Development of VTSAS 1.0 and application to an IPWR

An integral pressurized water reactor (IPWRs) is a class of reactors in which the main equipments of the primary loop system, core, steam generators (SGs), pressurizer (PZR), and main coolant pumps (MCPs) are housed in an integral reactor pressure vessel (RPV). In this study, a point reactor neutron kinetics model depended on the point kinetics with six groups of delayed neutron, a drift-flow once-through steam generator model, a nitrogen pressurizer model and other auxiliary models were established. A visual transient analysis program named VTSAS 1.0 has been developed to analyze the thermal–hydraulic characteristics of the IPWRs. Interactive visual input, real-time plotting and comparing functions and interactive visual output were implemented using mixed programming of Visual C + + language and FORTRAN90 language, which greatly facilitate applications in the engineering. The VTSAS 1.0 was applied to analyze the transient thermal–hydraulic characteristics of reactivity insertion accident (RIA) and sudden increase of feed-water temperature accident of an IPWR. The results obtained were found to be in reasonable agreement with those by RELAP5/MOD3. The research is significant to the improvement of design and safety operation of the IPWRs.

► A visual transient analysis program named VTSAS 1.0 was developed.
► The software was applied to a 140 MW IPWR and validated by RELAP5/MOD3.
► The IPWR is safe while a positive 0.12$ reactivity is inserted.
► The system parameters change slightly when the feed-water temperature increases.