Hasil Pencarian  ::  Simpan CSV :: Kembali

"The early twenty-first century has witnessed a rising number of global crises. These include climate change, widening income inequality, military and nuclear tensions between the major powers, repeated outbreaks of global pandemics, and an ongoing democratic recession. In particular, the deepening democratic recession has afflicted ostensibly both mature and newer democracies – contradicting theories of political development. In many countries, the political alliance between ethno- and religious nationalists has reignited assaults against democratic institutions, processes, and norms. This comparative country-case study, principally of Malaysia and the United States of America (US), explores the alliance between ethno- and religious nationalists by examining the forces and factors that have contributed to this combustible dynamic within the context of unsettled national questions, contested constitutional orders, and foundational national visions. Also examined are the narratives of fear, victimhood and privilege that have galvanised religious and ‘sons of the soil’ ethno-nationalists in resisting the building of inclusive multiracial democracies."

"ABSTRAKStruktur pengungkung reaktor nuklir yang berfungsi sebagai proteksi terhadap aksi lingkungan serta penahan gaya gempa merupakan struktur utama dengan faktor keutamaan tinggi. Penelitian ini bertujuan untuk memastikan kemampuan serta daya tahan struktur pengungkung reaktor nuklir terhadap gempa serta memperkirakan dampak penyebaran kontaminasi radiasi ke lingkungan pasca-kecelakaan. Gempa Pariaman, Padang digunakan sebagai input gempa dengan diskalakan pada gempa rencana periode ulang 10.000 tahun.Hasil penelitian menunjukkan struktur reaktor merupakan struktur sangat kaku dengan drift sangat kecil. Kondisi inelastis struktur tertutup baru terjadi ketika ditingkatkan hingga 2 kali. Struktur tertutup serta struktur terbuka yang diperkuat dengan kolom mampu bertahan hingga 1,5 kali gempa rencana sebelum melampaui tegangan ijinnya. Alur paparan penyebaran kontaminasi dapat melalui tanah (Groundshine), atmosfer (Cloudshine), hirupan (inhalation), kontaminasi makanan (ingestion) hingga aliran air (Aquatic Pathway).

---

ABSTRACT

Nuclear reactor containment structure that serves as protection against environmental action and retaining the force of the earthquake is the main structure that highly safety factor. This study aims to ensure the capability and durability of a nuclear reactor containment structure against earthquakes and estimates the impact of the spread of radiation contamination into the environment. Earthquake Pariaman, Padang is used as input to the scaled earthquake with return period of 10,000 years.

The results showed the reactor structure is very rigid structure with very little drift. The inelastic behavior of enclosed structure occurs when earthquake increased by 2 times. Structures closed or open structures with columns can last up to 1.5 times before the earthquake exceeded the stress limit. Chronology of exposure spread of contamination can be Groundshine, atmosphere (Cloudshine), inhalation, contamination of food (ingestion), or to the flow of water (Aquatic Pathway)."

"This study proposes a method of optimizing the dry storage design for nuclear-spent fuel from the G.A. Siwabessy research reactor at National Nuclear Energy Agency of Indonesia (BATAN). After several years in a spent fuel pool storage (wet storage), nuclear spent fuel is often moved to dry storage. Some advantages of dry storage compared with wet storage are that there is no generation of liquid waste, no need for a complex and expensive purification system, less corrosion concerns and that dry storage is easier to transport if in the future the storage needs to be sent to the another repository or to the final disposal. In both wet and dry storage, the decay heat of spent fuel must be cooled to a safe temperature to prevent cracking of the spent fuel cladding from where hazardous radioactive nuclides could be released and harm humans and the environment. Three optimization scenarios including the thermal safety single-objective, the economic single-objective and the multi-objective optimizations are obtained. The optimum values of temperature and cost for three optimization scenarios are 317.8K (44.7°C) and 11638.1 US$ for the optimized single-objective thermal safety method, 337.1K (64.0°C) and 6345.2 US$ for the optimized single-objective cost method and 325.1K (52.0°C) and 8037.4 US$ for the optimized multi-objective method, respectively."

"An unmanned surface vehicle (USV) is operated on the water surface for specific purposes. USV can be used in waters that cannot be entered by crewed boats, such as environments with high levels of threat or that are contaminated by nuclear, biological, or chemical waste. USVs can also be used for surveys in shallow waters, escorting military weapons, collecting environmental data, and coordinating with other underwater vehicles such as automated underwater vehicles. This study designs and develops simple USV rockets for maneuvering on the water surface. First, a simple USV system is designed. Next, mechanical and electronic components are selected, and the control program is implemented using the Arduino Mega 2560 microcontroller. Finally, the USV motion kinematics are analyzed, rocket thrust force is tested, and torque generated by the electric ducted fan (EDF) motor is measured. Ultimately, a rocket system with weight of 3920 g and length, width, and height of 720 mm, 500 mm, and 420 mm, respectively, is developed. The USV rocket is driven by an EDF motor with voltage and current of 1600 kV and 160 A, respectively, an electronic speed control, 6X Turnigy FHSS remote control, and two 18.5 V Li-Po 5500 mAh batteries as a power source. The USV has a maximum thrust of 40.7 N with torque of 1.41 Nm. Kinematics parameters such as angular acceleration and linear acceleration were also determined."

"The nuclear reactor is a source of primary radiation. Safety in the operation of thereactor protection system is implemented by the scram action. However scramwhich often happened is the failure of the operation and poses other risks. Thepurpose of this study is to determine the trigger and the reasons for scram withanalytic descriptive method through interviews, observation and documentreview, combined with the preparation of fault tree analysis. The obtained resultsshow that trigger of scram are, the neutron flux density is too high, too fastoperation period, unbalanced load, and the occurrence of positive transientreactivity. While the basic causes of the scram incident are, too fast control rod,irradiation sample composition, corrosion, weakening of the power supplydetector, emptying of the beam tube, and unbalanced neutron flux. Then scram asanticipation of the accident is also the feedback of operating experience forupdating on safety assessment so that failure of the operation can be minimized.Keywords The safe operation of nuclear reactor, reactor protection system, cause of theincident, suddenly shutdown of reactor.

---

Reaktor nuklir merupakan sumber radiasi primer. Keselamatan dalampengoperasian reaktor diterapkan oleh sistem proteksi dengan tindakan scram.Namun scram yang sering terjadi merupakan kegagalan operasi dan menimbulkanrisiko lain. Tujuan dari penelitian ini adalah untuk mengetahui pemicu danpenyebab dasar terjadinya scram dengan metode deskriptif analitik melaluiwawancara, observasi, dan telaah dokumen yang dipadukan dengan penyusunanfault tree analysis. Maka diperoleh hasil bahwa pemicu timbulnya scram, yaitukerapatan fluks neutron terlalu tinggi, periode pengoperasian terlalu cepat,pembebanan atau daya di teras tidak merata, dan terjadinya transien reaktivitaspositif. Sedangkan penyebab dasar kejadian scram, yaitu kenaikan batang kendaliterlalu cepat, kesalahan komposisi sampel iradiasi, korosi, pelemahan catu dayadetektor, pengosongan tabung berkas, dan fluks neutron tidak merata. Maka scramsebagai antisipasi kecelakaan juga menjadi umpan balik pengalaman operasiuntuk rekomendasi pemutakhiran penilaian keselamatan sehingga kegagalanoperasi dapat diminimalisir.Kata kunci:Keselamatan operasi reaktor nuklir, Sistem proteksi reaktor, Penyebab kejadian,Scram reaktor."