Analisis Desain Teras Gas-Cooled Fast Reactor (GFR) Berpendingin S-CO2 Berbahan Bakar Uranium Nitrit dengan Minor Aktinida

Telah dilakukan analisis desain teras Gas cooled Fast Reactor (GFR) berpendingin  S-CO2 berbahan bakar Uranium Nitrit dengan Minor Aktinida sehingga dapat beroperasi dalam waktu lama. Sistem suhu tinggi, keandalan spektrum cepat dan siklus bahan bakar tertutup GFR dapat meminimalkan limbah reaktor dengan penggunaan Uranium berkelanjutan dari minor aktinida. Karakteristik S-CO2 yang stabil, tidak mudah terbakar dan suhu puncak realtif rendah (~650oC) mampu mendinginkan teras reaktor.  Metode penyusunan bahan bakar menggunakan strategi burn-up Modified CANDLE. Strategi pembakaran MCANDLE dalam shuffling arah radial dengan dua skema pengisian bahan bakar, skema X (dari luar teras ke arah dalam) dan skema Y (dari pusat teras ke luar), telah diterapkan. Digunakan SRAC dan data JENDL-4.0 dalam perhitungan. Pada penelitian ini diperoleh studi parameter melalui perhitungan nilai faktor multiplikasi infinite, faktor multiplikasi efektif, reaktivitas dan distribusi daya. Hasil perhitungan menunjukkan nilai Keff sebelum penambahan Minor Aktinida untuk skema X dan Y adalah 1,0893 dan 1,0915. Setelah penambahan minor aktinida nilai Keff 1% - 7% pada skema X dan Y berada pada kondisi kritis dan setelah penambahan minor aktinida 4% - 7% reaktor berada pada kondisi superkritis. Reaktivitas reaktor pada skema X dan Y adalah 0,0939 dan 0,1089. Untuk distribusi daya arah aksial skema X dan Y 1,5285 dan 1,5323. Untuk distribusi daya arah radial pada skema X dan Y adalah 1,5862 dan 1,8320. Berdasarkan hasil tersebut penambahan minor aktinida dan skema penyusunan bahan bakar mempengaruhi kekritisan dan distribusi daya  teras GFR.

Desain Konseptual Teras Reaktor Cepat Berumur Panjang Berpendingin S-CO2 dengan Bahan Bakar Uranium Metalik Alam

Telah dibuat sebuah desain konsep teras reaktor cepat berpendingin S-CO2 dengan bahan bakar uranium metalik alam yang dapat beroperasi dalam waktu yang lama (berumur panjang). Metode penyusunan bahan bakar dilakukan menggunakan strategi burn-up modified CANDLE (Constant Axial shape of Neutron flux, nuclide densities and power shape During Life of Energy production). Strategi pembakaran CANDLE yang dimodifikasi dengan region pertama berada di dekat region terakhir telah diterapkan. Perhitungan teras reaktor dilakukan menggunakan modul CITATION pada sistem kode SRAC (Standard Reactor Analysis Code). Tahap awal penelitian dengan menghitung sel bahan bakar menggunakan modul PIJ sebagai input siklus telah dilakukan. Parameter perhitungan yang diamati adalah nilai faktor multiplikasi efektif (k-eff), distribusi daya arah aksial dan radial serta reaktivitas pada teras reaktor. Hasil perhitungan menunjukkan nilai k-eff dari awal siklus pembakaran sekitar 1,0490 hingga akhir siklus sebesar 1,0598. Distribusi daya arah aksial paling besar terjadi pada ketinggian teras 115 cm yaitu sebesar 1,9824 watt/cc. Sedangkan untuk distribusi daya arah radial paling besar terjadi di tengah teras yaitu sebesar 2,1697 watt/cc. Nilai  reaktivitas rata-rata selama waktu operasi sebesar 0,0562. Berdasarkan hasil tersebut, keadaan teras reaktor memenuhi syarat untuk beroperasi. The conceptual design of a fast reactor core has been made with S-CO2 as a coolant and natural metallic uranium as a fuel, which can operate for a long time (long-life reactor). The fuel preparation method uses a strategy of burn-up modified CANDLE (Constant Axial shape of Neutron flux, nuclide density, and power shape During Life of  Energy production). The modified CANDLE burning strategy with the first region near the last region has been implemented. The reactor core calculation is performed using the CITATION module on the SRAC (Standard Reactor Analysis Code) code system. The initial phase of research by counting fuel cells using the PIJ module as a cycle input has been carried out. The calculation parameters observed were effective multiplication factor (k-eff), axial and radial power distribution, and reactivity on the reactor core. The calculation results show the k-eff value from the burning of life (BOL) cycle around 1.0490 until the end of the cycle of 1.0598. The largest axial power distribution occurs at the reactor core height of 115 cm,  equal to 1.9824 watts/cc, whereas the largest radial power distribution occurs in the center of the core, which is equal to 2.1697 watts/cc. The average reactivity value during the operation time of around 0.0562. Based on these results, the reactor core condition qualifies for operation

ANALISIS NEUTRONIK KEKRITISAN TERAS REAKTOR NUSCALE BERBAHAN BAKAR DENGAN MENGGUNAKAN SOFTWARE OPENMC

[Title: Neutronic Analysis of the criticality level of the nuscale reactor core with  fuel using the  openMC software] This study analyzed the design of the NuScale reactor, which aims to determine the level of criticality by modeling the shape of the cell pin, assembly, and core with nuclear fuel in the form of uranium dioxide, which will be varied by changing the percentage of uranium-235 content as much as 0% to 7% by using monte carlo methods in OpenMC program code. This study was conducted to obtain the design of nuclear reactors as well as the calculation of the effective multiplication factor, fission reaction rate, and neutron flux distribution for two years of the combustion process (Burn-up). The result of the calculation for the effective multiplication factor and reaction rate states that the greater the percentage of enrichment in uranium-235, the greater the value of the resulting in both parameters. While the distribution of neutron flux produces the most significant value in the middle region or center of the fuel and is seen from the average value produced, and the smallest value is at the edge of the cell. The analysis of this NuScale reactor can later be used as a reference in preparing a safe and efficient reactor core. &nbsp

Studi Awal Pengaruh Kloroform Sebagai Pelarut Pada Proses Ekstraksi Molecularly Imprinted Polymer (MIP) Nano Kafein

Proses ekstraksi sangat penting dalam sintesis Molecularly Imprinted Polymer (MIP). Proses tersebut sangat menentukan jumlah kafein yang terbuang. Keberhasilan proses ini tidak hanya bergantung pada proses sintesis namun juga tergantung pada ukuran partikel templat dan pelarut yang digunakan saat proses tersebut. Sintesis polimer nano kafein telah berhasil dibuat menggunakan metode cooling-heating melibatkan MAA sebagai monomer fungsional, EDMA sebagai ikatan silang, BPO sebagai inisiator, dan kloroform sebagai pelarut. NIP juga dibuat sebagai polimer pembanding tanpa nano kafein. Serbuk nano polimer yang dihasilkan selanjutnya diekstraksi menggunakan kloroform, metanol/asam asetat (1:20), dan metanol. Terakhir polimer dicuci menggunakan metanol/aquabidest (1:20). Hasil FTIR menunjukkan adanya gugus fungsi amina yang merupakan gugus fungsi khas kafein. Nilai persentase transmitansi pada MIP nano kafein lebih besar dibandingkan polimer nano kafein. Hal ini menunjukkan bahwa proses ekstraksi templat nano kafein menggunakan larutan kloroform berhasil dilakukan. Hasil XRD menunjukkan MIP memiliki ukuran kristal yang lebih besar dibandingkan NIP. Ukuran kristal yang besar terlihat dari tingginya puncak intensitas yang dihasilkan

Design of Gas-Cooled Fast Reactor 600MWth with Natural Uranium As Fuel Circle Input

This article presents the conceptual design of gas-cooled fast reactor (helium), the small size of the long-lived 600 MWth. Early stages of the design is to determine the geometry of the terrace, the value of the volume fraction and the mass fraction of fuel, cladding and coolant structure to calculate the parameters of reactivity, burnup, power distribution and density changes nuclides U238 and Pu239. The calculation is done using SRAC-CITATION code. SRAC code with JENDL-3.2 Data nuclides produced macroscopic cross section values for the eight energy group. Multi-group numerical solution of diffusion equations for 2-D geometry terrace RZ performed by CITATION code. The study results showed that the scheme Modified CANDLE, thermal power output is 600 MWth, with a fuel cycle for 10 years. This reactor has the advantage of requiring only the input of natural uranium in the fuel cycle, without the need for enrichment processes that affect the economic value. Keywords : Reactor, natural uranium, modified candle, burnu

Analisis Distribusi Temperatur Media Penampung Bahan Bakar Bekas Reaktor Daya Eksperimental (RDE) Menggunakan FLUENT 6.3

ANALISIS DISTRIBUSI TEMPERATUR MEDIA PENAMPUNG BAHAN BAKAR BEKAS REAKTOR DAYA EKSPERIMENTAL (RDE) MENGGUNAKAN FLUENT 6.3. Konsep dan desain reaktor daya eksperimental (RDE) adalah mengacu pada HTGR (High Temperature Gas-cooled Reactor) dari teknologi Jerman yang telah diterapkan pada HTR-10 di Cina yang dirancang menggunakan bahan bakar yang berbentuk pebble bed. Setelah bahan bakar nuklir dimanfaatkan dalam reaktor nuklir, bahan bakar bekas  tersebut kemudian akan masuk ke dalam tempat penampungan sementara. Penelitian ini dikhususkan pada aspek temohidrolik karena peranannya yang sangat penting untuk menjamin keselamatan media penampung bahan bakar bekas Reaktor Daya Eksperimental (RDE). Oleh karena itu diperlukan alat bantu berupa progam (software) komputer dalam proses penganalisaan distribusi temperatur media penampung bahan bakar bekas Reaktor Daya Eksperimental (RDE). Program yang digunakan adalah FLUENT 6.3. Hasil perhitungan menunjukan bahwa terjadi penurunaan temperatur secara bertahap pada bahan bakar bekas  di setiap posisinya, dari titik pusat di posisi 0 m sebesar 110°C ke dinding media penampung di posisi 0,3 m sebesar 30°C. Sehingga dari hasil tersebut distribusi temperatur media penampung bahan bakar bekas reaktor daya eksperimental dapat dianggap aman tanpa kerusakan akibat dari pana

Molecular dynamics simulation of corrosion and its inhibition: comparison of structural stability of Fe/FeNi/FeNiCr/FeNiCrTi steels under high-temperature liquid lead

The liquid lead used in fast nuclear reactor has been known to be able to cause a significant damage to the steels. Therefore, finding new materials with high corrosion resistance is the goal of much research current days. Likewise, developing a way to prevent corrosion is also the goal of designers of nuclear reactors. In the present study, we studied materials: Fe, FeNi, FeNiCr, and FeNiCrTi (a type of SS 316L austenite steel), comparing their structural stability when interacted with molten liquid lead at 750 °C. The performance of each steel is compared under high-temperature molten lead coolant, checking the structure's stability to see the material resistance to corrosion attack of liquid lead. The corrosion can also be seen from the data of iron diffusion coefficient. The larger of the iron diffusion coefficient can be associated with larger corrosion because there is a high solubility of iron atoms from the steel surface to the molten lead. The popular way to prevent more corrosion is by injecting oxygen into the lead coolant. This current work uses the molecular dynamics method to simulate the corrosion and inhibition phenomena. The research aims to compare the performance of Fe, FeNi, FeNiCr, and FeNiCrTi under liquid lead at a temperature of 750. The diffusion coefficient of iron of material will be calculated to describe quantitatively the corrosion level of those structural materials and the corrosion inhibition by oxygen injection. The study has produced important results that adding Ni, Cr, Ti into a pure iron crystal to build alloy steel will make the material stronger, structurally compact, and more resistant to corrosion. For specific composition of steels, from weaker to stronger that resist from corrosion attack, it is possible to make ordering: Fe<<FeNi<FeNiCr<FeNiCrTi. The composition of FeNiCrTi steel in this work is Fe(75)Ni(10.57)Cr(14.05)Ti(0.40). The high corrosion of FeNiCrTi in the liquid lead is effectively reduced by injecting 0.0112 wt % oxygen into lead coolant as a limit value for maximum corrosion inhibitio

Analisis Gejala Chaos pada Dobel Pendulum

Telah dilakukan alanisis gejala chaos pada dobel pendulum. Analisis dilakukan dengan grafik times series, diagram ruang fasa dan plot Poincare. Diperoleh tiga karakteristik utama dinamika gerak: periodik, quasiperiodik dan chaos. Masing-masing keadaan dicapai bila dimasukkan kondisi awal posisi dan momentum yang bersesuaian

Kwant: a Python Package for Investigating Characteristics of Magnetic Graphene ?

Graphene is two-dimensional carbon atoms in the form of hexagonal lattice.It has extraordinary mechanical, optical, thermal and electronic properties. These properties have been predicted theoretically some decades before scientists succeeded for the first time in experimenting with the material in 2004. Since then, scientific publications on this 21st century material are increasing exponentially. Magnetism in pristine carbon materials is still in a controversy although magnetic properties of graphenedue to point defects have been investigated by some researchers. It would be interesting to calculate numerically the properties of this magnetic graphene using anopen source computer software. The purpose of this paper is to discuss applying Kwant, a free Python package, to study graphene using the interactive and open source web based environment Jupyter Notebook Apps. Hopefully, this will stimulate Indonesian academia to participate in graphene research by using the software