[en] The proceeding contains papers presented in the Fifth Scientific Presentation on Nuclear Fuel Element Cycle with theme of Development of Nuclear Fuel Cycle Technology in Third Millennium, held on 22 February in Jakarta, Indonesia. These papers were divided by three groups that are technology of exploration, processing, purification and analysis of nuclear materials; technology of nuclear fuel elements and structures; and technology of waste management, safety and management of nuclear fuel cycle. There are 35 papers indexed individually. (id)

[en] Analysis of B, Cd, Si and Cr elements in zirconium oxide was carried out. Zirconium oxide was made by precipitating zirconium solution with oxalic acid and calcination was at temperature 900^oC for four hours. Silver chloride compound as much as 10% was used as a distillation carrier and 7 step filtration was used to reduce the impurities element spectra having high density. It was found that B concentration is between 3.80 and 7.44 ppm, Cd less then 0.5 ppm, Si between 74.38-150.33 ppm and Cr between 19.90-45.76 ppm. (author)

[en] Destructive testing of nuclear fuel element during post irradiation examination in radio metallurgy installation may cause air contamination in the working area in the form of radioactive aerosol. Inhalation of the radioactive aerosol by worker will to become internal radiation source. Potential hazard of radioactive particle in the body also depends on the particle size. Analysis of internal radiation source and radiotoxicity showed that in the normal operation only natural radioactive materials are found with high radiotoxicity, i.e. Pb-212 and Ac-228. High deposit in the alveolar instersial (Ai) is 95 % and lower in the bronchial area (BB) is 1 % for particle size 11.7 nm and 350 nm respectively. (author)

[en] The investigation was based on Systematic Prospection (1996,1997) at Mentawa River and Ampola up stream which were found radiometry anomalous about 750-15.000 c/s on the metasilt outcrop. Form of uranium mineralization is uraninite which associate with tourmaline, quartz, and sulphide and fills WNW-ESE fracture. The aims of investigation were to know uranium mineralization in sub surface by radon gas measurement, surface radiometry, and topographical mapping. (author)

[en] Uranium contained in liquid waste has to be determined for nuclear material accounting purpose. The uranium content in the waste was determined by comparing it with standard samples which were prepared through extraction with TBP-Kerosene. Uranium determination was also done by addition standard method. The detection limit of fluorimetric method is in the interval of 0.01 to 5 ppm. Results of the two methods are close in accuracy i.e. 0.66 ppm and 0.64 ppm for tank-2752 and, 1.03 and 0.93 for tank-2753, respectively. (author)

[en] Chemical analyses on fuel element characterization is started from dissolution process. The chemical analysis for the characterization of fuel element is introduced by dissolution of object analysis. Dissolution of fuel element of uranium silicide-aluminum dispersion was studied using concentrated HNO₃ with additive of Hg(NO₃)₂, NaOH solution with additive of H₂O₂ and mixed concentrated acid of HCI-HF. NaOH solution will dissolve the cladding material, and HNO₃-Hg(NO₃)₂ will dissolve uranium fuel particle. (author)

[en] Separation of Rare Earths from U and Th of Bangka monazite digestion solution, by using NaOH reagent and precipitation system has been carried out. The aim of the experiment is to find a condition of RE(OH) sub.3 precipitation to produce maximal RE recovery and high purity of RE that are free from radioelements U and Th. Parameters studied were pH, NaOH normality and precipitation time. The optimal conditions obtained were pH 9.8, 1N NaOH and 3 hours precipitation time. At this condition recovery of the RE(OH) sub.3 is 99.79 % and Th 4.52 %. However uranium and phosphate were not detected. Purity of the products are RE(OH) sub.3 98.868 %, Th(OH) sub.4 0.009 % and the others 1.123 %. (author)

[en] The development of new fuel is studied in order to search fuels which have high density and stability against irradiation and thermal influence. The study focuses on thermal and irradiation stability over analyses on the phase structure, the density, the thermal stability in the γ-phase of metastable U-Mo at various Mo composition, and thermal compatibility of U-Mo with the aluminium matrix. The study shows that the γ-phase of U-9 % Mo and U-10 % Mo is relatively stable, while that of U-2 % Mo and U-5 % Mo is relatively unstable, and tends to transform into an equilibrium state and dissolve into α+δ and α+γ phases. Good thermal compatibility is indicated by U-9 % Mo and U-10 % Mo. U-Mo density, on the other hand, decreases with increasing Mo content. (author)

[en] In order to design a nuclear reactor, there are many factors that must be considered, namely neutronic, mechanic, thermohydraulic, fuel management, etc. In this experiment the study was focussed on reactor core thermohydraulic aspects, especially the fuel surface and fluid temperatures. Modelling of hexagonal configuration of reactor core and reflector was carried out. Then, the power generations were assumed constant at 250 k watt and 375 k watt for each fuel element. Simulation data were obtained from the fuel surface and fluid distribution temperatures, especially in the middle, edge and corner sub-channels. This model was prepared and analyzed using Fluent Version 4.25 package program in the Thermodynamic Laboratory of PAU-ITB. The result shows that this reactor core model gives low fuel surface and fluid temperatures. (author)

[en] The flouride and chloride ions in uranium oxide powder should be determined since they influence the performance of fuel element during irradiation in the reactor. Determination of flouride and chloride ion content had been done by selective ion electrode Potentiometry method from uranium oxide after separation from U using method pyrohydrolitic. The experiment showed that the maximum efficiencies of the pyrohydrolitic separation of flouride and chloride ions is 93.78±5.51 % and 95.71±3.08 %, with minimum detection of 0.019 ppm and 1.775 ppm respectively. Uranium matrix as much as 250 ppm showed significant influence on the measurement. (author)