Thermal and stability considerations of CANDU-SCWR sliding pressure startup

The feasibility of the sliding pressure startup of CANDU-SCWR is assessed from both thermal and stability considerations. The coupled neutronic/thermal-hydraulics stabilities are investigated for both super- and sub-critical pressure operating conditions. The startup system and startup procedure are designed. The detailed thermal-hydraulics analysis is assessed based on the subchannel analysis and a stability map is constructed based on non-dimensional parameters and frequency domain method. The results show that the maximum cladding surface temperature can be well restricted lower than criterion (850^oC), and the stability can be maintained by controlling the power and flow rate during startup. (author)