Thermodynamics of zinc chemistry in PWRs: effects and alternatives to zinc

摘要

In this paper, the favourable effect of zinc on radiation field control in pressurized water reactors is evaluated in terms of the properties of spinels, which are a function of the incorporated elements. In addition, the identification of an alternative element to zinc is described. Thermochemical calculations show that chromites have a higher stability than ferrites. Zinc has a high affinity for the relevant spinels. Cobalt and other elements should therefore be displaced from existing oxide layers. For the identification of an alternative element to zinc, the following selection criteria were used: activation behaviour, valency and ion radius of candidate elements; affinity for spinel formation and occupational health and safety aspects. Based on these criteria, magnesium was identified as a possible alternative to zinc.