57 KB537 KB60 KB199920252006Cizelj, LeonKončar, BoštjanLeskovar, Matjaž17 straništevilka:5letnik:52str. 292-308ISSN:0039-2480COBISSID:20019239URN:URN:NBN:SI:doc-UENWC22NenslAssociation of Mechanical Engineers and Technicians of Slovenia et al.Zveza strojnih inženirjev in tehnikov Slovenije et al.Strojniški vestnikeksplozijejedrski reaktorjinezgodepararačunalniške simulacijeSimuliranje eksplozije pare v reaktorski votlini s splošnim programom za računsko dinamiko tekočin| Simulation of a reactor cavity steam explosion with a general purpose computational fluid dynamics code|A reactor cavity steam explosion might occur when, during a hypothetical severe reactor accident, the reactor vessel fails and the molten core pours into the water in the reactor cavity. A steam explosion is a fuel-coolant interaction process where the heat transfer from the melt to the water is so intense and rapid that the timescale for the heat transfer is shorter than the timescale for the pressure relief. This could lead to the formation of shock waves and the production of missiles at later times, during the expansion of the highly pressurized water vapour, which might endanger surrounding structures. The purpose of the paper is to demonstrate how steam explosions can be treated with a general purpose Computational Fluid Dynamics (CFD) code, to give an insight into the steam-explosion phenomenon in a typical Pressurized Water Reactor (PWR) cavity, and to provide a rough assessment of the vulnerabilities of cavity structures to steam explosions. Toachieve this, a fit-for-purpose steam-explosion model was developed, followed by a comprehensive and reasonably conservative parametric steam-explosion study. The multiphase flow in the reactor cavity during the high-pressure pre-mixture expansion was simulated with the CFD code CFX-5.7.1 and the stresses in the reactor cavity walls were determined with the stress-analysis code ABAQUS/ExplicitDo eksplozije pare v reaktorski votlini lahko pride, če med hipotetično resno nezgodo v jedrski elektrarni popusti reaktorska posoda in se staljena sredica izlije v vodo, ki je v reaktorski votlini. Eksplozija pare je pojav medsebojnega delovanja goriva in hladiva pri katerem je časovna lestvica prenosa toplote s staljene sredice na vodo manjsa od časovne lestvice za tlačno razbremenitev. To lahko povzroči tlačne udarne valove in kasneje, med raztezanjem pare, ki je pod visokim tlakom, nastanek izstrelkov, ki lahko poškodujejo okoliške objekte. Namen prispevka je predstaviti, kako je eksplozije pare mogoče obravnavati s splošnim programom za računsko dinamiko tekočin (RDT), podati vpogled v dogajanja med eksplozijo pare v reaktorski votlini tipičnega tlačnovodnega jedrskega reaktorja, in podati grobo oceno ogroženosti sten reaktorske votline in reaktorske posode ob eksploziji pare. Za dosego teh ciljev smo najprej razvili ustrezen namenski model eksplozije pare in nato opravili obsežno, primerno konzervativno parametrično analizo eksplozije pare v poplavljeni reaktorski votlini. Večfazni tok v reaktorski votlini med raztezanjem visokotlačne mešanice razpršene taline, kapljevite vode in vodne pare smo simulirali s programom CFX-5.7.1 za RDT, napetosti v stenah reaktorske votline pa s programom za simulacijo mehanike trdnin ABAQUS/ExplicitTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaUniverza v Ljubljani, Fakulteta za strojništvo