Badan Tenaga Nuklir Nasional: Jurnal BATAN
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AN IMPROVEMENT OF ARJUNA 1.0 CONVEYOR SYSTEM FOR 3D IRRADIATION
No full textAn improved design of the conveyor system of Arjuna 1.0 electron accelerator for 3D object irradiation has been done. The penetration of low energy electrons is less than 1 cm in the surface, causing a challenge for the irradiation process for sterilization of 3D objects. We design a conveyor that can be rotated 360o to irradiate objects evenly. The dimension of this conveyor is 1750 x 600 x 800 mm and the maximum diameter of the object is 7 cm. Based on the Frame Bending Stress analysis to calculate the strength of the conveyor frame, it is shown that the maximum displacement is only 0.029 mm, which is very small so it will cause no disturbance to power transfer from the motor to the conveyor. The normal stress (Smax) is 3.926 MPa and the bending stress for Smax (Mx) and Smax (My), are 2.391 MPa and 3.925 MPa respectively. We also calculate the stress analysis of the 3 mm-thickness of the motor mount and found that the Von-Misses Stress, first, and third Principal Stress are 4.425 MPa, 5.01 MPa, and 1.95 MPa respectively. These results confirm that the design and the material used for the conveyor are safe because the stress is very low than the material’s yield strength which is 207 MPa. The power needed for this conveyor is 0.01724 kW, with a maximum speed is 880 rpm. The new model of 3D conveyor has been constructed and can be implemented to ARJUNA 1.0 to irradiate objects on all its surface
ANALISIS PENGARUH GEOMETRI FUEL ASSEMBLY TERHADAP KRITIKALITAS DAN DISTRIBUSI FLUKS NEUTRON DALAM TERAS REAKTOR RSG-GAS MENGGUNAKAN OPENMC
Full text linkReaktor Serba Guna G. A. Siwabessy (RSG–GAS) termasuk ke dalam reaktor riset berjenis MTR memiliki elemen bakar berbentuk pelat lurus dengan berbahan bakar uranium silisida kerapatan 2,96 gU/cm3. Penelitian ini bertujuan untuk menganalisis pengaruh geometri elemen bakar model pelat lurus terhadap kritikalitas dan distribusi fluks neutron dalam teras reaktor RSG–GAS. Simulasi Monte Carlo dengan OpenMC dilakukan pada lima jenis elemen bakar, yaitu dari RSG–GAS, HANARO, WWR-SM, MARIA, dan BRR, dengan massa U235 250 gram per elemen bakar. Hasil penelitian menunjukkan bahwa bentuk geometri dari elemen bakar yang berbeda-beda mempengaruhi nilai kritikalitas dan distribusi fluks dalam satu teras yang sama. Nilai kritikalitas tertinggi didapatkan pada elemen bakar dari HANARO kemudian diikuti oleh RSG-GAS dan terendah didapatkan pada elemen bakar dari WWR-SM. Distribusi fluks pada elemen bakar dari MARIA dan BRR ini memiliki distribusi fluks yang lebih bagus
Radioactive Mineral Distribution on Tin Placer Deposits of Southeast Asia Tin Belt Granite in Bangka Island
Full text linkBangka Island is an area rich in primary and secondary tin deposits. Tin deposits are formed around the contact between granite and older rocks, while secondary tin deposits are formed in the modern channels and paleochannels. Many previous researchers have researched radioactive minerals in primary tin deposits and modern channel deposits, but research on radioactive minerals in paleo channel deposits has never been carried out. The characterization of radioactive minerals in paleo channel deposits was done in this study to determine the potency of radioactive minerals in secondary tin deposits by comparing the content of radioactive minerals in paleochannels with modern channels and tin mine tailing deposits. The data used were mineralogical data and radioactivity data, along with the uranium and thorium content of the rocks from several previous studies. Data showed significant mineral content differences in paleo channel, modern channel, and tin mine tailings deposits. Mineral (monazite and zircon) content in tin mine tailing deposits was the highest. Source rocks for the radioactive minerals monazite and zircon are predicted to be the granitic rocks or tourmaline quartz veins of primary tin deposits. The radioactivity value of rocks in the paleo channel is relatively the same as the modern channel, ranging from 20 to 150 c/s. Uranium content in paleo channel is the same as modern channel deposits, ranging from 10 to 15 ppm eU. The thorium content of the rocks in the paleo channel ranges from 1 to 60 ppm eTh, while in the modern channel, it ranges from 1 to 45 ppm eTh. The radioactivity value and uranium content of the rocks are less effective for determining potential areas of radioactive minerals in placer tin deposits. In contrast, data on thorium content are quite effective for determining potential areas of radioactive minerals in placer tin deposits
Computational Fluid Dynamics Simulation of Temperature Distribution and Flow Characterization in a New Loop Heat Pipe Model
Full text linkThe loop heat pipe (LHP) is considered for passive cooling systems in nuclear installations. A combined approach of simulation and experimentation is essential for achieving comprehensive knowledge of the LHP. Research on the LHP using Computational Fluid Dynamics (CFD) is necessary to understand phenomena that are challenging to ascertain experimentally. This study investigates the temperature distribution and flow characterization in a new LHP model. The method used in this research is simulation using CFD Ansys fluent software. In the simulation, the LHP has an inner diameter of 0.1016 m. This LHP features a wick made from a collection of capillary pipes without a compensation chamber. Demineralized water is used as the working fluid with a filling ratio of 100% of evaporator volume. The hot water temperature in the evaporator section is set at 70°C, 80°C, and 90°C. The temperature on the outer surface of the condenser pipe is determined using experimental temperature inputs. An inclination angle of 5° and an initial pressure of 12,100 Pa was applied to LHP. The CFD simulation results show that the temperature distribution profile under steady-state conditions in the loop heat pipe appears almost uniform. The temperature difference between the evaporator and condenser remains consistent. The flow of working fluid in the LHP is driven by buoyancy forces and fluid flow, allowing the working fluid in the LHP to flow in two phases from the evaporator to the condenser and then condensate from the condenser back to the evaporator. In conclusion, the temperature distribution and flow patterns in the LHP are consistent with common phenomena observed in heat pipes. This modeling can be used to determine the profiles of temperature distribution and flow in LHP of the same dimensions under various thermal conditions
Investigation of Natural Circulation Flow Under Steady-State Conditions Using a Rectangular Loop
Full text linkPassive safety systems have garnered significant attention, particularly in situations where active systems fail. The comprehension of natural circulation phenomena plays a vital role in the advancement of passive cooling systems in nuclear power plants. The objective of this study is to examine the flow patterns under steady state conditions and assess the Grashof number. The experimental approach involved maintaining temperature differences of 60°C, 70°C, 80°C, and 90°C for a duration of 3 hours, with 3 replications. Alterations in temperature have an impact on the physical properties of water, such as density, viscosity, and specific heat. The calculations indicate that the minimum Grashof number occurs at 60°C (2.49×1012), while the maximum is observed at 90°C (9.42×1012), with an R2 value of 0.96533. Turbulent flow patterns were observed during each temperature fluctuation, which aligns with previous research on the Ress value of Grm/NG
PERILAKU KOROSI BAJA KARBON RENDAH PIPA PENDINGIN SEKUNDER REAKTOR DALAM INHIBITOR ZINK FOSFAT
Full text linkBaja karbon, dalam industri nuklir, salah satunya digunakan sebagai bahan struktur pipa pendingin sistem pengoperasian reaktor nuklir. Dalam pemakaiannya, pipa tersebut rentan terhadap korosi karena kontak dengan air pendingin. Inhibitor larutan zink fosfat yang berasal dari campuran zink klorida dan asam fosfat dengan variasi konsentrasi 25, 35, 50, 75 dan 100 ppm dalam NaCl 0,1% digunakan sebagai bahan untuk mempelajari pengaruh laju korosi baja karbon. Metode elektrokimia sangat membantu untuk mengamati perilaku korosi baja karbon dalam media zink fosfat. Metode yang dilakukan meliputi Open Circuit Potensial (OCP) selama 600 detik, Electrochemical Impedance Spectroscopy (EIS) pada rentang frekuensi 105 Hz sampai dengan 0,01 Hz dan Potensiodynamic Plot (PDP) pada rentang tegangan -1 Volt sampai dengan 1 Volt menggunakan potensiostat. Untuk menunjang hasil uji korosi, dilakukan pengamatan morfologi menggunakan SEM, komposisi kimia menggunakan XRF dan C/S Analyzer dan kandungan larutan zink fosfat menggunakan AAS, UV-Vis dan FTIR. Hasil yang diperoleh menunjukkan bahwa pada konsentrasi 35 ppm, laju korosi memberikan nilai yang lebih rendah dibanding pada konsentrasi lain. Laju korosi tersebut sebesar 11,7 mpy
Evaluation of Pixelated Plastic Scintillators Coupled to Multi-Channel Silicon Photomultipliers for Beta-Ray Detection and Source Localization
Full text linkThis paper presents a novel detector design for radiation detection technology, based on pixelated plastic scintillators coupled to multi-channel silicon photomultipliers (SiPMs). This detector combines the efficiency of plastic scintillators with the sensitivity and versatility of SiPMs, Overcoming the limitations of traditional photomultiplier tubes in terms of durability, power consumption, and sensitivity. The compact and modular nature of the detector makes it suitable for diverse environments and applications, such as portable radiation monitoring devices or integration into existing experimental setups. The performance of the detector was evaluated using beta-ray sources of 36Cl and 90Sr, and it was demonstrated that the detector can detect and localize the point source with high accuracy and resolution
Analisis Tingkat Absorbsi Berkas Sinar-X Pada Sintesis Komposit Kaktus (Opuntia Spp.) dan Timbal (II) Asetat (Pb(CH3COO)2) Sebagai Material Apron
Full text linkApron proteksi radiasi efektif dalam mengurangi paparan laju dosis radiasi sinar-X, namun sebagai baju pelindung radiasi masih memiliki kelemahan, diantaranya relatif berat (5 - 7 kg) sehingga akan berdampak buruk pada sistem musculoskeletal tubuh terutama pada posisi tulang belakang. Tujuan penelitian untuk memperoleh sintesis komposit material apron proteksi radiasi yang dapat menyerap radiasi sinar-X secara optimal dan nyaman digunakan. Penelitian ini menggunakan bahan serat kaktus Opuntia ficus-indica ukuran 80 mesh, disintesis dengan timbal (II) asetat sebagai bahan pengisi dengan variasi 20, 33, 50, 67, dan 80% sehingga diperoleh tebal komposit berkisar 0,36 - 0,74 cm. Pengujian menggunakan rontgen radiografi umum dan alat ukur radiasi Unfors RaySafe XI dengan energi 80 kVp, arus 50 mA, serta jarak antara tabung sinar-X dengan detektor sejauh 100 cm. Hasil penelitian menunjukkan bahwa makin banyak komposisi serat kaktus pada sampel, makin kecil nilai koefisien atenuasi yang diperoleh. Koefisien atenuasi maksimum adalah 3,85 cm-1 diperoleh pada variasi timbal (II) asetat 80% dengan tebal 0,41 cm dan berat RAR 84%. Pada variasi 80% tersebut diperoleh densitas paling optimal, koefisien atenuasi, dan RAR paling tinggi, serta HVL paling rendah.ANALISIS TINGKAT ABSORBSI BERKAS SINAR-X PADA SINTESIS KOMPOSIT KAKTUS (OPUNTIA SPP.) DAN TIMBAL (II) ASETAT (PB(CH3COO)2) SEBAGAI MATERIAL APRON. Apron proteksi radiasi efektif dalam mengurangi paparan laju dosis radiasi sinar-X, namun sebagai baju pelindung radiasi masih memiliki kelemahan, diantaranya relatif berat (5 - 7 kg) sehingga akan berdampak buruk pada sistem musculoskeletal tubuh terutama pada posisi tulang belakang. Tujuan penelitian untuk memperoleh sintesis komposit material apron proteksi radiasi yang dapat menyerap radiasi sinar-X secara optimal dan nyaman digunakan. Penelitian ini menggunakan bahan serat kaktus Opuntia Ficus Indica ukuran 80 mesh, disintesis dengan timbal (II) asetat sebagai bahan pengisi dengan variasi 20, 33, 50, 67, dan 80% sehingga diperoleh tebal komposit berkisar 0,36 - 0,74 cm. Pengujian menggunakan rontgen radiografi umum dan alat ukur radiasi Unfors RaySafe XI dengan energi 80 kVp, arus 50 mA, serta jarak antara tabung sinar-X dengan detektor sejauh 100 cm. Hasil penelitian menunjukkan bahwa makin banyak komposisi serat kaktus pada sampel, makin kecil nilai koefisien atenuasi yang diperoleh. Koefisien atenuasi maksimum adalah 3,85 cm-1 diperoleh pada variasi timbal (II) asetat 80% dengan tebal 0,41 cm dan berat RAR 84%. Pada variasi 80% tersebut diperoleh densitas paling optimal, koefisien atenuasi, dan RAR paling tinggi, serta HVL paling renda