Effects of process-generated hydrogen on RPV walls

1.3. Design of a reactor pressure vessel

1.3 Design of a reactor pressure vessel These mechanical requirements lead to a typical 20 cm thick steel wall for the RPV of a PWR. The reactor units of Doel 3 and Tihange 2 are build to the design by Framatome, now AREVA, in accordance with the ASME Code, Section III for Class 1 components. [1] A schematic representation of this type of RPV is shown in Figure 1.2. It can be seen that the total vessel is made of multiple rings which are welded together.

Figure 1.2: Schematic representation of a RPV like Doel 3 and Tihange 2 taken from FANC. [4] Each of these componenents is welded together to form the complete RPV. For Doel 3 and Tihange 2, the RPV is composed of 6 forged rings of which one has 6 nozzles, one inlet and one outlet nozzle for each of the three primary loops. All of these components are made in a low-alloy steel type SA-508 Class 3, except for the bottom plate and RPV head, which are made in SA-533 Grade B Class 1. [1] Both materials are low-alloy Mn-Mo-Ni steels. The inside of the RPV is cladded with a 7 mm thick stainless steel Type 308L/309L lining. The composition of each of these materials is given in Table 1.1. The total height of the RPV including the RPV head and the bottom plate is 13.2 m and has an inner diameter of 4.0 m. [1]

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