Transient analysis of OSU-MASLWR with RELAP5

Abstract The present paper deals with the assessment of original and a modified version RELAP5/MOD3.3 against OSU Multi Application Small Light Water Reactor (OSU-MASLWR). new implemented features regard suitable correlations for heat transfer coefficient evaluation in helical geometry. Furthermore, two different modelling Helical Coil Steam Generator (HCSG) are assessed. In first approach, HCSG’s primary secondary sides collapsed single pipe component. second model, three equivalent pipes conceived simulation ranks composing HCSG. Two power manoeuvring experiments reproduced. simulations highlight satisfactory agreement both transients. Nevertheless, code shows enhanced capabilities prediction HCSG operation. This is due to improvements adopted that allows better dryout phenomena occurring within tubes, as well estimation side coefficient. exchange propagated system, resulting more accurate inlet outlet core temperatures, flow rate.