The diaphragm is the large conical part separating the primary coolant PbBi in the vessel into the lower part (high pressure but low temperature) and the upper part (low pressure but high temperature).
 |
The diaphragm has numerous penetrations: - 2 groups of 3 penetrations are foreseen for the primary pumps and heat exchangers
- 2 large diametrically opposed penetrations for the in-vessel fuel handling machines
- a special shaped slot for the spallation loop confinement vessel
- some penetrations for the in-vessel inspection and in-vessel repair manipulators
- many penetrations for the smaller irradiation devices (in-pile sections).
|
Some of the penetrations in the diaphragm are fitted with guide tubes, which function is not only to guide the device to be inserted through the diaphragm but also to limit the leakage through the diaphragm and to provide some controlled cooling along the device. In addition, the diaphragm serves as the support structure for the primary pumps and heat exchangers casings, for the two interim fuel storage devices, for the core support plates and barrel and for the PbBi conditioning system.