This　paper　presents　the　solution　to　the　neutronics　equations　coupled　to　a　parallel　channel　model　containing　a　1D　heat　transfer　model　in　PWR　core　transient　calculation.　Unlike　traditional　coupling　techniques　where　the　coupled　field　equations　are　solved　separately,　Newton-Krylov　method　is　implemented　to　solve　the　coupled　nonlinear　field　equations　simultaneously.　The　related　Jacobian　of　the　nonlinear　system　is　analytically　derived　based　on　the　nonlinear　residual　functions　and　transferred　into　a　compressed　format　which　can　be　easily　handled　on　a　personal　computer　(PC).　Since　the　Jacobian　is　explicitly　constructed,　it　is　directly　passed　to　a　GMRES　solver　with　ILU　preconditioning.　A　new　solution　strategy　is　proposed　under　the　framework　of　Newton＇s　iteration,　in　which　the　nodal　coupling　coefficient　(NCC)　appeared　in　the　neutronics　equations　is　resolved　in　the　Newton　iteration　level.　The　proposed　method　is　studied　by　simulating　all　the　six　cases　in　the　OECD　NEACRP　PWR　rod　ejection　benchmark.　Results　indicate　that　that　nonlinearity　of　NCC　can　be　resolved　in　the　Newton　iteration　level　and　can　be　further　controlled　by　a　user　specified　number,　N-NCC.　Computational　simulation　also　shows　that　the　proposed　method　is　capable　to　converge　to　a　much　tighter　level　with　only　a　few　iterations.　(C)　2018　Elsevier　Ltd.　All　rights　reserved.