Nuclear reactor very high temperature

Refined niobium metal is most useful as an alloy with other metals. It is used to produce special stainless steel alloys, to make high-temperature magnets, as special metals for rockets and missiles, and for high- and low-temperature-resistant ceramics. Stainless steel that has been combined with niobium is less hkely to break down under very high temperatures. This physical attribute is ideal for construction of both land- and sea-based nuclear reactors. 

Concerning the coupling to a nuclear heat source the S-I process is the most intensively studied thermochemical cycle. Due to the high temperatures (> 800°C) needed for the H2S04 decomposition, the first choice is to combine it with a very high temperature reactor (VHTR). 

Both fusion and fission reactions can be used in bombs. The fusion re- A nuclear explosion at sea. actions require a very high temperature to get started, so they are initiated by fission reactions. (When controlled at slower rates in nuclear reactors, fission reactions are used to produce power and additional nuclear fuel.)... 

Atoms are first stripped of their electrons at very high temperatures this creates a plasma (ionized gas) of positive ions. Then the positive ions must be brought into close enough proximity, so that the strong attractive force between nucleons can overwhelm the Coulomb repulsion between them. Magnetic fields can confine hot plasmas of ions, provided that collective instabilities of these plasmas can be controlled. For a successful nuclear fusion reactor, three requirements must be met (1) The density of the plasma must exceed some critical value p. (2) The plasma confinement time must exceed some critical value t. (3) The temperature of the plasma must exceed some critical value 9... 

Niobium is used primarily in making alloys. For example, the addition of niobium to steel greatly increases its strength. One use of such steel is in the construction of nuclear reactors. Nuclear reactors are devices in which the energy of nuclear reactions is converted to electricity. Niobium steel is used because it keeps its strength at the very high temperatures produced there. 

Figure 3.37 is reprinted from Journal of Nuclear Materials, Vol. 376, S Ueta, J Aihara, A Yasuda, H Ishibashi, T Takayama and K Sawa, Fabrication of uniform ZrC coating layer for the coated fuel particle of the very high temperature reactor, pp. 146-151, 2008, with permission from Elsevier. 

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