Electrical problems trigger radioactive steam release at Palisades
And the fun continues!
Not that anyone really cares about the dangers of cumulative low level contamination, but:
http://michiganmessenger.com/52729/electrical-problems-trigger-radioacti...
Electrical problems trigger radioactive steam release at Palisades
Entergy’s Palisades nuclear plant near South Haven is venting radioactive steam into the environment as part of an unplanned shutdown triggered by an electrical accident.
This shutdown, which began Sunday evening, came just five days after the plant restarted from a shutdown that was caused by a leak in the plant’s cooling system.
Nuclear Regulatory Commission spokeswoman Prema Chandrithal said that the current shutdown happened because an object slipped during work on a circuit breaker and caused an arc that took out power for one of two DC electrical systems that power safety valves and other devices.
According to a notice filed with the Nuclear Regulatory Commission, the plant is stable and “controlling temperature using Atmospheric Dump Valves.”
“The steam that would normally go to the generators, that steam is now going into the environment … through the steam stack,” said Chandrithal. “This would have very low levels of tritium.”
Tritium is a radioactive isotope of hydrogen.
The plant is monitoring the levels and will report them to the NRC, Chandrithal said.
Palisades’ 798-megawatt reactor began operation in 1971, and through a license extension granted by NRC, may operate until 2031.
This is the second time it happened THIS YEAR
...and according to this article, it is NOT normal procedure for when there is a problem this plant but rather, evidence that the main emergency steam venting failed. AGAIN.
http://www.istockanalyst.com/article/viewiStockNews/articleid/4834614
The ADV is a backup system and last time they dumped, it WAS radioactive.
http://pbadupws.nrc.gov/docs/ML1102/ML110240643.pdf
The amount was unspecified, with the vague statement that it was "very low." What "very low" might mean to a nuclear facility that is assessing itself, I shudder to imagine, which is all I'm left to do with that meaty piece of data they provided.
An incorrigible optimist might think that this time it didn't do the same thing. I wish such a person well, but also encourage discernment.
ADV
The ADV is a backup system and last time they dumped, it WAS radioactive.
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Evidently you don't understand that ordinary water has a small amount of tritium within it. Mother Nature makes tritium, and it is in all our water. The important point in the cited report is that the amount was "within regulatory limits"; i.e within the normal amounts that are allowed to be released without harm.
A nuclear plant has multiple systems to reject heat. One method is to open the turbine bypass valves and send the steam directly to the condenser. That may or may not be sufficent depending on reactor power and whether the plant has full power rejection capability in its condensers.
The condensers are sized for the amount of heat they have to handle. In normal operation, the condenser has to reject about 2/3 of the reactor's power because 1/3 got converted to electrical energy.
Some power plants have the condenser sized so that is all the condenser can handle. If the reactor is at 100% power, and the condenser can only dissipate 67% of that energy; then you need some way to dissipate the other 33% that would have been dissipated by the generator. ADV is the way to do that.
Some nuclear power plants have 100% bypass capability. In these plants the condenser is sized bigger than it has to be, so that it can handle 100% of the reactor power. I don't know if Palisades has this capability or not.
If it does not; depending on the reactor power, turbine bypass isn't enough; and the ADV is normally needed.
Long term effects
I care about low level cumalitive radiation.Is this procedure a rare occurance in industry???
It's SOP
For a PWR, like Palisades; this is a normal procedure for short outages when you need to stop the turbine and generator, and keep the reactor running.
It normally doesn't release ANY radiation or radioactivity to the environment, and there's no evidence that Palisades is releasing any. However, the operators are monitoring to be sure.
For a BWR, like Fukushima, atmospheric dump is only done as an emergency procedure. Look at the following diagram of a BWR courtesy of the NRC:
http://www.nrc.gov/reading-rm/basic-ref/teachers/bwr-schematic.html
Imagine there is a valve in that steam line at the top. Imagine that this valve can divert steam from the turbine at right to the outside. In a BWR, there is only one loop of water, and it goes through BOTH the reactor and the turbine. Since it goes through the reactor, the water is slightly radioactive, and blowing it into the environment releases radiation.
However, Palisades is a PWR, see this diagram courtesy of the NRC:
http://www.nrc.gov/reading-rm/basic-ref/teachers/pwr-schematic.html
Again imagine there is a valve in the steam line at top to divert steam to the environment. However, note in this diagram, the loop of water with the steam and the valve DO NOT go through the reactor. The water in this line is NOT radioactive.
Notice that there is a separate loop that runs through the reactor. That loop has slightly radioactive water. But it is always pressurized, and always liquid; it doesn't boil to steam.
So for a PWR, like Palisades; atmospheric dump is a NORMAL function used when they have to stop the turbine.
In fairness, with a PWR, there is a SLIGHT chance of radioactivity release. You see the two loops come together in the tank labeled "steam generator". If there is a very small undetected hole, then a very small amount of the radioactive water could leak into the non-radioactive water. Therefore, a remote possibility exists for a very small release of radioactivity, and so the operator monitors the outflow to be sure that they are not releasing radioactivity.
The plant operator constantly monitors the steam generator for leaks. If the leaks are anything but little pinholes, they are immediately repaired.
Normally atmospheric dumps don't put any radioactivity into the environment, but the remote possibility exists, so it is monitored.
It is analogous to you running your car in the driveway without the transmission engaged. The heat from the car is being dumped into the air by the radiator. Now there is a small possibility that your radiator has a leak, and you will drip ethylene glycol onto your driveway. Ethylene glycol has a taste that pets and children like; but it is very poisonous.
So what do you do? Do you never run your car in your driveway? Or how about when you do, you check to see that you aren't poisoning your children or your pets with leaking ethylene glycol. If it leaks, you stop and clean it up.
Careful...
I've read news reports from newspaper and TV media serving the South Haven, Michigan area. ( I've been there - it's my father's home town. ) Those media outlets mention the venting, but not "radioactive steam".
The "radioactive steam" reports seem to come from "journalists" with an anti-nuclear bent.
Atmospheric Dump
According to a notice filed with the Nuclear Regulatory Commission, the plant is stable and “controlling temperature using Atmospheric Dump Valves.”
“The steam that would normally go to the generators, that steam is now going into the environment … through the steam stack,” said Chandrithal. “This would have very low levels of tritium.”
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Palisades is a PWR, which means it has a primary loop(s) that goes through the reactor and primary side of the steam generator, and another secondary loop that goes through the steam generator, turbine and condenser. Because the primary loop goes through the reactor and is exposed to reactor neutrons, it becomes slightly radioactive with tritium.
The secondary loop does not go through the reactor. When the plant does an atmospheric dump, it is steam from the secondary, non-radioactive, loop that gets vented to the atmosphere in lieu of going through the turbine.
I'd take the reports with a grain of salt. Most reporters seem unable to distinguish these characteristics and when they are told of venting or dumping of steam, they usually don't distinguish between the radioactive and non-radioactive loops.
If the steam generator had a leak that allowed some primary coolant water to get into the secondary coolant loop, that would provide a path to the environment for tritium. However, the amount would be insignificant.
Remember, that courtesy of Mother Nature, you have tritium raining down on you all the time. It is one of the radioisotopes that exists naturally in the environment.
Tritium is extremely rare in
Tritium is extremely rare in nature.
US government statement:
"Tritium comprises about a billionth of a billionth (10^-16 percent) of natural hydrogen."
This is hardly what people would understand to be "raining down on you all the time".
Please stop misleading people, you are just losing credibility as a result.
Reactor tritium
Evidently the above poster doesn't realize that the concentration of tritium in reactor coolant is also very low. Even if a reactor does release some coolant, the tritium inventory is low.
Reactor operators are only allowed to dump very small amounts of radioisotopes into the environment; i.e. levels comparable to natural background levels.
It remains to be shown if Palisades is actually dumping tritium, and if it did, the amount would have to be neglibly small.
Mathematically challenged!!
18 cubic centimeters of water has 18 gms of water which is a mole; and
thus has 6.02e+23 molecules of water. Each molecule has 2 hydrogen atoms.
So there are 1.2e_24 hydrogen atoms in that 18 cc's of water.
If only 10^(-18)th are tritium; then that 18 cc's has about a MILLION
tritium atoms. Not so rare.
You have NO credibility because you can't do simple arithmetic.
The objection is to the
The objection is to the poster's statement implying Tritium is present everywhere in high proportions, it is not. The statement about Tritium being rare comes from the US government, maybe you should take it up with them if you disagree?
Reactor tritium
Reactor made tritium starts out as natural deuterium in the water.
The fraction of hydrogen in water that is deuterium is 156 part per million.
Of that only a FRACTION is converted by reactor neutrons into tritium.
So the poster is correct that reactor-produced tritiated water has very low concentration of tritium; comparable to what is found in nature.
They are both low; but the anti-nukes seem to always go off the deep end when this small amount is produced by a reactor; but they ignore the larger amounts due to Mother Nature.
What is that old saying from the Bible about removing the mote from your own eye before you get so concerned about the small speck in your neighbor's eye.
"NRC Event Number:
"NRC Event Number: 47305
Facility: HATCH
Region: 2 State: GA
Notification Date: 09/29/2011
GEORGIA DEPARTMENT OF NATURAL RESOURCES NOTIFIED DUE TO
TRITIUM LEVELS ABOVE BACKGROUND DETECTED AT SAMPLE POINTS ONSITE
On Sept. 28, 2011, results from routine monitoring of groundwater at Plant Hatch indicated tritium was detected above historical background levels at two sample points on site. Additional samples were taken from the same points and analysis confirmed that tritium was present at elevated levels in both samples and that tritium had not migrated out of the general area of initial discovery.
Tritium concentrations up to 5.34 million picocuries per liter were observed.
Immediate actions were taken to locate the source of the leak and actions are in progress to stop the leak."
(Tritium is naturally present in surface waters at about 10 to 30 picocuries per liter (pCi/L) so this new Hatch plant leak has a concentration 250,000 times greater than natural levels).
Not in conflict
Why - there's no conflict. Evidently you think there is a conflict in
the statements "everywhere" and "rare".
There's no conflict at all. Tritium is everywhere and in low concentration.
The poster didn't say that tritium was in "high proportions"; that's something that YOU are fabricating.
Courtesy of Mother Nature, tritium is everywhere, in small concentrations, but enough so that you do get some of your background dose from tritium.
If the Palisades reactor is releasing tritium; the dose would be similarly small.
oh goody! More
oh goody! More "insignificant" and "negligible" and "small dose" radionuclides from nuke plants!
I'm all for nuke power if they can please get this S&!T under control.
I DON"T CARE if it's "insignificant" - STOP THE FRIGGIN LEAKS! It's all too common at way too many plants.
I'm tired of the arguments pro and con - everyone has an agenda. We sink trillions into a military industrial police state with unbelievable advanced technology, and we can't control leaks? Really?
Really.
I'm tired of the arguments pro and con - everyone has an agenda. We sink trillions into a military industrial police state with unbelievable advanced technology, and we can't control leaks? Really?
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Yes - REALLY!!! Do you have any idea how small an atom or a molecule is?
They are extremely small. So how do you take 2 pieces of metal or rubber or some other material and make them fit together so that molecules can't get through.
You can polish a surface to a fine sheen. But if you look at it under a microscope, it will have loads of hills and valleys. Those valleys are huge compared to the size of molecules; and molecules will "leak" through them.
Now you were saying how easy you "think" it is to make seals that are 100% leak proof?? If you "think" that, then you evidently don't understand the problem.
That's the problem with the scientifically illiterate; they don't understand when something is really, really, really difficult.
Our technology isn't unbelievably advanced. Being able to seal surfaces together so that something as small as a molecule can't leak out would be unbelievably advanced - in fact it would be just plain unbelievable.
I know it all sounds simple to you. But why don't your really think about it. Even if you do seal the joints with 100% efficiency; if you are running water through the pipe, then it is also corroding your pipe. There are little tiny pinholes where the pipe has been corroded through by the water.
Controlling leaks is really, really, really hard at the atomic scale.
These leaks sound much more
These leaks sound much more like a nightmare combination of
badly corroded plumbing and nuclear steam,
such as at Vermont Yankee Nuclear Power station:
"January 7, 2010 - Tritium Contamination Discovered
Vermont Yankee Nuclear Power station notifies the Vermont Department of Health that samples taken in November 2009 from a ground water monitoring well on site (identified as GZ-3) contained tritium. This finding signals an unintended release of radioactive material, and it means that other radioisotopes may have contaminated the environment.
February 14, 2010 - Major Source of Leak Found
A pair of steam pipes inside the Advanced Off-Gas (AOG) pipe tunnel are found to be badly corroded and leaking nuclear steam. The floor drain of this concrete tunnel was found to be clogged with construction debris and mud, which caused condensate from the steam pipes to pool inside the tunnel and leak out at a failed joint."
http://healthvermont.gov/enviro/rad/yankee/tritium.aspx
Leaks happen.
I DON"T CARE if it's "insignificant" - STOP THE FRIGGIN LEAKS! It's all too common at way too many plants.
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Seals are NEVER 100.00%. Consider your car. Does it leak oil? Look at your engine compartment and compare the engine to a new engine that you see at the auto dealers. Your car leaks. FIX the FRIGGIN LEAKS!!
Machinery leaks. Do your tires leak? Do you ever have to put more air in your tires? Guess what? They leak!!!
Evidently you are totally ignorant of the fact that all seals leak at a very small level.
About your car. As I stated above, your car leaks oil because your engine compartment is dirty. The oil is on the metal surfaces and holds the dirt. That oil is also getting in the environment.
Your car is polluting the environment with the oil that it leaks. So how come you are still driving your car when it is polluting the environment? Either fix your leaks, or don't drive your car.
What you say? The amount of oil that your car leaks onto the road and into the environment is insignificant; especially considering that asphalt road is made of oil and sand.
Radiation detectors can detect the most minute amounts of leakage in a power plant, and that is what we are talking about. Again, the environment is full of radioactivity and radiation all courtesy of Mother Nature.
Mother Nature outclasses all our nuclear activities when it comes to exposing us to radiation and radioactivity. Courtesy of the Health Physics Society at the University of Michigan:
http://www.umich.edu/~radinfo/introduction/radrus.htm
All those nuclear power plants and their small leaks contribute only 0.03% of your radiation exposure. Look at what Mother Nature gives you.
You wasted a whole lotta
You wasted a whole lotta time on a whole lotta nuthin' friend.
No one believes the "insignificant level' propaganda anymore.
And nobody is converted to an argument via patronization.
Try "Debate 101". You lose.
Just because you didn't understand it...
No one believes the "insignificant level' propaganda anymore.
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There is radiation and radioactivity in the environment normally. If a nuclear plant releases an amount that is a tiny fraction of what is normally in the environment, would you not call that "insignificant". Especially since people have different levels of radiation exposure because we don't all live at sea level.
Courtesy of the Health Physics Society at the University of Michigan, here are the sources of the average person's radiation exposure:
http://www.umich.edu/~radinfo/introduction/radrus.htm
We see that nuclear power ( "nuclear fuel cycle" in table ) accounts for 0.03%
Suppose we have someone living near the Diablo Canyon nuclear power plant. They are living near sea level, but they get 0.03% extra from Diablo Canyon.
Now consider someone that lives in Denver. They don't have the nuclear power plant; but because of the altitude, they are exposed to 4 times as much cosmic rays. Cosmic rays are normally 8%; but in Denver they are 32%
So who is getting more radiation? The person near Diablo Canyon that gets an additional 0.03% or the person in Denver that gets an extra 32% ?
Are people dropping like flies in Denver because of radiation? People in Denver are just as healthy as people on the California coast. They get a significant increase in natural background radiation and there are no harmful effects; or the effects are "insignificant".
Radiation from nuclear power plants is even less; and therefore "insignificant".
Some people can't deal with scientific facts when it conflicts with their politics. Radiation phobes are just as bad as global warming deniers when it comes to choosing their politics over scientific facts.
For what I really wish was
For what I really wish was the last time (but I know it isn't,) Cosmic rays don't get lodged in your lungs and the keep the neighboring cells nice and toasty for the rest of your life.
Then you need to study science
For what I really wish was the last time (but I know it isn't,) Cosmic rays don't get lodged in your lungs and the keep the neighboring cells nice and toasty for the rest of your life.
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Then I guess I'll have to explain the process to you since you don't know the science.
When cosmic rays interact with the atmosphere ( which can be the air in your airliner ), they produce a whole shower of sub-atomic particles, including neutrons. Those neutrons can then interact with atmospheric gases and produce radioactive atoms that can then get lodged in your lungs and keep your cells "toasty" as you put it.
Why are the anti-nukes always so damn self-righteous and arrogant when they don't know the science? We have an example here of someone getting outraged because they "think" that cosmic rays can't leave you with new radionuclides in your body.
You have radionuclides in your body that were created by cosmic rays high up in the atmosphere, and those radionuclides drifted down from the high altitudes at which they were created, and are now a part of your body and providing you with internal radiation exposure.
When you fly in an airliner, the radionuclides created by the interaction of cosmic rays with the atmosphere in your airliner don't have to drift down several miles. Those brand new radionuclides are sealed in the same metal tube you are traveling through the air.