Chemical Composition of Crud Depositing on BWR Fuel Surfaces

摘要

Deposition profiles of corrosion products on fuel surfaces and products chemical compositions were determined at Shimane Nuclear Power Plant, a low-crud BWR. The deposited amounts were expressed as functions of crud concentration in the reactor water, fuel burnup and flow velocity in a fuel channel. The results could be predicted satisfactorily by the crud deposition model based on microlayer evaporation and drying out phenomena. The amount depositing at high flow velocity gave saturated values which were inversely proportional to the flow velocity (∝1/v), while those at low velocity did not reach saturated values, but rather were proportional to 1/v3. The depositing corrosion products could be divided into two layers, inner and outer, with more Co ions being taken into the former layer.