BRATTLEBORO — The bottom line is that Vermont Yankee can melt down, leading to an environmental disaster. And it could do so in spite of its so-called emergency core cooling system.
We have been told by the nuclear industry for years that this could not happen, that American power plants had made improvements since the accident at Three Mile Island, that they were designed better than the plant at Chernobyl, and that such accidents simply could not happen, or at least that the odds were so small they were not worthy of consideration.
It turns out that what we were told was wrong.
The Vermont Yankee plant was built without consideration for a problem that turns out to be a serious design flaw. The temperatures at which a runaway meltdown starts were miscalculated by over 250 degrees F. In the event of a failure of the core coolant, the amount of time needed to respond is seriously reduced.
The book response to coolant loss is wrong, and the amount of time that would pass between a point where the engineers at the plant believe a problem is being handled properly and the point at which no action can stop a core meltdown is a mere 30 seconds.
The problem arises because of a misunderstanding in the nuclear industry over the nature of the zircaloy cladding used to hold nuclear fuel. The cladding reacts strongly with oxygen. In the event of a coolant loss, the fuel heats up rapidly, and at a temperature of just over 1,832 degrees F., the fuel cladding starts to oxidize, causing the temperature to increase rapidly.
In doing this, it is not taking the oxygen from the air, but robs it from water molecules, releasing hydrogen gas. As the temperature rises, ignition takes place, causing a very rapid rise in temperature. And when this happens, putting water on the fire only gives the zircaloy more material from which to rob oxygen.
This can happen in either the spent-fuel pool or the reactor itself. And since the basis peak cladding temperature is on the books at 1,960 degrees F., it can happen at a point where guidelines say things are still just fine.
The science behind this comes from the nuclear industry itself. Tests done on zircaloy-clad fuel provided the underlying data. These tests were done in the 1960s at Westinghouse and General Electric, before the Vermont Yankee plant was even built. Unfortunately, for whatever reason, the industry ignored them and went about its business, assuring itself and everyone else that it could not happen here.
How did this happen? We might go in for conspiracy theory, but really it is not necessary. When the statements of nuclear engineers are examined in the cold light of day, they cannot really mean that a meltdown is impossible, but just that they do not see a way for one to happen, having thought about it.
The failure does not have to be dishonesty; it can merely be one of lack of imagination, a failure to find a small amount of data buried in a mound of paperwork, and slightly wishful thinking.
But wishful thinking does not make us safe. And so the New England Coalition filed a petition with the Nuclear Regulatory Commission to take immediate remedial action at VY, to recalculate safe temperatures. The response was negative.
The NRC had already received a generic petition on the same subject applied to the entire industry and saw no reason to treat VY separately. Three years from now, the process will be completed, and in the meantime, everything has been hunky-dory so far, so why worry?
The NEC pointed out that VY is operating at above designed thermal power, and that, if the data is correct, it has a too-small margin of safety. The NRC is taking the whole thing under advisement and doing nothing else about it until the time of advisement has passed. In the meantime, we are left to wonder what else has been forgotten.
Bernie Madoff made a fortune on a Ponzi scheme even after complaints alerted the Federal Trade Commission. BP caused an environmental disaster even after a whistleblower alerted the federal government's Minerals Management Service.
Now, the NRC has been informed, and it is saying it cannot take less than three years to deal with a problem that can go from business as usual to another Three Mile Island, or even Chernobyl, in half a New York minute.