A method for at least partial dissolution, disruption and/or removal of deposits that include oxide scale from a steam generator in a pressurized water reactor in a wet layup condition, the method comprising: introducing an elemental metal and a complexing agent into a secondary side of the steam generator to form an aqueous solution at ambient temperature, wherein the aqueous solution comprises: purified water at ambient temperature having a pH from about 9,0 to about 12,5; from 0.001 M to 0.5 M based on the aqueous solution, of the elemental metal, wherein the elemental metal is zinc in particulate or colloid form being effective to release one or more electrons, to react with the oxide scale, and to result in release of one or more dissociated ions from the oxide scale; at least one pH control agent for establishing a pH range from about 9,0 to about 12,5 in purified water; and an oxygen scavenger and/or a reducing agent; wherein the total concentration of the elemental metal and complexing agent within the aqueous solution is the range of 0.025-6.0 w%; and the complexing agent is selected from the group consisting of a sequestering agent, a chelating agent, and mixtures thereof; reacting the elemental metal with the deposits to release an ionic metal; and either complexing the ionic metal with the complexing agent to form a precipitate or removing the precipitate. introducing an elemental metal and a complexing agent into a secondary side of the steam generator to form an aqueous solution at ambient temperature, wherein the aqueous solution comprises: purified water at ambient temperature having a pH from about 9,0 to about 12,5; from 0.001 M to 0.5 M based on the aqueous solution, of the elemental metal, wherein the elemental metal is zinc in particulate or colloid form being effective to release one or more electrons, to react with the oxide scale, and to result in release of one or more dissociated ions from the oxide scale; at least one pH control agent for establishing a pH range from about 9,0 to about 12,5 in purified water; and an oxygen scavenger and/or a reducing agent; wherein the total concentration of the elemental metal and complexing agent within the aqueous solution is the range of 0.025-6.0 w%; and the complexing agent is selected from the group consisting of a sequestering agent, a chelating agent, and mixtures thereof; purified water at ambient temperature having a pH from about 9,0 to about 12,5; from 0.001 M to 0.5 M based on the aqueous solution, of the elemental metal, wherein the elemental metal is zinc in particulate or colloid form being effective to release one or more electrons, to react with the oxide scale, and to result in release of one or more dissociated ions from the oxide scale; at least one pH control agent for establishing a pH range from about 9,0 to about 12,5 in purified water; and an oxygen scavenger and/or a reducing agent; wherein the total concentration of the elemental metal and complexing agent within the aqueous solution is the range of 0.025-6.0 w%; and the complexing agent is selected from the group consisting of a sequestering agent, a chelating agent, and mixtures thereof; reacting the elemental metal with the deposits to release an ionic metal; and either complexing the ionic metal with the complexing agent to form a precipitate or removing the precipitate.