Analisis Optimasi Komposisi Bahan Bakar Terhadap Moderator Pada Kekritisan Reaktor Lelehan Garam Bermoderator Zirkonium Hidrat Dengan Tipe Kisi Segi Enam

ELLY ISMAIL, Dr. Ir. Andang Widi Harto, M.T.; Dr.-Ing Sihana

2016 | Skripsi | S1 TEKNIK NUKLIR

Telah dilakukan penelitian netronik pada Molten Salt Reactor Transatomic Power (MSR-TAP). Perbedaan penting antara MSR-TAP dengan Reaktor lelehan garam (MSR) lainnya adalah penggunaan zirkonium hidrat sebagai moderator Penelitian ini bertujuan untuk menentukan komposisi optimum antara bahan bakar terhadap moderator serta tingkat pengayaan terbaik yang memenuhi syarat 1 < keff < 1,0065 agar reaktor berada dalam kondisi stabil saat beroperasi serta memiliki nilai koefisien reaktivitas void negatif. Parameter netronik yang divariasikan adalah tingkat pengayaan (1,8%, 4,5%, 4,8% dan 5,7%), persentase mol uranium pada garam bahan bakar (15%, 20%, 25%, dan 30%) dan diameter silinder moderator dengan variasi 1 cm sampai 6 cm (dengan selisih 1 cm). Aspek yang dianalisis yaitu aspek netronik berupa nilai faktor multiplikasi efektif (keff) serta aspek keselamatan yaitu koefisien reaktivitas void (alpha void). Proses kalkulasi parameter netronik menggunakan metode probabilistik Monte Carlo. Hasil penelitian menunjukkan desain optimum untuk MSR-TAP ada pada pengayaan 4,5%, variasi persentase mol uranium di garam bahan bakar 20% dan diameter moderator 4 cm, dengan nilai keff 1,00371 ± 0,00061. Sementara itu koefisien reaktivitas void sebesar -0,4264 void kuadrat-0,1203 void+0,0038 yang menunjukan desain ini memiliki koefisien reaktivitas void bernilai negatif.

A neutronic studies of Molten Salt Reactor Transatomic Power (MSR-TAP) has been conducted. The key difference between MSR-TAP and basic MSR is the use of zirconium hydride as moderator. The objective of this studies was to find an optimum moderator to fuel ratio and also an optimal enrichment level which fulfilled the requirements of 1 < keff < 1.0065 in order for the reactor to operate in stable condition and has negative void reactivity coefficient. The neutronic parameters such as enrichment level has been varied from 1.8%, 4.5%, 4,8% and 5,7%, mole percentage of uranium in fuel salt mixture has been varied from 15%, 20%, 25% and 30% and the diameter of moderator cyilinder has been varied from 1 cm to 6 cm with 1 cm gap. The aspects which were analyzed were neutronic aspect which is effective multiplication factor (keff) and safety aspect which is void reactivity coefficient (alpha void). The calculation was conducted using probabilistic Monte Carlo Method. The result showed that the optimum design for the studied MSR-TAP is at the following conditions: 5.7 % enrichment, mole percentage of uranium in mixture fuel salt at 20% and diameter of moderator cylinder at 4 cm. The value of its keff is 1.00371 ± 0.00061 while its void reactivity coefficient value is -0.4264 void square-0.1203 void+0.0038 which shows that this design has negative void reactivity coefficient.

Kata Kunci : Molten Salt Reactor Transatomic Power, Monte Carlo, faktor multiplikasi efektif, koefisien reaktivitas void, fraksi mol uranium, komposisi optimum