KSTAR Tokamak Neutronic Analysis

Summary form only given. KSTAR, which is to develop the construction techniques of a steady-state-capable advanced superconducting tokamak and to establish a scientific and technical basis for an attractive fusion reactor, is under construction in Korea. High-beta, beam-heated KSTAR deuterium plasmas should produce fusion neutrons. There are two competing D-D fusion reactions in a deuterium plasma, one ejects 2.45 MeV neutrons, and the other produces tritons which are confined in the plasma and undergo D-T reactions producing 14.1 MeV neutrons. The radioactivity evaluation, radiation protection and shielding, biological dose, nuclear heating of the cryogenically cooled magnets, and neutron activation of the surrounding materials would be investigated including skyshine effect. The expected amount of D-D neutrons yield per one year is 1.2times10²⁰ n/yr. All the neutron shielding, heating and activation calculations are based on these figure. The calculation was performed using MCNP4C2 with the KSTAR tokamak model that was constructed to include plasma facing component, vacuum vessel, coolant, PF and TF coil, coil casings, port and cryostat. However one top-half quadrant section of the KSTAR tokamak was selected for neutron flux calculation because it has complete up-down symmetry. It is reported that the neutron yield rate per a shot for 300 s pulse inside the PFCs is 2.5times10¹⁶ in tokamak. To carry out the neutron production isotopes from neutron reaction, the FISPACT was used. This calculation was performed for one million neutron particle histories