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> by many metrics the safest forms Safety costs money. Traditional pressurized water reactors have their water under a pressure of 150 atm. A stovetop pressu

> by many metrics the safest forms Safety costs money. Traditional pressurized water reactors have their water under a pressure of 150 atm. A stovetop pressure cooker has a pressure of 2 atm. Sometimes pressure cookers explode, and it's not pretty. Now take that, multiply by 75, and make sure it's safe. There's only one way to do that: very thick steel walls. Walls that can only be made with huge forging presses, like in this eye-popping quote [1] Westinghouse says that the minimum requirement for making the largest AP1000 components is a 15,000 tonne press taking 350 tonne ingots. There's currently no forge of this size in the US. There's one of 15000 t, but it can only take ingots of 175 t, half of what AP1000 needs. This is what keeps the costs sky-high. [1] https://world-nuclear.org/information-library/nuclear-fuel-cycle/nuclear-power-reactors/heavy-manufacturing-of-power-plants.aspx https://world-nuclear.org/information-library/nuclear-fuel-c...

richk449 4y ago
Is it really true that the forging of the pressure vessel is a significant portion of the billions of dollars it costs to build a nuclear power plant? As your link explains, there are plenty of forges capable of pressing the required ingot size - located in the places that have modern steel fabrication capability. The US doesn’t have these presses because the US doesn’t have modern steel plants - not because the presses are super rare.
- bombcar 4y ago
  And we built steel presses ages ago, I can’t believe we can’t build a new one if we really needed one.
- Manuel_D 4y ago
  Furthermore, presses of this capacity aren't exactly cutting edge. The US built several on the 1950s: https://en.m.wikipedia.org/wiki/Heavy_Press_Program https://en.m.wikipedia.org/wiki/Heavy_Press_Program
Manuel_D 4y ago
The vast majority of nuclear power plants were built before three mile island[1] and the accompanying increases in regulation. The point is, even the supposedly "unsafe" nuclear plants are still vastly safer than most energy sources. You're correct about the infrastructure needs to construct pressure vessels. That's a large part of why nuclear plants were cheaper when built at scale during the 1960s and 70s. It's a lot easier for heavy industry to recoup the investment of building a heavy press if they have an order of 40 pressure vessels instead of 4. 1. Which, by the way, resulted in no radiation exposures or lasting exclusion zone.
- dicknuckle 4y ago
  What makes you say there weren't radiation exposures? Plenty of locals had radiation burns and lasting effects.
  - saxonww 4y ago
    This is probably not true. Most studies showed no significant increase in radioactivity at all outside the plant. Some very motivated anti-nuclear groups argued otherwise, but... I guess it depends on who you want to believe.
- ncmncm 4y ago
  - clarionbell 4y ago
    You don't happen to have a source for that would you?
    - robertlagrant 4y ago
      The effects on the population in the vicinity of Three Mile Island from radioactive releases measured during the accident, if any, will certainly be nonmeasurable and nondetectable. During the course of the accident, approximately 2.5 million curies of radioactive noble gases and 15 curies of radioiodines were released. These releases resulted in an average dose of 1.4 mrem to the approximately two million people in the site area. This average dose is less than 1 % of the annual dose from both natural background radiation and medical practice. The 1.4-mrem dose may also be compared to differences in annual doses in background radiation from living in a brick versus a frame house, an additional 14 mrem/yr; or living in the high altitude of Denver rather than in Harrisburg, an additional 80 mrem/yr. The effect of this total dose, averaged over the population in the site area, will be to produce between none and one additional fatal cancer, and between none and one and a half total (fatal and nonfatal) cancers, over the lifetime of the population. In comparison, approximately a half million cancers are expected to develop from all other sources during this same lifetime. I don't know if the previous commenter was saying all two million people in the area are black, but they do seem to be considered in this Three Mile Island Report volume 1[1], page 153. [1] https://www.osti.gov/servlets/purl/5395798 https://www.osti.gov/servlets/purl/5395798 (PDF)
xyzzyz 4y ago
> Traditional pressurized water reactors have their water under a pressure of 150 atm. A stovetop pressure cooker has a pressure of 2 atm. Sometimes pressure cookers explode, and it's not pretty. Now take that, multiply by 75, and make sure it's safe. There's only one way to do that: very thick steel walls. Walls that can only be made with huge forging presses, like in this eye-popping quote [1] This is all just as true about steam pressure in coal power plants. In fact, we now build coal power plants that work with supercritical steam, at 220+ atmospheres.
- tyho 4y ago
  No, because if a coal plant springs a leak, if you are really unlucky a worker might die from a steam explosion. If a nuclear plant springs a leak the, if you are lucky, reactor containment is irradiated with high level waste, resulting in tens of billions of dollars worth of clean up liabilities. If you are unlucky you leak high level waste into the environment. Coal plants don't irradiate their steel with neutron radiation either, nuclear plants do, and it changes the material properties of the reactor structure over time.
  - Gud 4y ago
    How often has this happened?
    - HPsquared 4y ago
      Three Mile Island (Near miss) Davis Besse Soviet submarine K-19
      - clarionbell 4y ago
        So not often at all?
        Gwypaas 4y ago
        And now we've circled back to "sky-high cost". https://www.lazard.com/perspective/levelized-cost-of-energy-levelized-cost-of-storage-and-levelized-cost-of-hydrogen/ https://www.lazard.com/perspective/levelized-cost-of-energy-...
airtonix 4y ago
pfdietz 4y ago
Actually, the nuclear steam supply system is only a small part of the cost of a nuclear power plant (about 12%). https://world-nuclear.org/information-library/economic-aspects/economics-of-nuclear-power.aspx https://world-nuclear.org/information-library/economic-aspec...

richk449 4y ago

Is it really true that the forging of the pressure vessel is a significant portion of the billions of dollars it costs to build a nuclear power plant? As your link explains, there are plenty of forges capable of pressing the required ingot size - located in the places that have modern steel fabrication capability. The US doesn’t have these presses because the US doesn’t have modern steel plants - not because the presses are super rare.

bombcar 4y ago
And we built steel presses ages ago, I can’t believe we can’t build a new one if we really needed one.
Manuel_D 4y ago
Furthermore, presses of this capacity aren't exactly cutting edge. The US built several on the 1950s: https://en.m.wikipedia.org/wiki/Heavy_Press_Program https://en.m.wikipedia.org/wiki/Heavy_Press_Program

Manuel_D 4y ago

The vast majority of nuclear power plants were built before three mile island[1] and the accompanying increases in regulation. The point is, even the supposedly "unsafe" nuclear plants are still vastly safer than most energy sources. You're correct about the infrastructure needs to construct pressure vessels. That's a large part of why nuclear plants were cheaper when built at scale during the 1960s and 70s. It's a lot easier for heavy industry to recoup the investment of building a heavy press if they have an order of 40 pressure vessels instead of 4. 1. Which, by the way, resulted in no radiation exposures or lasting exclusion zone.

dicknuckle 4y ago
What makes you say there weren't radiation exposures? Plenty of locals had radiation burns and lasting effects.
- saxonww 4y ago
  This is probably not true. Most studies showed no significant increase in radioactivity at all outside the plant. Some very motivated anti-nuclear groups argued otherwise, but... I guess it depends on who you want to believe.
ncmncm 4y ago
- clarionbell 4y ago
  You don't happen to have a source for that would you?
  - robertlagrant 4y ago
    The effects on the population in the vicinity of Three Mile Island from radioactive releases measured during the accident, if any, will certainly be nonmeasurable and nondetectable. During the course of the accident, approximately 2.5 million curies of radioactive noble gases and 15 curies of radioiodines were released. These releases resulted in an average dose of 1.4 mrem to the approximately two million people in the site area. This average dose is less than 1 % of the annual dose from both natural background radiation and medical practice. The 1.4-mrem dose may also be compared to differences in annual doses in background radiation from living in a brick versus a frame house, an additional 14 mrem/yr; or living in the high altitude of Denver rather than in Harrisburg, an additional 80 mrem/yr. The effect of this total dose, averaged over the population in the site area, will be to produce between none and one additional fatal cancer, and between none and one and a half total (fatal and nonfatal) cancers, over the lifetime of the population. In comparison, approximately a half million cancers are expected to develop from all other sources during this same lifetime. I don't know if the previous commenter was saying all two million people in the area are black, but they do seem to be considered in this Three Mile Island Report volume 1[1], page 153. [1] https://www.osti.gov/servlets/purl/5395798 https://www.osti.gov/servlets/purl/5395798 (PDF)

xyzzyz 4y ago

> Traditional pressurized water reactors have their water under a pressure of 150 atm. A stovetop pressure cooker has a pressure of 2 atm. Sometimes pressure cookers explode, and it's not pretty. Now take that, multiply by 75, and make sure it's safe. There's only one way to do that: very thick steel walls. Walls that can only be made with huge forging presses, like in this eye-popping quote [1] This is all just as true about steam pressure in coal power plants. In fact, we now build coal power plants that work with supercritical steam, at 220+ atmospheres.

tyho 4y ago
No, because if a coal plant springs a leak, if you are really unlucky a worker might die from a steam explosion. If a nuclear plant springs a leak the, if you are lucky, reactor containment is irradiated with high level waste, resulting in tens of billions of dollars worth of clean up liabilities. If you are unlucky you leak high level waste into the environment. Coal plants don't irradiate their steel with neutron radiation either, nuclear plants do, and it changes the material properties of the reactor structure over time.
- Gud 4y ago
  How often has this happened?
  - HPsquared 4y ago
    Three Mile Island (Near miss) Davis Besse Soviet submarine K-19
    - clarionbell 4y ago
      So not often at all?
      - Gwypaas 4y ago
        And now we've circled back to "sky-high cost". https://www.lazard.com/perspective/levelized-cost-of-energy-levelized-cost-of-storage-and-levelized-cost-of-hydrogen/ https://www.lazard.com/perspective/levelized-cost-of-energy-...

airtonix 4y ago

pfdietz 4y ago

Actually, the nuclear steam supply system is only a small part of the cost of a nuclear power plant (about 12%). https://world-nuclear.org/information-library/economic-aspects/economics-of-nuclear-power.aspx https://world-nuclear.org/information-library/economic-aspec...