• 5 Posts
  • 98 Comments
Joined 2 years ago
cake
Cake day: June 14th, 2023

help-circle



  • I don’t know much about lay person explanations of nuclear engineering that are accurate and accessible. I can perhaps recommend the textbooks I used in my major? Nuclear engineering is a cousin to mechanical engineering, so if you have a background in differential equations then you have all of the tools necessary to start learning the material. The physics of nuclear interactions are mostly abstracted away into tables and data, (such as the Evaluated Nuclear Data File (ENDF) which you can browse online here) so you don’t need to learn Nuclear Physics beyond the complete basics.

    The introductory course at my old university, which kind of discusses general things rather than specifics, uses “Nuclear Engineering Fundamentals” by Masterson. From here if you’re specifically interested in nuclear reactors, you can study Radiation Physics (Turner’s “Atoms, Radiation, and Radiation Profection”), and then Reactor Physics (Lamarsh’s “Introduction to Nuclear Engineering” and Lewis’s “Fundamental of Nuclear Reactor Physics” and Duderstadt’s “Nuclear Reactor Analysis”). From there, if you have a background in Heat Transfer and Thermodynamics (very important) you can learn how practical (rather than abstract) reactors work using Todreas’s Nuclear Systems I. This covers mostly PWRs and BWRs. Undergrad doesn’t talk much in curriculum about other reactor types (Fluoride, Lead Eutectic, Breeders, etc) that’s mostly Graduate material.

    Please note this isn’t a complete major, there’s a lot of material about radiation protection and shielding and health effects and so on.


  • Hi, I’m a nuclear engineer. I’m not looking to specifically argue against you, or counter your points. Just to provide some information, some of the things you have said I will confirm, some I will not

    Not all modern designs have these safety features.

    It’s not clear to me which passive safety features, specifically, you’re referring to. Safety is a very serious concern, and there are many different ways to make a safe reactor. If you are specifically referring to powered off passive cooling via carefully designed convection, then there are reactors in development with this particular safety system, but they tend to be SMRs, such as NuScale. However, not all reactor designs need this. For instance, a molten fluoride salt dissolved fuel reactor doesn’t need circulation to prevent damage to the reactor in the event of an unpowered SCRAM, because if the salt gets too hot it will simply melt a plug in the salt that is actively being kept frozen, and allow the salt to drain into a series of tubes which have enough surface area to be passively cooled by the air in the containment building.

    However, if by modern reactor you are referring to the current generation (Gen 3/3+) of reactors, they are characterized, in part, by the incorporation of these sorts of passive safety systems. The existence of these systems are one of the things that makes a Gen 3 reactor a Gen 3 reactor. However, because the nuclear industry in the United States essentially stopped in 1996 as the first Gen 3 reactors were coming online, the only Gen 3 or better reactors you will find in the US are the reactors 3 and 4 at Vogtle, Westinghouse AP1000. (The recent plant that came online at Watts Bar in 2016, was originally built in the 70s and just turned on for the first time recently, so it’s Generation 2.)


    The US certainly does not currently have a good plan to handle nuclear waste that is currently politically possible to implement. However, there many options, and the problem is not actually urgent. All of the transuranic waste produced by the entire 80 year history of US civilian nuclear power fits safely in dry casks on about 3 football fields. Nuclear power just doesn’t make a lot of waste in an absolute sense because it is so much more energy dense than fossil fuels. This is a problem that we can take our time on to do right. The solution will probably involve some form of reprocessing, which will reduce the amount of waste by over 90%, and reduce the amount of time it takes for the waste to decay to background levels from over 10,000 years to just 300.

    That being said, other than the plans to put it in Yucca Mountain, which has been deeply unpopular with Nevadans, there are also studies about freezing and immobilizing it in a salt mine, which is being done by Sandia National Lab, and Savannah River National Lab is investigating encasing waste in glass and other relatively chemically inert substances for disposition. Probably other projects as well, these are just the ones I’ve come across in my this far short career. I’m personally not a super fan of disposing of transuranic waste without reprocessing, due to the 10,000 year thing, but that is the method currently favored by the government due to security concerns regarding the potential of proliferation during reprocessing.


    Opinion section:

    It is true that there is only so much investment and so much manpower to go around. And perhaps a future in renewables only is possible. But I’m not confident in that at the moment due to the requirements of energy storage, but I will readily admit to not keeping up with this area of study. Perhaps large advances in energy storage are possible, but as far as I am aware the technology isn’t there quite yet, and nuclear is possible with the technology we have now (provided we can muster the political will to get them built, but historically, frankly, that has been difficult).

    Overall, I look at this largely the same way I look at solutions to “fixing traffic.” The solution is trains, not a million whiz bang things that try to be new and cool and exciting. Not individualized self driving pods, that can dynamically connect and disconnect. Not a fleet of robo-taxis. Not a hyper loop. Just trains. Trains are the solution and they are unpopular, because they are boring, proven technology, there’s nothing to sell, no value to add, no capitalist is going to want to do this because it’s a big investment and shareholder value blah blah blah. They are an AM* solution not an FM** promise.

    We have a functioning solution to energy that is politically difficult in nuclear reactors. And we have a half-solution that is easy to spin up in he private sector, but difficult to get us all of the way to carbon free in renewables. We are still waiting on the other half of the solution, and until then we’re simply stuck on carbon power to meet the difference. At least, that’s how I see it. But I only know what I know.

    Thanks for the taking the time to read this.

    * Actual Machines

    ** Fucking Magic









  • A serial web story by Wildbow named “Pact” has a pretty interesting soft magic system with a decent amount of depth.

    Description of Magic System

    All characters who can use magic in the story are not able to lie on penalty of their magic power being greatly reduced. The magic system is based around tiny spirits who listen to and judge people. There are powers in 3s, power in performance, powers in name, yet despite this the magic system still feels ad hoc, like you can make magic happen that you would not normally be capable of if you are just smart enough, poetic enough, and persuasive enough to the spirits…

    Magical beings feel Eldritch, actively dangerous, and typically very clever. The ones who are clever typically have very good mental models of what makes humans tick, yet clearly do not fall under the same rules.





  • I think you’re reading more intent in my post than was actually present. I’m not denying we did genocide to 100 million natives. All I’m denying is that Jackson specifically is significantly worse than the historically reasonable alternatives to the position. Had (for instance) John Quincy Adams, one of the authors of the Monroe doctrine and a big proponent of western expansion, won the presidency, I do not doubt that a similar overall trajectory would have taken place. Maybe we wouldn’t have specifically had a trail of tears moment, but there’s more to the genocide of native americans than just the trail of tears.

    And this is absolving responsibility of all the people who maintained slavery, which one could argue is even worse than jim crow.

    How so? I believe you’re arguing in good faith, but I honestly don’t see how you come to this conclusion from what I wrote?


  • I’m not really trying to weigh and decide if 6000+ deaths and forcible removal of 100k+ people from their homes is better or worse than 100 or so years of systemic oppression followed by more, quieter oppression. Instead, I’m looking at this from the perspective of alternatives.

    After the Civil War we very nearly had a moment when we could have maybe did something real for racial equality beyond anything we’ve seen even up to the present day. The Freeman’s Bureau was fighting for wages for former slaves, and was generally a force for working class empowerment. Black congressmen were already being voted into office rapidly. If it were left to do its work, it might even have helped to innoculate the Irish- and Italian-Americans against future union busting on Black/White racial lines a few decades down the line.

    Instead, after only about a year, Andrew Johnson started fighting and dismantling the Bureau, placing the former slaveowners back into a de facto master/slave relationship with their former slaves, giving the old Southern Democrats back their political power, and generally restoring the status quo as much as possible. The Bureau itself lasted only 5 or 6 years, don’t remember. The KKK rose up because reconstruction wasn’t there anymore to prevent it, because the Democrats wanted so bad to just put all of the states back in the union and go back to bad old days, and so on.

    That was never a realistic moment that I know of in American history where people against war with the native tribes of this land had outsized power and influence. Jackson completely ignoring the Supreme Court’s ruling was awful, but while the ruling was grounded in good moral and legal principles, it was, like it or not, extremely unpopular. There wasn’t an entire party with a supermajority in Congress that could have kept up the pressure on this issue.