118 Various methods for defining the kinetic transfer coe?cient have been examined by other researchers [IX-3–5]. In this model, the distribution coe?cient kd is used as one of the parameters for determining the kinetic transfer coe?cient [IX-4–5] as follows: ??? = ?????? (IX-4) ??? = ????? ????(???) ? (IX-5) The radionuclide migration model for the LPM phase is written as: ?(???) ?? + ?(???) ?? + ? ?(???) ?? + (? ? ??) ?(???) ?? = ? ?? ??? ?(???) ?? ? + ? ?? ??? ?(???) ?? ? + ? ?? ??? ?(???) ?? ? + ????? ? ?????? ? ???? + ?? (IX-6) where ws is the settling velocity of suspended particles, the fourth term of the right hand side represents the adsorption from dissolved phase to the LPM phase and the fifth term the desorption from the LPM phase to dissolved phase. The surface boundary condition is: (? ? ??)??? ? ?? ?(???) ?? = 0 (IX-7) The sea bottom boundary condition is: ????? + ?? ?(???) ?? = ??? ? ??? (IX-8) where Ps is the input of the radionuclides adsorbed to the LPM from the source point. dep and res are the deposition and resuspension terms, respectively. The deposition term is written as: ??? = ??(?)??(?)?(?) ? ?1 ? ?? ??? ????? ?? < ??? (IX-9) ??? = 0 ???? ?? > ??? (IX-10) where ?cd and ?b are the critical deposition shear stress and the seabed stress, respectively, and (b) means the variables at the deepest water layer. The seabed stress is written as: ?? = ??????? (IX-11) where ?w is the seawater density, CD the drag coe?cient and ub the bottom water velocity. The resuspension term is written as: ??? = ???? ? ? ?? ??? ? 1? ???? ?? > ??? (IX-12) ??? = 0 ???? ?? < ??? (IX-13) where M is the resuspension constant and ?cr the critical resuspension shear stress. These deposition and resuspension models are used for fine particles such as clay and silt. Fine particles are strongly a?ected by wind-waves. In this study, however, the e?ect of wind–waves was not considered and deposition and resuspension processes are solved only by the tidal current.