Neutronic and Thermal Hydraulics Analysis of Control Rod Effect on the Operation Safety of Triga 2000 Reactor

Abstract

NEUTRONIC AND THERMAL HYDRAULICS ANALYSIS OF CONTROL ROD EFFECT ON THE OPERATION SAFETY OF TRIGA 2000 REACTOR.Analysis of neutronic and thermal-hydraulics parameters of whole operation cycle is very important for the safety of reactor operation. During the reactor operation cycle, the position of the control rods will change due to reactivity changes. The purpose of this study is to determine the effect of control rods position on neutronic and thermal-hydraulics parameters in relation to the safety of reactor operation of the TRIGA 2000 reactor using silicide fuel of MTR plate type. Those parameters are power peaking factor, reactivity coefficients, and steady-state thermohydraulic parameters. Neutronic calculations are performed using a combination of WIMSD/5 and Batan-3DIFF codes and for thermal-hydraulics the calculations are done using WIMSD/5 and MTRDYN codes. The calculation results show that the reactivity coefficient values are negative for all control rod positions both at CZP and HFP conditions. The MTC value decreases when the control rod is inserted into the active core while the FTC value increases. The total ppf results and temperature in steady-state rise when the control rods are inserted of into the active core whereby the maximum value occurs at the position of the control rods of 20 cm from the bottom of the active core. The calculation results of ppf, reactivity coefficient, and thermal-hydraulics parameters lay below safety limits, indicating that the TRIGA 2000 reactor can safely use U 3 Si 2 -Al silicide fuel as a substitute fuel for cylindrical type fuel. ABSTRAK ANALISIS NEUTRONIK DAN TERMOHIDRAULIK PENGARUH POSISI BATANG KENDALI TERHADAP KESELAMATAN OPERASI REAKTOR TRIGA 2000. Analisis parameterneutronikdan termohidraulik dari seluruh siklus operasi sangat penting untuk keselamatan operasi reaktor. Selama siklus operasi reaktor, posisi batang kendali akan berubah karena perubahan reaktivitas. Tujuan dari penelitian ini adalah untuk mengetahui pengaruh posisi batang kendali terhadap parameter neutronik dan termohidraulik terkait keselamatan operasi reaktor TRIGA 2000 menggunakan bahan bakar silisida jenis MTR. Parameter yang ditentukan adalah faktor puncak daya, koefisien reaktivitas, dan parameter termohidraulika pada keadaan tunak. Perhitungan neutronikl dilakukan menggunakan kombinasi program WIMSD/5 dan Batan-3DIFF dan untuk termohidraulik dilakukan menggunakan program WIMSD/5 dan MTRDYN. Hasil perhitungan menunjukkan bahwa nilai koefisien reaktivitas negatif untuk semua posisi batang kendali baik pada kondisi CZP dan HFP. Nilai MTC berkurang ketika batang kendali dimasukkan ke teras aktif sementara nilai FTC meningkat. Hasil ppf total dan parameter dalam kondisi tunak meningkat dengan memasukkan batang kendali ke dalam teras aktif dimana nilai maksimum terjadi pada posisi batang kendali 20 cm dari bagian bawah teras aktif. Hasil perhitungan ppf, koefisien reaktivitas dan parameter termohidraulik berada di bawah batas keselamatan, ini menunjukkan bahwa reaktor TRIGA 2000 dapat menggu...

Analysis of Uncontrolled Reactivity Insertion Transient of Triga Mark 2000 Bandung Using MTR Plate Type Fuel Element

“…The equilibrium core configuration is obtained using 16 fuel elements and 4 control elements [3,4]. Calculation of neutronic, kinetic, and incore fuel management parameters as well as thermodynamic parameters in steady-state conditions have been carried out [5][6][7][8]. Based on the calculation results, the conversion core with 2 MW of nominal power requires an additional flow rate in the core [9], but the nominal power of 1 MW can use the current flow rate.…”