Criticality prevention coating material, criticality prevention coating layer, and method for forming the same

摘要

PROBLEM TO BE SOLVED: To provide a criticality prevention coating material and layer which can stably coat a surface of a melted core, and a method for forming the criticality prevention coating layer.SOLUTION: The criticality prevention coating material contains a thermal neutron absorber, an alkali metal silicate, and one or more kinds which are selected from a group consisting of sodium silicofluoride, primary aluminum phosphate, and aluminum polyphosphate. The criticality prevention coating material contains the thermal neutron absorber, cement, and a cement quick hardening material. The thermal neutron absorber is preferably made of gadolinium compound particles and/or boron compound particles.