Dian Fitriyani

Fractal Structures on Silica Aerogels Containing Titanium: A Small Angle Neutron Scattering Study

The fractal structure of silica aerogels containing titanium has been investigated by means of small angle scattering (SAS) technique, i.e. small angle neutron scattering (SANS). The SANS experiments were conducted using a 36 meter SANS BATAN spectrometer (SMARTer) in Serpong, Indonesia in the range of momentum transfer q, 0.006<q(A−1)<0.3. The ‘power‐law’ for a fractal object scattering pattern I(q)∼q−D observed from the all measured samples. The Fourier transform of a pair correlation model function was implemented in analyzing the structure factor from the ‘power‐law’ scattering profiles. The results are showing that the silica aerogels containing titanium has a mass fractal where its dimension Dm is larger than pure silica aerogels. The mass fractal dimension of silica aerogels containing titanium is relatively constant between 2.2 to 2.4 with the increase of acid concentrations during a sol‐gel process while the surface fractal disappeared.

Optimization of 200 MWth and 250 MWt Ship Based Small Long Life NPP

Design optimization of ship‐based 200 MWth and 250 MWt nuclear power reactors have been performed. The neutronic and thermo‐hydraulic programs of the three‐dimensional X‐Y‐Z geometry have been developed for the analysis of ship‐based nuclear power plant. Quasi‐static approach is adopted to treat seawater effect. The reactor are loop type lead bismuth cooled fast reactor with nitride fuel and with relatively large coolant pipe above reactor core, the heat from primary coolant system is directly transferred to watersteam loop through steam generators. Square core type are selected and optimized. As the optimization result, the core outlet temperature distribution is changing with the elevation angle of the reactor system and the characteristics are discussed.