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Reactor Shutdown Darkens South Florida
grassy_knoll asks, "So how fragile is the electrical grid, and just what technical problems could shut down five reactors?" "Five reactors at a nuclear power plant in Florida had gone down on Tuesday and two were now back online amid a massive power outage in the southern state, CNN reported. The report on the Turkey Point nuclear plant came as four million people had lost electricity in Miami and elsewhere in Florida, with traffic signals out and major delays on roads, authorities and media said."
I hear the problem originated with a drone in sector 7-G.
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Quo usque tandem abutere, Nimbus, patientia nostra?
good thing I backup IP over carrier pigeon.
Here is FPL's page on the Turkey Point reactor: About Turkey Point. Their site also has a News Releases page, which I'll be watching for updates whenever they get their PR department in gear.
512 MB RAM, 20 GB disk, 200 GB transfer, five datacenters. $19.95/month.
Oh, wait. This is Florida. Things already look like a Mad Max movie, minus Tina Turner and with a lot more cubans.
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your ideas are intriguing and i would like to subscribe to your newsletter.
---
Is this the MPAA? Is this the RIAA? Is this the DMCA? I thought it was the USA!
Now we're going to have yet another round of computer scientists and other pseudo-engineers telling us how they would have done it better.
Uh.. Turkey Point has *2* reactors and 3 major fossil fuel generators (As well as several generators under 5 MWs).
The power outage -- ie, some serious switch failures -- triggered the reactor shutdown. Nuclear reactors are great at supplying base load power but if all of a sudden the grid goes offline, they have nowhere to send that power and have to shut themselves down. (Power reactors don't do well with highly dynamic loads.)
It was not, as some posters seem to have misread even the summary, that the reactors went down first and caused the outage. Mind, once the reactors are down it takes longer to bring the whole grid back up, so in that sense it's contributory.
-- Alastair
... at least given how much crime shows draw on real life events, albeit massively embellished. Cue Horatio Caine.. 'Looks like someone's been left in the dark.. permanently.' *removes sunglasses*
The article says that a switch caused the power outage; if the transmission lines get shut off (perhaps the switch caused a cascading failure, as has happened before), of course power plants (no matter what type) will shut down --- there's nowhere for the power to go!
The system detected there was a problem and automatically shut the reactors down; The system worked! Maybe massive blackouts aren't the best result, but they are by far better than the worst result.
Demented But Determined.
just what technical problems could shut down five reactors?
If the article submitter had actually read the article, he might have noted the nuclear plants shut down because of an under voltage in the rest of the system (caused by a breakdown elsewhere). My guess is this is some kind of safety measure, otherwise why would you have the system shut down?
AccountKiller
Haha!
:p
Time for this Asia (China) resident to get his own back by tagging this story as 'andnothingofvaluewaslost'.
For those of you who don't know, a lot of the stories about Asian countries losing connectivity to large parts of the rest of the world were tagged as 'andnothingofvaluewas lost'. Of course, it could be argued that it is the countries that lost the connectivity that didn't lose anything of value, but hey.
I wonder why it is often stated that such places have lost their 'connection to the internet' when at least some of them probably don't much notice (China wouldn't notice much more than MSN not working, for example) - do people think that 'the internet' lives in the USA or something?
Max.
This is kind of a blow to the pro-nuclear power constituency, but outages are always a possibility. Safety nets and first response triggers are essential and this problem was corrected rather quickly so I still have confidence in the system.
On a side note:
I really hate how every problem requires a clarification that it wasn't Terrorists.
We live in a state of fear, and not a state of freedom. Are there people that really freak out and cry "Terrorists!" when something goes wrong these days. I'm not complacent just aware that the probability and capabilities of terrorist groups and there infrastructure aren't as ominous as the media and government perpetuate these days.
Did anybody seem to notice that while yes, the nuclear plants shut down, so did the coal plants. Neither of of the plants had problems. It was a problem with the substation.http://money.cnn.com/news/newsfeeds/articles/djf500/200802261723DOWJONESDJONLINE000845_FORTUNE5.htm
(NPR is running a story on it right now):
These plants were designed to shut down in case of a fall in the power reaching them from *other sources* (because they need, e.g., to run cooling pumps for a safe shutdown and can't count on their own power). I'm not sure why the outside power browned out, but it did, so these plants did what they were designed to do.
What would it take to trigger the automatic release of the control rods? An earth tremor above a pre-set limit, insufficient input of cooling water from rivers (or water that's too hot or too impure), a controller hitting the wrong switch, a software glitch, a glitch in a clock crystal screwing with timing calculations, a loose connector, a chip in an old-style spring-based socket catapulting itself into the air (which they had a nasty habit of doing), erronious control signals from other power stations, a downed power line on any segment with single points of failure, etc.
Of these, the vast majority apply to any power station - one line down not too long ago caused a blackout that covered three States and half of Canada. One line down between the east and west coasts about 14-15 years ago shut down large parts of the northwest USA for a couple of weeks. Cascading failures are inherent in the meta-stable mashup of networks that form the power grid. Too many SPFs, too little redundancy, too many communication glitches, too few contingency plans.
Personally, I think the grid needs to be massively redesigned, with far better (and more intelligent) signalling, far more redundancy at all levels and a huge upgrade on software and hardware (NT4 and Windows 3.11 are not acceptable to me for mission-critical systems - they're tried and tested, but they're not reliable and they're not secure).
Of course, this won't happen, massive cascading faults will continue to be reported on a regular basis, and people will continue to be surprised when they occur. Preventative maintenance on the scale needed to cure the system as a system is so expensive (even though it's one-off), the distributed costs of regular blackouts on even a gigantic scale look cheaper on the balace sheet, so an inefficient, decrepid, flawed power grid becomes the preferred option.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
It was due to a distribution line that failed. For those not familiar with how nuclear reactors work, two of the fission products of concern are I-135 and Xe-135. I-135 will decay into Xe-135 and Xe-135 is a very strong neutron poison (absorbs neutrons). During normal operations Xe-135 is produced from fission or I-135 decay and it is removed by neutron absorption of Xe-135 or by beta decay of Xe-135. If you are operating at high power and have a significant amount of Xe-135 in the core and you suddenly drop power the neutron flux that is removing a significant fraction of your Xe-135 from neutron absorption is gone. But the I-135 in the core still remains and more than compensate the reduction of Xe-135 from direct fission. The result is a Xe-135 spike that will overwhelm certain types of reactors forcing a shutdown and a waiting period for the Xe-135 to decay. For those familiar with the Chernobyl disaster, the reason that the control rods in that core were fully withdrawn was because they were trying to compensate for a xenon transient (since they were operating at high power before they dropped to low power for the test). The Turkey Point reactors don't suffer from the flaws that the RBMKs had, but they will still be shutdown due to xenon transients.
I was on campus completely oblivious that anything happened. My girlfriend called me six times in a row, and while I had the phone on vibrate as to not to disturb the interesting lecture on the horribly long lab I'm going to have next week, I was irritated and concerned. I called her after class to see what's up, and that's when I found out there was an outage. The science and engineering side have nice generators, hence my ignorance. The building my girlfriend, Cooper Hall, is a death trap. Apparently, the idiots at USF made sure that when the electricity is out, people are actually locked inside the building. All of the doors were locked from the inside. What the hell would happen if there's a fire? I understand that's the inferior side of campus, but there are people in my phonebook over there and therefore I'm concerned!
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Actually, I believe they shutdown due to a safety issue. When they lose grid power for powering water cooling pumps etc, their standard response is to shutdown for safety reasons. Yes I know, a power generating plant that gets power off the grid, but consider if the plant is unable to drive a turbine to power its own pumps, where does it get the power from? Okay backup generators, but they can also fail. From what I hear the current dropped enough from the grid to cause them to need to shutdown the reactors. This is a good safety thing. The bad thing is the issues on the grid that caused this and other sites to shutdown generation.
And now, we return you to regular scheduled blackout... if this were an actual emergency, you would of killed the person sitting next to you.
Tes
I smell something fivey .... the Pentagon!
Infuriate left and right
What I've heard on the radio so far (in Tallahassee, FL) is that the nuclear reactors have their coolant pumps connected to the grid so if the reactor ever had to be shut down the coolant would continue to flow, avoiding a meltdown. There was apparently a problem with the substation supplying (backup) power to the coolant pumps, and as a precaution the entire reactor shut down automatically.
E pluribus unum
that THIS is exactly how we will end up if we allow it to happen.
And THIS is exactly how we will end up if we don't. Newsflash, buddy, but the nuclear plant had nothing to do with it other than "being there", the problem was in a distribution switch that failed. These failures will happen no matter how many tree hugging hippies there are or are not, but I'm sure you won't let that stop you.
More information Here (pg 34) and here
I would want to know more about the maintenance on those switches, their rated capacity, and why enough could fail at the same time to reduce transportable capacity. Even with infinite switches, there'd be a non-zero probability of a complete across-the-board failure, but provided everything is well-maintained, you only need to guarantee that at any given point in the system, what you have spare exceeds what is likely to simultaneously fail, for an acceptable level of "likely".
Were there unnecessary single points of failure or inadequate backup mechanisms? Did so many switches fail at the same time because they were rated far too low for current usage or because poor maintenance degraded them below the ability to handle current usage? Nuclear reactors are extremely bad at handling dynamic loads, so what is going into developing mechanisms for soaking up (or burning up) power when grids do go offline? (Reactors aren't trivial things to restart.)
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
So, can I assume Fox News is reporting this is the result of a terrorist attack?
The electrical grid is a really tricky system. You've got generators putting in energy at a bunch of points. And the whole thing is AC, which means that, if you look at any particular point, you see the voltage (and current) going in a sine wave. If you drive the system at the correct phase, you're supplying power; if you're slow by 1/120 second, you're turning twice your capacity into waste heat, and you start blowing up substations. Furthermore, since electricity moves at a finite speed along the wires, you can't just have a really good clock and have everybody agree; the difference in phase you need depends on the distance between the power plants along the wires. The solution is to have the power plant measure the phase of the lines they're on, and generate with a matching phase.
Now, if something goes wrong somewhere down the lines, the power plant may not be able to get a good read of the phase. At that point, you just shut down the power plant, shut down the substations (so there isn't customer load on the lines), get the switching stations fixed, start the power plant up again in phase, and reconnect the customers. It's only if the switching stations are really destroyed that they'd actually run a power plant for local customers disconnected from the national grid, and they'd have to shut it down again in order to rejoin the grid.
What happened today is actually how it's supposed to work in case of an equipment failure: a regional blackout, some time to repair the malfunctioning equipment or swap in replacements, and then restoring power. When the grid doesn't handle the failure correctly, power lines melt down and power company manholes and buildings blow up and service isn't restored for days to some customers.
1998: "A massive power outage left millions of people without power Friday. The cause of the blackout is unclear."
2008: "A massive power outage left millions of people without power Friday. The government says terrorism was not involved, but the cause of the blackout is unclear."
Sigh . . .
Hey, there is a fate worse than death!
Blank until
I'd love to see the two of them in a debate with each other. That'd be great. Think of the drinking games you could create off that.
I want peace on earth and goodwill toward man.
We are the United States Government! We don't do that sort of thing.
I'd be a little scared of the vortex of intense stupidity that would form as these two approached each other. I mean, this would probably rip quarks from each other, rip space time and bring the dinosaurs back. I think, in the interest of galactic peace that these two be kept a minimum of two hundred miles apart.
The world's burning. Moped Jesus spotted on I50. Details at 11.
I'm afraid that can't be correct. He was "imprisoned forever by a force field powered by an eternal battery" and is thus incapable of making visits to Earth, even transiently.
... wait ... xeon transients - never mind
Oh
A substation. Not the reactor. Then the reactor went offline because of the undervoltage condition caused by that power outage. Neutron-absorbers in the fuel had *nothing* to do with this.
The backup generators have backups. All critical systems have at least double redundancy, that's why nuke plants are so darn expensive to build.
Naw, if anything it would take the form of a smug cloud, which isn't quite as impressive as ripping space time -- though no less deadly.
I want peace on earth and goodwill toward man.
We are the United States Government! We don't do that sort of thing.
Neutron-absorbers have something to do with minimum down times for nuke plants.
I'd have to guess the reactors generators were over-voltage due to lack of load and that triggered the shutdown. I can't imagine they ran the reactors control systems off the Miami substation.
John McAfee 'It was like that time I hired that Bangkok prostitute; to do my taxes, while I fucked my accountant'
The reactor shut down due to the no load condition. And they can't start it up for several hours due to xenon preclusion. If they didn't shut down the reactor it would have shut itself down due to the large xenon transient. This is common knowledge for nuclear engineers. If you lose your load on a nuclear reactor, you must shut down due to the massive xenon transient. If you are not familiar with this then you should read the reactor fundamentals handbook link above. This isn't rocket science.
Long before then we will run out of money to pay to OPEC and China.
I prefer the "u" in honour as it seems to be missing these days.
Most everything's been covered here, but I'll put my two cents in as a Nuclear Engineer (albeit in PA). Nuclear power plants run all safety systems on offsite power. This is a perfectly understandable setup, because if something goes wrong and we need to scram the reactor, the safety systems need to keep running. At my plant, we have two completely separate backup diesel generators to supply power in the event of loss of offsite power, but shutdown is nevertheless the automatic response, both because the diesels won't run forever and because a sudden loss of load messes with a very delicate balance of turbine power, reactor power, and load. Nuclear power is a popular black sheep for these kinds of events because people are afraid of it, and the news media profits from sensationalist broadcasting. Whatever garners the greatest response, they'll run with it. As for the grid as a whole, it is not a Florida problem. The same issue came up with that massive northeast blackout in what was it, 2003? The whole system is ancient, but it's too expensive to completely overhaul it, not to mention people wouldn't stand for the loss of power as systems were replaced and/or updated. In terms of power distribution, there's a delicate balance as plants come on and offline and demand goes up and down. Any significant transients (like this undervoltage line) just causes a complete mess. This is a problem that's only going to get worse as power demands continue to rise, especially if we don't build enough plants to keep a healthy amount of excess capacity.
I'm in Miami and experienced the horrific even (playing tennis for 45 minutes because I could not log into wow). I spoke to my bud in FPL (ze power company) and he told me that a massive transmission cable went down by aligator alley (I75 stretch that crosses the everglades). This created some load issues and a plant (non nuke) had to shut down to protect itself. This in turn routed more power to the rest of the grid creating the same effect we saw in California and in the NE in the past. Turkey Point, the nuke, was merely one of the plants that shut down to protect itself. Only reason we are talking about that one and not the others is that talking about nuclear power is sexy.
"This message was sent from an Apple
"nuclear power plant operation isn't rocket science"
- and that's why we don't have regular interplanetary space flight
I am not a nuclear engineer, so maybe I'm missing something obvious. That said, I don't understand why the system would automatically shut down due to a no load condition.
I understand why a backup generator for a house does this. It's to prevent linemen from getting killed touching lines that they assume are not hot while repairing a downed power line. One would not expect a lineman to assume a nuclear plant's output lines are not hot, however, so that reasoning doesn't apply.
I might be able to understand them shutting down the power output, if only to avoid problems when they have to resynchronize the phase of the power when the lines go hot again, but I don't see any reason that should necessarily be linked to the operation of the nuclear pile. The nuclear pile is just moving a bunch of steam around. It can do the same thing whether the turbines are under an output load or not.
At worst, I'd expect the water to move faster through the turbines because there wouldn't be as much resistance to spinning them, and maybe not even that, assuming there are governors on the turbines... unless, of course, the governors are simply insufficient to handle that situation, in which case that screams "design problem" to me.
I assume that the multi-day outage could have been avoided if the reactor were brought down slowly instead of being scrammed. If so, one would expect that a human being should be required to push the button to shut down a reactor for lack of load reasons, particularly when shutting it down completely requires a multi-day rest period for reaction byproducts to degrade. I would expect that the only time a reactor would be scrammed automatically is when there's a safety risk to its continued operation, and I don't see why a decreased load would qualify as a safety concern.
Am I missing something fundamental here?
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"the large and rapid build-up of additional Xenon reactivity load following a reactor trip can cause an extended (approximately 40 hours) reactor shutdown"
http://www.nuceng.ca/ep6p3/class/Module3D_XenonJun21.pdf
You know all too often I hear of IP over Carrier Pidgeon as the next generation of internet technology, something even bigger than Web 2.0 and software as a service. I'm sure it's going to actualize our paradigm shifts and all that but seriously lets get some cold hard FACTS into the discussion.
Firstly:
Where are the numbers on latency and bandwidth?
Details like this are frequently brushed aside when making unrealistic promises. Let's stop listening to the marketing department and talk to the engineers working specifically with IP over Carrier Pidgeon and IP over Avian Carrier in general. (From here on referred to as IPoAC) We have no hard numbers on packet size limits.
Secondly:
What is the average delay on DNS resolution?
Another salient fact glossed over is that IPoAC completely depends on DNS caches as name lookups are expensive. As well as how long does it take to train new carriers til they are able to follow the new routes?
These and other questions lead me to believe that IPoAC is entirely VAPOR and has most likely not even been successfully implemented in the real world.
Does anyone have any real stats we can use to examine this? Or is IPoAC just going to be rammed down our throats by another mega-corporation with an agenda? It's time to really open the discussion on IPoAC.
Cwm, fjord-bank glyphs vext quiz
The premise of continually saying it wasn't the fault of terrorists is to keep the belief that someday it could be terrorists in the mind of the populace.
As my evil minions say, "Hail Eris."
-- Nate
It's a shame there isn't a hydrogen electrolysis facility nearby to take the power when the normal users can't be reached.
The fundamental thing that is missing is the amount of power being generated.
You have to cool the steam down somehow, normally it looses energy by turning the generators but if that is not the case the energy needs to go somewhere.
The steam is normally re-condensed and then reused in a closed or semi closed loop depending on whether there are cooling towers. There is no way that the
cooling capacity would be able to dissipate the full load and hence the need to rapidly shut-down. This is the same for coal and gas plants as well.
The Xenon is what prevents you from starting the reactor once the grid problem has been fixed. Thus while the reactors had nothing to do with the cause of the shutdown, they can't simply be restarted the moment the problem is gone, you have to wait for several hours or even a day. The time period depends a bit on the precise reactor type, and some can be safely restarted without waiting for Xenon to decay. I don't know about the specific reactors in question, so I can't tell if this was an issue or not.
It's pronounced NEWK-yoo-lurr honey, NEWK-yoo-lurr.
-Arthur
Cave ne ante ullas catapultas ambules
I bet he'll write "". Same as he has almost every day since he retired.
ResidntGeek
and he told me that a massive transmission cable went down by aligator alley
The real story is that a bunch of electrons were pulled-over by a cop in Waldo for going c in a 25mph zone.
http://www.city-data.com/forum/florida/5365-moved-waldo-florida-speed-trap.html
This is the same for coal and gas plants as well.
This is the key point that the idiot with the +5 mods above is missing.
This shutdown has nothing to do with neutron poisoning, and everything to do with load loss, the same as any conventional power plant. Negative reactivity from 135Xe typically doesn't prevent restart for an hour or so, and as the news is reporting the reactors are running again they must have had then back on line fairly quickly.
And yes, I am a nuclear physicist, and my undergraduate education as an engineer included reactor design.
Blasphemy is a human right. Blasphemophobia kills.
LOL
Nothing to see here; Move along.
Just so you know, three weeks after Ice storm 1998, there were still about 700k people without electricity in the middle of winter(most houses use electric heating and usual temperatures around that time of the year are below zero).
I presume they want the easement to bury long distance powerlines, not the ones for local distribution. Wikipedia seems to mention that electric power transmission lines are very seldom underground. Of maybe they're concerned about being sued for EMF-related medical issues.
Jean-Francois Im's blog
LOL! I live in the Orlando area and we got the power back on after approx 40 min.. Slight chaos outside to say the least, people lose all their common sense when the traffic lights go out and start doing all kinds of smart things. Quite a few crumpled cars in the closest intersection.
If you mod me down, I *will* introduce you to my sister!
First off, There are not 5 nuclear reactors at turkey point. there are 5 units. units 1 and 2 are oil and natural gas(fossil) units 3 and 4 are nuclear and unit 5 is a gas turbine unit. The shutdown of the reactors DID NOT cause the blackout contrary to what the slashdot summary says. A failed switch and fire at an electrical substation outside Miami(read: not at the power plant) caused the grid to go into an imbalanced state at which time the plant experianced a loop(loss of offsite power) and did what they are supposed to do. There was no place for the power to go, so they shutdown to stop making it. All the power plants did what they were supposed to do. The fossils were presumably shut down. I'll find out more when I get to work. great, now i'm gonna be late.
Oh Crap, I'm an optimist.....
The AC had his facts in order. Even your quote backs him up. "The initiating event was a malfunctioning disconnect switch." The reactor shutdown was an (expected) response to the initiating event.
Fission products in the fuel have everything to do with why the plant was shut down. Operating nuclear plants run at a significant percentage of their capacity for reasons of economy. A sudden loss of load (as in the disconnect opening) results in the rapid rise in primary coolant temperature due to noplace for the energy to be dissipated. This will result in a reactor shutdown shortly after the load is lost (either by overtemperature or by turbine overspeed trip).
Heck, a sudden loss of turbine load can cause the turbine to overspeed, causing a turbine trip which in turn causes an automatic scram. Since every good discussion needs a car analogy, imagine driving up a steep hill and then knocking the transmission into neutral while keeping the accelerator mashed. RPM goes up, eh?
Even inserting control rods doesn't drop power fast enough to prevent heating up. After shutdown the fission products in the core continue to decay, releasing significant amounts of heat which must be dissipated.
That's what I love about slashdot... folks argue with experts without having a background to do so.
I'm an individual! Just like everyone else!
I should note that the ability to overcome the xenon transient is dependent on the geometry and neutron moderator configuration of the reactor. There probably are some reactors out there that would not be able to start up immediately. A link further down the page indicates that this is the case for heavy water-moderated CANDU reactors, which use natural unenriched uranium. The 20-hour startup I mentioned above occurred at a boiling water reactor.
According to various reports, the outage began with equipment failure and the loss of a distribution substation. Unlike major transmission links, distribution substations feed local loads and are not a part of the transmission system critical to the movement of power between alternate sources. The loss of a distribution system results only in the loss of loads, not generating or transmission capacity.
Two things may have happened here. Neither bode well for the system's condition.
It is possible that, following a fault at the distribution substation, the primary protection relays failed to operate. There are (or should be) backup relays. But these typically take longer to operate and allow the fault transient to push the system into an unstable condition. This is bad design. System stability should be maintained even if one station's protection fails.
It is also possible that, in spite of the proper design of primary and backup protection, the regional grid is being run too to its stability limits. A fault condition properly considered in the system design which should not have caused stability problems did so because the system was being run beyond prescribed limits.
Both of these possibilities suggest that, in spite of the big midwest outage we had several years ago, lessons have not been learned.
Have gnu, will travel.
Because then you're producing megawatts of heat in your generating plant....not a good idea.
Yes, and still they fail. We had a somwhat interesting event at one of our sites in Sweden, Forsmark: When a fault in the outbound net triggered a shutdown in a similiar way, a power spike at the internal system forced all of the backup generators down, stopping power to the pumps. Fortunately, they were able to be restarted manually.
There is some debate about whether we had a risk of meltdown (our reactors *do* have some shielding if that would happend), but still the lack of safety culture was heavily critizised, and the event was classed as INES-2, and is regarded the most serious in Sweden.
The Forsmark plant was seen as a "flagship" plant for modernity and safety; hosting many demonstration tours and such. Stil there seem to be some "Oops" event beacuse of complexity ...
Actually, nuclear plants ARE dependant on grid power for operations. It may seem odd that a plant generating many megawatts to a gigawatt of power needs an external supply, but it's a matter of safety. Were the plant to run exclusively on it's own power, a single malfunction could leave it in a state where it has no power for coolant pumps yet the reactor is at full power. So, if grid power to the plant drops, the reactor shuts down immediatly as a precaution.
The Chernobyl plant was carrying out an experiment to see how well it could shut down using energy from the inertia of it's own steam turbines in the event of a secondary cooling failure with no grid power. That wasn't a direct cause of the disaster.
If they were going c through aluminum transmission wires, they damn sure had better be pulled over. Violating the laws of physics is no laughing matter, son.
Coding with assembly is like playing with Legos. Coding an application in assembly is like building a car with Legos.