Supercritical　carbon　dioxide　(S-CO2)　Brayton　cycle　has　many　advantages　including　high　power　conversion　efficiency　at　mediate　temperature,　compact　configuration,　high　system　simplicity　and　low　efficiency　loss　using　dry　cooling,　which　make　it　well　suited　to　nuclear　reactor　applications.　S-CO2　power　cycle　can　be　used　as　power　conversion　system　for　almost　all　the　nuclear　power　systems　including　small　modular　reactor　(SMR),　Generation　IV　reactor　and　fusion　reactor.　It　can　also　be　used　as　a　self-propellant　and　self-sustaining　decay　heat　removal　system　to　enhance　the　safety　of　existing　commercial　nuclear　power　plant.　An　update　of　research　activities　is　needed　to　identify　the　unique　research　interests　and　challenges　of　S-CO2　power　cycle　based　nuclear　applications.　This　paper　is　a　review　of　the　research　activities　which　have　been　carried　out　for　S-CO2　power　cycle　based　nuclear　applications　worldwide.　The　characteristics　of　S-CO2　power　cycle　are　presented　first　to　explain　the　distinctive　features　of　this　power　cycle.　Then　the　progresses　in　the　experimental　study　of　integrated　S-CO2　Brayton　cycle　test　loops　are　reviewed　comprehensively　to　shed　a　light　on　its　technical　maturity　in　laboratory.　Moreover,　a　review　of　various　research　areas　concerning　S-CO2　power　cycle　working　as　power　conversion　system　or　heat　removal　system　for　nuclear　applications　are　carried　out.　Based　on　these　review　works,　the　challenges　and　perspectives　are　discussed　and　highlighted　in　the　paper.　Conclusions　can　be　achieved　that　S-CO2　Brayton　cycle　is　a　promising　option　to　broaden　nuclear　energy＇s　application　scope.　©　2020　The　Author(s)