As　the　main　carrier　of　fission　products,　aerosols　will　transport　in　the　containment　and　even　leak　into　the　environment　during　accident　conditions,　resulting　in　radioactive　pollution.　Thus,　it　is　of　great　significance　for　radiation　protection　to　study　the　aerosol　distribution　mitigation　measures　in　containment　after　severe　accidents.　A　multi-compartment　lumped　parameter　code　named　ATHROC　(Analysis　of　Thermal　Hydraulic　Response　of　Containment)　was　developed　to　analyze　the　thermal–hydraulic　behaviors　in　the　containment　after　accidents　for　China　advance　PWR.　In　order　to　satisfy　the　analysis　of　aerosol　behavior　in　containment,　an　aerosol　module　based　on　the　aerosol　dynamic　and　hygroscopic　models　was　added　to　the　code　and　coupled　with　spray　removal　mechanism　models.　Three　different　types　of　benchmark　experiments　were　selected　for　assessment　of　the　improved　code,　including　CVTR,　LACE　and　CSE　tests.　Most　of　the　predicted　results　of　thermal–hydraulic　responses　and　aerosol　distribution　are　in　realistic　agreement　with　the　experimental　data.　The　comparative　results　show　that　the　code　has　capabilities　to　accurately　predict　the　thermal–hydraulic　responses　during　spray　activation,　aerosol　distribution　and　removal　of　aerosols　by　spray　droplets.　And　the　problems　identified　in　the　code　will　be　further　optimized　in　the　future.　Currently,　the　developed　improved　code　satisfies　the　analysis　of　aerosol　behavior　in　containment　and　provides　a　design　for　aerosol　removal　for　spray　system　arrangement.　©　2020　Elsevier　B.V.