They don't explode like a nuclear bomb but they can have steam explosions.
2. A Chernobyl style accident is impossible with a light water reactor..
That is wrong. *Any* water cooled reactor could potentially have a steam explosion and any such reactor, with a sufficiently stupid design, could have a Chernobyl type accident.
4. Reactors all go critical. What you don't want is for them to go super critical.
5. No modern reactor can go super critical the fuel they use isn't enriched enough to go super critical and they all need a moderator like water to work.
That's not necessarily true (I think you're missusing the term "super critical") and it's not really the point. What you really don't want is for them to generate more heat than the coolant system is capable of dispersing.
At the time of Chernobyl, the US had (and I was working on) a similar reactor (graphite/water moderated, dual purpose). A great deal of effort was put in to proving that the same thing couldn't happen here. Thermal reactors (what most of them are) have an optimal ratio of water to fuel. Anyone with any sense designs their reactor to have less than optimal amount of water in the coolant. That way, any accident that causes the reactor to lose water also causes it to lose power. Chernobyl had more than the optimum amount. In the course of the accident the water started to boil (reducing the density) and the power increased, which caused more boiling and ultimately a steam explosion. A design like that would never get approved in any country with competant regulation and if one somehow got built it would get caught in the testing phase.
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1. Reactors don't explode..
They don't explode like a nuclear bomb but they can have steam explosions.
2. A Chernobyl style accident is impossible with a light water reactor..
That is wrong. *Any* water cooled reactor could potentially have a steam explosion and any such reactor, with a sufficiently stupid design, could have a Chernobyl type accident.
4. Reactors all go critical. What you don't want is for them to go super critical.
5. No modern reactor can go super critical the fuel they use isn't enriched enough to go super critical and they all need a moderator like water to work.
That's not necessarily true (I think you're missusing the term "super critical") and it's not really the point. What you really don't want is for them to generate more heat than the coolant system is capable of dispersing. At the time of Chernobyl, the US had (and I was working on) a similar reactor (graphite/water moderated, dual purpose). A great deal of effort was put in to proving that the same thing couldn't happen here. Thermal reactors (what most of them are) have an optimal ratio of water to fuel. Anyone with any sense designs their reactor to have less than optimal amount of water in the coolant. That way, any accident that causes the reactor to lose water also causes it to lose power. Chernobyl had more than the optimum amount. In the course of the accident the water started to boil (reducing the density) and the power increased, which caused more boiling and ultimately a steam explosion. A design like that would never get approved in any country with competant regulation and if one somehow got built it would get caught in the testing phase.