Measurement and evaluation of the irradiation test parameters for a specimen in a HANARO material irradiation capsule
A material capsule system has been developed for irradiation tests of nuclear materials in the core region of the High-flux Advanced Neutron Application Reactor (HANARO) and has been actively utilized for the various material irradiation tests requested by numerous users. For an irradiation test in the reactor, nuclear characteristics and irradiation temperature of the capsule parts are basically necessary for the safety analysis of the capsule and capsule detail design. The irradiation temperature and neutron fluence of the specimens are key parameters required by a user to analyze any neutron irradiation damage effects. Based on a basic design of a capsule, the reactivity effect, neutron flux/fluence, and gamma heating of specimens are calculated by the MCNP code. To compare the calculated neutron fluence of the specimens, thermal and fast fluence monitors (F/Ms) are installed in a capsule. After an irradiation, the F/Ms are dismantled and analyzed to obtain a neutron spectrum. The obtained fast neutrons (E>1.0MeV) by using the SANDII code are located within about a 20% error range of the theoretical values calculated by the MCNP code. The irradiation temperature of the specimens is analyzed preliminary by using the GENGTC or ANSYS codes based on the basic design of a capsule and gamma heating. During an irradiation test, the temperatures of the specimens in a capsule are measured and monitored by thermocouples. The DPA (Displacement Per Atom) and activation of the irradiated specimens are also evaluated by using the SPECTOR and ORIGEN2 codes, respectively, at HANARO.
Neutron Flux Characterization of Irradiation Holes for Irradiation Test at HANARO
The High flux Advanced Neutron Application ReactOr (HANARO) is a unique research reactor in the Republic of Korea, and has been used for irradiation testing since 1998. To conduct irradiation tests for nuclear materials, the irradiation holes of CT and OR5 have been used due to a high fast-neutron flux. Because the neutron flux must be accurately calculated to evaluate the neutron fluence of irradiated material, it was conducted using MCNP. The neutron flux was measured using fluence monitor wires to verify the calculated result. Some evaluations have been conducted, however, more than 20% errors have frequently occurred at the OR irradiation hole, while a good agreement between the calculated and measured data was shown at the CT irradiation hole.
Thermodynamics on the Carbochlorination of Titanium-bearing Ores
The equilibrium compositions of the multi-component, multi-phase and multi-reaction system of carbochlorination of titanium-bearing ores are calculated with HSC, a computational chemistry software. The thermodynamic equilibrium calculation of the reaction system shows that a complete conversion of titanium-bearing ores is feasible at a temperature near 200oC. At temperatures ranging from 800 to 1600oC, the products of the reaction system are all in gaseous phase. Thermodynamic analysis accords with the industrial practice. The simulated results provide reasonable scientific basis for improving suitable technological conditions of the carbochlorination reduction.