Description
Class G21C : NUCLEAR REACTORS
Subclass 1/18: Reactors Thermal reactors Heterogeneous reactors, i.e. in which fuel and moderator are separated moderator being substantially not pressurised, e.g. swimming-pool reactor (G21C 1/22 takes precedence) moderator and coolant being different or separated, e.g. sodium-graphite reactor coolant being pressurised