Badan Tenaga Nuklir Nasional: Jurnal BATAN
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EFFECTS OF FUEL DENSITY ON REACTIVITY COEFFICIENTS AND KINETIC PARAMETERS OF PEBBLE BED REACTOR
Full text linkEFFECTS OF FUEL DENSITY ON REACTIVITY COEFFICIENTS AND KINETIC PARAMETERS OF PEBBLE BED REACTOR. Few decades ago a large number of nuclear reactors were designed to use HEU as the fuel. But the use of HEU is being discouraged since it can be used as a nuclear explosive material which makes its proliferation potential. Most of the HEU-fueled nuclear reactors in the world are either closed or converted into other types that have LEU fuel with 235U enrichment below 20%. To extend lifetime, LEU fuel with high density is developed. The change in fuel density from low to high will also change core neutronics and thermal-hydraulics of the reactor, and as a result, it affects the transient response of the reactor. This paper studies the effects of fuel density on reactivity coefficients and kinetic parameters of pebble bed reactor through several calculations with MCNP6 code combine with ENDF/B-VII.1 continuous energy cross-section nuclear data library. The overall calculation results show that the Doppler temperature coefficient (DTC) increases with increasing fuel density, but the moderator temperature coefficient (MTC) decreases due to hardening of neutron spectrum. Kinetic parameters such as effective delayed neutron fraction (βeff), prompt neutron lifetime(ℓ) and neutron generation time (Ʌ) which significantly reduced with increasing fuel density will strongly affect the reactor control and safety. The results of this work conclude that the selection of 9–15 g/cm3 fuel density should be considered carefully given that its effect on reactor controllability.Keywords: Fuel density, reactivity coefficients, kinetic parameters, MCNP6, ENDF/B-VII.1
STUDY OF FISSION GAS BUBBLES AND INTERACTION LAYER ON IRRADIATED U3Si2-Al DENSITY OF 4.8 gU/cm3
Full text linkSTUDY OF FISSION GAS BUBBLES AND INTERACTION LAYER ON IRRADIATED U3Si2-Al DENSITY OF 4.8 gU/cm3. Uranium-silicide compound fuel dispersed in aluminium matrix (U3Si2-Al) have been used in a large number of research reactors around the world because of its excellent behavior under irradiation. This fuel also provides high uranium density with typical fuel loading up to 4.8 gU/cm3 to compensate for the reduced fissile amount in LEU. To improve the density of current U3Si2-Al (2.96 gU/cm3) used in Indonesian GA Siwabessy Multipurpose Research Reactor, U3Si2-Al dispersion fuel plate with density of 4.8 gU/cm3 (U235 ∼19.75%) had been irradiated in RSG GAS for 175 days at 15 MW power to burnup level of approximately 40%. The characterization was performed using SEM-EDS and optical microscope to study microstructure of the irradiatted fuel, largely the fission gas bubbles and the interaction layer between U3Si2 fuel and Al matrix. The average diameter of the bubbles with diameter from 0.06 to 0.55 µm was 0.21 µm. The interaction layer was identified as U(Al,Si)2,3 with thickness of approximately 1.5 µm. The relatively small fission gas bubbles and the interaction layer didn’t cause swelling on the fuel and the overall performance of the fuel plate was very good.Keyword: LEU, uranium-silicide, post-irradiation examination, interaction layer, fission gas bubbles
Geostatistical Ore Body Modeling on Uranium Mineralization in Remaja Sector, Kalan Area, West Kalimantan
Full text linkManual ore body modeling on Remaja Sector, Kalan, West Kalimantan generally takes a long time and is subjective. On the other hand, automatic modeling (implicit modeling) is faster, objective, and equipped with uncertainty factors. This study aimed to analyze the comparison between the geostatistical Sequential Indicator Simulation (SIS) ore body model to the manual ore body model. The lithology database was used as input for variogram analysis and SIS simulation. The directional variogram was used to construct an experimental variogram for the lithology with orientation data. The orientation of the lithologies corresponds to the anisotropy of their variogram map. The SIS was carried out in Block A and Block B with block sizes of 6×6×6 m3 and 5×5×5 m3 respectively. The simulation results were processed to produce a lithology probability model. By using maximum probability as block lithology, simulation results were well validated by the composite database histogram, the lithologies along the tunnel on the geological map of level 450 masl of Eko Remaja Tunnel., and the lithologies along boreholes. The weakness of the geostatistical ore body model was the results depending on the input parameters. Meanwhile, several advantages of the geostatistical ore body model were a faster processing process, equipped with an uncertainty factor, and the block size of the model has taken into account the distance between grade data so that it can be used directly for grade estimation. Quantitatively, the geostatistical ore body model had a higher average percentage of conformity to the lithology of the mineralized zone along the borehole than the manual ore body model.Manual ore body modeling on Remaja Sector, Kalan, West Kalimantan generally takes a long time and is subjective. On the other hand, automatic modeling (implicit modeling) is faster, objective, and equipped with uncertainty factors. This study aimed to analyze the comparison between the geostatistical Sequential Indicator Simulation (SIS) ore body model to the manual ore body model. The lithology database was used as input for variogram analysis and SIS simulation. The directional variogram was used to construct an experimental variogram for the lithology with orientation data. The orientation of the lithologies corresponds to the anisotropy of their variogram map. The SIS was carried out in Block A and Block B with block sizes of 6×6×6 m3 and 5×5×5 m3 respectively. The simulation results were processed to produce a lithology probability model. By using maximum probability as block lithology, simulation results were well validated by the composite database histogram, the lithologies along the tunnel on the geological map of level 450 masl of Eko Remaja Tunnel., and the lithologies along boreholes. The weakness of the geostatistical ore body model was the results depending on the input parameters. Meanwhile, several advantages of the geostatistical ore body model were a faster processing process, equipped with an uncertainty factor, and the block size of the model has taken into account the distance between grade data so that it can be used directly for grade estimation. Quantitatively, the geostatistical ore body model had a higher average percentage of conformity to the lithology of the mineralized zone along the borehole than the manual ore body model
Ore Mineralization Characteristics in Hydrothermal Alteration at Mangunharjo and Surrounding Areas, Pacitan, Indonesia
Full text linkThe research area is located in Mangunharjo-Grindulu, Pacitan (Indonesia), as part of the Southern Mountain Tertiary Volcanic Arch. Outcrops of quartz veins-riched volcanic rock associated with sulfide minerals are found in this area. The Southern Mountain Oligo-Miocene magmatic arc is known as the potential area that contains precious metal deposits. The study aimed to determine the characteristics of the mineralized zone in this area. The research methods are geological surface mapping, thin-section observation, mineragraphy, and X-Ray Diffraction (XRD). The results show that the constituent lithologies were andesitic lava, breccia, and tuff; co-ignimbrite breccia, dacitic pumice and tuff, and dacitic dike; and pyroxene-rich andesitic volcanic rocks. The geological structure is dominated by oblique normal faults, strike-slip faults, and upward oblique faults associated with shear joints filled with quartz veins. Fieldwork observation, thin-section analyses, and mineragraphic and XRD observations identify three alteration zones in the hydrothermal system: the advanced argillic zone, the intermediate argillic zone, and the chloritized zone. By the mineral’s association, it is interpreted that the advanced argillic zone was formed at a temperature of 220-330oC and pH 3-6 due to dissemination with side rocks located near the hydrothermal flows; the intermediate argillic zone and the chloritized zone were formed at a temperature of 150-300oC and a pH of 5-6 due to chloritized alteration of the hydrothermal fluid carrying the ore. This alteration zone has no economic potential for precious metal minerals so it is better to be developed for education, conservation, and natural laboratories.The research area is located in Mangunharjo-Grindulu, Pacitan (Indonesia), as part of the Southern Mountain Tertiary Volcanic Arch. Outcrops of quartz veins-riched volcanic rock associated with sulfide minerals are found in this area. The Southern Mountain Oligo-Miocene magmatic arc is known as the potential area that contains precious metal deposits. The study aimed to determine the characteristics of the mineralized zone in this area. The research methods are geological surface mapping, thin-section observation, mineragraphy, and X-Ray Diffraction (XRD). The results show that the constituent lithologies were andesitic lava, breccia, and tuff; co-ignimbrite breccia, dacitic pumice and tuff, and dacitic dike; and pyroxene-rich andesitic volcanic rocks. The geological structure is dominated by oblique normal faults, strike-slip faults, and upward oblique faults associated with shear joints filled with quartz veins. Fieldwork observation, thin-section analyses, and mineragraphic and XRD observations identify three alteration zones in the hydrothermal system: the advanced argillic zone, the intermediate argillic zone, and the chloritized zone. By the mineral’s association, it is interpreted that the advanced argillic zone was formed at a temperature of 220-330oC and pH 3-6 due to dissemination with side rocks located near the hydrothermal flows; the intermediate argillic zone and the chloritized zone were formed at a temperature of 150-300oC and a pH of 5-6 due to chloritized alteration of the hydrothermal fluid carrying the ore. This alteration zone has no economic potential for precious metal minerals so it is better to be developed for education, conservation, and natural laboratories
Influence of Applied Potential on The Structural and Optical Properties of Cu2O Thin Films Grown by Electrochemical Deposition
Full text linkCu2O thin films have been deposited on indium-tin-oxide (ITO) coated glass substrate by electrochemical method or electrodeposition. The effect of deposition potential on the microstructure and optical properties of Cu2O thin films was studied. Electrodeposition for two Cu2O thin films was carried out at –0.5V and –0.6V relative to the standard calomel electrode (SCE) as a reference electrode. Cu2O thin films were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), and UV-Visible spectroscopy. The diffraction pattern indicated the cubic structure of the Cu2O crystal has been well grown. The lattice parameters of Cu2O films slightly increased as the potential of electrodeposition increased. The crystallite size of Cu2O films significantly increased as the applied potential increased. Cu2O thin films showed a smooth and flat surface morphology based on SEM images. The optical transmittance of the Cu2O thin films drastically decreased as the applied potential increased due to the film thickness increasing. The bandgap energy of Cu2O films based on the Tauc plot increased as the applied potential increased, that is 2.0 eV for the film deposited at -0.5V and 2.13 eV deposited at -0.6V
MECHANICAL PROPERTIES OF PINEAPPLE LEAF FIBER/ EPOXY COMPOSITES WITH 0°/0°/0°/0° AND 0°/90°/0°/90° FIBER ORIENTATIONS
Full text linkMECHANICAL PROPERTIES OF PINEAPPLE LEAF FIBER/ EPOXY COMPOSITES WITH 0°/0°/0°/0° AND 0°/90°/0°/90° FIBER ORIENTATIONS. Pineapple leaf fiber can replace synthetic fiber because of its environmentally friendly and abundant availability in Indonesia. The purpose of this study was to obtain the mechanical properties of the pineapple leaf fiber/epoxy composite with 0°/0°/0°/0° and 0°/90°/0°/90° fiber orientations. Pineapple leaf fiber from Subang Indonesia was pre-treated through alkalization. The composites were fabricated by hand lay-up, followed by the vacuum bagging method. The results showed that the flexural properties of both composites were higher than the tensile properties of both composites. The flexural strength and modulus of 0°/0°/0°/0° composites were higher than those of 0°/90°/0°/90° composites, with the values of (109.57 ± 8.12) MPa and (7.08 ± 0.62) GPa respectively. Morphological observations using a Scanning Electron Microscope (SEM) showed that pineapple leaf fiber and epoxy had strong interfacial bonds and few voids. According to SNI 01-4449-2006 for fiberboard, pineapple leaf fiber/ epoxy composites with 0°/0°/0°/0° and 0°/90°/0°/90° fiber orientations were categorized as high-density fiberboard type T2 45, because both composites had a density higher than 0.84 g/cm3 and a flexural strength higher than 45 MPa
Sensing Properties of ZnO-SWCNT Hybrid Nanostructure Coated on Flexible Substrate for CO2 Gas Detection
Full text linkWe report sensing properties of functionalized single walled carbon nanotubes (f-SWCNTs) deposited on the flexible substrate of silicon (Si) and polyethylene tereptaphalate (PET). Deposition of f-SWCNT on Si rubber and PET surface was conducted by applying different manner of spray coating and dip coating techniques, respectively. Surface modification of f-SWCNT by ZnO nanostructure layer were applied by hydrothermal process.The research study were conducted to know the effect of substrate material and ZnO structure on the f-SWCNT surface which embedded in those flexible polymer substrates. The results reveal that f-SWCNT on Si substrate (f-SWCNT/Si) do not have a good response in gas sensing performance. In meanwhile f-SWCNT on PET substrates (f-SWCNT/PET) is more sensitive about 1.6% with 3s in response. ZnO structure layer modifying the surface structure of f-SWCNT enhance the sensitivity and responsiveness of the sensor with sensitivity of 4.1 % in 2s response after CO2 injection. Effect of bending treatment of the sensor and its stability were further investigated. Morphological surface of f-SWCNT network and crystal structure of ZnO and f-SWCNT were also observed by scanning electron microscope (SEM) and X-ray diffraction, respectivel
ESTIMATION OF NEUTRON AND PROMPT PHOTON DOSE RATE DISTRIBUTION IN TMSR-500 USING MCNP6
Full text linkThorium Molten Salt Reactor-500 (TMSR-500), one of the Generation IV nuclear reactors, is designed by Thorcon International, Pte. Ltd, which is projected to be built in Indonesia. The reactor core is radially surrounded by B4C shielding, but not the upper part. As the silo hall sits above the reactor core and is accessible by reactor personnel, the dose rate must be calculated in the area to ensure the workers receive an annual dose below the acceptable limit. The dose rate from neutrons and photons as the result of fission reactions are the only sources to be calculated in this research, without taking the source from fission products into account. This research aims to obtain the dose rate distribution of neutrons and prompt photons using Monte Carlo code MCNP6. The reactor was assumed to operate at a nominal thermal power of 557 MWth. Dose rate calculation was obtained from flux Tally F4 and converted into dose rate using Dose Energy Dose Function (DEDF) factor. Conversion factors of flux to the dose were based on ICRP-21 and ANSI/ANS-6.1.1 1977. The result of the calculations showed that the distribution of neutron and prompt photon fluxes does not reach the silo hall
ANALYSIS OF COGENERATION ENERGY CONVERSION SYSTEM DESIGN IN IPWR REACTOR
Full text linkThe acceleration of national development, especially in the industrial sector, requires an adequate national energy supply. There are various types of energy sources which include conventional energy sources as well as new and renewable energy sources including nuclear energy. The problem is how to utilize these energy sources into energy that is ready to be utilized. BATAN as a research and development institution in the nuclear field has taken the initiative to contribute to the development of technology for providing electricity and other thermal energy, particularly reactor technology as a power plant and a provider of thermal energy. This research aims to analyze the design of the IPWR type SMR reactor cogeneration energy conversion system. The IPWR reactor cogeneration energy conversion system which also functions as a reactor coolant is arranged in an indirect cycle configuration or Rankine cycle. Between the primary cooling system and the secondary cooling system is mediated by a heat exchanger which also functions as a steam generator. The analysis was carried out using ChemCAD computer software to study the temperature characteristics and performance parameters of the IPWR reactor cogeneration energy conversion system. The simulation results show that the temperature of saturated steam coming out of the steam generating unit is around 505.17 K. Saturated steam is obtained in the reactor power range between 40 MWth to 100 MWth. The results of the calculation of the energy utilization factor (EUF) show that the IPWR cogeneration configuration can increase the value of the energy utilization factor up to 91.20%