Study on the heat transfer to the supercritical pressure fluid for supercritical water cooled power reactor development

The Supercritical Water Cooled Power Reactor (SCPR) surpasses the current generation Light Water Reactors (LWRs) in thermal efficiency as well as in compactness/simplicity. Although thermohydraulics of SuperCritical Pressure (SCP) water has been extensively studied for fossil boilers, the SCPR core conditions are different from these. Therefore, the purpose of this development is to get better understanding of thermohydraulics performance of SCPR. We performed the test by using a small tube, which simulates the equivalent diameter of the SCPR fuel bundle. The heat transfer characteristics including heat transfer deterioration were compared with that of large tube. It is found that there is no difference in the heat transfer characteristics between small and large tube. Furthermore, the test results were compared with published heat transfer correlation. Watts' correlation for normal heat transfer shows the best predictability among them. On the other hand, for the deteriorated heat transfer, modified heat transfer correlation was proposed