1. It's a calandria type reactor.

2. The calandria arrangement in the furnace floor flue gas channel that is formed by the ondol pier bricks with circular sections greatly lowers the local resistance loss of flue gas.

3. Natural circulation evaporator with external calandria is used in the evaporation process for the production of 72% (wt) flake caustic soda.

4. Condensate from the first - effect calandria is used for preheating the feed.

5. Hot vapor from this unit passes to the second-effect calandria and causes boiling in the second evaporator.

6. The paper presents a design of passive heat-switch between pressure tube and calandria tube of Thorium-based Advanced Nuclear Energy System.