RSG Component/Assembly Specification Requirements Challenges Design Fabrication QC
1 Channel head Maintain thermal rating Maintaining reactor coolant flow rate within specified limits X X
Maximize number of heat transfer tubes
Eliminate stay cylinder Optimizing primary side volume X
2 Tubesheet Withstand primary-to-secondary full dP Optimizing tubesheet thickness X
Limit on tube hole runout Tubesheet drilling X X
Minimize number of hole surface imperfections
3 Tube bundle Limit on number of tube dings at time of delivery Controlling tube bundle sag during assembly X X
Monitoring temperature distribution during PWHT of the channel head-to-tubesheet weld
4 Tube-to-tubesheet joints Ensuring adequate tube-to tubesheet joint strength, leak resistance and corrosion resistance Qualifying tube-to-tubesheet joint X X X
Controlling tube-to-tubesheet joint crevice depth X X
Limit on allowable tube-to-tubesheet crevice depth
5 Tube supports Preventing tube wear Configuring tube-to-tube support interface X
Preventing tube denting at tube supports
6 AVB support structure Preventing tube wear AVB structure assembly X X X
7 Feedwater distribution system Elimination of susceptibility to water hammer and thermal stratification Configuring inlet piping to feedwater ring X
Resistance to erosion/corrosion
8 Moisture separators Limit on allowable moisture carryover Designing moisture separator assemblies X