Analysis of Neutronic Safety Parameters of the Multi-Purpose Reactor–Gerrit Augustinus Siwabessy (RSG-GAS) Research Reactor at Serpong

Abstract

The main safety parameters of Multipurpose Reactor–Gerrit Augustinus Siwabessy (RSG-GAS) have never been evaluated periodically and neutronically require to be evaluated in terms of stuck rod reactivity, shut-down margin and temperature reactivity coefficient are treated by experiment. Meanwhile, power peaking factors and maximum fuel burn up are treated by calculations. The diffusion method did the calculation using the computer code. Safety parameters are very important aspects for the operation and design improvement. The results of the experiment and calculation about the safety parameters of RGS-GAS core are utilized for safety evaluation as part of a research reactor operation Periodic Safety Review (PSR). It presents reactor calculations as a method for their determination assuming use of computer codes such as WIMSD-5B using ENDF.BVII.0 and BATAN-FUEL. According to the experimental data and calculation, neutronic safety parameters have met the safety analysis report such as reactivity coefficient is negative and met the shutdown margin at stuck rod condition nothing has violated the safety margin. The results can be used as the periodic safety review for renewal operation license from Nuclear Energy Regulatory Agency of Indonesia (BAPETEN) as the regulator body. These results also can be used as a reference for new research reactor MTR type advanced design in the future.

The effect of adding impurities to the high density fuel matrix on the reactivity of the RSG-GAS core

“…On the 10 x 10 core grid positions there are 40 standard FEs (each consists of 21 fuel plates as depicted in figure 2), 8 control elements (CEs, each consists of 15 fuel plates as depicted in figure 4) initially loaded with 250 and 178.6 g 235 U respectively, Be reflector elements and other irradiation facilities. This fuel loading corresponds to uranium meat density of 2.96 gU/cm 3 . With the original nominal core cycle of 25 days, 8 burn-up classes with an average burn-up step of approximately 7 % loss of 235 U the core produces energy of 750 MWD per cycle [11].…”

“…One of the PTKRN-BATAN main program is to conduct an assessment of the safety of the RSG-GAS core so that the reactor can operate safety and safely [1][2]. The change of fuel from low density to high density is expected to occur in the RSG-GAS core because its performance increased and fuel used is also more efficient [3]. However, in the use of high density fuels, there is a problem that occurs, namely the "bottle neck" effect where there is a problem of uranium interaction with imperfect cladding [4].…”

Comparison of Measured and Calculated Control Rod Reactivity of the RSG-Gas Core

“…The flow diagram of the neutronic parameter calculation can be seen in Figure 5. The Batan-FUEL code is used for calculating the criticality search of an equilibrium core without simulating the transition cores [19]. Therefore, those capabilities strongly depend on the cell calculation.…”

Prediksi Isotop Bahan Bakar PWR Menggunakan Prrogram Wimsd-5b

“…Reaksi isotop U-235 dan U-238 pada temperatur 841K dihitung dalam kisi benchmark menggunakan program WIMSD-5B. Parameter integral yang dihitung adalah faktor multiplikasi tak terhingga (k-inf), komposisi isoptop dan tampang lintang makroskopik seperti koefisien difusi, tampang lintang absorpsi, tampang lintang removal, nufisi untuk kelompok energi 69 [15] yang dihitung dengan energi termal 0,625 eV. Komposisi dan radius yang mewakili sel didefenisikan dalam data material dan spektrum yang disesuaikan dengan ke-empat daerah tersebut dan hal ini sudah dilakukan oleh paket program WIMSD-5B.…”