Explanation
The materials has no obvious volume change due to the shape change caused by irradiation, which often occurs in the nuclear fuel coating materials and structural elements (such as pressure tube and calandria). irradiation growth often occurs in crystal with low symmetry. Atoms knocked out of lattice nodes by neutrons, etc., preferentially re-enter lattice nodes of crystal in a certain crystal direction, so that crystal grow in this direction and contract in other crystal directions.
Classification
Energy Materials -> Nuclear energy materials