F - MECHANICAL ENGINEERING
F28 - HEAT EXCHANGE IN GENERAL
F28D - HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
G - PHYSICS
G21 - NUCLEAR PHYSICS
G21C - NUCLEAR REACTORS
F - MECHANICAL ENGINEERING
F28 - HEAT EXCHANGE IN GENERAL
F28D - HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
F28D15/0233 - {the conduits having a particular shape, e.g. non-circular cross-section, annular
G - PHYSICS
G21 - NUCLEAR PHYSICS
G21C - NUCLEAR REACTORS
G21C15/02 - Arrangements or disposition of passages in which heat is transferred to the coolant
G - PHYSICS
G21 - NUCLEAR PHYSICS
G21D - NUCLEAR POWER PLANT
G21D7/00 - Arrangements for direct production of electric energy from fusion or fission reactions
G21D7/04 - using thermoelectric elements {or thermoionic converters}
H - ELECTRICITY
H01 - BASIC ELECTRIC ELEMENTS
H01J - ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
H01J45/00 - Discharge tubes functioning as thermionic generators {
Y - NEW / CROSS SECTIONAL TECHNOLOGIES
Y02 - TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
Y02E - REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
Y02E30/00 - Energy generation of nuclear origin
Y02E30/30 - Nuclear fission reactors