# Gallium reactors

by snorkack
Tags: gallium, reactors
 P: 319 How useful are reactors cooled by gallium alloys? Ga has cross section for neutrons of 2,9 barns. Somewhat high - but K has 2,1 barns, and NaK is mostly (76 %) K. Pure Ga melts under +30 Celsius. The reactor may freeze - but it is much easier to melt than Pb/Bi eutectic (+125 Celsius). Ga melting point can be further lowered by alloying. While In, Cd and Hg are neutron poisons, the other low melting metals are reasonable - Pb, Bi, also Sn (0,62 barns) and Zn (1,1 barns). Would a reactor with Ga-Sn coolant be convenient to handle? Ga/Sn melt is nowhere as reactive as Na/K melt, and also not poisonous until irradiated....
 Admin P: 21,597 Gallium's price has been on the order of $650/kg but could be has high as$750 to $970/kg as compared to sodium at around$150/kg. In a reactor, liquid metal embrittlement with fuel and structural materials is an issue. Liquid metals are usually used for fast reactors.
 P: 319 Clementine managed to work with mercury coolant - despite its huge neutron cross-section. How does the quoted price of gallium compare with the price of highly enriched uranium 235, or plutonium 239? These are presumably priceless because no one wants to sell them....