Yes, that's what happened, but I wouldn't say it was planned. Popular wisdom at the time was that the corium should have melted the whole way through the contai

Yes, that's what happened, but I wouldn't say it was planned. Popular wisdom at the time was that the corium should have melted the whole way through the containment vessel. The "popular wisdom" is utter propaganda bullshit; have you ever wondered why the popular at the time and mentioned in [1] "China Syndrome" is for some inexplicable reason is not longer bandied about? The design of the reactor vessel allowed for this and withstood the stress without the bigger concrete containment vessel even coming into play. Note even in [1]: Besides the insulating property of the fuel and the strength of the steel vessel, previous studies had shown the concrete bases on which U.S. reactors are built also would hold up against melting fuel, Beckjord said. That you are confounding the reactor and containment vessels in your posting suggests to me how effective that propaganda has been.