Harto Andang Widi, Agung Alexander, Putra M Yayan Adi, Azizi Rayhan Alghiffari, Kanaya Diva Jati, Gusti Alfonsus Rahmadi Putranto, Dwijayanto R Andika Putra
Department of Nuclear Engineering and Engineering Physics - Faculty of Engineering - Universitas Gadjah Mada, Indonesia.
Research Centre for Nuclear Reactor Technology, Research Organization for Nuclear Energy, National Research and Innovation Agency, Indonesia.
Heliyon. 2024 May 3;10(9):e30707. doi: 10.1016/j.heliyon.2024.e30707. eCollection 2024 May 15.
The GAMA Microreactor is a low-power nuclear power plant dedicated for remote area with a power output of 300 kWe. The primary characteristics of the GAMA Microreactor are its system compactness, design simplicity, and safe operation without moving parts. The fuel is uranium hydride powder, which works simultaneously as a moderator, contained within a stainless-steel vessel and surrounded by a graphite reflector. Liquid sodium-filled heat pipes are embedded in the fuel powder to extract fission-generated heat via passive coolant flow due to capillary action. As a part of the design process, neutronic parameters of the GAMA Microreactor have been determined using SCALE6.2 and OpenMC codes. Among the analyzed parameters are the excess reactivity as a function of burn-up, shutdown margin, control rod worth, temperature coefficient of reactivity (TCR), fuel density coefficient of reactivity (DCR), and reactivity coefficient due to hydrogen dissociation. From the calculation results, the GAMA Microreactor has a maximum excess reactivity of 0.049 at the operational temperature (700 °C) and 0.0788 at ambient temperature. The TCR value is negative (-2.267 pcm/°C) at the beginning of the cycle (BOL) and -4.9618 pcm/°C at the end of the cycle (EOC). Hydrogen dissociation imposes negative reactivity on the reactor both at the BOL (-0.2631 Δk/k-%dissociation) and EOC (-0.3524 Δk/k-%dissociation). Therefore, the GAMA Microreactor maintains its inherent safety characteristics over a considerably long operation time.
伽马微型反应堆是一种专为偏远地区设计的低功率核电站，输出功率为300千瓦电。伽马微型反应堆的主要特点是系统紧凑、设计简单且无运动部件即可安全运行。燃料是氢化铀粉末，它同时作为慢化剂，装在不锈钢容器中并被石墨反射层包围。装有液态钠的热管嵌入燃料粉末中，通过毛细作用以被动冷却剂流的方式提取裂变产生的热量。作为设计过程的一部分，已使用SCALE6.2和OpenMC代码确定了伽马微型反应堆的中子学参数。分析的参数包括作为燃耗函数的过剩反应性、停堆裕度、控制棒价值、反应性温度系数（TCR）、反应性燃料密度系数（DCR）以及氢解离引起的反应性系数。从计算结果来看，伽马微型反应堆在运行温度（700°C）下的最大过剩反应性为0.049，在环境温度下为0.0788。在循环开始时（BOL）TCR值为负（-2.267pcm/°C），在循环结束时（EOC）为-4.9618pcm/°C。氢解离在BOL（-0.2631Δk/k-%解离）和EOC（-0.3524Δk/k-%解离）时都会给反应堆带来负反应性。因此，伽马微型反应堆在相当长的运行时间内都保持其固有安全特性。
