OPEN THREAD 20200205

Basically, all legal free speech is allowed. We will assist the authorities in dealing with illegal speech. You are each other’s moderators. Have fun. And don’t forget to MAGA at nuclear levels.

Citizen U

Day 91 – PROTACTINIUM.

24 thoughts on “OPEN THREAD 20200205

  1. LOL

    But it is kind of crazy.

    It was originally, “protoactinium” as in “the thing before actinium” because the known isotope decayed into actinium. We did away with a syllable.

    But isn’t it just insane we named an element after its decay product?

    Of course the name for platinum is basically derived from Spanish for “silver” and mercury was long known as “quicksilver.” so naming one element based on another isn’t completely unheard of.

    Liked by 4 people

  2. The longest lived isotope is Pa-231, with a half life of 32,760 years. This totally blows away any of the “betweener” elements (between bismuth and thorium), including actinium itself, which is why it’s REALLY odd this element is named after one of its junior decay products.

    Another isotope, Pa-233, is a stepping stone from Th-232 to U-233; you add a neutron to the thorium, it then goes through a beta decay to become Pa-233, and another to become U-233. But care must be taken not to have any of it in the active zone of the reactor (I get this from wikipoo, which doesn’t elaborate as to why).

    Up until the 1950s, we didn’t really realize there was an actinide group. Mendeleev put thorium two spots below zirconium (hafnium wasn’t known yet) and uranium directly below tungsten; he figured an element needed to fit under tantalum, too. (And for some bizarre reason I don’t really understand, those aren’t bad fits chemically even though the elements really belong under the lanthanides).

    A visible amount of the stuff has been created, mostly in reactor waste. The UK put together 127 grams of it in 1961, making it available for scientific research.

    You can even see a picture of it on Wikipedia’s page.

    It’s 15.37 times as dense as water, in the broad 14-19 range inhabited ONLY by tantalum among the stable elements.

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  3. While present as only a few parts per trillion in the earth’s crust, protactinium isn’t that difficult to find if you know where to look — you could buy a gram for only around $280 in 2011. Unfortunately for “hammer and mule” prospectors, “where to look” is in spent reactor fuel.

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  4. Protactinium is such a nuisance in liquid salt thorium reactors that there’s a whole section of the plumbing dedicated to getting rid of it — “This is achieved using several meters tall columns of molten bismuth with lithium dissolved in it. In a simplified scenario, lithium selectively reduces protactinium salts to protactinium metal which is then extracted from the molten-salt cycle, and bismuth is merely a carrier.”

    Let that sink in for a bit. You need a cylinder several meters tall filled with molten bismuth with lithium dissolved in it. If that were your entire engineering challenge, you could do ok……but this is merely to provide a minor housekeeping function for the molten salt in your thorium reactor……because protactinium is such a pain in the tuchis. Which is why you you’re willing to “give it away” at $280/gram to get it off the premises.

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    1. At that, it’s a lot easier than preventing Pu-240 formation in breeder reactors.

      Breeder reactors exist to turn U-238 (not fissile) into Pu-239 (quite fissile); they do so by adding a neutron to the U-238 (which then goes through two beta decays, just like Th-233). However, the Pu-239, once formed, is also likely to glom onto a neutron and become Pu-240, which is NOT fissile; it’s a contaminant in the Pu-239 you’re going to all this effort to create.

      But since plutonium-239 and plutonium-240 are both plutonium, you can’t use chemical means to separate them. Protactinium can be separated from thorium and uranium much more easily because it reacts differently with other chemicals.

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      1. Sorry, but as the humanities major in this crowd of squints and given the consistent shock and awe produced by this “U”-f’ing-believable blog, I lobby for and hereby nominate this element as the Official Mascot Element of the UTree:

        Liked by 3 people

  5. A carpenter was giving evidence about an accident he had witnessed. The lawyer for the defendant was trying to discredit him and asked him how far away he was from the accident.

    The carpenter replied, “Twenty-seven feet, six and one-half inches.”

    “What? How come you are so sure of that distance?” asked the lawyer.

    “Well, I knew sooner or later some idiot would ask me. So I measured it!” replied the carpenter.

    Liked by 4 people

  6. Some men in a pickup truck drove into a lumberyard. One of the men walked in the office and said, “We need some four by-twos.”

    The clerk asked, “You mean two-by-fours, don’t you?”

    The man said, “I’ll go check,” and went back to the truck. He returned and said, “Yeah, I meant two-by-four.”

    “All right. How long do you need them?”

    The customer paused for a minute and said, “I’d better go check.”

    After a while, the customer returned to the office and said, “A long time. We’re gonna build a house.”

    Liked by 3 people

  7. A carpenter finds a genie in a lamp. The genie tells the man, “I can only grant you one wish. What is it that you would like?” The carpenter responds: “You know, carpentry is my passion. I would love to be able to talk to my tools. They are my friends, after all”. The genie makes it so.

    Later, the carpenter is working on the frame of a house when he sees his hammer next to him. The carpenter says to the hammer, “Well, I can talk to my tools now. What would you like to say?” The hammer replies, “I’m hammer”
    “Yes, I know that” says the carpenter. “Is that it?” “I’m hammer” says the hammer. The carpenter is frustrated and turns to his trusty wrench. The carpenter says, “What about you? What can you say?” “I’m wrench”, says the wrench. Now the carpenter is really frustrated. He asks his saw, ladder, tape measure, and screw driver the same questions, only to receive “I’m saw, I’m ladder, I’m tape measure, I’m screw driver”.

    The carpenter is starting to lose it and gives up for the day. He drives home, knowing that he may be able to forget his wish and relax in front of the television. He walks through the front door and heads to his computer to check his emails, when he comes across a plank of wood sitting in front of his computer. Across further inspection, the carpenter sees that the plank is typing a very long joke into Reddit. “What in the world is going on?!”, exclaims the carpenter.

    “I’m board.”

    Liked by 3 people

  8. Employment Standards determined a small woodworking shop owner was not paying proper wages to his help and sent an agent out to interview him.

    “I need a list of your employees and how much you pay them,” demanded the agent.

    “Well, there’s Jake my finisher who’s been with me for 3 years, I pay him $900 a week.

    The apprentice Tom has been here for 6 months, and I pay him $500 a week.

    Then there’s the half-wit that works here about 18 hours a day. He makes $10 a week and I buy him a case of beer every Friday,” replied the owner.

    “That’s the guy I want to talk to; the half-wit,” says the agent.”

    The owner says, “That would be me.”

    Liked by 3 people

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