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25th Anniversary Of Three Mile Island
fbform writes "March 28, 2004 is the 25th anniversary of the Loss Of Coolant Accident (LOCA) at the nuclear power plant on Three Mile Island, Pennsylvania. It's a good time to reflect on the impact it has had on our nuclear safety policy and interface design in general."
Oblinks to related wikipedia articles:
Three Mile Island
List of nuclear accidents
Fusion power is the way to go. It's potentially much safer and can generate a ton of electricity without air pollution.
Especially pebble bed reactors.
That would make things much worse in the event of a meltdown. The radioactivity has to go somewhere, and instead of being pelted into the air or lingering in and around the reactor it would wind up getting leached into the soil and causing massive contamination of any watercourses within a few kilometres, which would probably be even worse and slow down long-term dispersal of radioactive particles.
Compare the Soviets worst accident- dozens dead in the short term, thousands dead early from long term effects- with the United States worst accident- Three Mile Island. The radioactivity release from TMI was projected to cause less than 1 premature death from the hundreds of thousands of people potentially exposed to anything, and in twenty five years since, no one has been able to prove that they were adversly affected by the accident, healthwise.
Including the people who work there.
Nuclear Power is perfectly safe when done right, and it's done right in the US. The worst that could happen in the US in an accident condition is that parts of the power plant are destroyed. And for even that to happen, so many very closely watched things would have to go wrong that it's basically not going to happen.
So shut off your lights if you don't like nuclear power, and go back to your cave.
Alcohol, Tobacco and Firearms should be the name of a store, not a government agency.
Chernobyl was a completely different animal to TMI. Operators at the plant brought that disaster entirely upon themselves. They were doing an "experiment" to see what the minimal resources were to keep the plant operating, overriding automatic shutoffs and other alarms in the process. Eventually, they overrode one alarm too many.
TMI was much more of a true accident. A valve malfunctioned to start the whole thing, something that didnt require a direct human action to occur.
The One Rule Of Chess You'll Ever Need: Don't play someone who carries a kit in their bookbag.
If they had used analog dials instead of digital readouts, the operators would have seen a bunch of dials all pegged high, instead of seeing what looked like an instrument failure.
Given that data, there's chance that when steam bubbles started forming in the primary system outside of the pressurizer (your "voids"), the operators would not have shut down the primary reactor coolant pumps (the big pumps that circulate water between the core and steam generators). The operators shut down those expensive pumps because the steam bubbles caused them to start cavitating, which would eventually destroy them. If those pumps had been kept running, the core would have received some cooling, and the operators would have known that more was wrong...
Maybe if the operators had known that core temps were going through the roof they would have acted totally differently.
PS - I have no idea how the operators could have missed a stuck-open relief valve - even a steam relief valve from the top of the pressurize. When those things lift, it sounds and feels like a train going by...
People do not realize that:
1) 80% of electricity in France is nuclear (Paris vacation, anyone?)
2) There is more radiation in the U.S. Congress due to its granite construction than is permitted outside a nuclear plant
3) If you take 4 cross-country airplane trips, you get more radiation than allowed at nuclear plants
4) If you live in mountains (Colorado) you also get more radiation, due to the altitude
5) Best estimates are for 325 long term general population deaths arising out of the Chernobyl radiation escape. Guess how many cancers due to oil/coal burning plants elsewhere?
6) Current nuke plant designs have a bias for automatically stopping the reaction at the slightest or even gravest out of spec situation. Imagine your car's engine designed to stop every time you rev up/speed/your dome light burns out.
Fact is, greenies have scared the public, we are currently poisoning our air with oil/coal power plants, creating thousands of new cancers every year. Thanks, tree-huggers.
The next pasture is always greener
The parent is correct.. if worded badly.
TMI was a case of automatic safety systems being overrided by undertrained human operators. As the story paragraph mentioned, TMI was a stark lesson in control systems design.
In the control room the operators had no feedback about how much water was in the reactor core, just one gauge showing the level of water in the pressurizer tank near the top of the system. When a valve near the top of the pressurizer stuck open (referred to as the PORV or pressure operated relief value) the steam that normally kept the water near the bottom of the pressuizer tank started leaking out. More water flashes to steam.... and TMI is now losing water. The operators saw the opposite, the water level was rising on the level gauge for the pressurizer and they started reducing and eventually draining water out of the system thinking some malfunction was causing water to be introduced. None of the operators was able to step back from the initial theory that water levels were rising, despite large amounts of contradicting information. (Hours into the incident an off-duty operator arrived and with a fresh set of eyes figured out what was happening)
There are a lot more things that went wrong that night... (the initial shutdown was caused by water accidentially getting into the compressed air supply for the pneumatic control systems in the steam room, a valve closed at the wrong time and burst one of the steam lines to the power turbines)
TMI is a fascinating example of how multiple redundant systems still can fail, given a long string of "coincidences" One can argue that failures of this type are like winning the lotto, their is little chance of it happening on on particular day, but given enough days it is certain to happen to someone. Hence the need for "fail safe" designs.
As an ex-nuclear machinist's mate aboard a US Navy sub I can tell you for a fact that the record is perfect. The 2 subs lost (Thresher & Scorpian) were not due to nuclear accidents. The original design and construction of the USS Enterprise included 9 reactors (9? whew!) in which 7 were subsequently removed. Each could power a city of about 250,000 people effectively. And by the way, most nuclear power plants ARE run by ex-Navy personnel. Most of them hire no one but ex-Navy.
[SIG] Remember Mattel handheld games?
For years now, the folks guarding nuclear plants have been armed to the teeth.
They have no-fly zones around nuclear plants now. Not really because flying inside the line gets you shot down, but so they can aim a SAM at an incoming threat without worrying about hitting the wrong plane (not that they're worried about hitting the wrong plane - it's really that they're worried about missing the right one).
So let's pretend we're mad as hell and not going to take it any more. What's the plan?
9/11 style air attack won't work. You'll either get SAMed or the containment building will likely survive the impact.
Armed assault will be met with armed resistance. The minute the attack starts, someone presses the panic button and the cavalry arrives.
No, the only credible terrorist threat in my mind is an inside job - someone gets a job as a plant worker and sabotages the plant. If the plant were a fail-safe design, however (as a previous posted pointed out, current plants are designed with redundant systems, but are not fail-safe), the worst the criminal could do is shut the plant down and perhaps try and disperse the fuel with explosives (note that due to a failsafe system, he won't get any help dispersing the fuel from the plant itself). His ability to smuggle explosives into the plant without being detected will limit the effectiveness of that plan. Never mind that he'd have to be able to breach the containment building (yes, even a fail-safe reactor will likely have one).
Sabotage is certainly a threat at current nuclear facilities, just as it is a threat at, for example, petrolium refineries (I'd actually put Richmond, CA ahead of, say, San Onofre on a threat list). Better design mitigates that risk, just as it mitigates so many other risks.
After rocky flats, the detroit reactor neer explosion, hanfords non stop spew of radiation and of course after the nation had been glowing with nuke test fallout for 30 years, THEN they decide to wimp out because a reactors failsafes actually began working to the point where there was little radiation leakage ? WTF ?
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The russians on the other hand, their main food production area is not EPA weenie HOT, its will I die of this THIS year hot. And they keep all the reactors of the same type going because if they shut them down they'll FREEZE to death.
In the US most of our energy problems are self inflicted, political scams to run up energy sales prices, the oil companies sticking it to the consumer every time the EPA sticks it to them, calfornia sucking up all the cheap natural gas so they can have "clean" power and then the people in the northern states who relied on that for home heating now have their bills tripple or more. While those using heating oil and some cases even just electricity are now paying less while carbon fouling the air like crazy. And don't think that coal is "non-nuclear" the ash from burning that doesn't go up in the air is contains enough uranium and thorium to be a potential source of reactor fuel. http://www.ornl.gov/info/ornlreview/rev26-34/text
At least in a nuclear plant they keep the waste and fuel contained, not blasted out of a smoke stack or floating around on some barge until they can find a country to unload it in.
The energy has to come from some place. And it HAS to come from YOUR BACK YARD because the grid wasn't made to have power generated in a designated dirty state like kentucy, or tennessee and transmitted all the way to the east coast. The question is, do you want CO2 and thorium ash spewing plant in every city, or a reactor powering 12 cities and giving some neurotic mommies a panic attack 6 times a day.
As for alternate energy, solar cells take a lot of power to make, windmills take energy to machine and transport to the location, micro-turbines/water wheels require a certain type of landscape and water supply. All these are great if you live in the middle of nowhere. Solar heating/cooling is great if you can afford to have it worked into your house.
But the bulk of your power needs still come from coal and nuclear power. And nuclear power can't continue if you have to bury every ton of concrete ever touched by 12 extra neutrons in some dump. And coal burning can't go on for another hundred years or we'll run out of air. This means we have to come up with some sort of reasonable nuclear regulation, acceptable loses, etc.
No, that's simply not true.
Union Carbide in Bhopal: 3000 to 8000 dead; over 100000 injured.
Chisso Corporation at Minimata: mercury poisoning kills hundreds, with at least 3000 people afflicted.
The Grandcamp in Texas: Fertilizer explosion kills nearly 600; over 3500 injured.
Chernobyl: fewer than 100 deaths to date; fewer than 1500 known attributable radiation-related illnesses. Potential premature deaths due to excess radiation exposure estimated to be 3000, but we'll have to wait and see.
Nuclear power is dangerous, but there's a lot worse out there. Look up deaths attributable to coal-fired power plants sometime.