My argument is that there is no purpose for the containment walls. They are theoretically yet another barrier to leak of radiation on top of the fuel rods and

My argument is that there is no purpose for the containment walls. They are theoretically yet another barrier to leak of radiation on top of the fuel rods and the piping itself but I would argue this as unnecessary. Chernobyl should have had a containment vessel. This would have averted that disaster. Three Mile Island had a catastrophic systems failure with a partial meltdown yet only 1 inch of the 7 inch thick reactor vessel was affected. Some xenon gas and other radioactive elements were released to the atmosphere but of minimal quantities.