Flow diagram of the BN-800 SG APS: 1 – evaporator; 2 – superheater; 3 – fast-acting sodium valves; 4 – reaction product discharge line; 5 – discharge header; 6 – stage I and II separators; 7 – sodium diaphragm; 8 – gas diaphragm; 9 – backup discharge line; 10 – fast-acting water (steam) valves; 11 – sectional gas cavity; 12 – pilot water (steam) safety valve; 13 – buffer tank; 14 – monitoring of hydrogen in gas; 15 – monitoring of hydrogen in sodium; 16 – sodium flow meters; 17 – detectors of gas bubbles in sodium.