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I didn't say it was going to be another Chernobyl exactly but you are simply BS'ing everyone if you are trying to claim everything was within the parameters of the design and there was no danger.


That's why I'm not saying that. It is well documented that several parameters exceeded their design limitations during the accident. And yes, there was danger and the reactor could have been even more destroyed. But it wasn't danger of blowing skyhigh and then continuing to burn for days, a la Chernobyl, e.g. danger of spreading significant amount of radioactivity into the environment.


In particular you are leaving out the wild card which was a 1000 cubic feet 1000 PSI Hydrogen bubble that formed in the vessel from the breakdown of the superheated water.


No, I'm not leaving it out. While it was a cause of great concern at the time, it was later determined that there was not enough oxygen in the vessel which could have caused the hydrogen explosion (one reason for this is of course that the superheated water didn't simply "break down" as you imply, rather it is a reaction with the Zr cladding where the cladding is oxidized).

For more information see e.g. this report sumamry.


It had an explosive potential of 3 tons of TNT which would have been enough to breach the vessel and containment if it had exploded.


See the link above. There wasn't enough Zr in the reactor to produce enough pressure to break the containment building.

Additionally, Westinghouse (the manufacturer) did some calculations where they concluded that the pressure vessel and high pressure system itself would perhaps have been able to contain the estimated 3000-4000 PSI blast pressure from the hypothetical hydrogen explosion.


If so the core might well have done a China Syndrome and melted through the floor of the vessel and containment building.


Yes, it was certainly a very real risk that the core would have melted through the pressure vessel, but how did you imagine it would melt itself out from the containment building? Gravity pulls the core downward while it ought to go sidewards if it is to reach the containment walls.


There was enough water pooled at the bottom of the vessel there was also a significant chance of a steam explosion when the melting core hit it and that could have also breeched the reactor.


Perhaps. But again there's the containment building preventing further catastrophy. OTOH, as the core was partially submerged in that same water, there was little possibility of a sudden big clump of molten core dropping into it as the water constantly cooled the core. And if the water wouldn't have been there in which case the core would have melted more dramatically, well there wouldn't be water there either to cause the steam explosion, now would it? ;-)


All in all you seem to be claiming certainty about a situation that was unprecedented and anything but certain.


I'm claiming that TMI couldn't have developed into a Chernobyl. They were radically different designs, so spreading FUD about light-water reactors on the basis of Chernobyl is totally ridiculous.

Additional work is limited because of high radiation dose rates in the vicinity of tanks containing contaminated water.
link

There are other reports which mention the high level of radiation in the water being cleaned up from the basement.

Our feelings represented by a Victorian poet...

Here is an example law, in this case building codes, being proprietary. More info here.

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Perhaps. If you trust your sensors. As TMI showed (a PWR, mind you) there are situations where you can get misled. In situations where you have multiple conflicting indications, operators can have a tendency to fixate on the wrong sensor reading (same thing happens to pilots). A related point is that analysis of operator-error-induced accidents in many situations shows that the operators were acting on the basis of faulty information, rather than simply not following procedure.

You are right in that these plants can be safely operated on very simple anaglog backups, but that's not really the problem. The issue is that you are presenting operators with two sets of information (analog backup, and the nice new computer interface). These systems clearly have different levels of security and reliability. You are hoping that if these systems start to disagree that the operator will do the right thing and trust the backup. But that is not always the case (and in any event his thinking may be influenced by the faulty indicator).

This is not a safe practice. Backups and redundancies are nice, but all the systems have to operate at something like the same level of reliability and security. Otherwise the less reliable system is worse than useless; bad data is worse than no data.

That someone would even think of bringing a Windows box anywhere near a nuke control room, let along connect it to the freaking net, however indirectly, gives me nightsweats. And I've worked in nuke control rooms.