Model for the Transient Analysis of the Integral Reactor Concept

Međunarodni konzorcij pod rukovodstvom Westighouse/BNFL-a sastavljen od industrije, sveučilišta, razvojnih i elektroprivrednih poduzeća razvija projekt modularnog, integralnog, lakovodnog reaktora srednje snage, IRIS (akronim od International Reactor Innovative and Secure – Međunarodni, inovativni i sigurni reaktor). Odlike su IRIS-a inovativna, napredna inženjerska rješenja s osloncem na dokazanu tehnologiju lakovodnih reaktora. Sistemski program za termohidrauličke proračune RELAP5/Mod3.3 odabran je za analize prijelaznih pojava u reaktoru IRIS. Razvijena je nodalizacija IRIS reaktora za program RELAP5/Mod3.3 koja uključuje osnovne kontrolne i zaštitne funkcije. Zaštitni sustavi, posebice sustav za hlađenje u nuždi i sustav za boriranje jezgre u nuždi također su ugrađeni u model. Razvijeni model kvalificiran je za stacionarno stanje. Analizirani su akcidenti loma glavnog parovoda i male izljevne nezgode. Rezultati proračuna iskorišteni su za kvalitativnu ocjenu primjenjivosti modela za analize prijelaznih pojava reaktora IRIS.An international consortium of industry, laboratory, university and utility establishments, led by Westinghouse/BNFL, is developing a modular, integral, light water cooled, medium power reactor, the International Reactor Innovative and Secure (IRIS). IRIS features innovative, advanced engineering, but it is firmly based on the proven technology of Pressurized Water Reactors (PWR). RELAP5/Mod3.3 code has been selected as the main system code for the transient analysis of the IRIS reactor. A nodalization for the RELAP5/Mod3.3 code of the reference IRIS design has been developed with a basic set of protective functions and controls. Engineered Safety Features were also implemented, in particular the Emergency Heat Removal System and Emergency Boration Tank. Developed model has been qualified at the steady state level. The analysis of the Main Steam Line Break (MSLB) and Small Break Loss of Coolant Accident (SBLOCA) were performed. The results of the calculations were used to qualitatively evaluate applicability of the developed model for the transient analysis of the IRIS reactor