Host: The Japan Society of Mechanical Engineers
Name : The 30th International Conference on Nuclear Engineering (ICONE30)
Date : May 21, 2023 - May 26, 2023
The core of an advanced gas-cooled reactor (AGR) is constructed with a large number of nuclear graphite components. These components form channels for fuel and control rods and also restrain the core by incorporating a keying system. The structural integrity of these components is of prime importance for safe operation of the AGR. Fuel channels are built-up of cylindrical bricks which are exposed to fast neutron irradiation and radiolytic oxidation during the life of a reactor and as a result the fuel bricks experience highly non-linear changes in deformation and material properties. These highly non-linear deformation and material property changes generate a complex stress state within the fuel brick and its interacting graphite components. The behaviour and assessment of graphite components is, generally, conducted using time integrated finite element (FE) modelling and analysis. The deformation and material properties which are used in these types of assessments are calculated as a function of fast neutron irradiation, irradiation temperature and weight loss, to reflect radiation ageing of nuclear graphite over the reactor’s life. This paper provides insight to complex finite element analyses conducted using COMSOL Multiphysics to predict keyway root cracking and seal ring groove wall cracking of graphite fuel bricks.
