What are the advantages of a gas as a coolant? (instead of heavy/normal water)
(in a fission reactor)
The gas can be cooled and condensed to a liquid, then evaporated. When the liquid (gas) evaporated, it turns into a gas AND absorbs energy. Then it can be regenerated.
In a fission reactor, the choice of coolant plays a crucial role in its overall efficiency and safety. Here are some advantages of using a gas, such as helium, as a coolant instead of heavy water:
1. Higher heat transfer capability: Gases generally have lower density compared to liquids, which makes them more efficient at transporting heat. Helium, for example, has excellent heat transfer properties due to its low viscosity and high thermal conductivity. This means it can absorb and carry away heat more effectively than water.
2. Lower pressure requirements: Gases are compressible, meaning they can be circulated with lower system pressure requirements compared to liquids. This can simplify the design and construction of the cooling system, reducing costs and potential failure points.
3. Reduced risk of coolant leakage: As gases are less dense than liquids, they have lower mass and are less likely to cause significant damage or contamination if a coolant leak occurs. This reduces the risk of radioactive material being released in the event of a coolant system failure.
4. Minimized neutron moderation: In some reactor designs, especially those utilizing fast neutron spectra, using a gas coolant helps to minimize neutron moderation. Heavy water, on the other hand, has a high hydrogen content, which can slow down (moderate) neutrons and reduce reactor efficiency in fast neutron reactors.
5. Compatibility with materials: Gases like helium have lower corrosive properties compared to liquids like heavy water. This is particularly important as it prolongs the lifespan of reactor components and minimizes potential damage caused by coolant corrosion.
To further investigate the advantages of gas as a coolant in fission reactors, you can refer to scientific literature, research papers, or consult experts and nuclear engineers specializing in reactor design.