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In the currently available authoritative sources, there are no clear records of violent chemical reactions occurring directly between nuclear fuel and liquid metallic sodium; under normal operating conditions in sodium-cooled fast reactors, the compatibility between the two is fairly good. I. Characteristics of interaction under normal operating conditions: Direct contact is extremely rare: During normal operation, nuclear fuel is enclosed within a stainless steel cladding, while liquid sodium, used as a coolant, flows only outside the cladding; thus, the two do not come into direct contact. Indirect material compatibility: Liquid sodium has good overall compatibility with the stainless steel material of the fuel cladding; only very slight mass transfer occurs. A small amount of alloying elements dissolve in the high-temperature areas, while a trace amount precipitates in the low-temperature areas. The erosion of the cladding is only in the order of tens of micrometers, and this does not have any direct effect on the condition of the nuclear fuel inside. II. Potential risks under abnormal operating conditions When the fuel cladding is damaged, nuclear fuel (such as MOX mixed-oxide fuel or metallic fuel) comes into direct contact with high-temperature liquid sodium, and the following situations may occur: Some fission products react with sodium to form corresponding sodium-based compounds ； Such scenarios fall within the category of design basis accidents for sodium-cooled fast reactors, and the reactor’s safety systems can manage related risks through redundant design, preventing any uncontrolled safety issues from arising.