Critical Reflections about Doel3 & Tihange2

Integrity reactor vessels Doel 3 and Tihange 2

Page: 4

Figure 1: Principle of a nuclear reactor [ 21 ] .

2 Main points of criticism on the Electrabel safety cases

1. Hydrogen as cause of the flaws. The normal volume H 2 necessary to form 41 cracks in 1dm 3 steel at cracking pressure amounts between 818 ml and 1374 ml, which is 6 to 10 times more than the 131 ml H 2 which was dissolved in the steel. However, not all hydrogen takes part in crack formation. It is estimated that only 61ml H 2 is available for crack formation. Then 13 to 22 times 61ml H 2 is necessary to form the cracks. This would implicate that hydrogen flaking cannot be not the only cause of the flaws, but that another cause has resulted in flaking and / or that the flaws have been growing during time. This is discussed in more detail in section 4.

R.Boonen & J.Peirs

May 18, 2017