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[en] In support of closing the nuclear fuel cycle using non-aqueous separations technology, this project aims to develop computational models of electrorefiners based on fundamental chemical and physical processes. Spent driver fuel from Experimental Breeder Reactor-II (EBR-II) is currently being electrorefined in the Fuel Conditioning Facility (FCF) at Idaho National Laboratory (INL). And Korea Atomic Energy Research Institute (KAERI) is developing electrorefining technology for future application to spent fuel treatment and management in the Republic of Korea (ROK). Electrorefining is a critical component of pyroprocessing, a non-aqueous chemical process which separates spent fuel into four streams: (1) uranium metal, (2) U/TRU metal, (3) metallic high-level waste containing cladding hulls and noble metal fission products, and (4) ceramic high-level waste containing sodium and active metal fission products. Having rigorous yet flexible electrorefiner models will facilitate process optimization and assist in trouble-shooting as necessary. To attain such models, INL/UI has focused on approaches to develop a computationally-light and portable two-dimensional (2D) model, while KAERI/SNU has investigated approaches to develop a computationally intensive three-dimensional (3D) model for detailed and fine-tuned simulation.
[en] With thermodynamic spinel models, the cation distribution and free energy change dependent on temperature was calculated. For the spinel containing Co, Zn, Fe or Ni at 250 .deg. C, the calculated results showed the composition of Co0.15Fe0.85[Co0.85Fe1.15]O4, and Zn0.75Fe0.25[Zn0.25Fe1.75]O4. FeFe2O4 or NiFe2O4 was shown to have almost complete inverse spinel composition. The mixing of Fe-contained ferrite and Co-contained one gave the composition of Fe2+0.479Co2+0.00075Fe3+0.520[Fe2+0.021Co2+0.499Fe3+1.479]O4 at 250 .deg. C. Ni0.75Fe2.25O4 was synthesized by co-precipitation and identified with XRD, SEM, XPS and EDX. When potassium carbonate and secondary distilled water were used as solution pH controlling agent and co-precipitate washing agent, respectively, the final composition ratio of Ni and Fe in the ferrite appeared to be almost identical to the initial one. These results would be based on modelling of mixed spinel chemistry, deduction of calculation equations and synthesis of 3-component spinels
[en] We investigate the high temperature thermodynamical chemistry behaviors of the spinel compounds concerning the radiation field formation. The characteristics of cation distribution in the spinel lattice was estimated by thermodynamic calculation. The non-stoichiometry and the change of free energy of single and mixed spinel compounds containing Fe2+, Ni2+, Co2+ and Zn2+ were calculated and evaluated. It appeared that the ferrites containing iron, nickel or cobalt had inverse spinel structures, while that containing zinc had a normal spinel structure. Each calculated value of the chemical compositions, x and y, in a binary or ternary mixed spinel system, A2+xB2+yFe3+1-x-y(A2+k-xB2+1-k-yFe3+1+x+y)O2= (the k is initial mole fraction), in which A or B is Fe2+, Ni2+, Co2+ or Zn2+, was shown to be compound-dependent. The whole free energy changes of site transfer and formation appeared to be thermodynamically well mixed when k was 0.5 and when the temperature was higher. In addition, Nickel ferrite was synthesized by co-precipitation method and identified, and a chemical system for solution pH controlling and co-precipitate washing were selected
[en] The buildup rate of tritium in heavy water moderator and coolant of pressurized heavy water reactors in Wolsong Nuclear Power Plant is about 4MCi/a. The control of tritium is of increasing concern to the power reactor industry and general public in Korea. The properties of the metal/hydrogen isotope system such as the total storage capacity, the equilibrium pressure isotherms, and the influence of impurity helium on the kinetics of hydrogen isotopes, etc. were studied. The most prominent safety related aspects associated with the safe storage, analysis and recombination reaction of hydrogen isotopes were also studied
[en] This study conducted 'R and D Planning' for the projects which will be partially terminated at 2004. In each field, there are three projects in reactor and nuclear fuel field, seven in nuclear safety field and two projects in RI production and radiation application field. The followings are the detailed contents for each project. Research of present states of WIN web site world-widely, Introduction of activity of women in nuclear working in our country through web site of WIN-Global, Acquisition of information materials through active participation in WIN-Global association(10th WIN-Global Annual Meeting), Construction of database of women in nuclear and technical exchange infra in nation
[en] The Periodic Safety Review(PSR) of the existing nuclear power plants is required every ten years according to the recently revised atomic energy acts. The PSR of Kori unit 1 and Wolsong unit 1 that have been operating more than ten years is ongoing to comply the regulations. This research project started to develop the techniques necessary for the PSR. The project developed the following four techniques at the first stage for the environmental assessment of the existing plants. 1) Establishment of the assessment technology for contamination and accumulation trends of radionuclides, 2) alarm point setting of environmental radiation monitoring system, 3) Development of Radiation Safety Evaluation Factor for Korean NPP, and 4) the evaluation of radiation monitoring system performance and set-up of alarm/warn set point. A dynamic compartment model to derive a relationship between the release rates of gas phase radionuclides and the concentrations in the environmental samples. The model was validated by comparing the result with the samples. The results of the research will be used in the Periodic Safety Review of the nuclear power plants in operation
[en] International collaboration with WIN-Global. 1) Evaluation on current status for the foundation of WIN-Korea and investigation on the 1st to 8th WIN-Global conferences for the arrangement of 9th WIN-Global conferences 2) Manifestation on the roles of WIN-Korea and WIN-Global 3) Encouragement of active participation for WIN-Global activies -Establishment of internet net working for effective communication through the internet net working between women in science in Korea and other foreign countries. 1) Preparation and Organization of Women in Korea 2) Foundation of WIN-Korea Home Page in Net 3) Assembly of data for the net work construction in Korea - Enhancement of international cooperation between WIN-Korea and WIN-Global 1) Invitation of 9th WIN-Global Conference in Seoul, Korea 2) Enrollment of one of the Executives and Strengthening the activity of WIN-Korea as member of Board members 3) Characterization on main movements of WIN-Global through the active participation in international activities. - Arrangement for the 9th WIN-Global conference 1) Opperation of Organizing Committee and Supporting Committee and Secretariat 2) Supporting the 9th WIN-Global Confernce
[en] The detailed designs and development of components of NBI, RF, ECH, and LHCD heating and current drive system have been performed. The prototype ion source for the KSTAR NBI system and the beam line components such as calorimeter, neutralizer, bending magnet, and ion dump had been developed. The power supplies for the stable beam of 120 kV and 65 A including acceleration power supply, deceleration power supply, arc power supply, and filament power supply have been developed. Finally a KSATR NB test facility has been completed at KAERI to test and upgrade the ion source and the beam line components. The RF system is under development. Antenna has been fabricated and tested. Transmission components (vacuum feedthrough, impedance matching and water-cooled transmission line) for transmitting MW level of power have been developed. For transmitter, we optimized performance of 100kW transmitter and completed the fabrication of 300 kW transmitter. We will finalize the procurement specification of 2 MW transmitter system in the third phase. The detailed design of a 500 kW, 84 GHz ECH system has been completed. The gyrotron has been fabricated and successfully tested at Communications and Power Industries(CPI), USA. It is delivered to POSTECH, and under short pulse conditioning test with a pulse modulator operated at 20 μs with 60 Hz repetition rate and a acceleration power supply (APS). The ECH transmission line components are being purchased from General Atomics (GA), USA. The LH frequency of the 2.0 MW LHCD system is chosen to 5.0 GHz for extending the density limit condition. The LHCD system is under design process. The basic design of the 5.0 GHz LHCD launcher (coupler) has been finished using the HFSS and ANSYS programs.
[en] In an experiment on TiO2 photo-catalysis of five nitrogen-containing organic compounds, the changes of pH and total carbon contents were measured, and the dependence of their photo-catalytic characteristic upon their chemical structures were investigated. -- calculation of the effect of ionic carbon species in an aqueous solution on thermodynamic equilibrium, pH and conductivity showed a small quantity of organics could lead conductivity increase and pH reduction. -- Based on the results of photo-catalytic experiment of ethylamine, phenylhydrazine, pyridine, urea or EDTA, irradiated for 180 minutes after adsorption onto titanium dioxide for 60 minutes, relationship between nitrogen atomic charge and the first-order rate constant was as the following: R (1st - order rate constant) = δ (ε - a )1/3 + b where, ε : atomic charge of nitrogen in a molecular, δ, a and b : corrective coefficients
[en] The ZrCo getter beds are built of a primary vessel which contains the ZrCo powder and of a secondary outer vessel. The purpose of the secondary outer vessel is to capture permeated or leaked tritium and to present a good thermal insulation when properly evacuated. A third volume, a helium filled loop, is installed in the primary volume to remove the decay heat and is used to perform tritium accountancy measurements. In this report the authors verified that ZrCo can be used safely under a low pressure and temperature