Provided is a zinc-based plated steel sheet having a post-treated coating filmed thereon including: a steel sheet; a zinc plated layer formed on the steel sheet; and a post-treated coating formed on the plated layer, wherein the atomic ratio (O/M) of oxygen (O) to metals (M) contained in the post-treated coating is greater than 2 and less than 20, and a method for post-treating a zinc-based plated steel sheet. According to this, the zinc-based plated steel sheet having the post-treated coating formed thereon has the effects excellent in lubricity, weldability, adhesiveness, film-removing property and paintability. As the method of post-treating a zinc-based plated steel sheet of the present invention employs a simple coating method irrespective of the kind of plating layer, the process is simple and economical and the process operation cost is low.

A method for depositing zinc on the surfaces of a coolant loop of a nuclear power plant includes: providing within a portion of the coolant loop a treatment solution comprising zinc and optionally one or more noble metals and/or reducing agent(s); allowing the treatment solution to remain in the portion for a treatment period; and removing the treatment solution from the portion. According to various embodiments, an average temperature of the treatment solution over the course of the treatment period is less than 150 C. or 100 C. According to various embodiments, an instantaneous temperature of the treatment solution remains below 150 C. or 100 C. throughout the treatment period. The zinc deposition treatment may be applied (1) before the plant is first put into power-generating operation or (2) during an outage following power-generating operation and optionally following a chemical decontamination to remove any oxides formed on surfaces of a coolant loop during prior power operation period(s).