Shielding Research On Main Container Of Lead Cooled Fast Reactor

Lead-cooled fast reactor ?LFR? is considered as one of most promising concept of the fourth generation nuclear energy systems, which can be used for both electric power generation and long-lived radionuclide transmutation. Thus, LFR has been a hot area of research for many years. The main vessel is important part of reactor security, which can prevent reductive material leaking and make sure it's reliable operation.In this paper, the MCNP and Geant4 Monte-Carol software are used to research on the shielding properties of the European Lead Fast Reactor. This research is divided into three Parts. Firstly, Using MCNP Monte Carlo Cord to establish an accurate European Lead Fast Reactor model. Then a critical calculation was carried out to obtain core physical parameters, such as power, neutron flux and spectrum distribution. The power and neutron flux distribution results show a good agreement compared with references. Secondly, neutron and gamma flux density of the reactor barrel and main vessel are obtained by shielding calculation basing on the power distribution. To solve deep penetration problem and reach higher precision in shielding simulation, adjusted model, generate particle source and weight window variance reduction techniques are adopted in the shielding calculation. The shielding comparison results show that the B₄C can be the best material in the neutron shielding compared to YSZ ?ZrO₂ +Y₂O₃?,Ferro Boron,and Ferro tungsten. In order to maximize effectiveness,the B₄C is selected as the best shielding material.Shielding calculation is carried to obtain photon and neutron axial flux density distribution of barrel and main containers of reactor. The maximum neutron flux in main vessel is below the limit value of ASME. So the arrangement of the fuel and the shielding are reasonable and scientific to ensure the main vessel radiation safety. The last part research is about the accuracy validation of the MCNP shielding simulation through the C++ program of Geant4. To verify the Geant4 simulation accuracy,B₄C's neutron reaction cross section in low energy region is simulated by the Geant4 program. The results show a good agreement compared with ENDF cross-section database with MCNP calculation results. The next, writing C++ program of Geant4 platform is adopted to validate the accuracy of MCNP shielding. Comparison trend between Geant4 and the MCNP results are accord with very good, so the shielding simulation results by MCNP has certain feasibility and reliability.