Key Emerging Issues and Recent Progress Related to Plant Chemistry/Corrosion in PWR/VVER/CANDU Reactors 2014–2015

(LCC11 AR)
Operational issues with their link to other aspects are of large interest for Utilities as well as Regulators, Designers, Manufacturers and Laboratories. This LCC11 Report is covering two technical aspects dealing with: 1) Recycling of waste in primary coolant and, 2) Secondary water chemistry options and Hide out return of impurities from Steam Generators (SG).

Recycling of primary water wastes, is becoming more important to minimize both chemical and radiochemical releases into the environment. A specific focus is given to Tritium impact since this element is not eliminated by purification systems and thus recycled together with concentrates and distillates.

The secondary side chemistry is one of the key factors that are influencing safety, reliability and particularly availability of PWR and VVER Nuclear Power Plants. This Report gives: 1) all the relevant information to select the best chemistry options with the type and concentration of reagents that are used – with their advantages and disadvantages and, 2) the relation between the chemistry specification at SG blowdown and the various options of secondary treatment and purification systems.

The Hide out process and influencing parameters for different types of chemical elements and Hide Out Return of species from the Steam generators is also covered in this Report.