The only reason reactors are dangerous is because everyone was still using the disaster plan from the 1960s. Cooling a melting reactor can be done very safely now if people put the effort in. This is a much cleaner solution than solar; wtf are we supposed to do with all of the solar cells every 10 years or so... landfill?
Specifically, the "design basis" accident in the 1970s was a "double guillotine" failure of the coolant intake at the bottom of the reactor.
In real life people are scrupulously careful in designing pressure vessels and pressure vessels just don't break like that -- not the way that people suck in storage tanks every day.
In the 1980s it was realized that the real "most likely" accident is that the power runs out at the plant and they are unable to manage the heat output -- if you can swirl some water around it is not that bad, but if you can't, you get Fukushima.
Modern (post-1990) designs keep enough water around that the reactor can stay cooled for two weeks without power. Had Fukushima kept a few spare diesel generators at a site above the flood waters we'd probably never have heard about trouble there on the news.
Solar cell recycling is a thing, it is easy to melt them down to get the silicon, they are even expecting to recycle the CdTe cells from First Solar. Solar cells are more like beer cans, cars and airplanes (recycle almost 100% of the steel and aluminum) and less like houses (landfill.)
I assume you are being ironic suggesting that putting solar cells into landfill is more problematic than disposing of spent nuclear fuel - and decommissioning old, radioactive installations.
Solar panels have a relatively short lifespan, require and enormous amount of material compared to the energy they generate, and contain toxic elements that never break down.
In contrast, all the nuclear waste generated by the world since the invention of nuclear energy can fit into a single Highschool auditorium.
For perspective, a giant freight ship that burns two tons of crude fuel per hour could run on 5g of plutonium per year.
You're right and wrong. The waste amount is rather small, but the steel, concrete, and water required to contain that amount is several orders of magnitude larger.
The parent is ignoring those containment requirements (or relying heavily on technologies that are still in the research phase).
But that 5g requires years of storage in a reasonably large body of water to cool it down, and then several tons of steel and concrete to store it safely.
What "certain toxic elements than never break down" would that be? Typical lifespans are estimated to be 25-30 years. I doubt that any other power plant will run that long without requiring major maintenance.
It’s an inexact measurement to give you an idea of how little waste is actually produced.
I used to feel very anti-nuclear, mostly out of fear and lack of information. Then I read more about it and learned that taking point.
Other sources I find from a quick google use different comparisons, like this one[1]:
> In fact, the U.S. has produced roughly 83,000 metrics tons of used fuel since the 1950s—and all of it could fit on a single football field at a depth of less than 10 yards.
> Used fuel can be recycled.
> More than 90% of its potential energy still remains in the fuel, even after five years of operation in a reactor.
Or this measurement[2]:
> a typical 1,000-megawatt nuclear power station, which would supply the needs of more than a million people, produces only three cubic metres of vitrified high-level waste per year,
Well, optimistically, there’s about 250,000 tons of high level nuclear waste worldwide, which represents about 13,000 cubic meters of waste. Auditoriums tend to max out at 5000 cubic meters, so, it’s fair to say it would take a few auditoriums. Best way to put it that can be understood visually is that it’s about 5-6 olympic sized swimming pools worth of waste. And generally the high level stuff is mixed in with other waste people don’t bother to separate, so could be considered a few times more than that.
Nuclear waste isn't really waste. That's part of the reason why projects like Yucca Mountain haven't been completed.
Natural uranium is a mixture of U235 and U238, an LWR consumes U235 and a small amount of the U238. It gets maybe 2% of the energy out of the uranium and most of the long-lived radioactivity is Pu239 and related actinides that have value as fuel. (In a reprocessing cycle almost all of the waste decays in 500 years.)
Reprocessing nuclear fuel to produce uranium and plutonium powder is a straightforward technology.
What's not straightforward is fabricating fuel out of that powder. The most practical way to alloy oxides of U and Pu is to put them through a high-energy ball mill that fuses together nanoparticles of U and Pu.
The HEBM can make something like Silica into a deadly poison, so just think what it can do with Plutonium!
It seems impossible to run a Pu fuel fab that is a safe place to work without using a respirator full time. The French seem cool with it, but it violates the labor laws in every other country. To make it worse, fuel fabrication is a labor intensive process which involves somebody putting pellets into a fuel rod with gloved hands.
There are alternatives (co-precipitation, liquid fuel reactors, robotics) but they have to be developed to close the fuel cycle.
Because currently fresh uranium is cheaper than reprocessing spent fuel. Further, to really close the fuel cycle and get the full benefits of reprocessing you need breeder reactors, another technology that exists and is proven to work, but with current Uranium prices isn't yet competitive with thermal reactors and a once-through fuel cycle.
None of the cost estimates on this subject really make sense because of the period of time involved.
For instance "no nukes" think it is a scandal that we could spend $100 billion on Yucca mountain, but the average nuclear plant makes about $500 million per year in electricity so that is about 2 years of energy production. It's significant, but it's not crazy.
A reprocessing cycle could easily take a century to fully burn U238 so "what it costs" is influenced by what you think interest rates will be (or should) be for next 100 years.
Fuel cycle costs are nearly zero compared to the cost of the steam turbine at an LWR. If the price of uranium tripled, it would make little different in the basebar price of electricity.
Advanced fuel cycles, today, are mostly long-term insurance against Uranium prices rising significantly.
And nope, given reprocessing, breeding, Thorium, and Uranium extraction from seawater, we're not going to run out of nuclear fuel for tens of thousands of years, if ever.
The scale of the waste created matters. Nuclear energy is about 20% of the US load, and in the entirety of the last 50 years has generated about 100,000 tons of waste. By 2050, the US is estimated to have about 10% of its electricity come from solar panels, and for 78 million tons of waste to have been created by this. We’re essentially talking two orders of magnitude more waste being created, so even if the waste involved is less of a problem it’s far from trivial. And solar panels have plenty of toxic materials in them, so it’s not like just dumping them in a landfill is safe for the surroundings either.
If we figure out a good way to recycle solar panels, then it won’t be an issue. If we do just throw them into landfills, the waste issue with solar is only marginally better than nuclear.
Well, the efficiency warranty is usually at least 80% until 25 years, so 10 years seems a bit short.
If there are enough of them, recycling can be made efficient, and disposing of them would in any case be easier than for the spent yet radioactive materials. If we wanted to we could even enclose in glass container the nasty stuff, and it would not decay its container at nearly the same rate as the radioactive stuff.
I think the problem is that doing it right requires "putting in the effort".
Unless there is a 100% idiot-proof reactor is made, mistakes and crises will still happen, maybe less often, but still sometimes, and it will kill the PR of nuclear.
The recycling argument against renewables is usually a strawman. Very few things can be recycled economically, so its an easy argument to trot out against something you don't like.
OTOH, if we decided that it was a priority to recycle more stuff and minimally subsidized it, suddenly a lot of stuff would become viable to recycle, including wind turbine blades and solar panels.
Solar panels are mostly silicon in two different forms: glass and substrate. Both can be recycled if it is a priority.
I'm sure the world will let countries freely access nuclear material, when it took the US years and a whole lot of political capital to sell nuclear raw material to a country like India.
For the same reason people 60 years ago talked as if they'd solved all the potential hazardous problems of jet travel. There will always be a little more you can squeeze out of a technology, but at some point it is good enough to be considered safe.
In the worst case scenario there is some unknown physics that leads to a jet engine destroying the universe. There is no way to prove that such a disaster can't happen. You may say "well that's absurd, we know how jet engines work" and that's exactly what I'll say about nuclear reactors.
Yes, we know exactly how catastrophic a nuclear accident can be .. and have no sensible solution for nuclear waste other than bury it and hope for the best.
Well any old working directory that exists at startup is removed. So an attacker would not be able to create the directory before the user runs the program. And they would have to be logged in as the user in order to edit the pngtopdf.py file as it is created with 0700. Also, I would rather specify the actual bytes directly and force a lazy programmer to look at the ASCII table over using []byte(" "). These are just some of my after-thoughts.
> So an attacker would not be able to create the directory before the user runs the program
I said it was a race. An attacker would race with the program's deletion of the directory to recreate it. This race is really easy to do, and there have been numerous CVEs for this sort of race.
> And they would have to be logged in as the user in order to edit the pngtopdf.py file as it is created with 0700
That's not true.
If I own a directory, I can delete and recreate the files in that directory, even if I don't own the file, even if the file is 0700. Feel free to experiment around to see this.
Hmm okay. I'm going to start fixing that part and also attempt some CGO/objective-C to replace the python dependency. I had figured that removing any possible directory that could be seen as an application directory (at app-startup) would alleviate the issue you described. Thanks for the feedback though and also taking the time to look.
That's a fantastic idea. I actually looked into it because I really didn't want to use Python to create the output PDFs. I have experience making C bindings in Go, but had issues with Objective C (I also don't know Obj-C). If you are able to remove the Python dependency with a CGo please open a PR! Thanks for the feedback too...
Thanks for the feedback. Yeah the Python part is definitely a bit hackish. Do you have any other recommendations on other problems? I'm still learning Golang and would like to improve. Thanks!
It took me a few to respond, but I'll make some recommendations now:
1. Use filepath.Glob if you want to glob
Most of [0] can be replaced with filepath.Glob. You should probably also respect TMPDIR if it's set, which ioutil.TempDir etc will do.
2. ExitErr shouldn't be used, especially not within nested functions.
You have 'defer os.RemoveAll(tmpDir)'. defers won't get called if you `os.Exit(1)` as you do in ExitErr. You should be instead doing `return nil, err` all the way back up to `err := RunApp()`, and printing the error there. That will let defers run. In general, using os.Exit anywhere other than in the main function is an antipattern.
3. Your parallel processing should be using a waitgroup or errgroup. A slice of channels is super fragile.
In [1], do something like the following:
// before the for loop
var wg sync.WaitGroup
// in each iteration of the for loop
wg.Add(1)
go func(name string) {
defer wg.Done()
cli.ImageRoutine(fileName)
}(fileName)
// at the end, to wait
wg.Wait()
Use an errgroup if you need to cancel it.
The channel thing you're doing now is more fragile than a waitgroup, and harder to reason about.
4. use of exported functions / unexported functions is all over the place and inconsistent.
There's a few other things, but that's what I've got offhand. I can't actually run the code because I only use linux, and it obv doesn't run on linux. Oh, I guess that's another thing, you want some build tags to make it more clear it won't run on linux.
Hi TheDong. I put most of the changes you recommended and I am much happier with the overall project. I decided to remove the Python part though and went back to the Imagick bindings. There's probably still some things to fix but thanks again for taking the time to look and advise.
I learned to play that game in bootcamp... actually from a buddy of mine that was definitely not white. And it definitely had nothing to do with racism. However it had everything to do with punching the person that looks! :)
This line is pretty funny: "C++ is still the most common language for writing games, and not without reason. I still do almost all of my contract work in it. I dislike it intensely." hahaha poor guy
funny... I literally just downloaded that for Ubuntu today and made my first Go app... I'm actually considering using it for C and Python as well. I typically use Netbeans for C and Pycharm for Python, but both have a ton of features that I don't use, sometimes slowing me down. I like the sleek feel of VS Code and it has been running flawlessly on Linux. Also a big fan of the Abyss theme.
Ah... well I used to run a mildly popular website... I originally wrote it to "bot" my site 24/7.... it can be used to see the index of your site depending on keywords. Also you can drop payloads with it... use it for brute force password guessing... or you can use it for SEO as well... even though it searches with Bing, Google may know about the visits if you use Google Analytics... many use cases may present themselves with very minor modifications to the code... enjoy!
I completely agree with you