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from the what-do-I-do-with-all-these-burner-inserters? dept.
Submitted via IRC for Bytram
U.S. greenhouse emissions fell in 2017 as coal plants shut
Greenhouse gases emissions from the largest U.S. industrial plants fell 2.7 percent in 2017, the Trump administration said, as coal plants shut and as that industry competes with cheap natural gas and solar and wind power that emit less pollution.
The drop was steeper than in 2016 when emissions fell 2 percent, the Environmental Protection Agency (EPA) said.
EPA acting administrator Andrew Wheeler said the data proves that federal regulations are not necessary to drive carbon dioxide reductions.
[...] While Wheeler gave the administration credit for the reductions, which mainly came from the power sector, the numbers also underscore that the administration has not been able to stop the rapid pace of coal plant shutdowns.
[...] Natural gas releases far less carbon dioxide when burned than coal and a domestic abundance of gas has driven a wave of closures of coal plants. In 2017 utilities shut or converted from coal-to-gas nearly 9,000 megawatts (MW) of coal plants.
[...] The trend of U.S. coal plant shutdowns is expected to pick up this year, with power companies expecting to shut 14,000 MW of coal plants in calendar year 2018.
(Score: 3, Informative) by requerdanos on Thursday October 18 2018, @11:19PM (2 children)
You ask almost rhetorically, but there's an answer, and it's "both." Wastes are chemically separated, the waste you want to remove (because it's a helpful medical isotope you're harvesting, or a short-half-life waste that you want out of the fuel) stays out, and the waste you don't want to remove goes back in.
That's true of relatively inefficient solid fuel designs, but in liquid designs you don't need something to be "attractive as a fissile material" for the same reason you don't need super-enriched fuel or any other magic tricks to make the design work.
The fuel is a salt. Salt is not some inert thing added to the fuel. Sure, different salts (uranium salt vs. protactinium salt vs. plutonium salt. vs. etc.) will have different profiles and fission at different rates with respect to free neutrons in the mix. But they still fission, and they break down, and they release energy.
"The salt" is not the moderator. It's the fuel. Molten salt designs often use a body of graphite adjacent to the liquid fuel as moderator, perhaps augmented by beryllium mixed in with the fuel.
By chemical separation, at any given time, without shutting down the reactor, you can remove as much or as little of any component of the fuel. The fuel is always exactly the mix you want it to be. But here's the thing: Several of the molten salt fuel cycles just don't produce more than trace amounts of long-half-life waste; their waste is in the hundreds of years vs. bazillions. Processing "waste" as fuel is a benefit of the molten salt design, but not a requirement.
When Chernobyl blew its top, lots of powdered highly radioactive stuff blew around the world, contaminating it.
Water that's still being pumped over the melted cores of Fukushima Daiichi is soaking up radioactive stuff and spreading it out to sea, contaminating it.
If you took a molten salt reactor and drove a truck through it, or blew it open with dynamite, or some such, and the fuel spilled all around, then the liquid would turn to a solid that would then result in a local clean-up.
Because there's no powder, nothing to form aerosols, there's no powder to blow around the world.
Because it's a fail-safe instead of fail-insanely-stupid design, you don't have to pour water over it for 50 years to "keep it turned off", so you aren't creating a wastewater stream of highly radioactive end results of bad planning. It doesn't have to be next to an easily pollutable body of water for the same reason.
Sure, local contamination would be a "bad thing", but not in the same class of "bad thing" that just about every currently operating reactor spends its life trying to achieve, stopped only by an incredible flow of coolant that must-absolutely-must continue for the things not to bring about armageddon.
Especially rushing dangerous-by-design reactors into production, then using only that type of design for decades, through catastrophe after catastrophe.
What I claim is that a safe-by-design molten-salt reactor is worth pursuing, and a meltdown-by-design solid fuel reactor probably isn't. Neither design is a case of "solved issues", though both designs are at least proven technology [wikipedia.org], and you're the one saying something is solved, not me.
But, you know, one design will kill everything within 100km if you miss a day watering it, while the other design just turns itself off and waits for further orders if everyone takes the day off and does nothing.
Yet 99% of the effort and almost all the money go towards the meltdown-design and not the fail-safe design. I've heard theories ranging from "the molten salt reactors aren't good at making material for bombs" and "President Nixon had to make a choice and chose the solid fuel designs", but the end result is, we have meltdowns and radiation instead of cheap energy and happiness. Why?
I get that that idea offends you, and you make a lot of noise, but you haven't said anything that changes it. I really want to know--why does the idea of a safe reactor by design bother people so much?
(Score: 1) by khallow on Friday October 19 2018, @12:00AM
It's a variant of Ludditism. Anything that makes nuclear power safer makes it more likely to be adopted on a wider scale than present. Can't have that. So we end up with stringent opposition to any improvements in nuclear safety (both R&D and actual construction), be it safer reactors, breeder reactors for reprocessing used fuel rods, waste storage, etc. And thus, the present sad state of affairs in the US, where we're for a nuclear accident from ancient reactors and poorly stored fuel rods, to finish off the US nuclear industry.
(Score: 0) by Anonymous Coward on Friday October 19 2018, @03:40AM
Asshole
insanumingenium was calm and rationale asking relevant questions. You really want to poison the well by throwing around ad hominem insults that directly contradict such simple words as "I am not trying to say that nuclear power isn't an option, or that research into nuclear power is a bad idea."
A safe design bothers nobody, and after the various catastrophes we've had so far it seems pretty damn reasonable for people to be cautious. Why attack someone who seems willing to meet you part way?