BETHSY 9.1b test calculation with TRACE using 3D vessel component

Recently, several advanced multidimensional computational tools for simulating reactor system behavior during real and hypothetical transient scenarios were developed. One of such advanced, best-estimate systems codes is TRAC/RELAP Advanced Computational Engine (TRACE), developed by the U.S. Nuclear Regulatory Commission. The TRACE comes with a graphical user interface called SNAP (Symbolic Analysis Package). It intended pre- post-processing, running codes, RELAP5 to input deck conversion, database generation etc. code still not fully development it will have all capabilities RELAP5. purpose present study was therefore assess 3D capability on BETHSY 9.1b test. semi-converted (using manual corrections) from deck. fluid dynamics within vessel modeled compared 1D dynamics. calculation both calculation. Namely, geometry used in basically same, what gives very good basis comparison codes. only exception model case V5.0 Patch 1 RELAP5/MOD3.3 4 calculations. test (International Standard Problem no. 27 or ISP-27) 5.08 cm equivalent diameter cold leg break without high pressure safety injection delayed ultimate procedure. facility 3-loop replica 900 MWe FRAMATOME pressurized water reactor. In general, presented calculations agreement results are comparable calculated results. For some parameters they better, this mostly due better tuning flow, influences timing transient. When comparing calculation, latter slightly better. reason already there much space further improve other may be that phenomena one dimensional (for example, external downcomer modeling). However, when heater rod temperatures investigated, advantage three treatment clearly demonstrated.