experiments so far have been with pulses of magnetic fields to contain the plasma so cooling the containment materials occurs naturally. To produce electric energy you need a steady state fusion reaction and cooling the containment became a severe problem which is not near a solution.

So, where does a practical solution for electrical power from fusion stand? It is hardly any nearer than it was 60 years ago. Researchers have learned a great deal about plasma physics, but they are still far away from obtaining electrical energy. They have made almost no important engineering steps toward that goal.