The impact of steam generator replacement on PWR primary system contamination

Frédéric Dacquait (1) , Hervé Marteau (1) , Luc Guinard (2) , Gilles Ranchoux (2) , Stephane Taunier (2) , Matthieu Wintergerst (2) , Jean-Luc Bretelle (2) , Alain Rocher (2)

1 LMCT - Laboratoire de Maitrise de la contamination et de la Chimie des Caloporteurs et du Tritium
2 EDF - EDF

This paper analyses the impact of Steam Generator Replacement (SGR) on PWR primary circuit contamination. It presents a comparison of the activities deposited inside the primary system and released during refuelling outages after SGR with three different SG tube alloys (600, 690 and 800) and different SG tube manufacturing processes. A SGR has a great impact on the primary system contamination. After SGR, whatever the SG tube material is, the typical variations are the following: • The Co-58 contamination increases for 1 to 3 cycles, and then decreases to very low levels in some cases, mainly depending on the manufacturing process of the replacement SG tubes. • The Co-60 contamination tends to decrease on the primary coolant pipes and increases by a lower rate on the new SG tubes. This analysis highlights the importance on contamination levels after SGR of both the corrosion product deposits on the primary surfaces before SGR and the surface finish of the SG tubes related to their manufacturing process.

Mots clés: steam generator replacement; PWR; primary system contamination

Domaines: Matériaux; Chimie-Physique [physics.chem-ph]

Frédéric Dacquait, Hervé Marteau, Luc Guinard, Gilles Ranchoux, Stephane Taunier, et al.. The impact of steam generator replacement on PWR primary system contamination. International Conference on Water Chemistry of Nuclear Reactor Systems, NPC 2010, Oct 2010, Quebec, Canada. paper 5.04. ⟨cea-04463799⟩