Patent ID: 7637653

Claim:
A method to determine corrective actions of a steam generator of an operating nuclear power plant, comprising: modeling heat transfer characteristics of deposits over the heating surface of a steam generator tubing by analytically deriving descriptive model parameters, the model parameters comprising the deposit thickness, δ, the deposit porosity, ε, the deposit copper content, Cu, the effective fraction, K, of the deposit full thickness conductive heat transfer resistance, which lies between the tubing and deposit steam channel, and the deposit tortuosity, τ, wherein individual parameters δ, ε, Cu, K, and τ evolve in time as a function of a B parameter as follows: ɛ = ɛ 0 ⁢ e [ - t B ] , ⁢ τ = 1 + τ 0 ⁡ [ 1 - e [ - t B ] ] , ⁢ K = K 0 ⁡ [ 1 - e [ - t B ] ] , ⁢ C ⁢ ⁢ u = C ⁢ ⁢ u 0 ⁢ e [ - t B ] , ⁢ and δ = M i ( 1 - ɛ ) ⁢ ( S ⁢ ⁢ D ) ⁢ ( A T ) , ⁢ wherein M i is the mass of deposit inventory, SD is the deposit solid density, A T is the tubing outside diameter surface area affected by deposit, t is the number of days since startup of the reactor or since the occurrence of a significant operational or maintenance event of the steam generator, B is a time constant describing parameter evolution, ε 0 is the maximum possible porosity, τ 0 is the maximum possible tortuosity, K 0 is the maximum possible resistance, and Cu 0 is the maximum possible copper content, and wherein the modeling comprises calculating the B parameter on the basis of either empirical deposit measurement data or historical thermodynamic data and deposit inventory mass data for the operating plant under evaluation; identifying a set of preventative and/or corrective maintenance alternatives for the steam generator to accomplish steam generator deposit objectives, based on the modeling; determining through the modeling a power production impact of the set of preventative and/or corrective maintenance alternatives for the steam generator; and initiating a maintenance alternative on the steam generator, based on the determination of the power production impact of the set of preventative and/or corrective maintenance alternatives for the steam generator.