Corrosion of steels in lead bismuth eutectic (LBE) cooled reactors can be mitigated by forming a protective oxide layer on the steel surfaces. The amount of oxygen necessary to ensure continuous oxide layer formation on fuel cladding depends on the characteristics of the steel and on the local temperature, local oxygen concentration and velocity of the LBE in contact with the steel. The most critical areas from a corrosion point of view are high temperature and low oxygen concentration regions. Wire-wrapped fuel assemblies (FAs) which are foreseen to be used in LBE cooled reactors, are characterized by hot spots and quasi-stagnant areas where oxygen could be depleted. Experimental measurements to verify whether the oxygen concentration in those critical areas is sufficiently elevated for oxide layer formation, are practically impossible. This information can be however obtained by numerical modeling. This paper focuses on the development of a numerical model of oxygen mass transfer in a 19-pin scaled fuel assembly (FA) representative of the MYRRHA reactor core. Oxidation of steels and oxygen transport from the bulk of the LBE to the surface of steels were simulated simultaneously. The simulations provide a local oxygen concentration mapping at steel/LBE interface enabling to identify the regions of the core which could be prone to corrosion due to oxygen depleted LBE. Operation recommendations for the MYRRHA reactor were given based on the simulation results.

铅铋共晶（LBE）冷却反应堆中的钢腐蚀可通过在钢表面形成保护性氧化层来减轻。确保在燃料包壳上连续形成氧化层所需的氧气量取决于钢的特性以及局部温度，局部氧浓度和与钢接触的LBE的速度。从腐蚀的角度来看，最关键的区域是高温和低氧浓度区域。预计将在LBE冷却反应堆中使用线绕式燃料组件（FA），其特点是热点和准停滞区域，这些区域可能会耗尽氧气。几乎不可能进行实验测量来验证那些关键区域中的氧气浓度是否足够高以形成氧化物层。但是，可以通过数值建模获得此信息。本文着重于开发代表MYRRHA反应堆堆芯的19针比例燃料组件（FA）中的氧气传质数值模型。同时模拟了钢的氧化和氧气从LBE主体到钢表面的传输。该模拟在钢/ LBE界面处提供了局部氧气浓度映射，从而能够确定由于缺氧的LBE而易于腐蚀的芯区域。根据模拟结果给出了MYRRHA反应堆的运行建议。同时模拟了钢的氧化和氧气从LBE主体到钢表面的传输。该模拟在钢/ LBE界面处提供了局部氧气浓度映射，从而能够确定由于缺氧的LBE而易于腐蚀的芯区域。根据模拟结果给出了MYRRHA反应堆的运行建议。同时模拟了钢的氧化和氧气从LBE主体到钢表面的传输。该模拟在钢/ LBE界面处提供了局部氧气浓度映射，从而能够确定由于缺氧的LBE而易于腐蚀的芯区域。根据模拟结果给出了MYRRHA反应堆的运行建议。