中法核工程与技术学院核声论坛（总第165期）

Abstract:

Since the beginning of nuclear industry, corrosion issues have been a major concern. Less than two years after start-up, stress corrosion cracking (SCC) occurred on the stainless steel tubing of the steam generator of the Nautilusprototype in USA. This overview of stress corrosion cracking (SCC) of austenitic alloys in water cooled reactors focuses on an historical perspective, from the first cracks on stainless steels, to the choice of Alloy 600 in Pressurised Water Reactors (PWR) followed by its prohibition and includes considerations regarding the SCC of stainless steels in Primary PWRs circuits.

We propose to go back to the beginning of nuclear industry, to the choice of the Alloy 600 despite experimental evidences, to the scientific and technical disputes. Finally, the large cracking observed on steam generator tubing lead to the replacement of Alloy 600 by the use of Alloy 690 (or Alloy 800) at the end of the 80s. 

The talk includes an overview on SCC of stainless steels in Primary PWR circuits, with a summary of the last events in French PWRs.

Feed-back observations lead to an evolution of the fundamentals of SCC phenomena:There is no more immunity, but there is a continuum across austenitic alloys regarding the sensibility to stress corrosion cracking. No evidence in laboratories and in plants of true thresholds values or of immunity. There are low SCC susceptibility regimes, but the reappearance of enhanced susceptibility may occur as few parameters are changed. 

About the speaker：

Damien Féron is Professor at the INSTN (French Institute for Nuclear Science and Technology) and has been Director of Research at the French Atomic Energy and Alternative Energies Commission (CEA).  He is (co)editor of 18 books or special issues, mainly in the field of biocorrosion, seawater corrosion and nuclear corrosion. Among other responsibilities, he served as President of the European Federation of Corrosion (EFC, 2017-18) and as President of the World Corrosion Organization(WCO,2019-22).