Departemen
Teknik Nuklir dan Teknik Fisika telah merancang reaktor terapung bernama Gama-Float.
Penelitian tahap awal mengoptimalkan faktor multiplikasi <!--[if gte msEquation 12]>k?<![endif]--><!--[if !msEquation]-->
<!--[endif]-->? dan
siklus bahan bakar. Pada penelitian tahap lanjut, penambahan racun bakar
gadolinia berhasil menurunkan <!--[if gte msEquation 12]>k?<![endif]--><!--[if !msEquation]-->
<!--[endif]-->? di awal
siklus operasi, namun didapati koefisien reaktivitas suhu moderator positif,
yang tidak memenuhi kriteria keselamatan. Untuk mengatasi masalah ini akan dicoba
menggunakan torium sebagai material tambahan pada bahan bakar reaktor Gama-Float.
Akan dilakukan
simulasi pada model FA reaktor Gama-Float yang telah ditambahkan torium,
simulasi dilakukan menggunakan POLARIS yaitu modul baru yang
dikembangkan dalam sistem kode SCALE untuk melakukan analisis lattice
physics dua dimensi (2-D). Simulasi dilakukan pada berbagai variasi
persentase torium, suhu bahan bakar, suhu moderator, dan persentase void.
Dilakukan analisis pada nilai <!--[if gte msEquation 12]>k?<![endif]--><!--[if !msEquation]-->
<!--[endif]--> sepanjang burnup untuk mengamati
performa netronik dari FA setelah dilakukannya penambahan torium dengan
persentase tertentu.
Hasil penelitian ini
menunjukkan bahwa seiring bertambahnya jumlah torium maka semakin rendah nilai <!--[if gte msEquation 12]>k?<![endif]--><!--[if !msEquation]-->
<!--[endif]--> pada fase BOC tetapi semakin cepat pula bahan
bakar sampai pada fase discharge burnup (DB) dan
koefisien reaktivitasnya akan semakin cepat bernilai positif. Dilakukan pula
seleksi dan pemeringkatan pada FA yang memenuhi performa neutronik yang
diinginkan, diperoleh FA dengan performa neutronik terbaik adalah FA dengan
konfigurasi pin 14x14 dan persentase massa torium sebesar 5%.
The Department of Nuclear Engineering and
Engineering Physics has designed a floating reactor named Gama-Float. The
initial research optimised the multiplication factor <!--[if gte msEquation 12]>k?<![endif]--><!--[if !msEquation]-->
<!--[endif]--> and fuel cycle. In advanced research, the
addition of gadolinia fuel poison succeeded in reducing <!--[if gte msEquation 12]>k?<![endif]--><!--[if !msEquation]-->
<!--[endif]--> at the beginning of the operating cycle, but a positive moderator
temperature reactivity coefficient was found, which did not meet safety
criteria. To overcome this problem, it will be tried to use thorium as an
additional material in the Gama-Float reactor fuel.
Simulations will be carried out on the FA
model of the Gama-Float reactor that has been added with thorium, simulations
are carried out using POLARIS, a new module developed in the SCALE code system
to perform two-dimensional (2-D) lattice physics analysis. Simulations were
carried out at various variations of the percentage of thorium, fuel
temperature, moderator temperature, and percentage of voids. Analyses were
carried out at the <!--[if gte msEquation 12]>k?<![endif]--><!--[if !msEquation]-->
<!--[endif]-->value throughout the burnup to
observe the neutronics performance of the FA after the addition of a certain
percentage of thorium.
The results of this study show that as
the amount of thorium increases, the lower the <!--[if gte msEquation 12]>k?<![endif]--><!--[if !msEquation]-->
<!--[endif]--> value in the BOC phase but the faster the fuel
reaches the burnup discharge phase and the reactivity coefficient will be
positive faster. Selection and ranking of FAs that fulfil the desired neutronic
performance were also carried out, and the FA with the best neutronic
performance was obtained with a pin configuration of 14x14 and a mass
percentage of thorium of 5%.
Kata Kunci : torium, koefisien reaktivitas, Gama-Float, fuel assembly
