Freewill
Platinum Member
- Oct 26, 2011
- 31,158
- 5,072
- 1,130
I have worked at Three Mile Island, it is a very nice, operating plant. A Babcock and Wilcox plant, I think maybe 11 of our 100 plants were built by B&W.
Nothing is absolutely safe. The manufacture and distribution of the gasoline for your car has killed many more then either the American or French commercial nuclear power. Irresponsible nuclear power is a threat.
In the US there has been no deaths as a direct result of nuclear power operations. The worse being the following:
5. Three Mile Island Accident, Pennsylvania USA 1979 – Level 5
28th March saw two nuclear reactors meltdown. It was subsequently the worst disaster in commercial nuclear power plant history. Small amounts of radioactive gases and radioactive iodine were released into the environment. Luckily, epidemiology studies have not linked a single cancer with the accident.
Just so you know, there were not two nuclear reactor meltdowns at TM. Unit 2 melted down and for the most part the containment structures held. Unit 1 is still in operation today. The meltdown occurred because of incredible human error and plant design. Both of which have been corrected.
That said there was at least one incident that I think more troublesome. The David Bessie plant and the ALMOST breach of the reactor head. It was clearly the result of managements, and the NRC, drive to make money. IF the head would have breached at power it is anyone's guess what would have happened, my thoughts, it would have been the end of nuclear power in America
- See more at: Top 10 Nuclear Disasters in the World
The Davis Bessie incident. I was trained and did a few of the inspections that resulted from that problem. It was corrosion of the Reactor Head, the tubes that penetrate the head were welded in with dissimilar metals that began to corrode. At Davis Bessie the head was literally paper thin, literally, but the pressure is low enough in the reactor that it never breached or broke through and was discovered during a refueling outage.
I imagine if the reactor head was breached the Radioactivity alarms would of triggered and they would of shut the plant down automatically, with all the safety retrofits since Three Mile Island it is doubtful anything less than a safe shutdown would of been the result.
The steam from a failed reactor head would be contained in the containment vessel, which inside the containment building, 3 levels of safety.
Thus far no nuclear reactor vessel in the USA has ever failed.
All reactor heads have been replaced and are inspected.
Maybe the containment at DB would have held, we don't know that for a fact. Considering a 30 foot crack was found in the containment who knows? Loss of coolant accidents are designed for and trained for so maybe the opening of a football sized hole would have been able to be contained, probably but still maybe. As I recall DB is a pressurized reactor with a primary at about 2250 PSI, not really low pressure. Also, the leak was caused by cracks around the nozzles causing boron to leak out eating away at the the none stainless steel head. Fortunately the Stainless steel liner held at about 3/8 of an inch think.
The real problem I see with DB was the NRC inability to get them to inspect their head in the first place. First Energy sued the NRC to allow them to keep running. Boron contamination was everywhere in the reactor building and there was a literally water fall of boron from from the head. Air monitoring filters were being clogged by boron. Yet management made the assumption it was a flange leak on a control rod mechanisms without verifying it. What if that nozzle had not moved, by accident more or less, when they were doing inspections?
And what happened to management after gross mis-management was found? They scattered to the wind. The plant manager went to England and the rest were buried within First Energy. ONE lone engineer was held accountable, as I remember.
It appears to me that the lessons were learned from DB. First Energy paid dearly for their ignoring, what appears now, to be a very obvious safety issue. Let's hope the nuclear industry remembers what happen.
Here is the NRC's report of what happened:
NRC: Overview of Reactor Vessel Head Degradation
Here is wijpedia's version, which lacks some details.
Davis–Besse Nuclear Power Station - Wikipedia, the free encyclopedia
Davis Besse Nuclear Power Plant