Practically all the fusion projects discussed and investigated up to now are the demonstrative projects or devices. The main goal is to show that Qα can be of the order of unity or more. But some other problems of future thermonuclear reactor are delayed to the far future, or ignored. Among these problems is a alpha- particles problem which partially was investigated as the problem of ITER.1–6 Some aspects of this problem related to the fusion reactor are discussed below.