PRoAtom

(Всего: 0)
от на 21/11/2021

Dear AC²-Users, we are glad to announce that a new version of AC² has been released. The AC²-2021 distribution includes ATHLET 3.3, ATHLET-CD 3.3, COCOSYS 3.1, NuT 2.0 and ATLAS 5.1P1.1, and comes with many new models and improvements. Highlights of the new program version are: ATHLET was assessed and further developed for the simulation of passive safety systems in advanced and innovative reactors / reactor concepts and SMRs. It now features improved correlations allowing a more accurate simulation of heat transfer in passive heat removal systems (including compact heat exchangers and heat pipes). In addition, various two-phase flow models like the entrainment model or the mixture level evaporation model were revised to extend their range of applicability. The new code version also offers improved models for the simulation of research reactors and a new water properties library that provides more precise thermodynamic and transport properties at low pressure (at or below atmospheric). The new version of ATHLET-CD offers the possibility to model the reactor core more flexibly. Now, not only concentrical but an additional azimuthal nodalization of the core is possible. This allows not only finer resolution of the reactor core itself and makes it easier to transfer standard ATHLET core nodaliziation, but also enables the simulation of accidents in the fuel storage pool with an appropriate level of detail. Furthermore, the retention and cooling of the melt in the reactor pressure vessel (IVR, In-Vessel Retention) was a key topic of the ATHLET-CD development. Now you can analyse the phenomena in the lower plenum in greater detail for more realistic results. The new version of COCOSYS includes numerous improvements of the COCOSYS main modules with view to code application range and code robustness, covering containment thermal-hydraulics, aerosol and fission product behaviour and the behaviour of the core melt outside the pressure vessel. The new generic core catcher model was developed with the main objective to include core melt retention and cooling in thermal-hydraulic containment simulations particularly for Gen III+ NPP. It considers all important phenomena such as interaction with the sacrificial material or stratification of the melt. Furthermore, COCOSYS now includes the first version of the newly developed module NewAFP (new Aerosol and Fission Products) for simulating aerosols and fission product behaviour in the containment and the reactor building. The optional Numerical Toolkit (NuT) received a complete overhaul of its code moving from Fortran to C/C++. In particular, this comes with the benefits of an improved communication architecture allowing NuT to support numerics in ATHLET and ATHLET-CD not only for stand-alone simulation runs but for coupled computations with COCOSYS as well. With the new version the computing of Jacobians was speed up and NuT takes ATHLET's steady state calculations into account too.