The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 13 2 2019 11 26 Pebble bed reactors simulation using MCNP: The Chinese HTR-10 reactor Pebble bed reactors simulation using MCNP: The Chinese HTR-10 reactor 177 182 1028 FA SA Hosseini M Athari Allaf Journal Article 2019 11 26   Given the role of Gas-Graphite reactors as the fourth generation reactors and their recently renewed importance, in 2002 the IAEA proposed a set of Benchmarking problems. In this work, we propose a model both efficient in time and resources and exact to simulate the HTR-10 reactor using MCNP-4C code. During the present work, all of the pressing factors in PBM reactor design such as the inter-pebble leakage, fuel particle distribution and fuel pebble packing fraction effects have been taken into account to obtain an exact and easy to run model. Finally, the comparison between the results of the present work and other calculations made at INEEL proves the exactness of the proposed model.   Given the role of Gas-Graphite reactors as the fourth generation reactors and their recently renewed importance, in 2002 the IAEA proposed a set of Benchmarking problems. In this work, we propose a model both efficient in time and resources and exact to simulate the HTR-10 reactor using MCNP-4C code. During the present work, all of the pressing factors in PBM reactor design such as the inter-pebble leakage, fuel particle distribution and fuel pebble packing fraction effects have been taken into account to obtain an exact and easy to run model. Finally, the comparison between the results of the present work and other calculations made at INEEL proves the exactness of the proposed model. https://ijpr.iut.ac.ir/article_1028_3806734b256c27e41ec2c6bffa26d9e7.pdf