Modeling heat transfer through corrosion product deposits on fuel rods in pressurized water reactors

•Liquid-saturated regime, wick-boiling regime, and film-boiling regime are heat transfer regimes of CRUD.•Vapor film exist within the CRUD during the heat transfer regime beyond the wick-boiling regime.•Disjoining force becomes dominant during film boiling when heat flux is large.•Heat transfer rate during film boiling is highly sensitive to pore radius.