Neutronics of the TCV Fusion ReactorFortuna, Mark (Avtor) Snoj, Luka (Mentor) Blanchard, Patrick (Komentor) Čufar, Aljaž (Komentor) Fusion NeutronicsTCVFusionNeutron ShieldMCNPRadiological protectionNeutron radiation presents major challenges in the development of larger fusion reactors. The TCV, a medium-sized tokamak, needed an upgrade of the radiological shield due to an upgrade of the plasma heating system and a subsequent increase in neutron yield. Before using the MCNP code to design the radiological shield, the reference model of the TCV facility needed to be improved. This was achieved by adding simple shapes to represent tokamak components and building structures. The accuracy of the model was assessed in comparison to neutron H*(10) dose measurements. When designing the radiological shield, MCNP simulations were optimized with the ADVANTG code, while neutron yield estimates were based on results of TRANSP calculations. The inclusion of homogenized representations of tokamak components enabled us to reduce the C/E values at 12 locations at the TCV facility from the range [1.6, 10] to [0.6, 4.2]. The improved model enabled us to test different configurations of the radiological shield, which resulted in a design with a predicted reduction in neutron doses by 2000 times in the control room. Additional measurements intended to measure the attenuation of polyethylene contributed to the improvement of the computational model, and measurements of the directional dose further validated the model, with C/E values in the range [0.75, 2.0] for 10 measurements at 5 areas of the TCV facility. While the use of a homogeneous "fog" that surrounds the tokamak proved successful in further improving C/E values, unless absolutely calibrated measurements of neutron yield become available, it should be replaced by more detailed models of tokamak components and cables. Also, instead of the H*(10) dose, which we have used because other neutron measurements were not available at the time, a much more appropriate quantity for model validation would be more physically direct based on reaction rates of reactions with well known cross-sections.20252025-09-14 08:15:04Magistrsko delo/naloga173228VisID: 153384COBISS_ID: 248473091sl