title: Radioactivity evaluation for the KSTAR tokamak.
abstract: The deuterium-deuterium (D-D) reaction in the KSTAR (Korea Superconducting Tokamak Advanced Research) tokamak generates neutrons with a peak yield of 2.5 x 10(16) s(-1) through a pulse operation of 300 s. Since the structure material of the tokamak is irradiated with neutrons, this environment will restrict work around and inside the tokamak from a radiation protection physics point of view after shutdown. Identification of neutron-produced radionuclides and evaluation of absorbed dose in the structure material are needed to develop a guiding principle for radiation protection. The activation level was evaluated by MCNP4C2 and an inventory code, FISPACT. The absorbed dose in the working area decreased by 4.26 x 10(-4) mrem h(-1) in the inner vessel 1.5 d after shutdown. Furthermore, tritium strongly contributes to the contamination in the graphite tile. The amount of tritium produced by neutrons was 3.03 x 10(6) Bq kg(-1) in the carbon graphite of a plasma-facing wall.
authors.affiliation: Pohang Accelerator Laboratory, POSTECH, Pohang 790-784, Korea.
authors.forename: Hyunduk
authors.initials: H
authors.lastname: Kim
authors.forename: Hee-Seock
authors.initials: HS
authors.lastname: Lee
authors.forename: Sukmo
authors.initials: S
authors.lastname: Hong
authors.forename: Minho
authors.initials: M
authors.lastname: Kim
authors.forename: Chinwha
authors.initials: C
authors.lastname: Chung
authors.forename: Changsuk
authors.initials: C
authors.lastname: Kim
mesh_terms: D003198:Computer Simulation; D003252:Construction Materials / Q000032:analysis*; D019544:Equipment Failure Analysis; D007723:Korea; D018499:Linear Energy Transfer; D008422:Materials Testing; D008962:Models, Theoretical; D009502:Neutrons; D010315:Particle Accelerators / Q000295:instrumentation*; D011829:Radiation Dosage; D011835:Radiation Protection / Q000379:methods*; D011874:Radiometry / Q000379:methods*