If they made the core material removable then the bulk of the machinery would be worthless. 98% of the effort in reactor power is sourcing/producing the nuclear

If they made the core material removable then the bulk of the machinery would be worthless. 98% of the effort in reactor power is sourcing/producing the nuclear material. There are also ways to poison the core so that it is inoperable unless you got a large nuclear processing facility to remove the contaminates from the core material. But I find that an inferior solution since it leaves behind dirty bomb materials.