The research aims to measure the radiation dose rate over the radiation shielding which is made of paraffin and aluminium and to determine the best shield material for the safety of radiation workers. The examination used MCNP (Monte Carlo N-Particle) simulator to model the BNCT neutron source and the shield. The shield should reduce radiation to less than the dose limit of 10.42 µSv/h, which is assumed to be the most conservative limit when the duration of workers is 1920 h. The first design resulted in a radiation dose rate which was still greater than the limit. Therefore, optimization was done by adding the lead on the outer part of the shield. After optimization by adding the lead with certain layers, the radiation dose rate decreased, with the largest dose being 57.60 µSv/h. Some locations over the limit could be overcome by other radiation protection aspects such as distance and time. The paraffin blocks were covered by aluminium to keep the shield structure. The lead was used to absorb the gamma ray which resulted from the interaction between the neutrons and aluminium.

Cancer is a malignant tumor that destroys healthy cells. Cancer treatment can be done by several methods, one of which is BNCT. BNCT uses 10B target which is injected into the human body, then it is irradiated with thermal or epithermal neutrons. Nuclear reaction will occur between boron and neutrons, producing alpha particle and lithium-7. The dose is estimated by how much boron and neutron should be given to the patient as a sum of number of boron, number of neutrons, number of protons, and number of gamma in the reaction of the boron and neutron. To calculate the dose, the authors simulated the reaction with Monte Carlo N Particle-X computer code. A water phantom was used to represent the human torso, as 75% of human body consists of water. Geometry designed in MCNPX is in cubic form containing water and a cancer cell with a radius of 2 cm. Neutron irradiation is simulated as originated from Kartini research reactor, modeled in cylindrical form to represent its aperture. The resulting total dose rate needed to destroy the cancer cell in GTV is 2.0814×1014 Gy.s (76,38%) with an irradiation time of 1,4414×10-13 s. In PTV the dose is 5.2295×1013 Gy.s (19,19%) with irradiation time of 5.7367×10-13 s. In CTV, required dose is 1.1866×1013 Gy.s (4,35%) with an irradiation time of 2.5283×10-12 s. In the water it is 1.9128×1011 Gy.s (0,07%) with an irradiation time of 1,5684×10-10 s. The irradiation time is extremely short since the modeling is based on water phantom instead of human body.Keywords: BNCT, Dose, Cancer, Water Phantom, MCNPX

PREDIKSI KESETIMBANGAN ADSORPSI URANIUM PADA  AIR DAN BERBAGAI SEDIMEN. Kegiatan penelitian, pengembangan, penambangan, dan pemurnian uranium berpotensi menimbulkan pencemaran lingkungan. Uranium merupakan salah satu logam berat berbahaya karena bersifat racun dan radioaktif sehingga perlu diketahui sampai sejauh mana sebaran uranium di lingkungan. Penelitian ini bertujuan meramalkan model kesetimbangan adsorpsi uranium yang dapat berlaku umum pada berbagai sedimen. Manfaat yang diharapkan dari penelitian ini adalah sebagai  data dukung bagi kegiatan analisis dampak lingkungan dalam pembangunan PLTN. Percobaan adsorpsi uranium dijalankan dalam sistem batch. Air limbah sebanyak 100 mL yang mengandung uranium dimasukkan ke dalam erlenmeyer dan pH larutan diatur menjadi 7. Sebanyak 0,5 g sedimen dengan berbagai kandungan bahan organik, dimasukkan ke dalam erlenmeyer. Erlenmeyer ditempatkan dalam shaker dengan kecepatan 100 rpm selama 6 jam dan dibiarkan selama 24 jam sampai tercapai kesetimbangan. Filtrat yang terbentuk disaring dan dianalisis menggunakan spektrofotometer.  Lima model kesetimbangan isotermal diajukan untuk mendekati data kesetimbangan. Kesetimbangan Chapman cocok dalam mendekati data percobaan pada berbagai sedimen dengan berbagai kadar bahan organik. Hasil olah data menunjukkan hanya bahan organik yang signifikan berperan dalam adsorpsi uranium. Berdasarkan asumsi hanya bahan organik yang mengadsorpsi uranium diajukan suatu metode yang dapat dipakai untuk meramalkan kesetimbangan adsorpsi uranium yang berlaku umum pada berbagai  sedimen. Sebagai hasil, kesetimbangan Chapman memiliki nilai parameter α, β, γ berturut-turt sebesar 255 mg/g bahan organik; 0,049 L/mg, dan 1,9.

Abstract. Quality management system program of in Vitro / in Vivo Test Facility of Boron Neutron Capture Therapy at Kartini Research Reactor. The quality manajement system program of in vitro / in vivo test facility of Boron Neutron Capture Therapy (BNCT) methode as quality assurance requirement for utilization of radial pearcing beamport of Kartini research have been done. Identification and managementof technical specification and parameters meassurement of to the radial piercing beamport have been determined for preparing in vitro / in vivo test facility. The parameters are epithermal neutron flux is9,8243E+05n cm -2 s -1 and thermal neutron flux is 3,0691E+06n cm -2 s -1 , radiation shielding of parafin,dimension and size of piercing radial and instrumentatin and control systemfor automatic transfer of in vitro / in vivo samplels have been documented. Management system of the documents for fullfil basic guidance to perform working job of in vitro / in vivo at the piercing radial beamport of Kartini Research Reactor in order purpose utilization of the reactor for safety worker of the radiation area, society and invironment beeing safely Keywords : in vitro / in vivo test facility, neutron flux, radiation shielding,

A design of beam shaping assembly (BSA) installed on cyclotron 30 MeV model neutron source for boron neutron capture therapy (BNCT) has been optimized using simulator software of Monte Carlo N-Particle Extended (MCNPX). The Beryllium target with thickness of 0.55 cm is simulated to be bombarded with 30 MeV of proton beam. In this design, the parameter regarding beam characteristics for BNCT treatment has been improved, which is ratio of fast neutron dose and epithermal neutron flux. TiF3 is replaced to 30 cm of 27Al as moderator, and 1.5 cm of 32S is combined with 28 cm of 60Ni as neutron filter. Eventually, this design produces epithermal neutron flux of 2.33 × 109, ratio between fast neutron dose and epithermal neutron flux of 2.12 × 10-13,ratio between gamma dose and epithermal neutron flux of 1.00 × 10-13, ratio between thermal neutron flux and epithermal neutron flux is 0.047, and ration between particle current and total neutron flux is 0.56.