Byron nuclear power plant loses power and shuts down
Corrected copy Yesterday, the Byron nuclear power station lost power to Unit 2, which had to shut down. During the shutdown, the plant vented steam from the plant secondary side, which MIGHT contain minute quantities of tritium based on the assumption of some leakage between the primary and secondary through steam generator tubes.
Here is a local newscast discussing the incident. The quiz for the day is to see how many specific public relations faux pas you can find in this report of what is apparently an exceedingly minor event at one of Chicago’s most important industrial facilities.
Byron Nuclear Reactor Loses Power, Venting Steam: MyFoxCHICAGO.com
On Thursday, January 26, I spoke to Bud Ryan, an antinuclear activist who has recently produced a film titled The Forgotten Bomb aimed at reenergizing interest in efforts to rid the world of nuclear weapons. We agree on that issue, but Bud has expanded his antinuclear activism to opposition to nuclear energy and even to the point where he questions the value of nuclear medicine. The conversation on Atomic Show #179 – The Forgotten Bomb was a bit different from the normal fare on The Atomic Show. We ended by agreeing to continue disagreeing. It is worth listening to the discussion, in my opinion, if only to learn more about what motivates people to fight so hard against of the best tools that man has ever discovered.
PS – I hope that the comment system issues that have been plaguing Atomic Insights since Sunday have been solved. If they haven’t, I suppose that you will have a little difficulty taking the quiz. However, please understand that no comments have been lost or inadvertently deleted; they have just been taking longer than normal to show up in the thread.
Follow-up reports on Byron Unit 2 loss of offsite power
NRC NEWS (January 31, 2012) – NRC BEGINS SPECIAL INSPECTION AT BYRON NUCLEAR PLANT
Unit 2 remains in a safe and stable shutdown condition and the diesel generators continue to supply power to the plant as planned for this type of incident. There was a steam release from the non-nuclear side of the plant with trace amounts of tritium. This type of steam release is used by nuclear power plants to release pressure in order to maintain the plant in a stable condition. Doses to the public from this type of release are significantly below even the most stringent Federal protective limits and, therefore, do not pose a risk to public health and safety.
Rockford Rochester Register Star (January 31, 2012) – Unusual Event’ at Exelon’s Byron nuclear plant is over
Exelon Nuclear officials say an equipment failure in a switchyard near the plant triggered the automatic shutdown of Unit 2.
The company, which continues to investigate the shutdown, said the plant is “in a safe and stable condition with no impact to public safety.” The plant is about 20 miles southwest of Rockford.
Christian Science Monitor (January 31, 2012) – What Got Vented Into the Air?
Where did the tritium come from?
It’s a byproduct of the nuclear reactions that take place in the plant’s reactors and boron, used in a reactor’s coolant to help control the reactor’s chain reactions. It found its way into the vented steam at Byron because the piping that carried the reactor water through the steam generator has some small leaks, Lochbaum says.
One error is yours–the station did NOT vent primary coolant, which contains large amounts of tritium. The plant used the steam generator Power Operated Relief Valves (PORVs) to vent steam from the SECONDARY in order to remove decay heat from the primary.
As to the video, they did correctly quote the NRC spokesperson, who mislead people that the operation of the PORVs was necessary to remove the pressure in the reactor. Pressure control was maintained by normal operation of the pressurizer system. It is correct that without decay heat removal the pressure in the primary would have risen, but the statement is still misleading as the design method of decay heat removal until shutdown cooling can be put is service is through the steam generators. If the plant had not lost power, the circ water pumps would have kept the condenser available to remove that heat, but without them the design mode is through the SG PORVs. Also, that video, like everyone other one I have seen, shows the cooling tower, which is not releasing steam from the SGs.
I have corrected the post. I apologize for the mistake. My excuse is that I had no idea why anyone would consider secondary side water to have ANY tritium in it. Even if there is a minute quantity of tritium, how can venting the plant during a shutdown release anything other than routine stuff since secondary side water always has a certain amount going to the atmosphere through various pathways?
I apparently need to add to my education.
The amount of tritium even in the primary system isn’t large – less than 60 Curies total at equilibrium for such a large plant. It’s not enough to kill anyone, even if all of it were vented purposefully. CANDUs fairly routinely emit entire PWR inventories worth of tritium. No health effect. The stuff just floats away, diffusing it to way below background levels of radition very rapidly.
The Fukushima reactors vented a considerably larger amount of tritium, since most of the primary coolant was lost. Even that is of no health concern.
“…vented primary coolant”? Are you sure about that Rod? The NRC Event Notification Report only mentions that the aux feed pumps and atmospheric relief valves are in service, which would be normal for this type of trip. But those would be secondary side, not primary. If they were venting primary coolant to the outside, I think that would be mentioned in the report, as it would be quite abnormal.
Shouldn’t they be evacuating Illinois? [/sarcasm]
Not at all. After the movie The China Syndrome, everybody knows that a nuclear plant meltdown would “render an area the size of Pennsylvania permanently uninhabitable.”
They should be evacuating Pennsylvania.
Yep, Byron is a Westinghouse 4-loop PWR: http://www.nrc.gov/info-finder/reactor/byro1.html
If they are “venting primary coolant”, essentially they’ve got a LOCA outside containment and should be declaring a Site Area Emergency. The Unusual Event is the required declaration for loss of offsite power, and is not radiologically related.
Obviously they are just cooling the plant by dumping secondary steam to atmosphere, which may contain minute amounts of tritium from previous primary-to-secondary steam generator tube leaks. Steam-driven aux feed pumps will also have a release path to atmosphere.
They would be better off just saying “no release above Tech Spec limits”, rather than being absolutely technically, literally correct about barely detectable and meaningless quantities of tritium that will just confuse and inflame folks. Once again, the nuclear PR squad loses a game.
They are probably releasing far less activity than a coal plant or a methane well does during routine operations. Let’s send some breathless reporters out to cover that!
The reason the news media aerial shot shows the massive steam column coming from the (unaffected) Byron Unit 1 cooling tower is:
1 – most of them don’t know the difference between a containment building and a cooling tower, and if they took the time to find someone who does, it might delay their news flash by 5 minutes and the other guy would get the scoop;
2 – the release from the tower is much more massive and obvious, compared to the much smaller atmospheric steam dump from the affected unit in the background. The natural reaction of the public is “oh, my god, look at all that tritium coming out of there!”
Even so, I thought the reported at the scene did a fair job at not reaching for a fear-mongering angle, which is often irresistibly tempting for those folks.
I’ve been trying to “fight the good fight” over at sfgate.com (the online version of the San Francisco Chronicle). The general anti-nuclear comments have been along the lines of “Tritium, must run away”.
Finally got around to backing you up Paul. Sorry I was late.
Indeed, like HuffPost, SFgate is a habitat infested abundantly with ignorant atomophobes, “spewing” hackneyed clichés and nonsense.
But then I love playing antie whack-a-mole as much as Elmer Fudd likes hunting wascally wabbits. Good thing he never ran into me. I would have taken that shotgun and wapped it awound his neck.
Dang! I should have said “Elmer FUD”!
As it is mentioned in the lead article, I am reposting this comment from the Atomic Show #179 – The Forgotten Bomb
This was only Atomic Show that I had to listen to in stages. The depth of this person’s ignorance, and the obvious lack of research of the topic makes me wonder how he can arrogate himself the title of documentary filmmaker. You must have the patience of a saint, as I would have lost it with him in the first ten minuets.
Another book this clown should read is John Mueller’s Atomic Obsession: Nuclear Alarmism from Hiroshima to Al-Qaeda to get a little perspective.
How radioactive is the steam? I know it’s almost nothing but it’s easier to minimize concerns of others with hard numbers.
Exelon also operates the Braidwood plant in Illinois. Braidwood had a tritium leak a few years ago from I believe the S/G blowdown line. This was blown way out of proportion by the news media, so now every time an Exelon plant releases anything, they have to mention tritium.
Yeah, like the Space Shuttle costs were always “overblown”. If we allow people like David Walters to have their way, and get the taxpayer sucker to backstop nuclear then you can count on a lot of nuclear engineering problems being swept under the rug as:
@Dipster – so you really believe that this event was something worth worrying about? What do we have to do to gain the credibility to be truthful and help people understand the difference between a real issue and an event without any consequences.
The best place to start is to not require the manning of special emergency response centers for the minor things.
If its not a problem then don’t make it look like a problem.
What happens is this type of thing turns into. Because that steam is so deadly. It requires emergency response actions for any amount of steam release.
Did David Walters comment on this blog post? I must have missed it.
Nope, just reading the replies. Muchado about nothing, which is the point of this blog entry. Zzzzzzzzz.
If it’s any consolation, you guys seem to be paying much more attention to this incident than the rest of the world. This doesn’t seem to be getting much press attention.
Google News doesn’t have it on the front page (maybe if you actually searched for it, you’d probably find it). NPR hasn’t posted anything about it. I haven’t had time to check other news outlets, but this doesn’t seem to be something which anyone is worrying about (other than the full-time anti-nukes).
Jeff… It’s Super Bowl this weekend… can’t have any “real” news take up valuable Pre-Show Time! hehe
This is, so far, just a local story. However, if pro nuclear advocates do not understand the facts and prepare to respond when/if necessary, the floor will be dominated by the antis who never let such an event pass without notice.
The environmentalist shown was mad that no numbers were released by the NRC. I would guess that if numbers were released that the fellow would not believe them. A no-win situation. However, the simple solution is that any person or group can go measure the radiation themselves. Of course it would then be hard to spread FUD.
My guess is that detecting any radiation from this particular incident would be very difficult for an average joe.
If there was anything significant, Greenpeace would be all over it by now. Same for the UCS.
And don’t kid yourselves, they have the measurements at hand. But it won’t serve their purpose to publish them.
The transient, in my opinion, is noteworthy because it involved a Loss of Offsite Power. Those who understand Probablilistic Risk Assessment and Event Fault Trees know that this in an initiator of interest in CDF and LERF.
The NRC dispatched an AIT to Wolf Creek recently due to a Loss of Offsite Power.
In the post 2011 era – earthquakes, flooding and Loss of Offsite Power will raise regulatory interest. Rightfully so. Trace of tritium = not an issue.
One of the units at San Onofre was taken offline due to a steam generator tube leak. This story from ABC News made the top of the Drudge Report.
If something makes it on Drudge, there are going to be eyeballs on it. Again, the actual radiation released is insignificant in the big picture. But San Onofre is in California and some people are convinced this is another Fukushima about to happen.
For some perspective, here’s a reference that calculates how much activity and waste a coal and nuclear plant produces:
Coal fired powerplants emit “up to 82 Curies” of radiactive noble gasses, uranium & thorium particles, and radioactive halogens (bromine and iodine) per year.
Wow, coal plants emit many times more radiation in normal operation than nuclear plants in a power outage venting operation. And the the coal radiation types are much more dangerous (bioaccumulating iodine, uranium, and thorium). Somebody alert the breathless journalists.
There must be some form of Emergency Nuclear Truth Rebuttal Squad (a nuclear carnival collective maybe? dialing up the media during these kinds of incidents to get the story straight and in perspective (i.e. the health effects of this accidental discharge is equivalent to these two smokestacks belching soot for 24 hours, etc) or at least get it on the record that the media refused a corrective rebuttal to help make their report accurate and fair. It makes no sense for slanted alarmist reporting and Arnie to consistently get away unchallenged like this.
Is it normal operating procedure to vent radioactive steam from the non-nuclear side of the plant when there is a loss of offsite power, and back-up generators are working fine? Something doesn’t add up here. If the emergency system “worked as planned” and the public was “never in danger,” why evacuate workers from the site? Why were back-up generators and main and back-up cooling systems not adequate to keep the plant in a stable condition? Exelon says all is fine, but the situation looks pretty murky and abnormal based on the little information that has been released about this “unusual” event. NRC is launching a “special investigation” on equipment concerns and water pumps for this plant (soon to reach the end of it’s 40 year operating license).
“Is it normal operating procedure to vent radioactive steam from the non-nuclear side of the plant when there is a loss of offsite power, and back-up generators are working fine?”
Depending on the feed into the plant from the grid, when a PWR like Byron loses offsite power and trips, a number of very large high capacity pumps like Reactor Coolant Pumps and Circulating Water Pumps may not be available. The secondary side steam that is now shunted around the turbine generator and normally dumped straight to the condenser may now have to be vented to atmosphere because the CW pumps are not available to cool the condenser. This is not the preferred flow path, but it is acceptable on a loss of offsite power.
The emergency diesels are only designed to support emergency loads like safety injection pumps and electric aux feed pumps. They are not nearly large enough, nor designed to, power RCPs or CW pumps.
As for the steam being radioactive, unless there is a steam generator tube rupture in progress, the amounts of activity released are truly negligible. It is like saying the person you sleep with is radioactive, or that granite countertop in your kitchen is radioactive – true, but of no concern. Nukes consistently shoot themselves in the PR foot by scrupulously identifying anything measurable above background as “radioactive”. By that measure, the coal plant down the road is constantly emitting “radioactive steam” (and particulates), and the banana pile in the supermarket is “radioactive material”. As I said above, they should just say “no release above Tech Spec limits”, and be done with it.
“If the emergency system “worked as planned” and the public was “never in danger,” why evacuate workers from the site?”
Because the loss of off-site power procedurally requires them to declare an Unusual Event, and enter the site Emergency Plan. Activation of the Emergency Response Facilities may or may not be required. So just send the secretaries and non-essential people home until everything is sorted out. Again, their super-conservative attitudes and actions are suspiciously misconstrued and come back to bite them.
“Why were back-up generators and main and back-up cooling systems not adequate to keep the plant in a stable condition?”
Who says the plant wasn’t in a stable condition? It was using steam-driven and possibly emergency diesel-driven aux feed pumps to feed the steam generators, which were steaming off to atmosphere to balance the decay heat being produced by the shutdown reactor.
“Exelon says all is fine, but the situation looks pretty murky and abnormal based on the little information that has been released about this “unusual” event.”
Unusual Event has nothing to do with frequency – it is the official NRC name for a low-significance event procedurally requiring activation of the site Emergency Plan. The next level up would be called an Alert. As for “murky”, nuclear utility PR is not the best thing that they do – unfortunately whatever they do say is often misinterpreted and spun up anyway. Some complain that they are not getting enough information, others complain of being spoken to in nuclear technobabble.
“NRC is launching a “special investigation” on equipment concerns and water pumps for this plant (soon to reach the end of it’s 40 year operating license).”
They always will send a AIT (Augmented Inspection Team) out on something like this to see if it was something the utility could have prevented, if the operator and management response was appropriate, and if corrective actions are thorough. Don’t worry as a taxpayer – they will be billing Exelon $278/person-hour for the privilege. Sorry, Byron is not reaching the end of its 40-year operating life – their license goes to 11/06/2026: http://www.nrc.gov/info-finder/reactor/byro2.html . And so far there is no reason they should not get a 20-year extension.
“Something doesn’t add up here”
I don’t want to squash your healthy skepticism, but really the only thing that doesn’t add up is your understanding of PWR operations. And its hardly your fault – if the utilities, the NEI, and the ANS were out there educating the public a little better we wouldn’t have this energy crisis/climate change/antinuclear fiasco we find ourselves in. It’s a dirty job, but unlike me, some of them get paid to do it.
CANDU reactors regularly vent tritium gas during normal operations and no one gets into a knot over it.
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