A computer program for porous fuel element directly cooled by helium gas

The heat-transferring flow analysis code POROUS-2 was developed for a new type of the coated particle fuel elements recently proposed for gas cooled fast reactors (GCFR). In the first part of this report, the concept of the new fuel element GBR-2 and a GCFR loaded with this fuel elements are explained. The concept and the performance characteristics of conventional pin-cluster fuel elements are also presented for comparison. In the second part. The computational model and the heat-transferring flow equations employed in the POROUS-2 code are described and discussed. The computational steps of the code are also explained with flow charts. Finally, example calculation is described. The input parameters and computational conditions used are presented together with the main results of the calculation, such as axial pressure distribution and flow rate and radial temperature distribution. (Aoki, K.)